Retired American living in France with a new toy

[Douglas St.DennyParticipant @douglasst-denny31997]

Posted by Phil Whitley on 09/02/2016 21:02:29:

What you really need is a "growler" to test the armature, repeat after me.

"At the electrical repair shop"

Bonjour Monsieur, ave vous un grondeur pour tester mon armature.

LOL…

[Douglas St.DennyParticipant @douglasst-denny31997]

Posted by Phil Whitley on 09/02/2016 20:53:20:

Hi all, Can I just jump in here and suggest that the motor be tested direct on to the mains, without the speed controller in circuit. It sounds like the brushes are good, and the comm is smooth and clean, and the motor is running, but not developing any power? It fails under load? If this is correct, and it is not overheating or smoking I would respectfully suggest that the speed controller IS the fault, rather than the motor. I would go through with a multimeter to check the field windings continuity and resistance, and also a visual check of the soldering of the armature wires into the commutator. No point in replacing the motor till you know it is definitely at fault. When these motors fail they usually emit lots of magic smoke. flashes and bangs. I assume the speed control is electronic, and electronics made down to a price is bad news after the initial warranty period!

Good luck with it!

Phil

Thanks Phil,

The first thing I did was the "sniff" test. No smell at all. Then visual inspection for scorching/burning broken wires, melted bits or oozing resin. Nada.

I spent significant time with my multi meter checking connections etc. Tomorrow I will attach it directly to the house wiring and report the results, if still alive afterwards.

Douglas

Edited By Douglas St.Denny on 09/02/2016 21:15:12

[Martin ConnellyParticipant @martinconnelly55370]

I know the motor seems to run fine with no load but struggles when loaded. I would check the brushes are not worn to the limit where they make some contact but not enough for high current. Brushes worn to the limit will give the problems you have and may be a cheap and easy fix. You can nearly always find a suitable brush even if it needs filling down to fit the brush holder. Check to see if the spring pushing on the brushes is hitting a part of the holder or if the connecting link wires (if the brushes have them) are not pulled up tight.

Martin

[duncan webster 1Participant @duncanwebster1]

There seems to be more posts about brushed motors and electronic speed controllers than anything else. On my little Perris I have a 3 phase motor and inverter, both industrial quality. When I bought the lathe it had a sewing machine motor, waste of time, putting on a cut slowed it down alarmingly. I replaced that with a Parvalux squirrel cage, much better, but then I got hold of the 3 phase motor as a swap and it's never been better. If you can dump the Chinese motor and fit a proper one you'll not be sorry!

[clogsParticipant @clogs]

Douglas, private message me …it may be of interest….

clogs

[Howard LewisParticipant @howardlewis46836]

Coming in late, others have raised the possibility of the brushes needing replacement.

(My big Bosch pistol drill ran perfectly, and then next time refused to start. New brushes and as good as new! Fortunately, the comm was undamaged)

Also, during your checks with the meter, did you check continuity across the windings on EVERY commutator segment? If one winding was open circuit, it would have trouble starting, on that position, and be down on power. I have even heard a motor with a burned out winding knock once it was set running.

Just a thought, as a non electrician.

Howard

[Douglas St.DennyParticipant @douglasst-denny31997]

Posted by Howard Lewis on 13/02/2016 18:42:14:

Coming in late, others have raised the possibility of the brushes needing replacement.

(My big Bosch pistol drill ran perfectly, and then next time refused to start. New brushes and as good as new! Fortunately, the comm was undamaged)

Also, during your checks with the meter, did you check continuity across the windings on EVERY commutator segment? If one winding was open circuit, it would have trouble starting, on that position, and be down on power. I have even heard a motor with a burned out winding knock once it was set running.

Just a thought, as a non electrician.

Howard

Thanks Howard. The brushes are fine. Still plenty long. The springs are ok too. I connected it directly to the mains as was suggested earlier, and the devil ran like it should ! Now I'm thinking a fault in the controller, as was suggested earlier, and which I didn't think was possible.

In any case, I'm a happy camper, playing with a toy that will someday actually work. In the mean time, I'm enjoying the detective work, meeting interesting and helpful people here and generally being happy to be on this side of the dirt.

I am sure I can dig up a controller for a test that can handle the 150W. Even a foot pedal controller from a sewing machine. My wife's machine for example. Please don't tell her…

Douglas in cool and very windy Feytis.

[Phil WhitleyParticipant @philwhitley94135]

Good news Douglas, have you been inside the speed controller yet? Could be an idea to refit the motor and run the motor with the cover off the speed control (fingers clear!!) if this is possible, you will then pick up any arcing dry joints. After that check for any browned components, then check smoothing/suppression capacitors for leakage, BUT, you can probably get a new speed control to handle the wattage of this motor far easier than the fault finding!

Phil

[Phil WhitleyParticipant @philwhitley94135]

Just thought of something, the most likely component to wear out rather than fail is the potentiometer in the speed control, and that can be tested directly with your multimeter!

Phil

[Author]

Posts