Motion Control drivers and motors

[irving2008]

I am using a similar BOB but was half the price and made by a CNC user, the board is milled on a CNC machine itself and comes with 4 PCB stand-offs.

http://www.cncdoctor.co.uk/ParallelP...ard(P.004).pdf

Bruce. That BOB MUST be used driving the opto's in ACTIVE LOW configuration. It will not have enough output drive to drive the optos in active high mode. The signals on the MDSxxx are labeled thus Step+, Step- and Dir+, Dir- The - connectoins neednto go to your driving signals and the + connections to a source of +3.3 or +5v power. This can be got off a USB connector, off a spare disc power connector inside the PC or via a cheap 5v regulated wall-wart.

[bruce_miranda]

So the ACTIVE LOW configuration needs to be done in Mach3 for the Motor Outputs correct?

[irving2008]

So the ACTIVE LOW configuration needs to be done in Mach3 for the Motor Outputs correct?

Yes you will need to tell the software which way up the signal is... The MDSxxx series of drivers recognise the rising edge of the signal so the PC must pulse the output LOW to cause the required motion.

[bruce_miranda]

Do I need to change anything in the Driver i.e. Jumpers or anything or can I leave them as default?

[Gary]

No the drive does not need to be changed for sinking inputs.

[bruce_miranda]

This seems like an easy solution. I just hope that I can cancel the order on that BOB I just bought if this works.

Oh my half price comment was related to the BOB I bought as compared to that sold by Motion Control - but its not as nice looking as the MC one.

[Gary]

It does the same as the one we do, so £10 was a good deal.
We are designing a new motherboard that lets you plug up to four MSD542/556 directly into the board and on the other side it will have the connectors for the motors and a 25 way connector for the parallel port or smooth stepper.
This will eliminate the wiring from the bob to the drivers.

This seems like an easy solution. I just hope that I can cancel the order on that BOB I just bought if this works.

Oh my half price comment was related to the BOB I bought as compared to that sold by Motion Control - but its not as nice looking as the MC one.

[bruce_miranda]

I have GOOD news to report, my motors are now spinning very well. I used the USB to supply 5V to the drivers and everything suddenly started to work.
Thanks a lot irving2008.

Oh in the meanwhile I also rebuilt my laptop and then reconfigured things using these instructions here and everything works quite well. http://pminmo.com/PMinMOwiki/index.php5?title=Laptops

I have now an issue where if I jog the axis suddenly at no certain point the motors will stall but if I release the key and jog again it continues just fine. Jogging slower the motors stick less often but still stick about once per end to end travel. How do I resolve that issue.

[Gary]

At what speed are they stalling?
Is it happening between a specific speed range?

[bruce_miranda]

They seem to stalling at all speeds and even without any load connected i.e. motors not connected to machine. Also it happens only when I continously jog from one end to another.