[etard]

Hey guys, been playing with manual machines long enough to realize that if I want to make real parts, CNC is the only way to go. I spotted this HF 9 x 20 on CL and snatched it up for $250. I was pleasantly surprised by the condition when I got her and will begin taking the saddle apart to see how best to adapt some stepper motors with ballscrews to the crosslide.

If anybody has any suggestions or links to conversions, please help a brother out ( I could use all the help I can get).

I plan on front mounting the X axis motor and rear mounting the Z axis. I am budgeting for around $1200 + computer. That should put the complete CNC lathe at $2000 which seems reasonable.

I have access to a Bridgeport at work, so I can machine the mounting plates, belt covers, and odd bits myself. I also am taking the CNC course at the local Community College which gives me access to Mastercam, solidworks, and the Haas CNC machines. If my conversion goes well, I can offer mounting plates for others at a good price.

There seem to be plenty of guys converting the 7 x whatever lathes, but I have not seen a complete write up on the 9 x 20's. If anybody has any links, please post them here.

A few questions:

1. What size stepper for the Z axis? I would like to get some decent feed rates so I will be going 1:1 reduction on the leadscrew. Would a NEMA34 be a good idea, something with about 5-600 oz/in.?

2. Do I really need dual ballnuts on the X axis ballscrew? I see a lot of guys doing this, is it really that big a deal for backlash? I am envisioning the cutter only being pushed in one direction, so the results should be repeatable as long as I program sufficient lead-in before contacting the part. Thoughts?

I found a ballscrew on ebay that had a bellows around it to protect from chips. It looked a lot like the fork boots on dirtbikes, so I may buy a set or two for covering the Z screw.

Bellows



Obligatory Pics:

[recordingwhiz]

keep us in the loop on your conversion, I got one myself (Grizzly variant), have been considering it as well, just want to get good with it manually first, then convert it when I outgrow it and get a bigger manual mill.