Re: stepper/servo motors

Hi Tei,

I have converted my 7x12 Minilathe.

For this size lathe, servos would be overkill. Using the Xylotex 2.5A
Microstepping drive with a 200+ OzIn (Z axis) and 150+ OzIn (X axis)
such as the Vexta PK268-E2.0 (230Ozin for Z) and PK268-2A (187 OzIn
for X) through 2:1 timing belt drives would be perfect.

I have an older half-stepping L297/298 based 2A driver with 187 Ozin
PK268-2A's geared 2:1 on both axis, and it works fine. A little more
Rapid speed on Z wouldn't hurt. I could either get that with a
beefier motor, or less friction such as a ball screw.

I got the motors new surplus from some place in LA over a year ago.

The X axis is a PITA to do, as there is so little space for the nut
under the cross slide. I used a 10x3mm ISO Trapazoid (ACME) leadscrew
with two brass nuts in an anti backlash set up. Not ideal, but works.
My z is a 16x4mm ISO leadscrew. So far I haven't got around to making
proper bearing blocks, so it is running in brass bushes in the
stanard chinese cast iron bushing blocks - hence the friction.

TurboCNC is a great program, as it has single point threading (G78),
synced to a 1/rev encoder which is easy to do. Runs on any 486 DX. It
was originally written for a 7x12 conversion, cost nothing for an
unlimited trial, and only $20 to register and get the source from
Dave at DAKENG.com

I have a few things in the turbocnc yahoo group under
Files>frankensieg, and have been drawing up my conversion. Drop me an
email to mark ot wrathall dit com, if you want any further info.

Regards,
Mark

--- In CAD_CAM_EDM_DRO@yahoogroups.com, "teilhardo" <teilhardo@y...>
wrote:

> Hi everyone,
> I recentely acquired a harbor freight 7 X 10 minilathe and want to
> convert it to CNC. My question is, should I go with servo or

stepper

> motors (if servo system, what is the best controller?) and what is

the

> best place on the web to get these motors for the most reasonable

price?

> Thanks a lot,
> Tei Newman