Turning a benchtop mill/drill into a lathe?

[tootalew]

Long time lurker here with a desire for a benchtop lathe with a 5c spindle. I have already aquired a small headstock for the project and various other parts. I have drawn many designs for this lathes using differant linear equipment and after seeing the current lathe in the project log, I fear that having a base made from solid stock might be foolish. Then last week I noticed a Harbor Freight mill drill sitting idle in the shop due to the round column. I took off the column and sat the head stock on it thinking....bingo there is my lathe.....any thoughts?

[307startup]

If you don't mind my asking...where did you pick up your Dunham headstock? And how much did it cost?

[zephyr9900]

tootalew, I think that shows good promise of a sturdy gang-tool lathe. Brilliant idea!

Wyld, they are not Dunham but three Hardinge headstocks have sold on eBay in the past two weeks for $41, $128 and $139. I was surprised to see them turn up with such frequency.

Best regards,

Randy

[tootalew]

I bought the headstock from Dunham, they are the only company that makes a 5c headstock for sale. I searched for several years, even bought a feeler headstock, but the headstock alone weighes 120 lbs. This headstock cannot handle production though, the bearings are just not big enough.

A gang lathe is excactly what I want, and there are a few venders on ebay that sell gang tool holders, just need enough movment to make it work.

Most of what I turn is cast arcylic, much of it starting off square, which is why I want a 5c spindle.

The only problem I foresee, is the acme screws which are 3/4 - 6. Matching that size in a ball screw, it will be real tough to get a ball nut inside there.

[zephyr9900]

Interesting, tootalew. I just bought a Feeler 2d-op lathe (Hardinge DSM-59 clone) and I'm going to build a CNC gang-tool X-Z mechanism for it.

I see that Dunham cartridge spindles are pricy when they get to higher RPM's (4-5k). What RPM is your headstock good for?

Are you sure you need such beefy ballscrews? 3/4" are up in the Bridgeport retrofit range. The forces from turning should be much lower than milling.

P.S. Seeing where you live, does Rockford Ball Screw have a factory outlet store?

Best regards,

Randy

[tootalew]

3,600 rpm is the top speed. At around $1400.00 its the el cheapo. The timing pulley if I recall was around $400.00 The collet closer is my biggest beef, its just a camed lever that when closed is inline with the collet. Have yet to spin the headstock under power just yet and am concerned that it will open during operations. But even if I end up spending $5000.00 building my toy, where else can you buy a tabletop cnc bench lathe with a 5c Spindle for that kind of money? I am not sure I am going to use the drill/mill, but sorta like the frankenstien look of it.

I han not even given thought to making the leadscrews a small diameter, they are 3/4 now and just thought if I do go ahead with this I would try to keep the screw size the same size. I will have to give that a bit more thought.