HF 7 x 10 CNC

[slatronic]

I finally pulled the trigger and picked up a HF mini lathe. I couldn't pass it up at $399 and I had a 20% off coupon that expired in a week. Been thinking about doing for some time. This isn't going to be a fast build, more of a side project.

I already have a G540, 2 387oz and 1 425 oz steppers from an old sherline mill build. I now have a Novakon NM135 mill. I'm planning on using ballscrews and some sort of gang tooling(this is for you Bob). I figure I can stick a couple tools on there. Not planning on doing anything much bigger than an inch in diameter. I already have a manual 11 x 26 grizzly for big stuff. The x axis ballscrew will probably be mounted on the back side of the crosslide.

Any suggestions from all the vets out there would be greatly appreciated. Already done a bunch of searching and have plenty of ideas. My biggest question is how to properly setup the ballscrews.

[knudsen]

Just a thot, I've never done cnc, maybe this is standard stuff, but you might consider removing the cross slide from the carriage and design the tool holder to sit on the remainder and use the lead screw for lateral movement. This would increase rigidity and give you more room to make a big honkin' tool holder with a zillion tools on it

You'd be surprised have big of work you can hog through with a 7x, given time and low speed range, that is

[blades]

That is a good idea, and it's exactly what I did on my 7x10. It does make it a bit more sturdy.

[RotarySMP]

Blades, Doesn't your X axis drive belt get full of swarf? I used to have an exposed belt on my 7x12 conversion, but it is now enclosed.

[blades]

Not yet Mark, as of now it's still a bench queen and hasn't seen any real work (not to mention that it's not fully operational yet).
Funny you mention it though, because just today I was thinking I needed to come up with some sort of cover for it.

[RotarySMP]

I tend to abuse mine as it is my only machine (on an inner city balcony).

This photo shows my original set up.
http://www.wrathall.com/Images/118_1886.JPG. I need to update my website with how it is now, like this.
http://www.cnczone.com/forums/attach...0&d=1187200756

I am making a proxxon collet spindle at present,
My homebuilt spindles
and bored a 40mm steel bar out to 18.5mm with drills, and then some of out to 30mm for bearing seats with boring bars. Especially big drills make huge bits of stringy swarf, which could easily get picked up by the belt.

[blades]

Nice setup Mark, excellent chip & swarf control, something I should take a closer look at.

[RotarySMP]

Makeing an enclosure gives one of the biggest advantages of a CNC. you don't get swarf everywhere.

[slatronic]

I got to spend some time tearing down and cleaning up the lathe today. Tons of grease but nothing a little kerosene cant handle. Took off most everything I won't be using for the conversion, which is a lot. Might have some spare parts for sale if anybody needs anything. I'll have to go through it. Casting looked pretty solid. Checked the spindle and measured less then 1 tick on my .0005" indicator, so I'm gonna say .0003" TIR. Not bad for a $320 lathe.

There's a lot of great ideas out there. Just need to shift through and figure out what to try. I'm think I'm gonna start simple then slowly add new parts and improvements from there.

[justin bowser]

I'm fixin' to do the same thing. This lathe is in HF's Memorial Day flyer for $349 so I plan on snagging one. Right now I have an old "Light Machine Corp" CNC which is just too small to do very much with. I'll need to at least servo the spindle so I can do threading but may be able to get by with steppers on X and Z with ball-screws.

I look forward to you making all of the mistakes so that my build will go smoothly! ;-D