Hey all question for anyone who has worked with belt drive motors. (skip to the end for the question bit)
Still working on that delta combination sander I got, called up the guy who had the three motors for $30, on my way there he called me and said he tried them out, and they run hot, and don't start every time, so he gave me them free. Not only that, but I actually got four!
Two 1/2 hp, one might be a 1 hp based on the cap size, forgot to check the label, and one is a 1/3hp.
Now, he was right, they didn't start every time, you had to turn it, and after a little bit it started vibrating around like it was going to explode, and the whole cord was getting quite warm, so much you would start to be worried it might melt the insulation. I also changed the cap to another one and it started to smoke a bit, very dry smoke, not what you would expect from a cap, anyways I unplugged it asap.
Anyways, got a rubber mallet, and took it apart, and firstly some black, basically soot I guess, fell out the end, a decent bit, one of the other motors has a load of it in the capacitor compartment, and looked at the contacts on the rotor.
Rust city baby. There was very little clean metal left on them. The contacts on the armature were not too bad, not worth cleaning, but man the rotor ones were, so I took some 100 grit sandpaper (which I got a roll of for 75 cents at a garage sale, best find I've had for a while lol) and cleaned them up, took a decent bit, and some cramped fingers, but got them much, much better. No before and after picture sadly, but I'll be making a video on the process using one of the other motors to show people how to do it.
Purrs like a kitten now, runs a decent bit before the cord heats up at all, and that's just a couple inches near the plug, however, after leaving it run for 10-15 minutes, it's heated up a decent bit. It wasn't much at first but it does gradually build up heat, and it got to the point where the whole middle metal frame (basically not the end umm, cowels?) was quite warm, sort of like it had been sitting out in the sun on a +30 Celsius day.
So, I'm wondering, how hot are these things supposed to run? It is thermally protected, and I probably won't be running them for long periods of time, but I was wondering what sort of temperature these get up to in normal operation conditions?
Going to take my multimeter and thermocouple out later to see what the actual temp is, I am just wondering if it is fine that they get a tad warm. Original motor was blown so I have nothing to compare it to.