John, noticed in the video you started out with a low opinion of roll forming taps. Hopefully you now see they are quite a good way to tap. Specifically, they create no mess or chips, so doing a large number of tapped holes on a project works really well (example: fixture plates). I use them a lot on my CNC and get really great results. I have also started playing with thread milling, but honestly for most of my tapped thru holes I use roll taps. Cutting taps leave chips and debris that sometimes get into the adjacent holes and cause issues. Roll taps don't, nor do they jam or break very often.
John. If you really want to go first class with you fixture (You probably wont). On your moving jaw drill and ream or bore a hole at each parts location so you can install a small piston with a o-ring seal. Drill a cross hole to intersect all the pistons holes with small pipe plugs at each end. Start each piston in each hole than fill full of oil (try to eliminate as much air as possible ). Mount the jaw and clamp all the parts than crack one of the plugs to bleed off some air (like bleeding breaks). The hydraulic pressure will balance the force on all the parts even if they very in length. The only down side to this is you have to have a full fixture or blank parts in every station.
when you drill it just counter sink the hole a few thou over the major diameter of the thread pitch and that will keep you from having any burrs. it doesnt have to be much just a little bit of a lead in chamfer
You can use form taps by hand, I do it all the time, but they really shine with power tapping. They are great for fixing damaged threads as they don't remove any extra material and will self align into the existing threads. Run them with coolant/oil always!I find that way lube (use your tamp oil it's free!) or EP grease works well on steel/stainless, or run your coolant about 10% and you should get about 2-3 times the life out of a form tap vs a cut tap. The hole size is supercritical, on small holes you need to be within a couple of thousands to get perfect threads.
Yep, every bit of tapping I do is by hand with form taps and one of those spring loaded tap guides to keep everything in check. Mostly 2-56 blind holes and it works like a champ. Everynow and then I break em but the material is usually titanium so i just soak it in ferric chloride till the tap dissolves.
Yep, every bit of tapping I do is by hand with form taps and one of those spring loaded tap guides to keep everything in check. Mostly 2-56 blind holes and it works like a champ. Everynow and then I break em but the material is usually titanium so i just soak it in ferric chloride till the tap dissolves.
+Widget Works Manufacturing Inc. Ha, seems like I'm not the only one with a preference for form taps for hand use! another nice feature of them is that they allow tapping into thinner workpieces than would be advisable when using regular cutting.
+krawutzimon actually just got done hand tapping a couple 10-24's(form/roll tap) in a mounting bracket for a remote operator panel for my surface grinder.
I recently switched over our taps 100% to form taps in our CNC operations. We are form tapping very successfully in all the materials we machine (4142, D2, A2, 1018, HRS, Aluminum, Stainless ext) except for Ampco. We have almost completely eliminated tap breakage plus the performance with water based coolant with form taps vs cut taps is much improved. It was a good move for us in the way of reliability, thread quality as well as it cut down on our tooling costs.
That's awesome man, and form taps are the way to go for sure. If you use carbide drills you can drill then form tap and then use the spot to clean up the burr.
+NYC CNC I just got a question from production about forming tap. They want to know if the can use it and I did not know much about it. Thank you again John. I think they can use it :)
I have been using form taps for over thirty years, they do 90% of the tapping in my machine shop. I work in mostly 300 series stainless, 17-4 stainless, aluminum and brass. Stronger taps as far as breakage, particularly in blind holes and superior threads to cut taps. Lastly, there is no need dig out or blow out chips trapped in blind holes because roll-form taps do not create chips. I prefer OSG and Cleveland twist cobalt (M42) form taps. As always, very nice video.
Nice coverage of the basic differences between the three types of taps. I was surprised at how loosely the soft jaws held the parts, even when there were only two workpieces in place. I expected trouble with a full load, but thought that two would be held firmly. With the forming tool you would want a hole slightly larger than the average between the major and minor diameter of the thread. This is reasonable, because you are displacing the metal that was between the average and major diameters into the space between the average and minor diameters. Since there is more volume in the outer hollow cylinder than the inner hollow cylinder (because it has a larger average diameter), you need to "cheat" the hole a bit larger to have room for the extra volume. If it were a cut thread, the hole would be right for maybe 45% or even 40% thread. The coarser the thread (longer pitch), the more you need to cheat the extra room because longer pitches go deeper into the stock with a v-form thread. The formed-is-stronger effect is generally true for external threads because external threads are generally made on round stock (usually by rolling between two grooved plates) where the grain runs generally parallel to the axis of the round. Cutting threads in such stock will cut the grain. Forming threads deforms the grain so it runs in and out of the body of the screw into the threads. You also need to start with stock which is a smaller diameter than the final thread diameter since some volume is displaced outwards into the dies. You see this same effect when knurling - the knurled diameter is larger than the original stock. (There is also some strengthening effect from work-hardening, especially in Stainless Steel.) When forming internal threads it is not always clear which way the grain runs in the stock. It would have run parallel to the long axis of the stock as it passed through the rolling mill, but the hole to be threaded in the final piece may run into the end grain (in which case the formed-is-stronger effect would be about the same as for external threads) or across the grain (in which case the effect would be less). In these parts the hole runs across the grain as the part is a cross-drilled piece of round stock.
A few things: 1) Form taps work fine by hand. I don't buy cut taps in anything smaller than 1/4", and I use my form taps in everything from my CNC machine to hand drivers to a cordless drill (not an impact, a drill with a clutch). They work great, don't break with anything like the regularity of cut taps (in the small sizes for sure), and lend themselves very well to automated operations due to the lack of chip production (no chip breaking or rats nests to deal with). The DO require better lubrication than a cut tap does, for obvious reasons. B) You're getting a bur because you're not chamfering the hole before you thread it. Spot, drill, chamfer to a depth greater than that of the thread you will be making, THEN tap. Any other sequence or edge prep will result in burs and secondary hand operations. 3) If you watch your cycle time and take tool cost vs tool life into account, a form tap will beat that thread mill every single time, even with that Tormach's lackadaisical tap cycle. They don't hurt so bad when you break one either. IV) You should curse more often. It's not natural for a grown-ass man in an industrial shop setting to say "Darn". ;-)
John, It is actually ok to go ahead and run the thread forming tap through again. You are correct about the spindle orientation, but the spring tension will adjust the tap to the correct height to match the threads. If for some reason it does not due to tension then you could pull down and guide it into the hole until it starts. Great videos!
Don't be afraid of form/roll taps. I would love to see more on tapping in future videos. They last longer and are faster that cut taps. And are faster than thread milling.
I was going to suggest square stock, but I see another commenter was already on that. Another possibility is to mill some small flats into the radius on the small diameter ends to key into the softjaws. And another wild idea...turn some small pointy "crush zones" on one end of the part. A hard enough opposing jaw could deform the longer parts enough to get a good grip on the shorter ones.
Gh3 taps produce standard sized threaded holes, GH4 slightly looser, and GH5 the loosest. I use GH5 taps in plastic and bronze/brass, because those materials tend to shrink after tapping.
The reason a rollform tap drill is larger is because you are forming or squeeshing the material inwards towards the center of the tap. If you check the hole after being tapped you will see it has shrunk. Great video... love the slow mo!!!HHHHoooooolllyyyyy sssshhhhiiitttt!!!!
Funny Video..;-) Have you considered making soft jaws with a small v or dish and just slide the barstock in between, drill and tap holes ensuring they are spaced to allow for parting, then do the lathe work. Would allow for greater, even clamping pressure in all axis and allow you to do all ops as full thru-holes. Then you can just debur the hole length of bar on the wheel prior to feeding to the lathe. You can buy taps with a built-in chamfer to save tool changes etc, last company I used was Guhring which I noticed had them I think.
I've found that countersinking the hole before, tapping reduces/eliminates the burrs. It also, makes it easier to start the tap, when running it by hand. They tend to look cleaner too.
I'm glad you mentioned the issue about being able to hold all your parts securely in 1 soft jaw. I have run across this also. Maybe a good topic for a video, I could share a couple tricks I have learned. I'm not a big fan of tape, pucker on my part, LOL.
Great video, just subscribed. Form taps are a fickle mistress, and performance is WAYYYY more material dependent than cutting taps, in my experience. The reason they're "stickier" than cutting taps is partially due to the "springback" (technically elastic recovery) of the material. Basically after you push all the material into the shape of the thread, the thread is actually trying to bounce back to its previous shape as much as it can.
I form tap whenever I can. I don't have a lot of form taps, but the ones I have I use every time it's possible. I like that there are no chips to clean out, and I believe the threads are stronger, and are very nice. In my experience, form taps give more consistent threads than cutting taps. I've never power tapped, only by hand every time. I always use Tap-Magic fluid whether I'm form or cut tapping.
John, just started watching the video but curious if you could model the soft jaws once. Save it as "master soft jaws" and open and re-save that file to your new project. That way you don't have to model the jaws every project. I'll keep watching!
The reason you drill the form tap hole larger than a standard tap is the deformed material "squishes" out... you basically drill to half way between the major and minor diameter. The excess material from the major that would normally be cut is pushed into the minor. I use them all the time to tap from M2-M5 in brass and copper but they work well in aluminum as well. I don't ever work on steel unfortunatly so I have no experience but for soft metals they are much less likely to get gummed up and snap in the part in my experience.
are u supposed to use the form-tap in a tap head? I used a Collet (because of the high torque) the few times I form tapped. Of course in a good machine (DMG 105V linear) :) .
Form taps are cool. 1/4x20, blind hole, 3/4" deep thread almost to the bottom in soft steel. I can usually tell when it's ready to break but that's after 1000's of holes on one tap. Never any luck with oil based lube but it likes the regular water based coolant.
Good tip about not using an impact driver to drive the vise. Were the arguments against doing so in regards to the speed or the constant impacts from the driver? I occasionally use a drill if I need to open my vise all the way for cleaning or changing jaws and a drill seems to drive it smoothly, but it is much faster than I drive it by hand.
the rol tap (thats what we call it at my job) pushes material away but the material jumps back to its original position. thats why it tight when you try it. then again you do get stronger thread and a perfect fit. so if you are going with that. keep in mind that they need a new quick turn in the lathe to remove the bur
You make great videos keep up the good work. When I countersink tapped holes I almost always go .015 to .03 per side larger then the thread major dia.( aslong as the print allows). This takes care of any burr that may form on the entrance side of the cut. For Ex. For a 3/8-16 I'll use a 1/2" drill mill or a #6 center drill. And make the chamfer dia .406-.437. It also makes the appearance of the hole more attractive. In die making a large chamfer helps to strengthen the first threads in hardened tool steel to keep them from pulling under pressure while a die is running in a press.
Form taps work well in most materials except CAST!! it's to brittle to form in alot of cases. Anytime I need a thread. 25 or smaller I always roll tap, plus it is a stronger thread!😁
I love form taps. For aluminum it acts like nothing if even there. Works great on zirconium too. I use it for titanium as well even though many say not to. Just gotta get your tap drill size perfect
Drill and tap a set screw thru the unmilled jaw in each pin position. We do this on alot of similar parts. Clamp the vise jaws together, then tighten the set screw as a secondary hold.
11:15 reason for the larger tap drill diameter is that the form tap not only pushes material outward to form threads, but also swedges it inward in an equal amount. So if you were to form tap a hole, and then use a gauge pin in the hole, you'd see that the minor diameter gets smaller after tapping.
Kerosene works good to cut/tap steel with. A little bit of slick with a lot of cooling. Aluminum is very gummy and coolant is not really required, just something slick to keep it from sticking to the tool.
do you have all the parts made? concave the end of the part about .002"-.005" and kick your federate way down when you get to the last .025"-.050" to get rid of any nub that might be left to help with rotation in the vise. also it might be a good thing to center drill the pockets in the jaws to help clear chips and hold better for faster loading(looks like that might have been done?) most of the time we used a few little vises rather than load more than two parts in once vise
Except for hardened materials, we form-tap just about everything at work - blind or thru, doesn't matter. For deep holes, I find it better to fill them with lube instead of coolant. If you use the correct hole size and cleaned them for chips - it's gonna run until Christmas. There's also special formtaps for aluminum.
We use them on almost everything to. Including some pretty hard materials with the use of "ER" (energy release). Shits stickey and makes a mess but makes it possible to use form taps on just about anything. Just coolant for aluminum. Great for blind holes, and they don't have much of a lead generally so you don't need to grind them. In my experience sometimes it's hard to get your minor right. They look super shinny and pretty, but if you look at them under the scope the crest of the thread is pretty jagged and shitty looking (I suspect the cause of the minor dia issue). And if you're using them near the edge of a finished part you'll want to do you milling after you tap bc they will deform the material and you'll have a bump along the length of your hole. Also you can't tell when they are dull, sometimes you'll see the coating go but most the ones we buy are grey. I use a "emuge" holder for anything smaller then an 8-32, anything larger, highly recommend a rigid holder.
And for up to 54 HRC you can use pulver metal HSS taps, they cut really beatifully and we use them often together with carbide drills to get those missing screw holes :)
I believe someone mentioned the Guhring web site as a good resource for tap drill sizes. That's the site I use as well (and I spent a fair amount of time testing as many as I could find). I don't think UA-cam will let me link to it, so I'll just put everything in the URL after the domain (which it pretty easy to figure out)... /Tech/TapDrill/default.aspx If you're going for 75%-ish threads, a chart is fine, but the Guhring site lets you adjust for other thread percentages as well.
spot drill to full diameter with a 7/16 or 15/32 to eliminate the burr without adding a step. The form tap hole is bigger because material is extruded back into the hole during forming ie the id of the hole shrinks in the process. Formed threads are much stronger because the grain in the material is continously rather than cut into short segments that can shear in tension.
So far I have only ran form taps on my 1100. I have only ran a M4 tap but haven't broken it yet. When possible I found it is better to drill and form tap before facing the part to remove the raised material.
We use form taps all the time in the lathe. You can tap to the bottom of a blind hole which means u don't have to go past the width of the part off tool. In our case it's a 3mm part off so I just drill/tap part length plus 3mm. Benefit of that is when the hole continues into the next part it can easily start to walk off centerline more and more.
FYI to anyone using a form tap on a Haas VMC we have all our posts include a M42 to command high gear for the spindle. We tap with ER32 holders and a tap collet not a torsion head and you will break taps without running the machine in high gear in a rigid holder setup.
Glue a small spring washer between each threaded bolt and the jaw to fix it better? Just make sure they just using a part of their "way" so there wont be any permanent deformation over time. For deburring maybe a ball-mill if it doesnt take to much process-time. Just let it run from left to right and stop at each hole to go down a bit. For the backside turning all parts or using a backward deburring tool or a threadcutter on a 3D Path.
A tip for your clamp fixtures. Use a stack of Belleville Disk springs in each pocket for pins that may be a couple thou off. I had a job once that required several hundred pins be milled flat on two thirds of one surface, then drilled in two places and drilled and taped in one. Then a key slot was end milled in the lower part of the flat. I made a fixture with ten V slots that could be clamped in a vise but did not figure in the length. The pins did not have a critical spec for the length so they were all cut with a couple thou difference each. After building the jig I would have a few pins that would try and rotate during the first pass. I solved the problem with a stack of belleville disk springs in each pin pocket that gave me roughly 2200# of clamp force on the pins that were a bit short.
I would really recommend using a spot drill with a larger angle than the drill point. LakeShore has 140deg spot drill that I've found are 1000x better than a 90deg spot drill, especially since most machine drills are 130-135deg. Also since the spot angle is larger you can easily go a little deeper to create a chamfer on the hole for the tap or thread mill or whatever. That will go a long way in reducing the burr.
+War Machine LLC I thought the main goal of spotting was to keep the chisel edge of a normal drill from contacting the stock, which prevents walking. Seems like a 90º spot would do this job, and with a 90º spot you'd have a nice 45º chamfer left over. Wouldn't a hole made by a 140º spot drill be closer to flat (180º) than 90º?
+Hirudin I've heard that theory and bought into it for a long time. Experience and many drill bits later has proven otherwise. The larger spot forces the drill into the center much better and is much easier on the drill. That chirp you hear when drill first engages it it chattering and wobbling around throwing the hole position off. Do that with a carbide drill, especially a large one, you rapidly chip the cutting flutes. Once you use a larger spot all of these problems vanish.
Awesome video! I just stumbled across your UA-cam channel by accident. I like the idea of the endless applications that soft-jaws offer. I saw that your work piece turned easily. I over engineer everything in my head, but it also leads to good ideas. So, with that said, I had a crazy idea. What if you were to drill and tap the back side of the moveable soft-jaw for set screws? You could even maybe drill them at a downward angle to put downward pressure on your work pieces...
The form tap requires a larger hole because you are displacing material, the minor diameter of the threaded hole is smaller than the diameter you drilled to because when you form the thread the material the material you're coming at the major diameter of the thread "moves" to fill the minor diameter. The reason it's stronger is because you're maintaining the "grain structure" of the material. The main benefit imho is the finish of a form taped hole, it's phenomenal, like a mirror, and the finish is how you judge your tool life, when the finish goes away, time to change the tap.
I was thinking the same thing. LoL +NYC CNC I think it was the true shock and awe of the moment. No worries, that's one of the things we like, true emotion and enthusiasm in what you are doing.
drill cross holes in soft jaws slightly lower in vertical plane to force parts more downward to stop the spin you experienced and also you can make a V cut rather than a radius for parts to sit in to create less of a bearing surface, anything with more sides than a radius. combined this will stop the rotation as well as compensate for the discrepancy in part length leading to the parts coming loose from the fixture
You can use form taps on manual drill presses etc. but be sure to use the right spindle speed as a certain speed is neccessary for the optimal "flow" of the displaced material. Not sure if some tool manufacturers wrote something about the "flow", if I read it on the web or if it's just my own idea. So hand tapping should only be an exception for form taps. At my job we use form taps for M4 to M10 in common steel (1.0038) and stainless (1.4571 IIRC 316Ti) and copper. For steel and copper we just use the water based flood coolant or internal coolant through the collet without a sealing disk in front of it.Further we higered the concentration of the coolant (Castrol Alusol MF-X) from 6% to 8%. For stainless we program M0 and use Rocol cutting oil without waterbased coolant. Further the Rocol oil is used on any manual machine for thread forming.I would always form threads, at least on manual machines, if it's not forbidden by your customer. E. g. the tip of the thread flanks that are not entirely closed due to the nature of the process are a no go for the food industry because they are much less than optimal for cleaning the internals of your production line. IMHO cold forming would be the best description for forming taps as this is exactly what happens.
+Hirudin No problem. The large the threads get the better you can also see this in your finished thread. www.pronic.com/upload/fckeditor/Image/Support/Rollformed%20thread%20process.jpg flowdrill.com/sites/all/themes/fdtheme/images/flowdrill_process_page_image.jpg
+Ed Ginsberg Some parts, some materials. Absolutely. I had similar parts to what he is making and we could not form tap them because it changed the OD too much and through the part out of tol.
I don't know if you learned this yet. This was 7 years ago. I had problems with form taps. I started peck tapping and the problems went away. Plenty of coolant, or we had this honey like substance.
If you were to center the part so that the hole is between the two jaws instead of the majority of the part is over one jaw. Even if some of the hole is over the soft jaw, maybe not over the fastener for the soft jaw. I think that rubber strip is better than the sand paper we used to use.
The form tap would have run a lot smoother if you had lubed it. Also run a countersink on each side of the hole to get rid of the burs. This might me relegated to a hand operation.
With the form tap on the floating head that you are using you may need to program it to tap deeper just because the way it floats before it engages. And there is nothing you can do for the treads having burrs on the top you can run the spot drill again to clean it no extra depth and the back you are better off with a belt sander then a chamfer tool
Would it be worth running a quick chamfer after tapping for a "lead in" to your threads and also cleaning up that leading edge? At the end of the first full tap, it looked like the tap was rubbing a bit at the end when it was coming out of the hole, it just sat there for a bit. If you had a round wire brush that was the right diameter, could you just run a brush in and out to help break off the burrs?
we use uhmw strip 1/4 X 2 and cut the same length as jaw width instead of that red padding strip and you can use them a long time over a year in some cases. and put some serious clamp power on it
You need to fix your tap cycle. It should feed in at the pitch or just slightly faster than the tap pitch to get the compression holder to grab, then stop, then reverse and feed out at nearly 2x the speed of the pitch so that it puts the holder in tension and the tap snaps out of the hole at the top. You are buggering up your threads by not feeding out faster.
NYC CNC Try 1.1 times the pitch, to start with. If the tap continues to dwell at the opening when reversing, keep upping the return feed to 1.2, then 1.3 until it's putting the tap holder in tension. The problem is that your holder is getting compressed so much at the lead-in of the hole, when retracting at feedrate it's dwelling and rubbing the tap.
Awesome video! Why not just drill into the cap screw counterbore in the jaws? It wont screw up your ability to flip them as it clamps mainly on the back. You shouldn't have any problem running all stations of that. Also you drill bigger for a form tap because it physically forms back into the hole to make the minor diameter. So for a 1/4-20 you drill .228 but it forms back close to the .201 you would normally drill.
+NYC CNC You were saying in the video that you were worried about drilling and tapping through on positions 2 & 3 but since your supporting them off the bosses on the end I don't see why It wouldn't work there as well. Especially if you are drilling and tapping into the open hole of the cap screw hole that mounts the jaws. Its like a built in clearance hole! haha
I know nothing about CNC (well, only what your videos have shown me), but it strikes me that the answer is staring you in the face. You've a long production run to do - make some properly sized soft jaws and go with the form tap. It was faster, produced a harder thread (important in your product) and the fit was good. I think someone else has mentioned countersink to get rid of the burr. Either mill the end flat, then countersink the hole on the flat surface, or go in with an oversize countersink. Having a burr will be unacceptable and its another operation that you will have to hand finish?
12.00 and 08.03 Time. It's not good with the z-axis retraction, it stops with thread in the hole, which is not good, you have to retreat to pull the pot out of the hole, not the star instead. Breaks the beginning of the thread. It's just an observation! Hello from Romania, I work on the CNC lathe!
Forming taps are the best. I have not used cutting taps for anything other than very low malleability materials. Throw them in a cordless drill. Hardly and chance of breaking them compared to cutting taps that have around half the total crossection. They will push a little material out as a bur, but about the same as a gun tap anyway. My travel kit is all screw machine drills and forming taps. Drills are sized to make a 60-65% thread. They also last far longer and leave a perfectly clean polished thread instead of microscopic chatter marks. Go ahead and drive them with an impact gun, they don't care.
Best thing to do is use a drill tap drill taps look like a drill but with theads its fast but another problem is ur tool holder is to wobbly you need to use a spring loaded holder that quick connects don't work to good
+David Moghaddam Does your tapping head have specs for largest recommended tap size? I have a Procunier Tru-Tap 15000 and the recommended largest forming tap on it is #8 (in aluminum). I'm pretty sure I've done 1/4-20 in it though. For reference, 1/4-20 is the largest recommended cutting tap size (in aluminum) for that tapping head. If you're thinking about using a 6-32 form tap with a tapping head that can handle a 1/2-13 cutting tap, I bet you'd be fine... well, as long as it's sensitive enough to reverse direction properly.
It's a Shars model that can use 0-1/4 in steel, however, I use primarily aluminum. I tried it with a 6-32 spiral flute tap and it gave me beautiful results. The smallest diameter I need is M3, and for any smaller 2-56 and 0-80 I have a hand tapping machine. I might be ballsy enough to tempt fate in the future, though. I just like the idea of a form tap and how clean it makes the threads. I, like John, am starting in an apartment. So, noise and chips are my enemies. Thank you for the advice.
Minor suggestion: It might be advantageous in the long run to wear gloves when working. Mineral oils, cutting fluids, grease etc can destroy the skin on your hands over time. Skin will absorb almost any fluid it comes in contact with..typically metal working fluids are not chemicals you want to be absorbing. I always wear nitrile exam style gloves when doing mill work or anything involving grease and oils. Although they do tear with regular use, it saves your hands from all kinds of little cuts and scrapes as well. Great videos though! It would be great to see more people making videos like this.
Sometimes CNCs do crash, we have a haas VF2 with a chip conveyor, on long production runsyour chips can fill up on the y axis way cover behind the table. if you're using the whole table movement and you're drilling or whatever right at the front of the table, the small amount of swarf behind the table can overload the y axis and move the table during machining cutting the machine out. i bent a 14mm drill. i reckon this is a design flaw and the machine should have better removal of chips, the y axis cover is too flat so the coolant won't push the chips off when it's flowing down. i had to pause the machine after every 5 drilled holes and clean the ways out and each part had 96 holes 22mm diameter on a triangular pcd in the centre, 2 m16 holes directly opposite and 16 30mm holes on a pcd around the outside and we had 30 of these parts to do in 1045. that job was a real PITA.
That (cnc) operator beard tho. There will be a bur because it's round surface and it's not countersunk. Flat surface with counter and you can't get any bur.
8:19 You can see the tap bouncing around on the top thread -not good! You need to reduce your dwell so that you get just the slightest amount of extension in your holder.
You drill a bigger hole to give the thread somewhere to form into. If you cut a standard size hole there would be to much material and nowhere for it to flow into. Thanks, good video.
You are using a wrong holder for the form tap.. never use the click holders for regular taps with a form tap... the pressure from the form tap will click it because it needs more power to push it in ... i always use a collet or veldon holder for form taps.. works like a charm.
I enjoyed this video, and learned about "thread milling" which is new for an old tapper dude. You mentioned about the formtap and the deforming of the bottom of the hole. I found this info which may be late by now: a)...Forming taps run better at speeds 1-1/2 to 2 times faster than a cut tap, and require much more attention to lubrication of the tool,... b) Cutting taps may be a better choice for "through-holes" as they won't require a separate operation to repair the distortion at entry and exit caused by the forming tap. ... www.natool.com/blog/2016/07/cutting-taps-vs-forming-taps Also I'm upgrading my SIEG X2 Mini Mill to CNC which has an R8 Collet. Questions: 1) What are the collets that you use? Are those tapping collets, which spin in reverse on extraction, or does the spindle turn in reverse in the G-Code? Keep up the great work!
Plus you are overconstraining the positioning of the part if you have the shape in both of the jaws. Having the locating features in the fixed jaw provides absolute positioning each time and no matter where the moving jaw is, it is still the same.
not many machinist are like John (upbeat positive). too many old school guys scared of the younger generation and now their wondering why they cant find help.
+canid song Yes. Do you see any reason why starting a comment by saying "the phrase is..." without any context can be problematic? OK, fine. The phrase is "work hardening". Now we all know the phrase. Just insert *the phrase* "working hardening" SOMEWHERE into the 15 minutes of monologue of this video. Thanks, great tip!
John, noticed in the video you started out with a low opinion of roll forming taps. Hopefully you now see they are quite a good way to tap. Specifically, they create no mess or chips, so doing a large number of tapped holes on a project works really well (example: fixture plates). I use them a lot on my CNC and get really great results. I have also started playing with thread milling, but honestly for most of my tapped thru holes I use roll taps. Cutting taps leave chips and debris that sometimes get into the adjacent holes and cause issues. Roll taps don't, nor do they jam or break very often.
John. If you really want to go first class with you fixture (You probably wont). On your moving jaw drill and ream or bore a hole at each parts location so you can install a small piston with a o-ring seal. Drill a cross hole to intersect all the pistons holes with small pipe plugs at each end. Start each piston in each hole than fill full of oil (try to eliminate as much air as possible ). Mount the jaw and clamp all the parts than crack one of the plugs to bleed off some air (like bleeding breaks). The hydraulic pressure will balance the force on all the parts even if they very in length. The only down side to this is you have to have a full fixture or blank parts in every station.
That is a very good idea. That is something I will have to make note of. Never know when it may come in handy.
when you drill it just counter sink the hole a few thou over the major diameter of the thread pitch and that will keep you from having any burrs. it doesnt have to be much just a little bit of a lead in chamfer
You can use form taps by hand, I do it all the time, but they really shine with power tapping. They are great for fixing damaged threads as they don't remove any extra material and will self align into the existing threads. Run them with coolant/oil always!I find that way lube (use your tamp oil it's free!) or EP grease works well on steel/stainless, or run your coolant about 10% and you should get about 2-3 times the life out of a form tap vs a cut tap. The hole size is supercritical, on small holes you need to be within a couple of thousands to get perfect threads.
Yep, every bit of tapping I do is by hand with form taps and one of those spring loaded tap guides to keep everything in check. Mostly 2-56 blind holes and it works like a champ. Everynow and then I break em but the material is usually titanium so i just soak it in ferric chloride till the tap dissolves.
Yep, every bit of tapping I do is by hand with form taps and one of those spring loaded tap guides to keep everything in check. Mostly 2-56 blind holes and it works like a champ. Everynow and then I break em but the material is usually titanium so i just soak it in ferric chloride till the tap dissolves.
+Widget Works Manufacturing Inc. Ha, seems like I'm not the only one with a preference for form taps for hand use! another nice feature of them is that they allow tapping into thinner workpieces than would be advisable when using regular cutting.
+krawutzimon actually just got done hand tapping a couple 10-24's(form/roll tap) in a mounting bracket for a remote operator panel for my surface grinder.
I recently switched over our taps 100% to form taps in our CNC operations. We are form tapping very successfully in all the materials we machine (4142, D2, A2, 1018, HRS, Aluminum, Stainless ext) except for Ampco. We have almost completely eliminated tap breakage plus the performance with water based coolant with form taps vs cut taps is much improved. It was a good move for us in the way of reliability, thread quality as well as it cut down on our tooling costs.
That's awesome man, and form taps are the way to go for sure. If you use carbide drills you can drill then form tap and then use the spot to clean up the burr.
I'd argue for punch tapping.
THIS GUY HAS REALLY PASSION ON THIS ...AS ALWAYS IN ALL HIS VIDEOS.
COOL VIDEO.
+NYC CNC I just got a question from production about forming tap. They want to know if the can use it and I did not know much about it. Thank you again John. I think they can use it :)
I have been using form taps for over thirty years, they do 90% of the tapping in my machine shop. I work in mostly 300 series stainless, 17-4 stainless, aluminum and brass. Stronger taps as far as breakage, particularly in blind holes and superior threads to cut taps. Lastly, there is no need dig out or blow out chips trapped in blind holes because roll-form taps do not create chips. I prefer OSG and Cleveland twist cobalt (M42) form taps. As always, very nice video.
Nice coverage of the basic differences between the three types of taps.
I was surprised at how loosely the soft jaws held the parts, even when there were only two workpieces in place. I expected trouble with a full load, but thought that two would be held firmly.
With the forming tool you would want a hole slightly larger than the average between the major and minor diameter of the thread. This is reasonable, because you are displacing the metal that was between the average and major diameters into the space between the average and minor diameters. Since there is more volume in the outer hollow cylinder than the inner hollow cylinder (because it has a larger average diameter), you need to "cheat" the hole a bit larger to have room for the extra volume. If it were a cut thread, the hole would be right for maybe 45% or even 40% thread. The coarser the thread (longer pitch), the more you need to cheat the extra room because longer pitches go deeper into the stock with a v-form thread.
The formed-is-stronger effect is generally true for external threads because external threads are generally made on round stock (usually by rolling between two grooved plates) where the grain runs generally parallel to the axis of the round. Cutting threads in such stock will cut the grain. Forming threads deforms the grain so it runs in and out of the body of the screw into the threads. You also need to start with stock which is a smaller diameter than the final thread diameter since some volume is displaced outwards into the dies. You see this same effect when knurling - the knurled diameter is larger than the original stock. (There is also some strengthening effect from work-hardening, especially in Stainless Steel.)
When forming internal threads it is not always clear which way the grain runs in the stock. It would have run parallel to the long axis of the stock as it passed through the rolling mill, but the hole to be threaded in the final piece may run into the end grain (in which case the formed-is-stronger effect would be about the same as for external threads) or across the grain (in which case the effect would be less). In these parts the hole runs across the grain as the part is a cross-drilled piece of round stock.
A few things:
1) Form taps work fine by hand. I don't buy cut taps in anything smaller than 1/4", and I use my form taps in everything from my CNC machine to hand drivers to a cordless drill (not an impact, a drill with a clutch). They work great, don't break with anything like the regularity of cut taps (in the small sizes for sure), and lend themselves very well to automated operations due to the lack of chip production (no chip breaking or rats nests to deal with). The DO require better lubrication than a cut tap does, for obvious reasons.
B) You're getting a bur because you're not chamfering the hole before you thread it. Spot, drill, chamfer to a depth greater than that of the thread you will be making, THEN tap. Any other sequence or edge prep will result in burs and secondary hand operations.
3) If you watch your cycle time and take tool cost vs tool life into account, a form tap will beat that thread mill every single time, even with that Tormach's lackadaisical tap cycle. They don't hurt so bad when you break one either.
IV) You should curse more often. It's not natural for a grown-ass man in an industrial shop setting to say "Darn". ;-)
John, It is actually ok to go ahead and run the thread forming tap through again. You are correct about the spindle orientation, but the spring tension will adjust the tap to the correct height to match the threads. If for some reason it does not due to tension then you could pull down and guide it into the hole until it starts.
Great videos!
Don't be afraid of form/roll taps. I would love to see more on tapping in future videos. They last longer and are faster that cut taps. And are faster than thread milling.
I was going to suggest square stock, but I see another commenter was already on that. Another possibility is to mill some small flats into the radius on the small diameter ends to key into the softjaws. And another wild idea...turn some small pointy "crush zones" on one end of the part. A hard enough opposing jaw could deform the longer parts enough to get a good grip on the shorter ones.
Gh3 taps produce standard sized threaded holes, GH4 slightly looser, and GH5 the loosest. I use GH5 taps in plastic and bronze/brass, because those materials tend to shrink after tapping.
exactly, because they elastically deform more before the plastic deformation starts.
The reason a rollform tap drill is larger is because you are forming or squeeshing the material inwards towards the center of the tap. If you check the hole after being tapped you will see it has shrunk.
Great video... love the slow mo!!!HHHHoooooolllyyyyy sssshhhhiiitttt!!!!
Funny Video..;-) Have you considered making soft jaws with a small v or dish and just slide the barstock in between, drill and tap holes ensuring they are spaced to allow for parting, then do the lathe work. Would allow for greater, even clamping pressure in all axis and allow you to do all ops as full thru-holes. Then you can just debur the hole length of bar on the wheel prior to feeding to the lathe. You can buy taps with a built-in chamfer to save tool changes etc, last company I used was Guhring which I noticed had them I think.
I've found that countersinking the hole before, tapping reduces/eliminates the burrs. It also, makes it easier to start the tap, when running it by hand. They tend to look cleaner too.
I'm glad you mentioned the issue about being able to hold all your parts securely in 1 soft jaw. I have run across this also. Maybe a good topic for a video, I could share a couple tricks I have learned. I'm not a big fan of tape, pucker on my part, LOL.
Great video, just subscribed. Form taps are a fickle mistress, and performance is WAYYYY more material dependent than cutting taps, in my experience. The reason they're "stickier" than cutting taps is partially due to the "springback" (technically elastic recovery) of the material. Basically after you push all the material into the shape of the thread, the thread is actually trying to bounce back to its previous shape as much as it can.
I form tap whenever I can. I don't have a lot of form taps, but the ones I have I use every time it's possible. I like that there are no chips to clean out, and I believe the threads are stronger, and are very nice. In my experience, form taps give more consistent threads than cutting taps. I've never power tapped, only by hand every time. I always use Tap-Magic fluid whether I'm form or cut tapping.
Time - 10:01 Feeellll THEEE PUUUUUUCCCCKKKKEEEERRR!!!!! Outstanding! I like it. Please keep up the vids!
John, just started watching the video but curious if you could model the soft jaws once. Save it as "master soft jaws" and open and re-save that file to your new project. That way you don't have to model the jaws every project. I'll keep watching!
The reason you drill the form tap hole larger than a standard tap is the deformed material "squishes" out... you basically drill to half way between the major and minor diameter. The excess material from the major that would normally be cut is pushed into the minor. I use them all the time to tap from M2-M5 in brass and copper but they work well in aluminum as well. I don't ever work on steel unfortunatly so I have no experience but for soft metals they are much less likely to get gummed up and snap in the part in my experience.
are u supposed to use the form-tap in a tap head?
I used a Collet (because of the high torque) the few times I form tapped.
Of course in a good machine (DMG 105V linear) :) .
Form taps are cool. 1/4x20, blind hole, 3/4" deep thread almost to the bottom in soft steel. I can usually tell when it's ready to break but that's after 1000's of holes on one tap. Never any luck with oil based lube but it likes the regular water based coolant.
Good tip about not using an impact driver to drive the vise. Were the arguments against doing so in regards to the speed or the constant impacts from the driver?
I occasionally use a drill if I need to open my vise all the way for cleaning or changing jaws and a drill seems to drive it smoothly, but it is much faster than I drive it by hand.
NYC CNC so what's the verdict on using impact drivers on the vice?
the rol tap (thats what we call it at my job) pushes material away but the material jumps back to its original position. thats why it tight when you try it. then again you do get stronger thread and a perfect fit. so if you are going with that. keep in mind that they need a new quick turn in the lathe to remove the bur
You make great videos keep up the good work. When I countersink tapped holes I almost always go .015 to .03 per side larger then the thread major dia.( aslong as the print allows). This takes care of any burr that may form on the entrance side of the cut. For Ex. For a 3/8-16 I'll use a 1/2" drill mill or a #6 center drill. And make the chamfer dia .406-.437. It also makes the appearance of the hole more attractive. In die making a large chamfer helps to strengthen the first threads in hardened tool steel to keep them from pulling under pressure while a die is running in a press.
Form taps work well in most materials except CAST!! it's to brittle to form in alot of cases. Anytime I need a thread. 25 or smaller I always roll tap, plus it is a stronger thread!😁
I love form taps. For aluminum it acts like nothing if even there. Works great on zirconium too. I use it for titanium as well even though many say not to.
Just gotta get your tap drill size perfect
Drill and tap a set screw thru the unmilled jaw in each pin position. We do this on alot of similar parts. Clamp the vise jaws together, then tighten the set screw as a secondary hold.
Ha! Looks like I was not alone in this idea. Slow, yeah, but it would look awesome if nothing else haha
Sure for a few parts, absolute no in production (I count 300 as production run). Why go through the trouble when a piece of tape works just fine?
11:15 reason for the larger tap drill diameter is that the form tap not only pushes material outward to form threads, but also swedges it inward in an equal amount. So if you were to form tap a hole, and then use a gauge pin in the hole, you'd see that the minor diameter gets smaller after tapping.
Kerosene works good to cut/tap steel with. A little bit of slick with a lot of cooling.
Aluminum is very gummy and coolant is not really required, just something slick to keep it from sticking to the tool.
We use WD40 at work for aluminum.
do you have all the parts made? concave the end of the part about .002"-.005" and kick your federate way down when you get to the last .025"-.050" to get rid of any nub that might be left to help with rotation in the vise. also it might be a good thing to center drill the pockets in the jaws to help clear chips and hold better for faster loading(looks like that might have been done?) most of the time we used a few little vises rather than load more than two parts in once vise
Except for hardened materials, we form-tap just about everything at work - blind or thru, doesn't matter. For deep holes, I find it better to fill them with lube instead of coolant.
If you use the correct hole size and cleaned them for chips - it's gonna run until Christmas.
There's also special formtaps for aluminum.
We use them on almost everything to. Including some pretty hard materials with the use of "ER" (energy release). Shits stickey and makes a mess but makes it possible to use form taps on just about anything. Just coolant for aluminum. Great for blind holes, and they don't have much of a lead generally so you don't need to grind them. In my experience sometimes it's hard to get your minor right. They look super shinny and pretty, but if you look at them under the scope the crest of the thread is pretty jagged and shitty looking (I suspect the cause of the minor dia issue). And if you're using them near the edge of a finished part you'll want to do you milling after you tap bc they will deform the material and you'll have a bump along the length of your hole. Also you can't tell when they are dull, sometimes you'll see the coating go but most the ones we buy are grey. I use a "emuge" holder for anything smaller then an 8-32, anything larger, highly recommend a rigid holder.
And for up to 54 HRC you can use pulver metal HSS taps, they cut really beatifully and we use them often together with carbide drills to get those missing screw holes :)
I believe someone mentioned the Guhring web site as a good resource for tap drill sizes. That's the site I use as well (and I spent a fair amount of time testing as many as I could find). I don't think UA-cam will let me link to it, so I'll just put everything in the URL after the domain (which it pretty easy to figure out)...
/Tech/TapDrill/default.aspx
If you're going for 75%-ish threads, a chart is fine, but the Guhring site lets you adjust for other thread percentages as well.
spot drill to full diameter with a 7/16 or 15/32 to eliminate the burr without adding a step. The form tap hole is bigger because material is extruded back into the hole during forming ie the id of the hole shrinks in the process. Formed threads are much stronger because the grain in the material is continously rather than cut into short segments that can shear in tension.
So far I have only ran form taps on my 1100. I have only ran a M4 tap but haven't broken it yet. When possible I found it is better to drill and form tap before facing the part to remove the raised material.
We use form taps all the time in the lathe. You can tap to the bottom of a blind hole which means u don't have to go past the width of the part off tool. In our case it's a 3mm part off so I just drill/tap part length plus 3mm. Benefit of that is when the hole continues into the next part it can easily start to walk off centerline more and more.
Exactly. No chips, no packing at the bottom, no broken taps.
FYI to anyone using a form tap on a Haas VMC we have all our posts include a M42 to command high gear for the spindle. We tap with ER32 holders and a tap collet not a torsion head and you will break taps without running the machine in high gear in a rigid holder setup.
Glue a small spring washer between each threaded bolt and the jaw to fix it better? Just make sure they just using a part of their "way" so there wont be any permanent deformation over time.
For deburring maybe a ball-mill if it doesnt take to much process-time. Just let it run from left to right and stop at each hole to go down a bit. For the backside turning all parts or using a backward deburring tool or a threadcutter on a 3D Path.
A tip for your clamp fixtures. Use a stack of Belleville Disk springs in each pocket for pins that may be a couple thou off. I had a job once that required several hundred pins be milled flat on two thirds of one surface, then drilled in two places and drilled and taped in one. Then a key slot was end milled in the lower part of the flat. I made a fixture with ten V slots that could be clamped in a vise but did not figure in the length. The pins did not have a critical spec for the length so they were all cut with a couple thou difference each. After building the jig I would have a few pins that would try and rotate during the first pass. I solved the problem with a stack of belleville disk springs in each pin pocket that gave me roughly 2200# of clamp force on the pins that were a bit short.
Cyrus Cosmo thats a great idea! thanx for sharing!
Cyrus Cosmo
that is a great idea thanks for sharing!
I would really recommend using a spot drill with a larger angle than the drill point. LakeShore has 140deg spot drill that I've found are 1000x better than a 90deg spot drill, especially since most machine drills are 130-135deg. Also since the spot angle is larger you can easily go a little deeper to create a chamfer on the hole for the tap or thread mill or whatever. That will go a long way in reducing the burr.
+War Machine LLC
I thought the main goal of spotting was to keep the chisel edge of a normal drill from contacting the stock, which prevents walking. Seems like a 90º spot would do this job, and with a 90º spot you'd have a nice 45º chamfer left over.
Wouldn't a hole made by a 140º spot drill be closer to flat (180º) than 90º?
+Hirudin I've heard that theory and bought into it for a long time. Experience and many drill bits later has proven otherwise. The larger spot forces the drill into the center much better and is much easier on the drill. That chirp you hear when drill first engages it it chattering and wobbling around throwing the hole position off. Do that with a carbide drill, especially a large one, you rapidly chip the cutting flutes. Once you use a larger spot all of these problems vanish.
Awesome video! I just stumbled across your UA-cam channel by accident. I like the idea of the endless applications that soft-jaws offer. I saw that your work piece turned easily. I over engineer everything in my head, but it also leads to good ideas. So, with that said, I had a crazy idea. What if you were to drill and tap the back side of the moveable soft-jaw for set screws? You could even maybe drill them at a downward angle to put downward pressure on your work pieces...
The form tap requires a larger hole because you are displacing material, the minor diameter of the threaded hole is smaller than the diameter you drilled to because when you form the thread the material the material you're coming at the major diameter of the thread "moves" to fill the minor diameter. The reason it's stronger is because you're maintaining the "grain structure" of the material. The main benefit imho is the finish of a form taped hole, it's phenomenal, like a mirror, and the finish is how you judge your tool life, when the finish goes away, time to change the tap.
With floating tap-holder you can tap again and again, i do it all the time. btw love your vids!
That slow motion "Oh shit" was great!
I was thinking the same thing. LoL
+NYC CNC I think it was the true shock and awe of the moment. No worries, that's one of the things we like, true emotion and enthusiasm in what you are doing.
+NYC CNC The pucker factor changes a man. Are these clamps going to come with stickers? I lost my SMW sticker. Thanks for your fantastic videos!
+NYC CNC So funny - I called out to my wife "OMG John said shit" :-)
drill cross holes in soft jaws slightly lower in vertical plane to force parts more downward to stop the spin you experienced and also you can make a V cut rather than a radius for parts to sit in to create less of a bearing surface, anything with more sides than a radius. combined this will stop the rotation as well as compensate for the discrepancy in part length leading to the parts coming loose from the fixture
You can use form taps on manual drill presses etc. but be sure to use the right spindle speed as a certain speed is neccessary for the optimal "flow" of the displaced material. Not sure if some tool manufacturers wrote something about the "flow", if I read it on the web or if it's just my own idea. So hand tapping should only be an exception for form taps.
At my job we use form taps for M4 to M10 in common steel (1.0038) and stainless (1.4571 IIRC 316Ti) and copper. For steel and copper we just use the water based flood coolant or internal coolant through the collet without a sealing disk in front of it.Further we higered the concentration of the coolant (Castrol Alusol MF-X) from 6% to 8%. For stainless we program M0 and use Rocol cutting oil without waterbased coolant. Further the Rocol oil is used on any manual machine for thread forming.I would always form threads, at least on manual machines, if it's not forbidden by your customer. E. g. the tip of the thread flanks that are not entirely closed due to the nature of the process are a no go for the food industry because they are much less than optimal for cleaning the internals of your production line.
IMHO cold forming would be the best description for forming taps as this is exactly what happens.
+1AB09CC3
Very interesting about the thread tips not being closed. Thanks! I'll try to remember that.
+Hirudin No problem. The large the threads get the better you can also see this in your finished thread.
www.pronic.com/upload/fckeditor/Image/Support/Rollformed%20thread%20process.jpg
flowdrill.com/sites/all/themes/fdtheme/images/flowdrill_process_page_image.jpg
just curious if the from tap causes the diameter of the rod being threaded has expanded?
+Ed Ginsberg Some parts, some materials. Absolutely. I had similar parts to what he is making and we could not form tap them because it changed the OD too much and through the part out of tol.
I don't know if you learned this yet. This was 7 years ago. I had problems with form taps. I started peck tapping and the problems went away. Plenty of coolant, or we had this honey like substance.
If you were to center the part so that the hole is between the two jaws instead of the majority of the part is over one jaw. Even if some of the hole is over the soft jaw, maybe not over the fastener for the soft jaw. I think that rubber strip is better than the sand paper we used to use.
The form tap would have run a lot smoother if you had lubed it.
Also run a countersink on each side of the hole to get rid of the burs. This might me relegated to a hand operation.
With the form tap on the floating head that you are using you may need to program it to tap deeper just because the way it floats before it engages. And there is nothing you can do for the treads having burrs on the top you can run the spot drill again to clean it no extra depth and the back you are better off with a belt sander then a chamfer tool
Whoa, Jared is sporting a serious Operator's Beard! :-)
Would it be worth running a quick chamfer after tapping for a "lead in" to your threads and also cleaning up that leading edge? At the end of the first full tap, it looked like the tap was rubbing a bit at the end when it was coming out of the hole, it just sat there for a bit. If you had a round wire brush that was the right diameter, could you just run a brush in and out to help break off the burrs?
Loved the slow motion " no shit " lol very cool video John. Thanks
we use uhmw strip 1/4 X 2 and cut the same length as jaw width instead of that red padding strip and you can use them a long time over a year in some cases. and put some serious clamp power on it
A bit late, but you could put a set screw through the soft jaw, against the end of each piece. Neat form tap!
You need to fix your tap cycle. It should feed in at the pitch or just slightly faster than the tap pitch to get the compression holder to grab, then stop, then reverse and feed out at nearly 2x the speed of the pitch so that it puts the holder in tension and the tap snaps out of the hole at the top. You are buggering up your threads by not feeding out faster.
NYC CNC Try 1.1 times the pitch, to start with. If the tap continues to dwell at the opening when reversing, keep upping the return feed to 1.2, then 1.3 until it's putting the tap holder in tension. The problem is that your holder is getting compressed so much at the lead-in of the hole, when retracting at feedrate it's dwelling and rubbing the tap.
Form tapping is great for tapping more deeper holes... we do it all the time at out shop.
Awesome video! Why not just drill into the cap screw counterbore in the jaws? It wont screw up your ability to flip them as it clamps mainly on the back. You shouldn't have any problem running all stations of that.
Also you drill bigger for a form tap because it physically forms back into the hole to make the minor diameter. So for a 1/4-20 you drill .228 but it forms back close to the .201 you would normally drill.
+NYC CNC You were saying in the video that you were worried about drilling and tapping through on positions 2 & 3 but since your supporting them off the bosses on the end I don't see why It wouldn't work there as well. Especially if you are drilling and tapping into the open hole of the cap screw hole that mounts the jaws. Its like a built in clearance hole! haha
does the vertical mill you have have a rigid tap cycle and you might want to put a larger chamfer with your center drill.
Try using same hole pattern on fixed jaw on clamping jaw. Depth just a little longer than turned ends
I know nothing about CNC (well, only what your videos have shown me), but it strikes me that the answer is staring you in the face. You've a long production run to do - make some properly sized soft jaws and go with the form tap. It was faster, produced a harder thread (important in your product) and the fit was good.
I think someone else has mentioned countersink to get rid of the burr. Either mill the end flat, then countersink the hole on the flat surface, or go in with an oversize countersink. Having a burr will be unacceptable and its another operation that you will have to hand finish?
12.00 and 08.03 Time. It's not good with the z-axis retraction, it stops with thread in the hole, which is not good, you have to retreat to pull the pot out of the hole, not the star instead. Breaks the beginning of the thread. It's just an observation! Hello from Romania, I work on the CNC lathe!
Can you run a normal tap in the same home twice using a t/c tap holder? If so I bet you could with form tap too.
Forming taps are the best. I have not used cutting taps for anything other than very low malleability materials. Throw them in a cordless drill. Hardly and chance of breaking them compared to cutting taps that have around half the total crossection. They will push a little material out as a bur, but about the same as a gun tap anyway. My travel kit is all screw machine drills and forming taps. Drills are sized to make a 60-65% thread. They also last far longer and leave a perfectly clean polished thread instead of microscopic chatter marks. Go ahead and drive them with an impact gun, they don't care.
Jared's beard should host a widget
Best thing to do is use a drill tap drill taps look like a drill but with theads its fast but another problem is ur tool holder is to wobbly you need to use a spring loaded holder that quick connects don't work to good
John I would form tap just because of the pucker factor with tread milling!!!!!!
Machine a flat with a mill that has a chamfered shoulder, then spot deep enough to create a chamfer, drill, and tap/threadmill.
It's kinda like riding a roller coaster, you just cant seem to control yourself when you come out alive LOL.
Would you recommend using a form tap or spiral flute tap for a drill press and reversing tapping head?
+David Moghaddam
Does your tapping head have specs for largest recommended tap size? I have a Procunier Tru-Tap 15000 and the recommended largest forming tap on it is #8 (in aluminum). I'm pretty sure I've done 1/4-20 in it though. For reference, 1/4-20 is the largest recommended cutting tap size (in aluminum) for that tapping head.
If you're thinking about using a 6-32 form tap with a tapping head that can handle a 1/2-13 cutting tap, I bet you'd be fine... well, as long as it's sensitive enough to reverse direction properly.
It's a Shars model that can use 0-1/4 in steel, however, I use primarily aluminum. I tried it with a 6-32 spiral flute tap and it gave me beautiful results. The smallest diameter I need is M3, and for any smaller 2-56 and 0-80 I have a hand tapping machine. I might be ballsy enough to tempt fate in the future, though.
I just like the idea of a form tap and how clean it makes the threads. I, like John, am starting in an apartment. So, noise and chips are my enemies. Thank you for the advice.
Minor suggestion:
It might be advantageous in the long run to wear gloves when working. Mineral oils, cutting fluids, grease etc can destroy the skin on your hands over time. Skin will absorb almost any fluid it comes in contact with..typically metal working fluids are not chemicals you want to be absorbing. I always wear nitrile exam style gloves when doing mill work or anything involving grease and oils. Although they do tear with regular use, it saves your hands from all kinds of little cuts and scrapes as well. Great videos though! It would be great to see more people making videos like this.
Sometimes CNCs do crash, we have a haas VF2 with a chip conveyor, on long production runsyour chips can fill up on the y axis way cover behind the table. if you're using the whole table movement and you're drilling or whatever right at the front of the table, the small amount of swarf behind the table can overload the y axis and move the table during machining cutting the machine out. i bent a 14mm drill.
i reckon this is a design flaw and the machine should have better removal of chips, the y axis cover is too flat so the coolant won't push the chips off when it's flowing down. i had to pause the machine after every 5 drilled holes and clean the ways out and each part had 96 holes 22mm diameter on a triangular pcd in the centre, 2 m16 holes directly opposite and 16 30mm holes on a pcd around the outside and we had 30 of these parts to do in 1045. that job was a real PITA.
+NYC CNC true, just found it really odd that a little swarf would overload the y like that.
That (cnc) operator beard tho. There will be a bur because it's round surface and it's not countersunk. Flat surface with counter and you can't get any bur.
Not only is the thread stronger but the tap is too. I use them in stainless steel all the time, they last for ages and ages.
"we gonna try it, probably break it"*huge smile*, man after my own heart haha.
I think form taps require bigger holes because they are squeezing material into the pockets of the tap.
8:19 You can see the tap bouncing around on the top thread -not good! You need to reduce your dwell so that you get just the slightest amount of extension in your holder.
why you not use hex material
You drill a bigger hole to give the thread somewhere to form into.
If you cut a standard size hole there would be to much material and nowhere for it to flow into.
Thanks, good video.
12:10 slomo had me laughing :D
You are using a wrong holder for the form tap.. never use the click holders for regular taps with a form tap... the pressure from the form tap will click it because it needs more power to push it in ...
i always use a collet or veldon holder for form taps.. works like a charm.
I watched this and had to try form tapping. At 1200 rpm I was amazed how much time I could save!
I put a video on my channel.
My preference really depends what I’m doing.
I enjoyed this video, and learned about "thread milling" which is new for an old tapper dude. You mentioned about the formtap and the deforming of the bottom of the hole. I found this info which may be late by now: a)...Forming taps run better at speeds 1-1/2 to 2 times faster than a cut tap, and require much more attention to lubrication of the tool,... b) Cutting taps may be a better choice for "through-holes" as they won't require a separate operation to repair the distortion at entry and exit caused by the forming tap. ... www.natool.com/blog/2016/07/cutting-taps-vs-forming-taps
Also I'm upgrading my SIEG X2 Mini Mill to CNC which has an R8 Collet. Questions: 1) What are the collets that you use? Are those tapping collets, which spin in reverse on extraction, or does the spindle turn in reverse in the G-Code?
Keep up the great work!
We only ever form tap on non magnetic materials in my shop. So aluminum and Stainless.
Hey John, Quick question on the thread milling. Is there a purpose for starting at the bottom and threading upward as opposed to downward?
Understood. Thank you.
Stainless LOOOVES ROLL FORM TAPS!
Slow mo " hoooolllllyyyyy sh......" ha ha. Needs to be a sticker.
Why can't you have a matching set of soft jaws, so the drilling is over the gap between them instead of over the jaw itself?
+DJ Delorie
This way he only has to machine one soft jaw. In other words, when this project is finished he'll still have one "good" (like new) jaw.
Plus you are overconstraining the positioning of the part if you have the shape in both of the jaws. Having the locating features in the fixed jaw provides absolute positioning each time and no matter where the moving jaw is, it is still the same.
great video! :D what I dont really understand why 60FPS was used for 720p and 1080p :D its just making harder to download :D
+NYC CNC but how? :D I have options to choose 1080p60, 720p60 and unless its 60fps I can have it in 480p :D
"hhhoooooooooooollllllyyyyyyyy ssshhhhhhhiiiiiiiiiiiiiiiitttttttt"
why cant you ridgid tap on that mill?
not many machinist are like John (upbeat positive). too many old school guys scared of the younger generation and now their wondering why they cant find help.
Great video :-)
Use molly D for your form taping
The phrase is work hardened. It doesn't happen, or happen substantially, to every type of metal though.
+canid song
Are you referring to what the form tap is doing? Seems like the word "forming" suits the process pretty well.
I'm referring to the hardening in the steel which happens during cold working processes which is referenced in the video.
I got that. I just wondered why you brought it up.
Did you watch the video?
+canid song
Yes.
Do you see any reason why starting a comment by saying "the phrase is..." without any context can be problematic?
OK, fine. The phrase is "work hardening". Now we all know the phrase. Just insert *the phrase* "working hardening" SOMEWHERE into the 15 minutes of monologue of this video. Thanks, great tip!