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

Hi Alan,
It looks like this electronic gear comes back time after time till
someone get it done and get the total cost for it.
Let's see, about 7 bucks for a a3977 another 10 for the necessary
board and components, Ps about 50 bucks, lcd another 10,at90s2313 I
think is about 5 we need two one for step generation and one for
display, numeric keyboard Don't know but Iwould guess about 10 bucks.
Now, 7+10+50+10+10+10 = 97 plus another 100 bucks for step motor =
200 bucks,300 for two axis if we can squeeze the code onto the chip.
Use it on you lathe, mill,indexing table,simple positioning
device,etc...
Not many people wants to have a computer near by just to run a
indexer, or a simple positioning system.
There is a lot of uses for it besides Cnc's.
It would be kind of a plc with a built in step motor drive.
Last week someone asked me to make a indexer to couple to a gear
cutter machine, so there is good uses for it.
I've being using those a3977 on 3 machines for about 1 year now,
none have failed.
Two machines are for pcb's profiling can get up to 100 ipm running
1/4 step resolution(very smooth drive).
also have a plasma machine 1.5m x 3.5 m using the same drive.
I'm using external diodes to help keep the heat down on a3977.
Can't get the motors running at high speed becouse of a3977 35v
limits but it's enough to spin a 260 oz/in step motor at about 600
rpm at about 8000 steps/s and 1/4 resolution.
I've played around with Bascom to programm the at90s2313 got to the
point of making the motors run by distance,cycle, sent by a terminal
programm but it was long time ago, I've to dig it out.
I'll join the electronic gear group and share what I Know about this
project, maybe we can get your code and my stepboard togheter and see
what happens.

Fogassa.



--- In CAD_CAM_EDM_DRO@yahoogroups.com, "Alan Marconett" <KM6VV@a...>
wrote:

>
> 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.
> >
> >
>