indexer/lathe combo for under $1K

[bob_dodd]

Frank , the aluminum flat stock is from 8020 , i machined the countersunk mounting holes with the cnc , the hardened rails are Bishop Wisecarver #2 you can get it from http://www.cadcamcadcam.com/cncmachinecomponents.aspx

The rack gear is .5" x .5" I think the pitch is 20 but I'll have to check as I've had the rack gears a year or so now Bob

[frank134]

thank you and if you can get back to me on the pitch that would be great. who did you get the 80/20 from?

[bob_dodd]

Frank the aluminum stock & extrusion i got on ebay from 80/20 , I'll check later today about the pitch when I get back into the shop Bob

[bob_dodd]

Frank you have a PM

[GioAttisano]

I'm currently setting up an indexer/lathe combo for my shopbuilt CNC router. I'd like to know what rotational speeds you guys with lathe modes have found useful for what type of work (diameter, wood species). I"ve been thinking slow is where its at, actually buying a grearmotor to give me 40-200 RPM, but unsure if that makes sense. Thanks!

[Brady Watson]

In lathe mode, you want to go a lot slower than you would initially think. Keep in mind that at 1 revolution per second (60 RPM) on a 3" diameter part, the bit is effectively cutting 3 X pi (3.1416) or about 9.5 inches per second(!)

My recommendation is to gear things down for max torque at low rpm, and a max RPM of about 300, to get the most versatility.

-B

[MogulTx]

I am setting up a Rikon to go on my machine. From your photographs, it looks like you guys set it up so that the centerline of the turning is relatively close to the Z zero for the machine. I am designing the structure that will hold the lathe at the moment- which will define where that centerline rests... and I am thinking that I will set my centerline about 1" below table bed, on the assumption that I will always have some material at the center of the piece I am turning, which will not be removed, so I will rarely get to the center line of the part with my bit, and the machine should be able to be set up to reach the center line anyway... is this about how you guys see things?

Thanks

MGM

[Brady Watson]

Set it lower than you think you need if you are going to be cutting 6" or greater dia parts. Drop that Z all the way down and then put the CL about 2.5" below that. If you HAD to, you could get all the way down to the center with an extra long cutter. Aside from this, most of your work will be from the top, so you need to account for bit length. Also consider if you would be machining off to the side, spinning and using the tool like an outside profile toolpath. I do about 99% from the top/apex of the workpiece.

-B

[Wildman]

I love your setup, I also have a Shopbot PRT Alpha and want to add a inder / lathe setup like yours, do you have the parts list you used to get your system up and running, and where you purchased them from?

Thanks

Jim Wildman

[blackhawk]

Jim - See posts #22 and #25. The only other parts are custom machined plates that I made out of aluminum.