Mike Hill
Cast Iron
- Joined
- Aug 28, 2004
- Location
- upper michigan
Hi all, I purchased a square dial mg 10ee a couple of years ago from a fellow pm member who purchased it from some unknown individual.
Well the machine had a few mechanical issues broken missing parts etc, and electrical issues, lately I have had some time to mess with it, when I first got it one of the reostates had a open in it I was able to source one of those, and after looking through past threads found out it had a couple of bad resistors, I replaced those this week.
So this is how the drive acts currently, when you turn up the speed knob the speed changes slowly upward till you get to about 2/3 of its travel then after that it rises quickly, till about 1200rpm then it lazily rises to its max of about 1500 rpms after several seconds of the pot maxed out.
When you turn the knob down fairly quickly speed will drop to zero then back up to speed where the pot was left oscillating the speed up and down till it stabilizes.
I have tried different brush timing on the motor (brush holder was loose btw) to gain rpm.
Voltage between a1-a2 seems low maxing out at 180 volts
This machine is missing its exciter, some previous owner added a transformer to the back of the machine, some kind of rectifier and a variable resistor on the ac side, 120 volts ac coming in 110 volts dc coming out, I tried bypassing the resistor but still have 110vdc coming out.
Any of this give clues what could be wrong with
1. Lack of speed
2. Rise of rpm not linear on speed knob
3. Osillation of speed when slowing down
Any help would be appreciated
Thanks
Mike
Well the machine had a few mechanical issues broken missing parts etc, and electrical issues, lately I have had some time to mess with it, when I first got it one of the reostates had a open in it I was able to source one of those, and after looking through past threads found out it had a couple of bad resistors, I replaced those this week.
So this is how the drive acts currently, when you turn up the speed knob the speed changes slowly upward till you get to about 2/3 of its travel then after that it rises quickly, till about 1200rpm then it lazily rises to its max of about 1500 rpms after several seconds of the pot maxed out.
When you turn the knob down fairly quickly speed will drop to zero then back up to speed where the pot was left oscillating the speed up and down till it stabilizes.
I have tried different brush timing on the motor (brush holder was loose btw) to gain rpm.
Voltage between a1-a2 seems low maxing out at 180 volts
This machine is missing its exciter, some previous owner added a transformer to the back of the machine, some kind of rectifier and a variable resistor on the ac side, 120 volts ac coming in 110 volts dc coming out, I tried bypassing the resistor but still have 110vdc coming out.
Any of this give clues what could be wrong with
1. Lack of speed
2. Rise of rpm not linear on speed knob
3. Osillation of speed when slowing down
Any help would be appreciated
Thanks
Mike