M45 Maxson Quadmount Motor Slow Running

[greeneagleking]

Hi,

I'm hoping someone can help solve my problem.

I am restoring a Quadmount and currently bench testing the 12v motor and I believe I'm not getting the full power required to turn the belts.

The current setup is 2x New 6V batteries hooked up together to make 12vs, wired and jumped to the motor. On connecting the positive lead to the battery there is always a lot of sparks, the motor then turns at a medium rate, the wires then continue to get very hot and start smoking. Have I connected it up correctly? Does anything stand out that I'm doing wrong?

The reason I say this is before I removed the motors from the mount I tested it and the motor ran much quicker as it should using the same jump setup. Since then all I have done is lubricated the gears and generally cleaned all the grease/dirt off. I have not delved into the motor so don't see why it suddenly won't run correctly. I have attached a photo of the setup.

Any help would be hugely appreciated.

Thanks,

Ben

[DDTrustee]

Out M45 motor does not run all that fast - however from your pictures I believe the wires you have from the battery to the motor might be a bit undersized....from memory that motor has a 50 or 60 amp breaker on it so I would expect it take 40-45 amps at 12 volts to run it......your wires will get hot unless they are the right gauge
check the table in the website here: https://www.engineeringtoolbox.com/amps ... d_730.html
also, the motor will run slower if the voltage drop is significant.....
6 or 8 ga would be about right.

[greeneagleking]

Thanks for the reply, I think I have found the issue.

I loosened off the gear cases just a little which enabled the gears to spin a little easier by hand. Tested it and it ran much smoother, with less overheating on the wires too. When I greased the gears I did not replace the paper gasket on the case, which I had assumed was just to stop leaks, but it seems it also acts as a shim/spacer on the bearings/gears. Do you think not having the gasket could cause enough friction to reduce rpm of the motor?

The gasket is part number - C130512 - In my manual, it doesn't state the thickness of the gasket. Would you know what size is required?

Thanks for your help,
Ben

[DDTrustee]

I have no info on the gasket but hard to believe it would cause enough friction to stop a 1- 1.5Hp 12 v motor!!!!!

[greeneagleking]

So I have made some progress, but I believe the motor is still not running at its full potential.

Current status:

1. The original 12v 100amp motor has been repaired and refurbished professionally and bench tests at 11.5v.
2. I'm using a 2x 6v setup and have a brand new 12v 130ah battery for testing as well.
3. The mount wiring, gears and pulleys are all connected as they should be (out of test rig now).

I have tested the motor with different load setups: (these readings were taken once motor warmed up, cold start is around 9v)

1. No belts - gearbox load only = 11v 80amps
2. Traverse belts only - 11v 130amps
3. All belts connected - 10v 180amps
4. All belts connected including a 12v 12amp boost from the mains to represent the power charger - 10.5v 150amps (connected directly from battery to motor)

As you can see as more load is added more current is drawn and as a result voltage drops. The cables get warm and the mount doesn't traverse at the 60degree per second benchmark. I am only looking for that extra 1v as I believe running at 11v would be optimum.

Do I need more battery cap? Are the new belts adding extra load? Am I worrying about a non-issue?

Any input would be appreciated

Thanks,
Ben

[Jeepman272]

Hi Ben
It looks like my motor has a short and will have to come out for repair, is there an easy way of removing it? Mine is on its three legs so i am working upside down
I can see the four nuts via the top plate, two at the front from underneath, but then on either side a casting which has a slider arrangement. Do the gearbox/diffs all have to come out?
Alistair

[hummermark]

No functions working but motor running in quadmount I measured 130 amps draw with a clamp over amp meter.