CNC conversion kit

[RotarySMP]

My image folder on the web site whon't help, as it has about 1000 photos of the kids, trips, lathe, etc.

Sorry if navigation is differcult. It seemed like a good idea at the time, and I'm too far down a track to change direction now

TurboCNC is only set up for a 1/rev encoder count, so using a regular 400 count encoder will gain you nothing. The opinion of the authors is that increasing the encoder resolution increases the computational overhead significantly.

If you run plenty of acceleration, turboCNC threads fine.

Go Ball screws.

[RotarySMP]

Sorry, I forgot to answer your question Jon.

I am using NEMA23 double stack Vexta PK268-2.0A 187Ozin motors for both Axis. If you take the chance while the lathe is disassembled to address the variable bed thickness, these motors are good for about 100-120 IPM rapids with the gibs quite tight. I didn't, so I have to limit rapids to about 50IPM so it doesn't stall out on the tight spots of the bed. Geared down 2:1 through 4 and 3mm pitch leadscrews, they have ample power at cutting speeds. The spindle motor power is the limitation here.

Addressing the bed thickness is really the right thing to do. You could just muscle the saddle around with a bigger motor, but it won't fix the saddle being a bit sloppy when tweaked up snug on the tight spots. Rick Kruger did a great write up here:

http://warhammer.mcc.virginia.edu/ty...s/Bedways.html

Did I mention to get ball screws? I didn't and am now redesigning to retro fit ball screws.

[JFettig]

Your right, the bed is a little messed up, I do notice this when moving from end to end. Mainly what I am looking to do is make a kit thats easy to strap on and go, that is if I ever decide theres a market for these to sell.


Jon

[DragnsBane]

sounds like something i would be interested in. if things don't work out for building them are you goin to put them up as shareware or just let it die? summer is about the time i am looking at for the purchases of my machinery so it would work out great.

[JFettig]

If I dont ever make this, I will post the drawings I have. Right now they are basic simple idea scale drawings

Jon

[JFettig]

Well I have designed and built a kit. Very simple kit, bolt on bolt off, easily convertable and unconvertable without any drilling of holes or anything. Just removing about 4 simple parts, total of 5 or 6 screws.

What kind of interest do I have in a kit like this? If there is interest, I will make up a few and put them in the classifieds and see how it does.
Also, what size motors? Nema 23 or 34, I think 23 is all you need really, I have some underpowered 34s on there right now.

The kit uses the existing hardware, existing leadscrews and uses the halfnut. I quickly measured .010 in x and z axis stock leadscrews and nuts. Its not bad if the gibs are tight.

Im uptight about my own designs, so I choose not to post pictures right at this moment.

Jon

[minilatheman]

Jon,

Whew! I think my timing couldn't be better. I just got a grizzly mini-lathe for x-mas. Ive been thinking of buying one for a long time, everyone was bugging me about what to get me for x-mas so I told them... and poof there it was. I couldn't be happier.

anyway I would like to convert it to cnc asap and am very interested in what you have to offer. I saw and read the thread for the stirling conversion plans but have no cnc "building" experience. Mechanically speaking I can make anything I need to convert one but I Am completely lost electrically and electronically.

any help you can offer would be greatly appreciated. If you have a bolt on kit that would be awsome.

please get back to me, Mike

[JFettig]

The offer I am and have been origionally considering is not the electronics, It can actually be quite simple if an xylotex kit, 24v power supply and some 150+oz/in motors are aquired and a little reading.
I personally cannot afford to build complete kits for the lathe, If I coudl I would. I may consider building one on request if time is there, but I will be starting my second semester in college in a few days and I dont know how much time there will be.

Jon

[JFettig]

I see over at xylotex.com they have a 3axis driver kit that minux 1 axis would be perfect or possibly close to perfect for this. Maybe little more powerfull motors would be nice for it.
I do not know what the current ratings are on these smaller motors are, but it looks like by what it says over at xylotex that they wouldnt be able to push full current on the motors they sell.
http://www.xylotex.com/3AxDriveBox.htm
Jon

[JFettig]

Here is a pic of my kit and Nema 34 motors. I am working on converting my mill over to my larger motors and a more powerfull controll box with a computer and everything right inside that bolts onto the column. When that is done, I plan on making a few of these kits.


Jon