Smoked my 8520 Mill motor today CRAP!

You were making chips and the motor just stopped? Or, the mill was off and you tried to re-start it?

If it was already running and then just stopped, then the start circuit wouldn't be to blame.
 
If the cap is good it may still be charged, discharge it before connecting to a multimeter and for your safety. If the cap is bad, you won't get continuity, it will show as open. Sometimes they pop or swell so if you immediately see signs of that you know the answer.

Unfortunately it can't be found at a common hardware store. Mcmaster carries them if you need it next day. If the cap didn't blow up, you should be able to see the value printed on it so you buy the new one (micro farad / μF).
You were making chips and the motor just stopped? Or, the mill was off and you tried to re-start it?

If it was already running and then just stopped, then the start circuit wouldn't be to blame.
Well, it was running and just stopped. However, I believe the motor was overloaded (to deep a cut) and the capacitor may have been jogging open and closed? I could hear it clicking off and on like a start up but since I know nothing much about motors, I didn't really give it much though.
 
As some mentioned, the start cap doesn't like frequent start/stops, especially if it's a cheap cap. That's how mine blew as I was working on a run of multiple parts. My run cap said made in Germany & the start cap said made in China.

When my start cap blew the motor either wouldn't turn or turn very slow and it would get very hot. While replacing the start cap I figured I would just change the run cap as well while I had it apart. They were cheap. I think I paid like $7ea and that's at Grainger plus they had it in stock at my local store.
 
Thanks for the reply Finster. just trying to understand how yours failed so hopefully mine doesn't suffer the same fate. :cool:
 
Thanks for the reply Finster. just trying to understand how yours failed so hopefully mine doesn't suffer the same fate. :cool:
Yea, I've been putting this mill through the paces to figure out what it can and can't handle. Guess I got 1 answer anyway. I was cutting a 11" railroad rail to make an anvil for my bench. I don't have a face mill or even a decent fly cutter so I was using a .5" carbide endmill taking about .100 and I think it was to deep and I was feeding to fast. Probably my own fault, lesson learned.
 
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Yea, I've been putting this mill through the paces to figure out what it can and can't handle. Guess I got 1 answer anyway. I was cutting a 11" railroad rail to make an anvil for my bench. I don't have a face mill or even a decent fly cutter so I was using a .5" cobalt endmill taking about .100 and I think it was to deep and I was feeding to fast. Probably my own fault, lesson learned.

.1 with a 8520??? Definitely too much with the rail. Hopefully you just blew the capacitor. I'm thinking you kicked out of run and forced the capacitor to kick in. Which you should have recognized way before you smoked it. I'm taking that 8520 away from you... you can't be trusted with it...:grin:
I've been looking myself for one for a while.
 
.1 with a 8520??? Definitely too much with the rail. Hopefully you just blew the capacitor. I'm thinking you kicked out of run and forced the capacitor to kick in. Which you should have recognized way before you smoked it. I'm taking that 8520 away from you... you can't be trusted with it...:grin:
I've been looking myself for one for a while.
Here is one that may be close to you? http://www.ebay.com/itm/132126198615?ul_noapp=true
 
Thanks already on it. Would rather buy from Craigslist as I can see it first, but I sent a query with lots of questions.
 
Well, it's been a very long day. IT'S FIXED! Thanks for the help everyone. It's a very long story but it turned out to be the starter capacitor like everyone thought. I took it to the motor guy today, he checked it out, put on a new capacitor, fixed a frayed wire, and answered 1000 questions I had. He loves to talk by the way. All of this for $20!!!!!! My GOD! I felt like I ripped him off and even offered him more money. This guy has my business from now on. Beyond that, this motor will do 220 or 110. I had it hooked up for 110 since that's what I have in the shop. He said, "let me show you something". He hooked it up on 220 and flipped the switch. The motor almost flipped over it had so much torque. I left there, headed to Lowes and picked up what I needed for a 220 circuit :D She is up and running on 220 now and it's like a different machine. :cheerful: Probably second hand knowledge to you guys but I know nothing about motors and very little about electricity. It's always been my Achilles heal. Just about anything else I'm competent in however, I'm learning. Things are great now and I'm making chips! :D
 
Yep, glad it was only the start cap. If you listen to the motor, you will hear when it kicks out of run and goes to start. There's a clicking as the centrifigul switch kicks in and out. Try to listen for when you are overloading it. Keep that machine well oiled. 220 also reduces heat to the motor, since you have more voltage, and less AMPS (heat).
 
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