akb1212
Aluminum
- Joined
- Jun 26, 2009
- Location
- Norway, Vestfold
For a long time I have been looking for others making DIY 4th axis capable of doubling as a lathe.
After all there are loads of commercial machines combining mills and lathes. Having seen one myself on an exhibition I thought that must be the perfect concept for hobbyist with limited available space. Especially when one can have a fairly serious (but somewhat aged) VMC for a reasonable price these days.
So my idea was to get a reasonably sized VMC (in my case I got a 1991 Maho HM 600E with tool changer) and then make use of most of the already fitted CNC capabilities and add a 4th axis capable of lathe work. In my case I can either put this on the table of the mill, or remove the angle table and attach more or less a full lathe stripped of its base and apron. If I do this it won't differ much from a commercial combimill.
With this setup I can even attach a trunnion table between the 4th axis and tailstock and I won't even need my old angle table. Except if I need to do exceptionally heavy work for which the whole setup with trunnion table won’t be stiff enough maybe.
So in order to get ideas of how to do this I started searching this and other forums for others doing similar things. At first it seemed impossible because 99% of all indexers I found used worm gears with way to high ratio to be able to rotate it fast enough to do anything close to what is needed to do lathe work. Direct drive systems seemed like the only option. And that isn’t DIY friendly enough for me.
It wasn’t until recently I found a guy doing exactly what I wanted, although on a much smaller mill.
He's using Mach3, and obviously there are issues making this hard in Mach3. But it appears he has cracked it and is able to make it work. And there is a long and very good thread about this on the Mach forum. Success! Mini Machining Center under Mach3 control - Video link
I'm impressed with what he's able to do with his setup. And I'd like to think I'll be able to get something similar set up on my mill eventually. Also check out his videos where he uses it as a shaper to make shapes impossible to make with a rotating tool. I have some internal splines I need to make, and will also try that out.
Then there is the question of what to use. Take a working manual lathe and start chopping on it until it suits my need, or make something from the ground up like he has done. In my case I'd like to be able to flip it over so that the bottom is bolted on vertically to where my table attach on my mill. That means the ways of the lathe would be useless since they are no longer facing the correct way. It's not like they will be used much since the apron is removed. The only thing it will be used for is the tailstock.
So I thought about using a linear rail for that. I have 2 x 3.5 meter long 40mm round linear rails from an old wood CNC (a Morbidelli U26) I had to slaughter for parts (no room for it, and my wife made me choose between it or the Maho).
Today I also realized the main part of the ball nut carriage from this router would be possible to use as a test headstock. It has a 1.5 kW DC servomotor attached via a tooth belt with a reduction to a hollow spindle that turned the ball nut. This spindle has a 50 mm int. dia. axial and radial ball bearing at each end. The problem with this is that it's only 130 mm between the outer bearing edges. I think this is short for a headstock. And it has a bore of 41.5 mm, so it’s fairly thin walled too. But I can keep looking for a suitable lathe headstock while using this as a test. The best thing would be a compact headstock from a small production CNC late of some sorts. But I’m not sure where to find one at a price I would be willing to pay. Anyway, after all I have everything on it including the drive. I just need to convert my machine to EMC2 to do this. Mach3 won’t handle my tool changer so I was planning on converting it to EMC2 anyway.
So, anyone like to comment on the idea?
I’ll try to get some Solidworks drawings made of this to give a better idea of my thoughts.
BTW, before you ask. My intention with this is to build Stirling motors and coolers of a usable size. Not just hobby sized things to verify that the principle works unable to do useful work. So lathe work with indexed milling will be needed for pistons, crankshafts and the like. And the idea of having this all done in one machine is very tempting. And it would save space since it would be the only big machine I would need. Until I go in to mass production that is.....
Anders
After all there are loads of commercial machines combining mills and lathes. Having seen one myself on an exhibition I thought that must be the perfect concept for hobbyist with limited available space. Especially when one can have a fairly serious (but somewhat aged) VMC for a reasonable price these days.
So my idea was to get a reasonably sized VMC (in my case I got a 1991 Maho HM 600E with tool changer) and then make use of most of the already fitted CNC capabilities and add a 4th axis capable of lathe work. In my case I can either put this on the table of the mill, or remove the angle table and attach more or less a full lathe stripped of its base and apron. If I do this it won't differ much from a commercial combimill.
With this setup I can even attach a trunnion table between the 4th axis and tailstock and I won't even need my old angle table. Except if I need to do exceptionally heavy work for which the whole setup with trunnion table won’t be stiff enough maybe.
So in order to get ideas of how to do this I started searching this and other forums for others doing similar things. At first it seemed impossible because 99% of all indexers I found used worm gears with way to high ratio to be able to rotate it fast enough to do anything close to what is needed to do lathe work. Direct drive systems seemed like the only option. And that isn’t DIY friendly enough for me.
It wasn’t until recently I found a guy doing exactly what I wanted, although on a much smaller mill.
He's using Mach3, and obviously there are issues making this hard in Mach3. But it appears he has cracked it and is able to make it work. And there is a long and very good thread about this on the Mach forum. Success! Mini Machining Center under Mach3 control - Video link
I'm impressed with what he's able to do with his setup. And I'd like to think I'll be able to get something similar set up on my mill eventually. Also check out his videos where he uses it as a shaper to make shapes impossible to make with a rotating tool. I have some internal splines I need to make, and will also try that out.
Then there is the question of what to use. Take a working manual lathe and start chopping on it until it suits my need, or make something from the ground up like he has done. In my case I'd like to be able to flip it over so that the bottom is bolted on vertically to where my table attach on my mill. That means the ways of the lathe would be useless since they are no longer facing the correct way. It's not like they will be used much since the apron is removed. The only thing it will be used for is the tailstock.
So I thought about using a linear rail for that. I have 2 x 3.5 meter long 40mm round linear rails from an old wood CNC (a Morbidelli U26) I had to slaughter for parts (no room for it, and my wife made me choose between it or the Maho).
Today I also realized the main part of the ball nut carriage from this router would be possible to use as a test headstock. It has a 1.5 kW DC servomotor attached via a tooth belt with a reduction to a hollow spindle that turned the ball nut. This spindle has a 50 mm int. dia. axial and radial ball bearing at each end. The problem with this is that it's only 130 mm between the outer bearing edges. I think this is short for a headstock. And it has a bore of 41.5 mm, so it’s fairly thin walled too. But I can keep looking for a suitable lathe headstock while using this as a test. The best thing would be a compact headstock from a small production CNC late of some sorts. But I’m not sure where to find one at a price I would be willing to pay. Anyway, after all I have everything on it including the drive. I just need to convert my machine to EMC2 to do this. Mach3 won’t handle my tool changer so I was planning on converting it to EMC2 anyway.
So, anyone like to comment on the idea?
I’ll try to get some Solidworks drawings made of this to give a better idea of my thoughts.
BTW, before you ask. My intention with this is to build Stirling motors and coolers of a usable size. Not just hobby sized things to verify that the principle works unable to do useful work. So lathe work with indexed milling will be needed for pistons, crankshafts and the like. And the idea of having this all done in one machine is very tempting. And it would save space since it would be the only big machine I would need. Until I go in to mass production that is.....
Anders