View Full Version : stepper motor driver for small CNC

01-15-2007, 12:25 PM
hello all,
iam building a small CNC machine for my personal use.
using steppers from old printers and scanners (they have some 6 and 5 wire).

i was following 3-axis driver details from electronic-lab (http://www.electronics-lab.com/projects/pc/008/index.html)
it uses ULN5804 chip.every thing was ok until i inquired abt the cost of that chip.its costing 500/- each.thats a lot for me.i can' spent so much on one chip.
so does any one have idea for a good driver chip with ckt details.which is available in market.

pls help me.

01-15-2007, 11:14 PM
L297+l293 or L297+L298 combo.
About Rs.200 for both.

01-16-2007, 06:44 AM
ohh both costs 200/-.that i can spend.
do u have any circuit for it?

and i need 3-axis movement.that means one combination for each axis or just 2 chips can drive all the 3 axis.
imean if one combo is only for 1 axis then i need overall 6 chips to run 3-axis

01-16-2007, 09:01 AM
Yes...one 297-298 combination for one stepper...

What are your specifications?

You can as well go for ULN2803 if the ratings match....just a bit more programming complexity...but very very cheap...

Check on the net for circuit for uln also the datasheets for ratings...

01-16-2007, 09:46 AM
iam using motors from pinter.i think they r very low torque type (12v).
and for drving these i want to use driver board connected to PC only no PIC or AVR in between.
so is it possible with 2803?

01-16-2007, 07:53 PM
The 297/298 is for simple logic drive-NO need for Microcontroller OR PC
You dont need those if you use a PC....Just 2803s. But you need 3 motor control???
That will complicate the drive via parallel port.
But , Why do you need a PC, when you can do without it???

01-16-2007, 08:10 PM
i need PC so that i can control the operation process.
like if i want to drill holes in PCB or engrave somthing on plastic or wood i need PC and some software to control the movement of axis.this is what exact CNC is.
my main aim is to engrave words on wood.of course the thickness will be less as iam using small motors.

so ultimately my plan for prototype machine is three axis (X-Y-Z)
X and Y will be cardboard made planes driven by steppers and Z is to handle the small engraver.
so all i need is driver that can drive 3 stepper motors via parallel port.

and what abt using one 2803 for each motor.i did lot of search but unable to find one which is capable for 3 axis.

if u have any more designs pls help me guys.

03-18-2007, 12:32 PM
Hmmm CNC, Stepper motors are a good choice. For mini mill use good quality stepper motors, not from printers. Nema23 type with 200 steps and around 1.6kg torque. you would need to do microstepping to get good resolution for cnc applications.The biggest problem is getting good steel linear bearings and also the coupling to the stepper motor. Allegro stepper drivers are good. You can use also L298 for 1.6kg stepper.
I have the plan and construction details for CNC, but it is not free and bought it on my visit to UK.

03-21-2007, 09:00 AM

ANYTHING that can be done was already done....