Stepper Motor Driver

[droddis]

I've just finished building the frame for my cnc machine, and now need a set of 3 stepper motors, and a good but cheap controller. Does any one know what sort of spec i need. I have seen 4 nema23 motors for £35 i think i will be buying them. Could anyone advise on a good controller. The motor specs i am thinking of using are:

Rated current 1.2A
Holding torque 0.314Nm (3.2kg-cm)
Rotor inertia 0.55kg-cm2
Detent torque 0.0492Nm (500g-cm).
Output shaft 6.3mm dia x 19mm long
4-connections flying lead 115 mm long

ARE THESE MOTORS SUITABLE, IF NOT COULD SOMEONE ADVISE ON A SUITABLE MOTOR.

[Oldmanandhistoy]

Hi,

The motors are extremely weak and would be no use for a CNC machine.

Have you got some pictures of your frame and some details would be needed to help with motor and driver specs.

John

[droddis]

Heres Where its upto so far.

http://allyoucanupload.webshots.com/...10415719457836

Ignore the bad cutting, its my very poor craftsmanship!!!

If you could help me with what motors i need it would be most helpful.

I have also seen some boards on http://www.diycnc.co.uk That seem a very good price are these suitable for what i need???

Thanks very much
David

[Oldmanandhistoy]

Without getting to technical I would buy these stepper motors http://cgi.ebay.co.uk/1-8-Nm-Stepper...QQcmdZViewItem . Better still go to there website http://www.motioncontrolproducts.co.uk and buy them there it should work out cheaper with a saving on P&P.

The driver boards you linked to will work fine for a hobby machine and my suggested stepper motors. As you will probably know there is a lot of boards similar and with the same ratings on the net.
I can’t comment on quality and reliability as I have never used them so you might like to do a search here and see if anyone else has/does use them. I do know that people have been unhappy with similar boards but I do not know if it was this one.

John

[droddis]

Thanks very much for the help. The boards i linked to which one is i need. I am unsure.

Which board would you recommend, i noticed most people use the hobby cnc boards, but they seem expensive in comparision.

Also does it matter that the motor is bipolar, and not unipolar, what difference does this make.

I am only using the machine to cut and engrave some 3mm plastic panels, so its not going to working too hard.

Thanks

David

[Oldmanandhistoy]

Three of these http://www.diycnc.co.uk/html/driver25.html.

It would be a good idea to buy this as well http://www.diycnc.co.uk/html/parallel.html .
I did use a Xylotex 3 axes board for a while; it is a well known American board and known to be reliable. Now I buy drives from Motion Control Products. I can’t recommend any other as I have not used them.

The motors used with these boards would need to be wired Bipolar and I would stick with bipolar boards if at all possible as you will get better performance from the motors. If you would like more information on stepper motors look here http://www.cs.uiowa.edu/~jones/step/types.html .

John