Tutorial Monster Moto Shield acts as a single motor driver = more power!

Hey Evan, that really sounds like a short of some kind. Have you metered out the connections to make sure nothing is shorted to your frame?

also could i just use this to run 2 100watt motors using SMC3
http://www.robotshop.com/en/saberto...TVo2mcINxPvh4cyyY3tYyRu6sSfGURZY2exoCH4Hw_wcB

ive put a test light on the frame and there nothing ...before i ground independent the motors the frame had 12v.. its doing it on multiable simulators i build all my control box the same so i can back to back then to see if its the box or motors it seems box..where should i check with the meter and what setting champ

thanks for your help btw also pit has been a great help thanks to you both

In your case there is no need for a 60A Sabertooth, the cheaper 3x32 does the job as well

https://www.dimensionengineering.com/products/sabertooth2x32

This one here mate ?
I thought if i used 100watt motors 61/1 worm drive 50nm that start up spike would be to high for a 30 amp boards..
thats why i went do the 2 mms path.. im building a platfrom to move a 180 kg sim with driver so i may have to go the 24volt path..

so at the end of the day i can use both boards with arduino and the smc3 software and script i use already mode 1

cheers mate

sorry ive found a link to here lol ... i think this look like a great way to go for my project have you yourself Pit used these ?

P = V *I
That said, using a 100Watt 24V motor is drawing 4.166666666666667 A only.

If you are willing to share the specs or sources of your motors we can look at this.

https://www.motiondynamics.com.au/zd1633r-12v-100w-30-55-rpm-8-50nm-torque-left-angle.html

there you go mate

i also just bought a sabertooth 2 x 60amp for $193.00AUD landed pretty good compaired to the mm at $118.00AUD

i got the bigger one just in case i need one for a bigger project the the future

Hey Evan, a test light might not reveal some issues. What might be a good test would be to unmount your motors where they can't complete any circuit through the frame and see if the problem doesn't clear up.

There are a number of ways shorts can manifest. It could be confined strictly to the high current motor circuit, but depending on your setup and what's going on, could be overwhelming the logic/control side of things. Maybe even both and either or both could lead to a hot motor and wrong behavior.

But we're flying blind here. Might be something else. But since you are having trouble, maybe unmounting them would be worth a try?

cheers mate

what ive already done is unbolted the motors and i tested them off the frame motor1 works fine motor 2 doesnt work until i touch that extra wire on the earth on the power supply..same as when its mounted.. ill take afew pics of the box and post them give me a sec brother

Hey Evan, I didn't know you already tried that. I'm out of ideas, now, but it still sounds like some kind of short but maybe not. Good luck with it, man.

the black wire is the one ive add from cutting the wire that was grounded to the body of the motor .. i use the black and the blue wire for motor 1 and the same for motor 2 But i have to gound the white wire for it to work..ive tested it on all 3 of my sim that are all working fine and i have the same issue everytime so 6 motors in total ive tested it on

thanks for your input brother

You don't have a wiper type of motor which uses chassis ground as -ve. No need for ground isolation.

Your motor is a 2 speed straight dc motor. There is no connection to the case and black wire.
blue is common and the black/white are the speed wires.
Restore the wires you cut and just use the blue & black as high speed.

12V

BTW you are using not isolated motherboard standoff screws, they can cause a short on the MMs!

sorry i'm wrong and they are wiper motors, the motor needs ground isolation.
Are you sure the motor isn't internally grounded? There could be a connection from one of the brushes to case and black wire.
try connecting high speed blue & black wires directly to a battery, it should run. Now with your multimeter on volts, one probe on +ve , put the other on the case, there should be no volts on the meter. Swap the black & blue wires and test the same.

If that all works ok then it is probably the MMs. Does act the same in non bridged mode?
Yes, do put fibre or plastic washers between board, if your screw scratches the solder mask it can cause shorts to gound.