Just a suggestion from my experience of CNC turning. The feed-rate for roughing the OD looks a bit conservative, you should be able to chip aluminium when roughing so you don't get a birds nest around the tool. There's not much you can do for the finishing as you want a slower feed for surface finish but roughing shouldn't be a problem unless you have really low HP. For drilling larger diameter holes, I would use a drill called a U-Drill. They're "inserted" drills, excellent for removing large amounts of material quickly, and they come in a range of sizes. They're also more solid than regular drills and don't kick off much, if at all, unlike yours did without a centre drill. Also you don't need to pre-drill the hole. and they leave a flattish bottom which helps if you want to face the back face of the OD, as I saw the boring bar kicked off a little bit when you were facing. You can also use them for boring if they're set-up properly ie. the tips are parallel to the X axis. Another note, I was taught to rough the OD past the parting off point...only by a few millimetres as this stops the parting off tool wandering on entry giving you a more parallel cut on the work piece. But great video, keep up the good work. Dan.
The only thing i would suggest for turning aluminum which you seem to do a lot of is investing in a DNMG tool holder (unless you already have one). The 55° insert angle should just better at cutting aluminum than a normal 80° insert i know this also depends on what insert your using and what not. I just know from personal use that 55° inserts just seem to cut really soft metal like aluminum and brass better than the 80° inserts. Also the 55° inserts are actually really sturdy compared to say the vnmg style inserts, so you can actually rough a part out with a 55° and finish with V-style insert or how ever you want to do it.
+adithmart That's something that I would think would be included as an option for the parting operation. Pretty sure that Sprutcam includes chamfer and rounding selections. Not sure why Autodesk doesn't include it...
Question, is the tolerance always off 1 thou in the same direction? Is it consistent being undersize? Could you add a compensation thou to the dimension to comp?
Apart from pushing the tool more and harder (which might help) you might want to try a specific aluminium geometry insert like Sandvik Coromant CCGX. They really do wonders even on manual machines.
I noticed that the boring bar deflection was massive, probably when it hit the bottom of the bore. Was it because of insufficient bar rigidity, some issues with the setup, or a mistake in the cam?
Are you still having issues holding proper tolerance? I have this lathe and turret and I'm having issues. I have noticed, the people using gang tooling get good tolerance and the people with turrets struggle. Something to do with the turret? Take a closer look at the part off in this video.
Loving this channel ;) I am buy no means an expert but I hear you mention tolerances and I'm not sure if anyone has mentioned this but try running the machine again with the coolant on. After running that large drill through, the heat will have made the material grow slightly and then shrink when cooled causing the tolerance issue. Of course I understand the coolant is off for video purposes ;) Keep up the great work ;) Certainly been helping me grow as well :)
Is it just me, or was there a bit of wobble in that thru hole? Is that because the stock was slightly out of alignment, or the drill was too big at first pass, or just me having bad eyes?
Thanks... I tried to ask without sounding like a troll... just trying to learn. Do you spot drill with just a smaller bit, or is there a "special" bit for that purpose?
+TheSageDad Generally you would use a larger spotting drill or centre drill...depending on your preference. Spotting drills are good as you can chamfer the hole before you drill it and they're generally quite rigid so you can have a nice accurate hole position.
One problem I see is that you rough and fine cut the outer diameter and then drill it. It is a big chance that the material change shape when doing so. Rough cut - Drill - Fine cut. I do a lot of big parts in Super-Alloys like Super-Duplex and when working with those parts the process is. Rough all dimensions - Put part away for 24 hours - Fine. A 500mm part usually expands about 0.6 mm/0.023" after Roughing + Hold time.
I was just about to ask roughly that. I thought it was always better to do the inner work first then do the outer. Especially if having a relatively thin wall.
I NOTICED YOU HAVE YOUR BORING BAR HANGING OUT FARTHER THAN YOU NEED YOU SHOULD SHORTEN THEM AS MUCH AS POSSIBLE ALSO GO INTO YOUR WIRING CABINET AND CHECK FOR LOOSE WIRES IN THE BUS BAR THIS CAN CAUSE THE MACHINE TO NOT HOLD TIGHT TOLERANCES
You must separate operations. First rough received and finish. For each must be added for turning or milling. When the final process outer diameter hole should have been drilled already. This ensures precise workpiece.
+NYC CNC I think what he is trying to say is that you should make sure everything is roughed first before finishing. As you said in the video, you were trying to concentrate on keeping tolerances, one of the best ways to do it is to rough turn the OD, then drill, rough and finish the bore, then finish the outside. If the walls of the bore and OD are quite thin, drilling after finishing the OD may cause it to expand or warp due to pressure/heat distortion.
+NYC CNC It is a small part but yes, you should rough all of the part and then finish the part. If you have the tooling space then finish with a different tool and not the roughing tool. You will hold .0005 when all is correct.
That was great, but it looked to me like you needed to use a center drill first to get that first drill to start straight. It also seemed like the cutoff tool was cutting in the wrong position which didn't allow the hole to go all the way through and left a step on the end of the part. Still a great tutorial.
+NYC CNC , it looked to me that the part was parted off a little long (maybe about a 1/16"?). It looks like unturned aluminum between the parting tool and the end of the part, so your through hole wouldn't be full sized. Looks like everything turned out pretty good. That aluminum can be pretty stringy until you get your RPMs and feed rate the way it likes it. Thanks for another fun widget combo.
Gotta push that roughing tool harder, to let the chip breaker on the insert actually break a chip. Being conservative on your feeds and speeds here is screwing you vis a vis chip control on your OD turning. You'll find that your dimensions are easier to hit too, if you control the chip better (reduces bar and tool deflection). Also, if the absolute position, ID, or concentricity on that thru hole matters (needs to be held to a specific tolerance of just a few thou), I'd suggest spotting it first, 'cause you could see, even with the naked eye, that the drill wandered like a lost puppy while starting that hole. Otherwise though, good video. It's aggravating my itch for a slant bed lathe though . . .
+NYC CNC Yes, more feed rate until it starts to actually break a chip. You need to keep the radial depth of cut at least as deep as the nose radius (a little deeper than the radius is better, shallower than the nose radius makes bird nests), and then push the feed rate up until the chip breaker on the insert starts to break a real chip. It can be done, even on aluminum. On my big manual lathe, I rough 6061 at 0.150" DOC (on the dia, 0.075" radial DOC) and 0.010" to 0.015" per rev feed. I use the same high sharp coated inserts that I use with stainless and nickel alloys (too lazy to change inserts to the uncoated polished ones, since the stainless ones I use have almost exactly the same geometry, but with a nice PVD coating system), and at that data, they break a very nice chip makes a little tinkling sound as it lands in the chip tray. Now, bear in mind that my lathe is a 16" swing that weighs north of 5k lbs, but that gives you an idea of how hard you should push it when roughing. When you're finishing, there's not a lot you can do to avoid the bird nests, but if you take a very light cut with a fine-ish feed at a very high surface speed, the chip will be very thin and willowy, so the bird nest can usually be broken up with coolant. They certainly won't have the strength to hold onto the turret like those big heavy ribbons you're making now do.
When customer submits a part and does not include their own tolerances, do you specify in your contract in that case a standard policy of what tolerance they will receive? I have been on the engineering end of things for my career, but we were schooled to include tolerances on anything important and exclude them on anything not based on the price factor. We are still schooled today that adding tolerances adds cost especially flatness tolerances. For you machinists out there who think engineers don't give consideration to every facet of the machining process, some of us do. There are good and bad professionals in machining and engineering. I personally believe, and evidently the manufacturing community disagrees with me, that every engineer should be required to build and test hands on everything they design before any consideration is given to production. In the case of consumer goods, and appliances etc, they should have to take one home and use it for a month before submitting it for production. I can say with confidence and experience, attitudes and work methods would change.
Very nice :) Push the roughing harder to break the chip. Proper insert geometry also helps. I like Iscar CNMG 431-NG (the 431 is insert size so yours might be different). Definitely spot drill if you can. Also check the center heights on the gang post...even the "bigass" drill looked like it wandered a bit. I think your parting tool is above centerline. It appeared to climb a bit. Check out www.edgetechnologyproducts.com/ for some excellent gadgets for setup. Have you considered a fogbuster for the lathe? You do alot of dry turning in aluminum and I think the same setup as your mill might help without blasting the camera with coolant. Gotta watch what you leave for a finishing pass on a flat bottom with that particular tool geometry. In many cases, it's a good idea to finish from centerline out to avoid trapping the chips behind the cut. Also a weird quirk...sometimes finishing from bottom out on the side walls can eliminate chatter. Keep on turnin!
Repeat-ability is a factor of the instrument though. Just because you get the same measurement doesn't mean that the strain of the component assembly was the same as before ;) The knob provides an adequate amount of torque that was also calibrated to, otherwise there wouldn't be a need to design it in the instrument in the first place.
+St0RM33 I calibrate measuring equipment/work in inspection/ use a mic hundreds of times daily. you can get mics with out rachet ' s and tbh you can adjust the ratchet to what ever you want, also when measuring a bigger shaft the ratchet is useless as you need the feel of it and listen to the squeak as you pass it over it.
garyhowe88 acceptable, but this is learnt from experience right? so unless you get some gauge blocks and measure them to learn the proper fill isn't the ratchet a more reliable way to measure things?
+St0RM33 Good test for anyone to find out if they can measure more repeatably using the ratchet or feel. Close your eyes when doing both and only open to read the number. Which is more repeatable for you on different geometries?
Just a suggestion from my experience of CNC turning.
The feed-rate for roughing the OD looks a bit conservative, you should be able to chip aluminium when roughing so you don't get a birds nest around the tool. There's not much you can do for the finishing as you want a slower feed for surface finish but roughing shouldn't be a problem unless you have really low HP.
For drilling larger diameter holes, I would use a drill called a U-Drill. They're "inserted" drills, excellent for removing large amounts of material quickly, and they come in a range of sizes. They're also more solid than regular drills and don't kick off much, if at all, unlike yours did without a centre drill. Also you don't need to pre-drill the hole. and they leave a flattish bottom which helps if you want to face the back face of the OD, as I saw the boring bar kicked off a little bit when you were facing.
You can also use them for boring if they're set-up properly ie. the tips are parallel to the X axis.
Another note, I was taught to rough the OD past the parting off point...only by a few millimetres as this stops the parting off tool wandering on entry giving you a more parallel cut on the work piece.
But great video, keep up the good work.
Dan.
+Daniel Way Right, thanks for the help. I apologize for my English.
+Daniel Way Agreed ;)
+Daniel Way Thanks man here too, sick info! Appreciated!
It turns out ID Turning / Boring videos are quite hard to find on UA-cam.... Thanks for this one.
Any suggestions how to bore out a timing pulley without taking the flanges off???
Just some food for thought for odd ball diameters you could by an emergency 5C collet and bore it to whatever diameter you need.
The only thing i would suggest for turning aluminum which you seem to do a lot of is investing in a DNMG tool holder (unless you already have one). The 55° insert angle should just better at cutting aluminum than a normal 80° insert i know this also depends on what insert your using and what not. I just know from personal use that 55° inserts just seem to cut really soft metal like aluminum and brass better than the 80° inserts. Also the 55° inserts are actually really sturdy compared to say the vnmg style inserts, so you can actually rough a part out with a 55° and finish with V-style insert or how ever you want to do it.
way cool Wednesday widget, thanks and Happy holiday!
Have you tried machining a chamfer or a radius with your parting tool? Part in, then chamfer, then finish parting.
+adithmart That's something that I would think would be included as an option for the parting operation. Pretty sure that Sprutcam includes chamfer and rounding selections. Not sure why Autodesk doesn't include it...
Question, is the tolerance always off 1 thou in the same direction? Is it consistent being undersize? Could you add a compensation thou to the dimension to comp?
Apart from pushing the tool more and harder (which might help) you might want to try a specific aluminium geometry insert like Sandvik Coromant CCGX. They really do wonders even on manual machines.
How do you like the shars mikes?
Am I correct in assuming that you're making a collar for an Ops Inc can? That's what that reminds me of, except they're normally steel.
I noticed that the boring bar deflection was massive, probably when it hit the bottom of the bore. Was it because of insufficient bar rigidity, some issues with the setup, or a mistake in the cam?
Are you going to be making any more videos of the 440, really interested in that machine
Are you still having issues holding proper tolerance? I have this lathe and turret and I'm having issues. I have noticed, the people using gang tooling get good tolerance and the people with turrets struggle. Something to do with the turret? Take a closer look at the part off in this video.
Loving this channel ;) I am buy no means an expert but I hear you mention tolerances and I'm not sure if anyone has mentioned this but try running the machine again with the coolant on. After running that large drill through, the heat will have made the material grow slightly and then shrink when cooled causing the tolerance issue. Of course I understand the coolant is off for video purposes ;)
Keep up the great work ;) Certainly been helping me grow as well :)
that boring bar looks loose in that toolholder
Is it just me, or was there a bit of wobble in that thru hole? Is that because the stock was slightly out of alignment, or the drill was too big at first pass, or just me having bad eyes?
Thanks... I tried to ask without sounding like a troll... just trying to learn. Do you spot drill with just a smaller bit, or is there a "special" bit for that purpose?
+TheSageDad Generally you would use a larger spotting drill or centre drill...depending on your preference. Spotting drills are good as you can chamfer the hole before you drill it and they're generally quite rigid so you can have a nice accurate hole position.
One problem I see is that you rough and fine cut the outer diameter and then drill it.
It is a big chance that the material change shape when doing so.
Rough cut - Drill - Fine cut.
I do a lot of big parts in Super-Alloys like Super-Duplex and when working with those parts the process is.
Rough all dimensions - Put part away for 24 hours - Fine.
A 500mm part usually expands about 0.6 mm/0.023" after Roughing + Hold time.
+Nikel87
And I forgot to say that I really enjoy your videos =)
So keep em up =)
I was just about to ask roughly that. I thought it was always better to do the inner work first then do the outer. Especially if having a relatively thin wall.
I NOTICED YOU HAVE YOUR BORING BAR HANGING OUT FARTHER THAN YOU NEED YOU SHOULD SHORTEN THEM AS MUCH AS POSSIBLE ALSO GO INTO YOUR WIRING CABINET AND CHECK FOR LOOSE WIRES IN THE BUS BAR THIS CAN CAUSE THE MACHINE TO NOT HOLD TIGHT TOLERANCES
You must separate operations. First rough received and finish. For each must be added for turning or milling. When the final process outer diameter hole should have been drilled already. This ensures precise workpiece.
+NYC CNC I think what he is trying to say is that you should make sure everything is roughed first before finishing. As you said in the video, you were trying to concentrate on keeping tolerances, one of the best ways to do it is to rough turn the OD, then drill, rough and finish the bore, then finish the outside.
If the walls of the bore and OD are quite thin, drilling after finishing the OD may cause it to expand or warp due to pressure/heat distortion.
+NYC CNC It is a small part but yes, you should rough all of the part and then finish the part. If you have the tooling space then finish with a different tool and not the roughing tool. You will hold .0005 when all is correct.
That was great, but it looked to me like you needed to use a center drill first to get that first drill to start straight. It also seemed like the cutoff tool was cutting in the wrong position which didn't allow the hole to go all the way through and left a step on the end of the part. Still a great tutorial.
+NYC CNC , it looked to me that the part was parted off a little long (maybe about a 1/16"?). It looks like unturned aluminum between the parting tool and the end of the part, so your through hole wouldn't be full sized.
Looks like everything turned out pretty good. That aluminum can be pretty stringy until you get your RPMs and feed rate the way it likes it. Thanks for another fun widget combo.
+NYC CNC Sorry, of course you were going to re-chuck the part and face off to proper length, I don't know what I was thinking.
How much does one of these machines cost? It would seem out of the reach of most guys.
Currently around $30,000 or so.
Gotta push that roughing tool harder, to let the chip breaker on the insert actually break a chip.
Being conservative on your feeds and speeds here is screwing you vis a vis chip control on your OD turning.
You'll find that your dimensions are easier to hit too, if you control the chip better (reduces bar and tool deflection).
Also, if the absolute position, ID, or concentricity on that thru hole matters (needs to be held to a specific tolerance of just a few thou), I'd suggest spotting it first, 'cause you could see, even with the naked eye, that the drill wandered like a lost puppy while starting that hole.
Otherwise though, good video. It's aggravating my itch for a slant bed lathe though . . .
+NYC CNC Yes, more feed rate until it starts to actually break a chip. You need to keep the radial depth of cut at least as deep as the nose radius (a little deeper than the radius is better, shallower than the nose radius makes bird nests), and then push the feed rate up until the chip breaker on the insert starts to break a real chip.
It can be done, even on aluminum. On my big manual lathe, I rough 6061 at 0.150" DOC (on the dia, 0.075" radial DOC) and 0.010" to 0.015" per rev feed. I use the same high sharp coated inserts that I use with stainless and nickel alloys (too lazy to change inserts to the uncoated polished ones, since the stainless ones I use have almost exactly the same geometry, but with a nice PVD coating system), and at that data, they break a very nice chip makes a little tinkling sound as it lands in the chip tray.
Now, bear in mind that my lathe is a 16" swing that weighs north of 5k lbs, but that gives you an idea of how hard you should push it when roughing.
When you're finishing, there's not a lot you can do to avoid the bird nests, but if you take a very light cut with a fine-ish feed at a very high surface speed, the chip will be very thin and willowy, so the bird nest can usually be broken up with coolant. They certainly won't have the strength to hold onto the turret like those big heavy ribbons you're making now do.
Well this wad "boring". But does anyone know the name of the song? I really like it. Lol.
+Axel “The Mysterious One” Dole
The song is Can't Slow Down, Reaktor Productions
cool video.
When customer submits a part and does not include their own tolerances, do you specify in your contract in that case a standard policy of what tolerance they will receive? I have been on the engineering end of things for my career, but we were schooled to include tolerances on anything important and exclude them on anything not based on the price factor. We are still schooled today that adding tolerances adds cost especially flatness tolerances.
For you machinists out there who think engineers don't give consideration to every facet of the machining process, some of us do. There are good and bad professionals in machining and engineering. I personally believe, and evidently the manufacturing community disagrees with me, that every engineer should be required to build and test hands on everything they design before any consideration is given to production. In the case of consumer goods, and appliances etc, they should have to take one home and use it for a month before submitting it for production. I can say with confidence and experience, attitudes and work methods would change.
that 60fps man. wow.
Very nice :)
Push the roughing harder to break the chip. Proper insert geometry also helps. I like Iscar CNMG 431-NG (the 431 is insert size so yours might be different).
Definitely spot drill if you can. Also check the center heights on the gang post...even the "bigass" drill looked like it wandered a bit.
I think your parting tool is above centerline. It appeared to climb a bit. Check out www.edgetechnologyproducts.com/ for some excellent gadgets for setup.
Have you considered a fogbuster for the lathe? You do alot of dry turning in aluminum and I think the same setup as your mill might help without blasting the camera with coolant.
Gotta watch what you leave for a finishing pass on a flat bottom with that particular tool geometry. In many cases, it's a good idea to finish from centerline out to avoid trapping the chips behind the cut. Also a weird quirk...sometimes finishing from bottom out on the side walls can eliminate chatter.
Keep on turnin!
Now work on that chip length!
And still doesn't know how to use the micrometer right...! USE THE SMALL KNOB!
Depends, most of the time I can get better repeatability using feel than the ratchet.
Repeat-ability is a factor of the instrument though. Just because you get the same measurement doesn't mean that the strain of the component assembly was the same as before ;) The knob provides an adequate amount of torque that was also calibrated to, otherwise there wouldn't be a need to design it in the instrument in the first place.
+St0RM33 I calibrate measuring equipment/work in inspection/ use a mic hundreds of times daily. you can get mics with out rachet ' s and tbh you can adjust the ratchet to what ever you want, also when measuring a bigger shaft the ratchet is useless as you need the feel of it and listen to the squeak as you pass it over it.
garyhowe88 acceptable, but this is learnt from experience right? so unless you get some gauge blocks and measure them to learn the proper fill isn't the ratchet a more reliable way to measure things?
+St0RM33 Good test for anyone to find out if they can measure more repeatably using the ratchet or feel. Close your eyes when doing both and only open to read the number. Which is more repeatable for you on different geometries?