Idea with old Hammond

[PermO]

MOTOR HEAT PROBLEM

If a mod mod wants to snip the off topic conversation from the tantalum thread, here's a place to paste it.

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[RoadrunnerOZ]

MOTOR HEAT PROBLEM

If a mod mod wants to snip the off topic conversation from the tantalum thread, here's a place to paste it.

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Hi I’m here. I’ll have a look through. Do you have the service manual for the L100?

 

[PermO]

No I don't and the organ is not really an organ anymore, it was a wreck and I saved the tonewheel assembly and some other bits.

Someone put a carkey starter on it at some point.

 

[RoadrunnerOZ]

No I don't and the organ is not really an organ anymore, it was a wreck and I saved the tonewheel assembly and some other bits.

Someone put a carkey starter on it at some point.

Cool. Did you keep the amp?

 

[PermO]

The old amp went to an amp guy who liked to restore it.
I still have the vibrato amp, not working though.
A friend of mine has the pedal set to play bass synth.

Also I think it ran less hot with the old capacitor.

The shorted winding made so much sense, in combination with the carkey, don't know if this is the original motor a lot of messing around had been done to it and three layers of paint.

 

[RoadrunnerOZ]

The old amp went to an amp guy who liked to restore it.
I still have the vibrato amp, not working though.
A friend of mine has the pedal set to play bass synth.

Also I think it ran less hot with the old capacitor.

The shorted winding made so much sense, in combination with the carkey, don't know if this is the original motor a lot of messing around had been done to it and three layers of paint.

May have come from trying to run it with the tonewheel system not fully lubed - you did lube the motor bearings - these are critical as if not fully lubed they generate a lot of heat - you can tell if they are the source by the heat being much greater near the shaft ends when it first starts?
Car key switch is irrelevant.
Wrong type or value of capacitor can cause run problems and pitch change - was this one/pair for the Hammond?
Shorted windings lead to rough running and start difficulty and the motor will soon blow - best to test it running without the generator connected and see if it heats up the same - if it does you may have a bad bearing or a shorted winding.
With bearings it’s easy to tell if you put your finger on the motor casing and feel for vibration, with the motor running free of generator load, whether there’s a bearing freezing up - this will happen immediately for a fractured bearing or with worn rough surface bearings after a short period of running as the bearing heats and starts to grab, also the tonewheel generator will slow down and pitch will drop.
Is the tonewheel system in pitch?

 

[Rob Flinn]

Hi I’m here. I’ll have a look through. Do you have the service manual for the L100?

See attached.

 

[RoadrunnerOZ]

See attached.

Thanks Rob, I was asking if he did as I already do have it - good to have it here.

 

[RoadrunnerOZ]

I’ve been fixing Hammonds since the late ‘70s and in very few cases has the motor needed to be replaced - pitch drift is the first indication of lube failure, or run cap failure causing pitch shift errors along with failure to start without assistance. Motor bearing failure the bearing will grab as soon as it gets hot and the metal expands and you get a drop in pitch as the RPM’s drop.
I had one that had dried out from being in storage for a long time and it took some time to free everything up.
The motors will run pretty warm but should not be too hot to touch - from cold it’s easy to track down dry or cracked bearings as the early source of heat is localised around the bearing and not the stator which takes a while to heat up. Shorted rotor windings will heat the motor shaft before the bearings conduct the heat to the case. A good test of bearings is to run the unit until hot and disconnect the motor shaft from the generator and turn the motor by hand and see if there’s any grab in a full rotation. Or run the motor for a second (disconnected) and see if it stops too quickly - when connected the generator system sort of acts as a flywheel.
Shorted stator windings will be localised to the winding area of the short.
An Infrared thermometer is a handy tool here to pinpoint temperature sources- one with a reasonably high distance/spot ratio.