Hi all,
It's my first post here on the forum, but i'm and arduino fan from quite long time. 
After played with some funny little circuit i'm thinking to make something serious, and my classic dream is a diy cnc machine... :
So i would like to use arduino as controller board for the stepper motor, i already know the reprap project and i've looked for the very nice "stepper motor driver 2.3" with DMOS chip, but my idea is to start with motor like the nema23 (rated about 2.6 ampere) so i need a more powerful driver.
I'm thinking about the LMD18200 chip, a H-bridge motor driver cabable of deliver 3Ampere continuos and 5Ampere peak, TTL and CMOS compatible inputs, and a pinout similar to the L298...
But after start to buy all the stuff it i would like to know if someone have successfully piloted it with an arduino, i've searched on the board but actually i didn't found nothing...
Anyone?
So you will be the first then. 
It shouldn't be any problem.
What voltage do you plan to run it from?
What design of CNC are you trying?
The chip looks super expensive (£14.50!)
Pascal Stang has a schematic using the LMD18200 driven by atmega processors:
http://hubbard.engr.scu.edu/embedded/avr/boards/index.html#motordriverv10
You may be able to get some LMD18200 samples from National.
Maybe you can do something with this:
http://cgi.ebay.com/4-Axis-CNC-Stepper-Motor-TA8435H-Driver-Board-Mach-2-3_W0QQitemZ170340896183QQcmdZViewItemQQptZLH_DefaultDomain_0?hash=item27a91bcdb7&_trksid=p3286.c0.m14&_trkparms=65%3A12|66%3A2|39%3A1|72%3A1205|240%3A1318|301%3A1|293%3A1|294%3A50
Hi, thanks for the reply
Yes the chip is a little expensive (and for microstepping i need 2 chip for every single axis), but on ebay you can find it for about half of that price.
My intention is to drive the motor with a voltage between 30-40 Volt, my final project is to build a cnc router mill of about 50x80cm , somewhat like that for example http://www.k2cnc.com/Machines/CNC-router-KT-1414_detail.asp
I would like to work with aluminium pieces, so i need a quite powerful motor for mill aluminium and move swiftly trought the axis, at least the nema23.
I've searched for some drivers on ebay, but they are not enought powerful for the nema23... (also that linked has a peak power of only 2.5ampere ),besides they have all already a parallel port, i can't interface it with arduino...
I would like to use arduino/sanguino also to override the old parallel port and drive the cnc with my laptop, i don't want to have a crappy case pc only for the parallel port!! 
Instead that "motorDriver 1.1" linked by transfinite is pretty interesting, i'vent found the pcb design but the schematic is quite simple...
I also like the "application note" at the bottom of the pdf manual:
"If overloaded, even for a moment, a catastrophic driver failure may result and cause a minor explosion or a significant fire. This is not a joke, 4” flames have been seen shooting out of a LMD18200 just after a major overload. "
Well... it look promising :
besides they have all already a parallel port, i can't interface it with arduino...
I don't see why you think that. Any hardware that can be interfaced by a parallel port can be driven by an Arduino.
Yes but it would be a double conversion ( on a complete driver board the signal is converter for the parallel port and after that i must acquire with arduino and convert it again), on dedicated cnc forum like cnczone i've read that the parallel port is already pretty slow and often step mode from 1/8th and above can cause some problem, so i fear that another conversion should lead to loss in stepping data...
Yes but it would be a double conversion
No you don't understand. It is not.
Having thought about this overnight I think you are getting a bit confused with what you are trying to do.
If you have software that outputs step and direction signals on the parallel port then you don't need an arduino at all because all an arduino does is to generate the step and direction pulses needed by your driver. There is no place for it to go and no roll for it to perform. The problem with software that has the "real time bit" in the host PC is that it is subject to all sorts of delays and interruptions from the operating system. The parallel port is not slow, it is very fast, but put an operating system round it like Windose and it is slow and intermittent.
The solution it to transfer the real time bit into a dedicated processor like the arduino, but as far as I can see the software you are tying to use doesn't allow for that.
Look at "ReplicatorG" that allows you to feed an arduino with gcode and let it look after converting the instructions into the real time pulses at a consistent rate that you need for smooth CNC control.
My concern about the parallel port are that i'm forced to setup a dedicated pc instead to use my laptop...so that why i'm motivated to use arduino/sanguino as interface.
Thanks for the link about ReplicatorG , is very interesting...in the meantime i've ordered a pair of lmd18245 in order to to build a basic setup and give a try.
When it will be done i'll post here some result