RE: [CAD_CAM_EDM_DRO] Re: Electronic Lead Screw & Power Cross Feed | Poor Man's CNC ?

Hi Fogassa,

Sounds like your board will certainly do the job! Just the Z axis, or both?


People can actually have both. Initially they can use "the box", and later,
if ever desired, connect up a PC and use the box(s) as simple drivers. Sort
of a "pass through" processor, and of course the stepper driver. I believe
both the Sherline CNC System and the newer Frogs can do this. BEST OF BOTH
WORLDS! (no I'm not a spy trying to convince you to go full CNC!).

I can certainly see the benefit of having a small, self contained "linear
controller" available for the lathe. Hey, I have a 5" EMCO lathe in the
"down stairs" shop that needs a little help! I have the spindle encoder
(EMCO) for it. I just never got around to CNCing it after I got the
Sherline lathe (CNC'd). Probably for the same reasons, another computer,
keyboard, monitor (not that I don't have plenty of these) and driver box to
set up in the garage, er, shop.

I've been planning to put my motion control code on a PIC (saying it for a
while!). But of course this makes me all the more interested in doing so.
...But I've got these 12_ R/C servos that want to talk to a PIC and I'll
probably work on that for the time being.

How complete/similar is your box's control ability to that of the Frog or
the Sherline linear (/circular?) controllers? I believe they use the same
driver (or part of) that the Sherline CNC System uses.

I of course am interested in motion control of all sorts. And even 'tho I
have CNC'd my Sherline mill and lathe, I still find both ends of the
spectrum interesting, from simple home made L/R drivers to help move a
single axis, to the full 4+ axis of the commercial machines.

SO I might hint that you can "design in" a future compatibility with full
CNC (step/dir input option).

I do so like to be able to key in a distance to move Z, and repeat a pattern
of three or four commands, this makes it easy to take off stock for to a
diameter, or face off. A feature that my CNC'd Sherline machines enjoy.
I actually have a "screen" in my controller program (STEP4) that allows
basically "interactive" machining. Give it a move command (like "G1 Z-4"),
or jog with the cursor keys, and you've got the start of the simple
operation described above.

THIS ALL COULD be added to a simple stepper controller "box" like you
describe, if you've got a numeric (plus a couple of keys) keypad on your
box, and of course a simple LCD display. But big BRIGHT LED's are easier to
read as to axis position.

Would you care to describe your box a little more? Either on/off line, or
the new E-leadscrew list would be fine. I'll have to think in "PICs", 'tho.
;>)

Alan KM6VV

> -----Original Message-----
> [mailto:CAD_CAM_EDM_DRO@yahoogroups.com] On Behalf Of afogassa
> Sent: Tuesday, December 06, 2005 7:16 AM
> Subject: [CAD_CAM_EDM_DRO] Re: Electronic Lead Screw & Power Cross Feed |
> Poor Man's CNC ?
>
> Right Bob,
> You've got it right.
> about two weeks ago I've post the same thread on electronic gear,
> but was turn down with the same "hook up a computer and you have a
> full cnc controller."
> I have a old south bend clone missing gears,and this would be
> perfect for it.
> I don't want to have a full cnc lathe, if I can cut threads it
> would be fine.
> As you mention there is a lot more than just hook up motors and get
> a computer to run it, after that done you still have to replace the
> leadscrews, learn how to programm fight with software control and
> have a big controller box and find a place to put it.
> Here is a nice and compact exemple:
> Atmel at90s2313
> Lcd
> a stepper drive based on a3977 from allegro.
> I make a stepper controller board based on the allegro microchip
> with galvanic opto isolated inputs and it's about 5 1/2 x 4 inches
> size could be smaller if I don't want it opto isolated.
> Get a code into the at90s2313 chip, and you'll have a box about 8 x 8
> inches that will do the job without a computer and costs less than
> $150 bucks.
>
> Fogassa.
>
>