Threadmilling: The Ultimate Guide! WW187
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- Опубліковано 21 лип 2024
- How to Threadmill: THE ULTIMATE GUIDE! Using Fusion 360, Machinery's Handbook, let's walk through how to calculate pitch diameter offset to machine threads! We got tired of CHASING our threads and wanted to find a reliable method. Join us on our myth-busting mission to find the truth about threadmilling.
Excel File Download: bit.ly/2ozRWIM
How to Threadmill | NYCCNC: bit.ly/2ozRWIM
NYC CNC Publishes weekly content on CNC, CAD, CAM & Manufacturing including the Wednesday Widget CNC project and Fusion Friday Fusion 360 tutorial! 5 Reasons to Use a Fixture Plate on Your CNC Machine: bit.ly/3sNA4uH - Наука та технологія
Great vid. There is another option to open the the thread without going deeper. That is to do a second pass with a vertical start depth offset. This increases the height in the root of the groove without actually going larger(deeper) in diameter. Makes for a stronger, smaller overall internal thread and you can use a smaller OD tool to create a larger major thread ( obvious tool limitations apply). This is something you can't do with an ordinary tap so might as well exploit the cnc capabilities.
Maybe that's step 4 in your excel sheet?
Also, add the once around 30 deg. chamfer at the beginning or end to deburr the hole. Bits already spinning right there at the rim...
Cheers John and thanks for all the work you put into these videos.
Great video John! I thread milled on a Bridgeport cnc powered by paper tape 40 years ago. Had to use a subroutine in polar coordinates to do a helix back then. Re-ground a woodruff cutter to 60 degrees. Wow, those last three sentences sounded like a old washed up machinist trying to be relevant today.
ATB, Robin
That sounds awesome. Your tape must have been 3 miles long! Haha.
That was not a nice thing to put now was it. we are all tiring to become relevant in a modern age . no need for the smart moth . son .
May be the Woodruff cutter may be the way for me to go grown to a 60 Degrees signal point cutting profile & driven by a router just may give me the way to ues my lathe it's pitch selection being the "computers" selection of feed & pitch in the same way we would do if single point threading on the lathe but using a spinning mill cutter in stand . cutting at 3000 3pm several light cut's yes that i think may do it .
I just want to say thank you. I have an extensive knowledge base when it comes to modeling with over 10 years of daily solidworks use but when it came to CNC i knew nothing. Over the past year or so i've been using yours and Lars Christensen' videos and the resources on your NYCCNC website to learn all i can. I've gone from not knowing anything about CNC to machining basic aluminum to mild steel and then on to titanium. And tonight i thread milling #2-56 internal threads in titanium like a boss. I appreciate every video you have ever posted as i've probably watched them all. Keep doing what your doing!
John - thanks for taking the time to put this together and post it! It's always been a '"bump the offset 'til the gage goes in nice" operation in my shop, and because of that I avoided it and jobs where I knew I wouldn't have a gage to check against. Just picked up a job where I won't have a gage, and now it won't be a total SWAG, thanks to the awesome calculator you put out, and some great background information. Thanks!
This channel is an INVALUABLE resource! You do all the hard work and all the tweaking, then come here and SHOW us how to do it, and GIVE us all the feeds, speeds, and calculations we need!
BRAVO!
This is seriously the gold-standard by which all training type videos on UA-cam will be judged by in my book. It is so well done! From the audio and video quality, the calculator shown with the picture-in-picture view of the mill running, to the professional way it was all explained - such an amazing video! Thank you!
4 years later and this is easily still THE BEST guide on the internet for threadmilling. When I look on the Autodesk forms for threadmilling information, the Autodesk moderators link to this video as their response.
A fantastic video along with a great set of beautiful calculators. I really appreciate the obsessive amount of details that were put into this content.
Thank you
EXCELLENT video John! I've been having a hell of a time cutting external threads on the lathe - they're always too tight. I imagine this same logic and maybe even your spreadsheet will resolve this issue. Thanks again and keep up the great work!
Incredibly well explained. You knocked it out of the park on this one. I can't wait to try this and not have to post 10 new programs to get a nice fitting thread! A huge thank you for going to so much effort to make this stuff accessible.
This is one of the best CNC videos ever made. Providing a spreadsheet is amazing. Thanks!
I've stumbled on a couple of good settings for this but the spreadsheet makes it seem easy! Thanks for taking the time and effort to put this together. I've been anxious for this video to release since hearing you mention it on the podcast...
Best wishes,
Tom Z
I have to say mazak have done an amazing job with thread milling on their controllers. I don't do much thread milling only a half dozen parts I make require it to get the max amount of thread in a blind hole but they have made it such a simple process to use. If I want to change a program that uses a normal rigid tapping cycle to a thread milling cycle all I do is go into the program and change the tool used for tapping from a tap to a thread mill and it will do the rest for me. It changes the program from rigid tap to a helical tool path starting at the bottom of the hole at whatever depth I set it as. It calculates all the information required with virtually no input other then putting the tool data in for say a 1/2"-13 UNC then putting the tool diameter in thats printed on the box and its done.
One of the best / educational videos you have done John !! Thank you !!!
Wow that's awesome! Thanks! Now I know why Everytime I program a thread mill we have to put major cutter comp to bring it to size. Saved this video for reference
Just headed over to Piersons website when you mentioned the kit and see they have been busy redesigning it! Nice work Jay looks great! Can't wait till I've saved up enough to get my mini pallet system :)
Your educational videos are absolutely fantastic, John. Thank you. My question: how would you cut an M12 x 0.5 in 6061 over a length of 1.3 in ?I own a Tormach 770.
I've watched this video probably 10 times over the past year or two and I finally understood the 3 steps. It didn't click until now that the minor diameter was to a flat, not the imaginary pointy tip and that's what the 2nd of the 3 steps is for. Thanks, you've made a lot of valuable videos but this is your most valuable.
One of your best most informative and useful videos. I have really had a hard time getting to the final PD. Usually takes me several offset bumps to get me where I need to be and then I have put notes of how much I needed as a manual note. Have you been able to use Fusion 360 to mill NPT threads?
Thanks John! Dealt with the same issue and figured it by out trial and error. Will use your sheet/method next time.
Holy cow, I get it now. Thanks. I'm psyched to order a mill tomorrow. I have done hundreds of M3 and M4 threads by hand and this will be nice, especially in copper.
Hello Pro Design,
Milling M3 or M4 is really no fun! I recommend for your application to use a fluteless machine tap without oil grooves, specialy for soft material like copper.
Glad, that i could help, keep in mind those taps need a precise hole diameter. I always drill that holes ~0,05mm (0.0019 inch) bigger for the start.
If the hole is too big you can see this on the peak of the thread dosent come close together. If the hole is too small you break your tool
Exactly it's a form tap.
There are tools on the market to mill M3 threads but it takes no time to fill such a tiny hole with chips if you dont have a internal cooling and then it becomes frustrating when you need more threadmills than the number of threads you have to do.
Very well organized around how we need to approach the idea of getting the threaded hole - it's that old adage... "Nobody buys a drill to drill things - you use the tool to GET a hole". Terrific round-trip guide starting with the desire to have a threaded hole, all the way to the point where you HAVE the hole. And you tell us how to adjust for variables along the way.
Excellent instruction borne of pain - that's how you know it's accurate content.
Holy cow John, I have had a thread mill for 3+ years and have not used it once simply because I could not figure out just how to use it. Thanks for this video, awesome stuff.
Thank you John looking to try some mill threading on tormach 440. spreadsheet and fusion fill got me started.
Hello John,
We often use a inside thread turning tool from the lathe to mill threads.
It gives you a full profile and the inserts are cheaper, but its slower.
ID orbitals are an absolute pain to deal with but the thread is amazing, yeah
Great video John ! Dumb question, how do you set your modular vice jaw distance so the mitee bites are at the correct distance apart to grip the work piece properly ?
Great video John. Interested to see you cut an external thread then view the actual profile.
Great Video, John. I haven't tried thread milling yet - but this is on the "To-Do" List
Thank you! I can’t wait to try this. Once again, a great video with a lot of great info!
Awesome video John, it has helped me a ton!!! Thanks!
2 questions and a tip:
1.) You didn't explain the 0.004 stepover value/calculation. How is that determined?
2.) With the updates/interface changes and new features in F360, is there an updated version of this video coming?
Tip: I learned the hard way that when using the Thread or Hole (Tapped selected) feature in F360, do NOT select the "Modeled" option. Otherwise F360 will bore your hole (if boring vs drilling) to the Major size, and the threading operation will not work correctly.
Yeah i have the same question about 0.004" step over
HI John
First off I love your work, best informative CNC tutorials on the web. Keep it up.
This thread milling one bamboozled me though, it left me more confused than when I started to look into thread milling. When I started to look into thread milling I thought, design hole, CAM hole as that's what Fusion is for but this video scared me :-)
So I asked on a FB group I'm on and a guy there had a simpler explanation (that is actually borne out with the description tooltip on fusion which is in brackets next) (NOTE: Required if the hole is drawn to the Minor size, or if the Boss/Cylinder is drawn to the Major size). He said you only need pitch offset diameter if you model the hole wrong. So say you need an M6 tapped hole (6mm metric major diameter, 5mm minor diameter) you can either model the hole in fusion by designing a 5mm or 6mm hole and threading it.
If you model a 6mm hole then it will be wrong for your drill size but perfect for thread milling, if you model a 5mm hole then it will be perfect for drilling but you will have to adjust for thread milling with the pitch dimater offset.
Now I haven't tried this yet as my thread mills turn up tomorrow so this could all be crap from me :-) However if this is the truth then I order you (not really I just ask nicely) if you could maybe update the video or just do a new one on pitch diameter offset to help others who may wander down my path :-)
Any way keep up the excellent work, you're helping so many noobies like me make a living from CNC.
Jools
Excellent stuff, as usual, John!
Thanks!
I broke down and put my mind to it. Got the thread mill working. Saves 1 minute per batch on my parts. That's two extra batches of parts per day!!! Now I use them in anything that needs a thread. Not only that but the threads are perfect. One part uses a plastic bolt so the threads have to be really loose. With the threadmill.. no problem!
Don't forget to add clearance if tapping a blind hole.
I really wouldn't mind if this excel sheet was behind a pay wall on the nyc cnc website. This is super valuable info and I think you should make some money off of it. keep up the good work, John!
Great video! One thing to note, 1/20=0.05" (not 0.5") :)
Is there a tutorial on making the threadmill itself in F360 for simulation purposes? Thanks for the awesome tutorial!
Is there a minimum thread size that you've found practical for threadmilling vs a tapping head on a Tormach? Is there a situation where you'd rather use the tapping head?
You guys do such a good job on teaching. Does your classes you have for fusion go over thread milling and designing?
Hi John! I see you used your Noga deburring tool, but what it you wanted to use the threadmill itself to make a small chamfer to take the edge off. How would you add it to the toolpath, given that the CAD/CAM program (Fusion 360) already knows where the center of the hole is (not to mention, the model of the tool itself)?
As you use your thread mill, will you compensate for wear like any mill through its use in the shop?
Great video. Did you cover the passes and depth calculation? Ex. 7 passes and .004" stepover. Also, I like to use the control vs. the computer for tool comp. If you need to adjust the gauge fit you can just alter the tool cut diameter in the tool table (+/- .001) and walk the pitch diameter right in. Thanks for the content. You are my go-to Fusion 360 wizard.
It looks like I can just visually adjust number of passes vs. desired stepover. I don't need to over-think it.
You know something that I frequently forget to do when thread milling is checking that the minor diameter of the hole in the model is correct and matches what I used to calculate the p.d. if you are scratching your head on why the thread is too tight, double check that :) obviously the thread toolpath is using the hole to interpolate so if that’s wrong then you thread will be under / oversize
Great video. I'm about to jump in and play with it some. Your spreadsheet linked only has NPT threads tho. and I didn't see any other tabs as shown in the video.
Fixed, a bug in excel. Turn off tabs then turn back on then minimize then maximize and bam, they are back. Odd, I never ran into that before.
Is there any easy way to change the spreadsheat to metric or will I have to try some differetn offsets for a good fit?
Learned a lot on this one! Thanks John!
What is your thoughts on using the drill operation and selecting thread mill? We have found we can input the final diameter in and if we want a tight thread we add 1/2 the crest or if we want normal we add the full crest and it comes out every time. Can you compare and contrast the two operations? Also have you seen away to program an interpolation turning in Fusion 360? Thanks
Thanks for figuring that out and sharing it with us!!!!
What is the tip offset when you are adding. Tool in fusion?
Great stuff, John. Definitely going to try this. Always get nervous tapping in some hastelloy projects with hours of run time already in it. I’d much rather break one of these in the hole. Don’t know why I hadn’t tried this before
Sheldon Robertson luckily, I haven’t scrapped anything in hastelloy due to a tap *knock on wood*
But I have scrapped a pretty expensive valve because of an incorrect offset on the 5-axis.
Sheldon Robertson I'm not positive where those valves end up, we make them for a client who sells them. I assume they're for something along those lines. We make them in 316L, AL6XN, and Hastelloy.
John, I'm a little guy with a haas that challenges your way of thread milling. I'd be glad to go into detail, record screen, etc. - BUT if you model your thread mill properly and generate a form tool, with the flat (can be done with ANY thread mill if modeled properly, regardless of supplied information from manufacturer), the PDO is as simple as major - minor. I was today years old whenever I figured this out, along with having used your method (which works), it dawned on me how it is able to be done all in fusion with little effort.
I'd be curious how you go about this!
Hey John, thanksfor great video. Wondering will you make a video how to machine a custom thread. What I mean by custom thread is non standard pitch. There are videos how to make different thread profiles, not offered by F360, but not machining it. Only 3d printing it. :( Thanks
Did you find the diameter and the surface feet/min on each tool through the tool manufacturer?
Great stuff John. Thanks !!!!
Also I’m going to school for my CNC machining and manual machining certification I’m understanding how to do the calculation for speeds and feeds but understanding what’s classified as low carbon medium carbon steel etc.. and stuff is a lot to understand but I understood how to find the basic thread major minor, pitch diameter and over the wire diameters. I’m sorry my thoughts are everywhere and to get speeds and feeds for threading rpms do you approach it the same way?
I did this in G code direct!!
In half an hour the program was ready.
The subrutines are in G91 the only thing you have to do is to give the center of the hole in G54
Simple and clean with CComp
Man I love machining! Great info 👍
Hi John , what about Metric in and out threads ?
So, a 5-axis machine could give more perfect threads?
(i.e. more like Sharp-V instead of Unified)
Don't You ever fell limited by the neck of the AB tools? There are many instances I can not get deep enough thread. Any thoughts? (Other than custom tooling)
It would be really nice if you would do a video on how to build thread mill tools in fusion 360.
Does it matter what size hole you select in fusion? For example, if I select a home that’s .250 will it still cut for a 1/4 20 thread?
Thanks for that!!! Is it avaliable for metric threads?
Can I get a copy of the excel file? the link you provided in your description is a duplicate of the NYCCNC website. Have a great week!
Also forgot to add that in the video you mentioned you would cover the number of step overs and the step over amount but didn't get to it. I have looked on the forums for clarification but have not seen much. I think the step over is really affecting the last pass and the number of step overs is breaking up the rest but input would be great on that. Thanks
Just awesome John . one question as i will never get a 770 mill can this be done on a 440 and would you show how well it would work please . and any correction's it may need . the little guy's lol
There would be little to no thread milling limitations on the 440. It's not really a taxing operation in regards to anything the 440 lacks over the other models. like hp etc.
I'm not at my CAD computer at the moment, so I can't check, but does Fusion 360 have the ability to shift the thread mill axially, so that the correct flat can be created in the root?
One of the reasons I don't angle the compound slide when single pointing a thread on the lathe is that when I don't have the correct insert, I can use a sharp tipped tool to cut to depth and then feed axially with the compound to form the flat and achieve the required pitch diameter.
Hey, old comment here but thought I'd chime in: if you want to do some axial offset, just right click your toolpath and choose "add to new pattern" make sure its set to linear pattern and that the direction is going up so you don't hit the bottom.
your pattern spacing (.003" or whatever) then becomes your additional offset amount!
When thread milling as shown, the mill is perpendicular to the material instead of following the thread's helix angle. Doesn't that change the angle of the threads?
Very well done, this is what america manufacturing needs, educational videos like this one. Thumbs up Jhon !
Outstanding, thank you!
Love this show.
How would a guy go about doing a pipe thread? model a tapered bore in fusion, interpolate a the tapered bore with the same tool? Would that work?
Sir, how do you apply for metric threads using your spreadsheet?
How do those formulas with with harder materials?
I really liked this video !!!! 👍🏻
Thanks for sharing this!
I have a question, I made my own thread mill model using the form tool feature so that it accurately represents the single form 4 flute thread mill I am using. I did this because there was no way to accurately make the thread mill in fusions thread mill option in the tool library because there is no way to make the neck the correct size, so when I simulate it, the neck of the cutter cuts into the minor diameter of my threads. In reality, it wouldn't do this, but I want my simulations to actually show what the cut is going to be doing. So back to my question, since I accurately modeled the tool using form mill, I have included the crest of my tool in the model, will this affect whether or not I need to account for the pitch diameter offset? And if so, what would be different? I'm having a hard time wrapping my head around whether or not it would affect anything. Unless I'm just not all there and there truly is a way to get the neck of my tool accurately represented in the thread mill option in the tool library...
but thread milling is significantly slower than ridged tapping yes?
Is that machinery handbook can be useful guide for cnc mill machines operator?
I'm using a Harvey 6-32 thread mill, they do not publish a crest spec for their products. How can I find this?
With the third correction wherein you back the toolpath out to account for the crest, the tool will no longer fit the shape of the desired thread. There will again be a gap between the sides of the tool and the desired thread profile, albeit considerably smaller than the one before the second correction.
Question:
When internal thread milling, what is the benefit of cutting on the "up stroke" instead of while plunging?
Thread milling on the "up stroke" has the bit climb milling which usually creates a better surface finish.
Nathanial Swearingen
Ah okay I didn't think about that. Makes sense now that you say it.
Thanks!
mlnlme1 climb milling.
Simple and clear explation
i'm new to thd milling & i'm wondering if there's a reason why you're cutting from the bottom up?
I'd imagine it has something to do with wanting to stick to climb milling opposed to conventional. With that, if you were reverse threading something, you'd probably start from the top. Just what I figure anyway.
Hi do you think you can provide the f3d for study?
Yesterday I tried to figure out why a offset of 0,7mm did a crappy thread Now i realize why..
Thanks :)
you should check out smi-cut thread milling
Hi guys - KIRK from NC, but I’m a Long Island guy originally. I’m looking to internal thread 1/4” BSP thread pattern into 15/32” holes in 1” PVC 40 Caps. Right now I’m.hand tapping with a bench vise and it highly sucks! I have a fairly new ShopBot Desktop XL (pretty stout unit), and would just love to make a Jig to firmly hold about 100 of these caps at once and let the CNC do it’s thing. I’m thinking after the hold down jig is built, that the actual processing is two steps (tools): one, the 15/32” mill bit, and the 2nd tool, the Tap itself. I don’t have Fusion, only latest Vectric V-carvePro. I know you guys do mostly higher level stuff with aluminum and not hard PVC, but do you think this project is ultimately workable?
You don't need CadCam software to treadmill. And now 360 has been crippled, you might need to know the old school method.
Use the main pgm to position at holes.
Use 1st sub pgm to position threadmill at depth and move to radial location using G91.
Call 2nd sub pgm the number of repetitions or threads to get threadmill out of the hole. It will be only one block in G91 for 1 thread.
Main pgm 1
G00 G90 X5 Y8
Z1
M98 P2
G90 G00 Z1
X10 Y4
M98 P2
G90 G00 Z1
X20 Y12
M98 P2
G90 G00 Z1
M30
SUB 2
G91 G01 Z-2 F50
Y.1 F.7
M98 P3 L12
SUB PGM 3
G91 G03 X0 Y0 Z.1 I0 J-.1 F.5
M99
.
Simple but I have used this on many CNC mills for 35 yrs.
Awesome job
Sundstand Aerospace cut AN hydraulic fitting with thread mill twenty years ago. Before that they used very expensive tools.
Thanks for share your knowledge awsome
Awesome video, but I have a question. Do you need a machine capable of rigid tapping to successfully threadmill, or is this away to circumvent that lack of capability?
You don't need rigid tapping but I think you do need helical interpolation. Not sure if that's a standard feature nowawdays
No need to have rigid tapping as the spindle rotation and tool movement don't need to be directly synced.
still have to buy lot of thread mills though. The only advantage i see is different pitches. In metric there are not that many. but i willl try it for unusual threads . i need to do an m50 1.5 a tap for that is 1000 euros..
Does the fact that the cutting edges of the threadmill sweep a perfectly horizontal path vs the inclined path (with incline depending on thread pitch) of the theoretically perfect thread cause any deviation from an ideal 60 degree V? Without doing any math or detailed analysis, it would seem that for the threadmill to properly fit an ideal thread it would need to be angled at the thread pitch angle. Since that's obviously not possible I would have thought it would end up cutting a V slightly wider than 60 degrees with the effect being worse the closer the threadmill diameter is to the drilled hole size. Thanks in advance for satisfying my OCD with any clarification :)
Brad Lotsberg the threadmill geometry compensates for the interference on the horizontal plane that your envisioning.
It would be a bunch of small flats.
But then the cutter would have to remain fixed and the part would move? Isnt always going to make a flat doing it this way.
Brad Lotsberg
That's something I had been wondering about for a long time too. A recent "This Old Tony" video cleared it up for me (the video had the word "Threading" in the title, I think, so look for that. Also, if you haven't seen This Old Tony's videos, you're missing out!)
The points of the thread mill are relieved so that, even though the cutting edge is sweeping in a horizontal plane, very little contact is made behind the exact edge that is doing the cutting.
As an analogy, imagine using the side of a piece of chalk to make a wide horizontal line on a chalkboard. You'd hold the chalk vertically and it would (basically) only touch the chalkboard along a single line of contact. If you continued to hold the chalk vertically, but drew an angled line instead, the chalk would still only have that single line of contact with the chalkboard, so the angled line would be drawn without distortion. The points of the thread mill are designed to do the same thing - they are designed to (basically) only have a single line of contact. (I hope that makes some sense!)
My thoughts exactly!
Every time I've seen John thread milling it's bothered me until I just melted my brain thinking about this for 20min and pictured cutting a thread on a lathe. The geometries are exactly the same in both cases! :-0
A lathe threading tool is just one flute of a thread mill, the angle is always measured square to the part, not offset to the pitch (the tool is always square to the part).
So the angle square to the thread (rather than the part) does actually change with the pitch.
I'd never thought of that before...
Great tutorial. I feel like for 90% of jobs though a proper tap and a rigid tapping cycle would make more holes per tool per dollar and do it faster. I would love to see a head to head on this. :-)
You are right, however thread milling has some huge advantages it there are multiple different threads, or if you machine is underpowered. I wouldn't expect a little sherline to drive a 1" tap through a block of steel, but you could get it done with a thread mill.
Milled threads are also more adjustable and clean.
Lastly, the versatility. One thread mill could replace a handful of taps.
But if your doing a production run with all one size hole, in a standard thread on a properly equipped machine, rigid tapping would be faster in the end.
I have a 5/8 11 thread mill I've been using for 3 years .it has done thousands of holes. Before we were using emuge taps and getting maybe 100-200 holes before replacing
Great video!
nice video!!!
Would measuring the OD of the tool and doing the trig give a usefully precise answer?
Jim's videos no need to measure the treadmill because the measurement is on the side of the box it comes in.
Yes... would if he didn't have the box. If it's an odd number of flutes then guesstimate. You should be able to get close. And you can always use cutter comp to bring it in to size
Sheldon Robertson haha you got that right.
Yeah thats true. With thread mills or any endmill I always keep the box in the top draw of the machine im running them in where it remains until I finish with the thread mill then its back in the box until I use it again but yeah it could easily get lost quite easily.
You would think so but in my experience it only gets you close and if it's an NPT threadmill your SOL. I always program undersized and comp to size during setup. Record the offset for the threadmill and your golden add long as you buy the same tool.
What about pipe threads?
7/16 gets no love ! Just kidding good video as always !
Fantastic