Re: low cost drivers

DASH,
An excellent post. It's about time that someone pointed out that
the emperor isn't wearing any clothes. You described my
experience
almost to the letter. But before we scare off the next wave of
newcomers, I would like to address your comments; there is a light at
the end of the tunnel!
First, I had a Sherline mill, knew nothing about CNC. Joined
Bill's
list early on. Read, read, read,…. Got Dan's 2Amp kit,
Sherline's
mounts and steppers, CncPro. All from recommendations from this list.
Had a 133MHZ PC, and an old PC power supply. Used half-step and
wired the motors half winding. Cut my first part on 1-1-2000.

> I recently put together a 2A kit. First let me say that it is very

well

> done and works well.

Agree 100%.

> I keep hearing people trivialize the amount of time that it takes

to

> put together -- don't be fooled: there are a lot of parts, the pins
> are close together, and unless you do this sort of thing for a
> living, it can take some time to put together right.

Right on. I hate to admit how long it took me. Crap, I didn't know
where pin xx on the DB25 was, I didn't even know what a DB25 WAS!
But, even tho the instructions were a bit terse, it could be worked
out, and Dan was always there to help.

> One MINOR nit is that the instructions in the kit only help you put
> it together (just look at how many posts there on this board about
> power supplies, wiring motors, etc). This took me some
> additional time, once again because I was trying to save money,
> when I wired up my "salvage" motors. Even using the
> "suggested" test software took some time to configure properly.

Right again. Got help from this list, found a booklet at Radio
Shack on Power Supplies, etc. All part of the learning process.
But, be warned, if you are as slow as me, it will take some work.

> Finally, this is no speed deamon. I can only get about 1000
> steps / second before I start loosing steps. This translates to a
> little over 7 IPM of motion.

Almost exactly, what I got. BUT I have to confess. This was all
hay wired together on the kitchen table. Now no one in his right
mind would admit to this, but there were jumpers, 4-conductor wire
from the kid's train set, (22, maybe 24 or 26 gauge?) powering the
steppers, alligator clips and thankfully I don't remember what else.
Hey, it was New Year's and a new millennium, and give me a break.
But, the good news. Installed proper cables, replaced the crappy
PC power supply, (which actually delivered about 9VDC under load)
with a 36VDC 10 amp one and now get 8000 steps/in. I KID YOU NOT!
That's 1200 RPM and 60 in/min! Way more than you want on a Sherline.
Like Randy, I set the max at 20 or 30. More than that and the lead-
screws start to vibrate.

> My conclusion: unless you are REALLY hard on cash, and are
> not REALLY sure this CNC stuff is for you, go for the assembled
> stuff. This goes double if you aren't that slick with a soldering
> iron.

DASH, I understand your conclusion, (been there, done that) but I
would not discourage newcomers from following in our footsteps. You
will save lots of money, learn a lot, have a bunch of fun, and end up
with a first class machine. As for soldering, get a soldering
workstation, and adjust the heat just so that it doesn't 'burn'
(oxidize) the tip. Get some small solder, .020 or .031 is about
right for this project, and you will solder like a pro in no time.
And ask anyone what it is like to watch that first part being cut!!
Almost better than ……oops that's another story..

My 2cents
al