replacing 4 wire dc motor with 2 wire - need help

[Karri_B]

I am replacing a 90v dc motor on a 30 year old skutt potters wheel. The original motor has a 5 wire plug which plugs into the controller. The replacement motor only has 2. Two of the plug wires are black and red and hook up to the motor. The other two plug wires are orange and white and hook up to what looks like a capacitor of some kind (MGH57EX). The 5th wire is green and grounds to the motor.
Do I just move the capacitor to the other motor? It is bolted to the inside of the motor "Cap"

 

[john monks]

What is the make and model of your potter's wheel?
Does the motor have the same part number as the old one?
Is there a value on the capacitor such as in UF or MFD?

 

[Karri_B]

more details

The wheel is a Skutt DC-1, purchased in mid '70s. The motor has a skutt plate on it. It says Permanent Magnet DC Motor, Model PM-1 Ser. 22 1 hp. HP 1 Max RPM 1725 Duty Special Temp Rise 130 degrees C, Volts 90 D.C. 12 Max Amps D.C. This motor is no longer available. On recommendation of Skutt Technical support I am replacing it with a leeson 098004.00 1/3 h, 90vdc 1750 rpm etc.
Only thing on capacitor is the letters MGH57EX. It has three terminals, and 1 and 3 are used.

 

[john monks]

Unfortunately I am unable to find the schematic for your machine. If it was me I would hook a big light bulb in series with the line, hook up the black and red wires into the controller, and see what happens. This does pose a risk of damaging something.
Maybe somebody else knows something I don't.

 

[Karri_B]

skutt motor replacement

I found out from Skutt tech support (There is a guy there about to retire who worked on these wheels in his early days) He told us that the capacitor is a heat overload switch. We were able to eliminate it from the wiring, but had to bug the two wires that were connected to it together (to make a complete circuit) in order for the motor to have power. He felt it was not necessary on a new motor.
It is all working fine now.

 

[BruceK]

Karri_B
I know this is a real long shot since the original thread is six years old.
Is the Leeson motor quiet? I have a five year old Skutt wheel that is really noisy. I’m pretty sure it’s a combination of brushes and bearings. The motor was made in India as a cost reduction, I’m assuming.
Thanks,
Bruce

 

[duke37]

I would not think that brushes could be very noisy but bearings can be. Try turning the motor by hand and feel if the bearings are smooth. Organ blower motors and Hi-Fi turntables use plain bearings because they are quieter.
Bearing life can be limited by fatigue of the rolling surfaces giving pits.
Ball bearings are not good at restraining axial forces but can do a reasonable job if a bearing with wide clearance is used.

Noise could also be generated by a rough supply.