CNC mini-lathe conversion help needed.

[minilatheman]

Hello,

First; a little about me so you better understand where I coming from and may be able to asess my level of involvement with cnc equiptment. I'm Mike. I'm new here. I found out about this place from the rcgroups.com I have been programing and opperationg cnc's full time for about 6-7 years now. Have worked with several Mazak lathes, and currently a Komo Router.

I currently have a Grizzly Mill, have thought about getting the microkinetics complete cnc kit for that.

On to the task at hand. I just got a Grizzly mini-lathe and wish to convert it to cnc for making my own varoius r/c hobby parts with the assistance of a CAD/CAM software. I am very capable of making any parts I may need to fit motors/ball screws etc. but completely lack the knowlage and or experience in the electrical/electronics dept.

What type of motors do I need... stepper, or servo? and how big and what is the difference btw them? what encoders do I need for them? cables wires drivers boards etc.

Where is a good scource/scources for the parts needed such as small ball screws, cog belts and pullys, motors encoders and or whatever I may need to do this.

I have spent hours looking at threads on this site for this info, and it's probably there but I don't know what would pertain to what I need for my small machine. Please help. I'll be very greatful for any advice or help I can Get, and would love to do a online step by step article on the buildup of the machine for others to see.

Thanks, Mike Dulian

motorbikemikexb9@comcast.net

[kong]

Hi Mike, I can only advise you on my own experiences converting a BV20m to cnc. There are probably better/cheaper solutions, but I like servos with Gecko 320's from www.geckodrive.com. Fot the mini lathe, speed is not a necessity, I went for a top speed of 1800mm/min so geared my servos down accordingly. Of course the gearing will depend on the pitch of leadscrew you go for, somethinkg like 5 TPI should be fine. The servos I used were 360 oz/in peak, but these were overkill, I reckon 200-300 oz/in peak will be fine when geared down slightly - even 150-200 on the x axis should be fine. Well theres a starter for you, hoep it helps

[JFettig]

For the mini lathe, Im going to have to say steppers for sure, probably higher power nema 23 frame motors are good. I have been talking to the guy over at xylotex and it sounds like he might be putting out a 2 axis board soon. I am debating weather or not I want to make up a few kits for this machine or not and how much they will cost.
The problem with the mini lathe is that there is no room for ballscrews in the X axis. that is unless you find some rather small ballscrews with small nuts. I know that when they get that small they get quite expencive.

If you stick with the regular screws, you by no means need microstepping drives, or 1/2 step or 1/4 step at the most in my opinion. With my gekos I have resolution down to .00004" wich is pretty pointless in having.

Jon

[minilatheman]

Thanks for the tips guys. Now I have some where to start looking and reading.

Jon, What software do you run and how do you like it.

[JFettig]

I run turbocnc right now, and I do like it quite a bit, it does what I want and is very customizable to do what I want it to do.

I have been wanting to try out cnczues and mach2 on my machines. I will soon try out mach2 when I get my computer and new controll boxes up on my machines.

Jon

[chelsea7]

Has anyone fitted conventional DROs to a BV20M?