>
> The first answer is usually a question. what is the size of the load you
> want to move ?
>
> if all you are doing is a drilling platform, then your little motors are
> probably good enough.
>
> Remember the loads to move a board are not much different than to move a
> printer head.
>
> I am not a motor expert, but have figured out that there are mainly two
> versions of stepper motors.
>
> the pressed can style. these are the ones you find in small printers and
> such.
>
> then there are the NEMA rated ones. NEMA17 is 1.7 inches square on the
> mounting plate
>
> NEMA23 are 2.3 inches square and NEMA34 are 3.4 inches square.
>
> a NEMA23 is common in laser printers are other machines so you should be
> able to find them as surplus for not too much money.
>
> Often 200 steps per rotation, with half stepping, you get a decent 400
> steps per rotation.
>
> pleanty strong enough for light wood routing, very light aluminum milling
> and more than enough for a drilling machine.
>
> Stepper motors are rated for voltage and amps.
>
> You can run them at rated voltage for minimal power, or use a chopper
> style driver and use a MUCH higher voltage. using 20 times the nameplate
> is very common. in fact if you check a data sheet, your 5 volt motor
> will show performance with a 48 V power supply.
>
> Of drilling only considder a solenoid for the Z axis. for routing, you
> can use a solenoid or leadscrew, but for milling, you need to use a very
> solid machine. adds to the complexity and cost. and that is one reason
> I am interested in a drill only version.
>
> HTHs
>
> and please post more questions. we all need to review.
>
> Dave
>
>
thank you very much for the NEMA description...
forget about the pressed can motors, i have plenty but obviously they are
too weak..
but i too have some NEMA like motors... (what stands NEMA for?)
they measure only 55mm at the mounting plate (also 55mm diameter on the
round section).
this is about 2.16 inches (how can you live with these units..... ;-) )
so this is ~nema23.
the motors are labeled "astrosyn miniangle stepper", type 23LM-c349-01,
6,8V (2 of them, 5V the third) 0,75A, 1,8Deg/Step
MINEBA co., ltd.
I found no datasheet for the c349 but in general these motors seem
common...
As i have them, for free, now, i will use them...
But i may upgrade later because they are not as big as i thought
the motors should be....
I played around with steppers some years ago, i read "control of stepping
motors, a tutorial, Douglas W. Jones"
(find easy with google - not a book, to read online...)
I only built the very simple circuits, but the document also covers driving
faster and at higher power (if i remember correct)..
i will read it again...
Can these motors drive the threaded rods direct?
I don't want gears or belts.....
You got me to finally give up the plan of making "the perfect machine" now.
I will make a unit from what i have, as cheap as possible.
I have the motors, for Rails steel square tubing will serve for now.
Some allthreads (metric) must be standing in some corner too...
The bearings, i don't think i have enough of them. I will get some abec
from the sports shop...
I also have to make the control electronics. should be no problem at all.
Will look what is available....
I have four STK6982 (ecg1736) stepper driver ICs... maybe i can use them?
they drove the motors in the printers from which i took all the stuff out..
there was also a power supply in (switched) which is adjustable up to 50
volts or so...
seems hard to get a datasheet for them.. (was a thread about also in
cad_cam_edm_dro)..
will see what i can do...
thanks for the hints, now i have to do some reading....
st