HF 4 x 5 micro lathe CNC

[blades]

Well, I decided to take the plunge and start a CNC conversion project for the HF micro lathe, since I've been thinking about it and talking about it. Borrowing the same basic concept of my 7 x 10, it looks like a little brother to it. Sort of like a Hardee's thickburger, only little.

The motor plates are cut from .125" steel on a waterjet cutter. The carriage block is some variety of tough nylatron type material that is used extensively at work. I couldn't find a suitable hunk of aluminum in the scrap bin, but this hunk of nylatron was perfect. The Z axis lead screw will be a 3/8-10 acme, just like on my 7 x 10. I could have re-used the existing lead screw, but I may have to sacrifice it for use on the X axis, depending on what I need to do to attach the timing pulley. The motors are NEMA 17's rated at 60 oz. in. from Keling.

The Z axis lead screw will be attached the same as on my 7 x 10, except I will be adding thrust bearings to each end of the motor. Think I will also add them to the 7 x 10. Although the motors like the ones on my 7 x 10 show no measurable end-play, I think the thrust bearings will be a good addition anyway, for very little cost.

What have I done.... now I have NO room on my workbench!

Apologies for the grainy photo quality (or lack of). Compliments of my iphone. My Samsung Eternity took FAR better pics, as seen in my 7 x 10 thread.

[plasmator]

Very nice thus far!

Anyone know what the smallest CNC lathe out there is?

[blades]

A Sherline may be smaller. Not sure if it's smaller in terms of capacity, but it looks smaller physically.

[knudsen]

Awesome!

[knudsen]

You have an iguana?

[blades]

You have an iguana?

Yeah, just 1 now (Alex). We had to get rid of the big guy when we moved into our current apartment/condo. We've just got the smaller one now, and she's spoiled rotten. She just got out of her "terrible two's" phase now that she's four, and she's settling down nicely. Alex is our 2nd, and Yoshi (the big guy) was our 3rd. Our first one lived with me when I was in WLaf.

[knudsen]

So cool. My wife would freak out if I brought one home! A friend of mine from high school now in Colorado has one named Iggy. He's an Iggy Pop fan.

[blades]

So cool. My wife would freak out if I brought one home! A friend of mine from high school now in Colorado has one named Iggy. He's an Iggy Pop fan.

For some reason I automatically heard a rimshot in my head when I read that!

[blades]

Ok, I've officially run out of motivation for this project. I got it done as far as shown in the pics, but along the way I have determined that the lathe is not really a good candidate for CNC, at least for the way I'm going about it. I'm not going to invest any additional time or $$ to attempt anything further on it.

1) The saddle does not sit flat on the ways, it rocks from corner to corner. I've filed the saddle in to remove a good amount of it, but it still has some apparent slop.

2) The gibs are just nasty to adjust. The gib plates are raw stampings, and it was apparent that absolutely no attempt was made to flatten them out or deburr them (they actually used the burr-side of the stamping as the functional surface). I did wonders to them with a file, but because of the rock in the saddle, it's nearly impossible to get the saddle reasonably slop-free.

3) The saddle locks up when sliding it on the Z axis, applying force only where the Z axis leadscrew is located. Even with the ways oiled, the saddle will bind and lock. Moving it by hand from the center of the saddle ( force applied between the ways as opposed to an offset force location where the leadscrew is), it slides just fine.

I'd be pretty pissed, or at least highly disappointed if I had paid $300 for this thing.
The best part of this lathe is the headstock/spindle/motor assembly. I'm 100% sure I can find a decent use for this part of it.

The only way I would pursue CNC'ing this lathe would involve scrapping the existing bed and cross-slide, and making a new one using linear bearings. And since I have neither the time nor inclination to do so, it's officially a dead project.

Onward and upward with the 7 x 10!

[knudsen]

Wow! I'm going to have to go have a closer look at mine

I was just looking at the belt on it today, and it seems it would be easy to add double or triple pulleys. But then I noticed the pulley on hte spindle is apparently held on by nothing. Pressed and peened? I can't see anything else holding it. Presumably there's a key. The motor pulley has a "C" clip.

Maybe you can make a CNC micro-mini-mill with that head, Bill.

[blades]

My thought was to put a timing belt on it for a smoother drive. But the multiple pulleys would give you multiple speed ranges, which would be nice. I've had the pulley off before, it's threaded on the spindle with the same thread size as the chuck and tailstock. Wasn't terribly tight either.
I was definitely thinking about using the headstock as a mini mill, maybe even attached to the 7x10.

I've got it on craigslist now (even listed it on the Indy craigslist, in case someone didn't mind the drive). been on all week, but no action. If it doesn't sell soon, I will probably dismantle it and ditch the bed & saddle. If I leave it assembled as-is, it will never get used. Hopefully your saddle/cross slide is better than mine. You've actually machined parts with yours though, so if you didn't see any issues with it then maybe it's ok.

[eartaker]

Remove the motors and CNC the 7X10. Now that I have the 9X30 I will probably CNC my 7X10 sometime. I have had lots of use out of that Lathe.