View Full Version : maximum amps

25-05-2009, 08:12 PM
Hi Can anyone give me some advice. I have purchased a driver board which allows the maximum current to be set for each stepper motor, the permissable values are 1, 1.5,2 and 2.5 amps, My motors have a rated current of 1.4 amps (4.34 volts) for bipolar parallel and 0.7 amps (8.68 volts) for bi polar series. My question is, should I be setting the current below the rated current of the motors or just above ?

Many thanks

Lee Roberts
26-05-2009, 12:04 PM
Yea set the drivers to 1.5a mate, what drivers are they? Routoutcnc ?

27-05-2009, 07:08 PM
Thought it would be ok to set to 1.5 but if I had messed up I would have had "her indoors" to answer to !!

The board is a SYSTEM 3 + from CRH Electrical Design.

11-08-2009, 09:30 PM
how are the system 3 drivers doing ....i was thinking about using them

11-08-2009, 10:54 PM
Hi jonm
The drivers are going well, very pleased with the purchase, Roy at CRH (diycnc.co.uk) is very helpfull too. I have only been at the cnc stuff a couple of months, so am fairly new to it and was a bit daunted to start but setting up the drivers couldnt have been easier.

Looking to add some limit switches soon and from the manual it seems this should be pretty easy too. Just a case of of connecting up a few wires, no config on the board needed.

Only thing I'm not sure about is whether multiple limit switches can be connected to the same input (I assume they can be connected in parallel - perhaps someone out there can advise me).

11-08-2009, 11:08 PM
Hi Pete

Your limit switches would need to be connected in series if using only one input.


11-08-2009, 11:13 PM
Hi Andy
Thanks for the info - Ive also just come accross the sticky posts from Lee - I should have looked on the forum first I guess.

John S
11-08-2009, 11:40 PM
how are the system 3 drivers doing ....i was thinking about using them

Fitted five of these now, no problems at all and they are a doddle to wire up.

I must admit I'm a bit old fashioned in that I much prefer separate drivers in the event something goes pear shaped but they have performed well on small power systems and work out very cost effective given the speed you can wire these up and the fact there is nothing else to buy other then a power supply.