- Joined
- Oct 20, 2014
- Messages
- 159
So I was cutting through about a dozen big blocks of aluminum. I've done probably 40 of these over the past few months.
I was doing some welding while the bandsaw was cutting, multitasking!
Each block takes about 3 minutes to cut. So while I was welding I heard the saw stop and saw the blade all the way down. Just like the previous 5 or 6...
I was right in the middle of welding so I didnt get up to put another block in the saw.
About 5 minutes later I finished welding and looked up at the saw.
There was smoke coming out of the motor. :thinking:
Went over and unplugged it.
Looked closer and saw the saw had not shut off. It had gotten caught on on the fixture I use to hold the piece I'm cutting because I must have installed it a little too far out.
CRAP....
So I waited for the smoke to stop coming out of the motor....5 mins later..still smoke coming out. :thinking:
Looked inside..couldnt see any flames..hmmm....
Finally after about 10 minutes no more smoke.
Tried plugging in the motor to see if it still worked..no dice. No sound no nothing. Shaft turns freely by hand...argh.
To continue the tradition of staying CHEAP with this saw I decided to try and fix the motor. BTW its definitely the original extreme-cheap-o chinese motor, not an upgrade.
First I took a look at the start cap. The plastic shrink wrap was torn open. The cap didnt smell over have liquid or any brown marks though. I wasnt sure if it was dead or just got hot or what. So I measured it and it was 27mfd while the label says 100mfg. Kind of makes sense it would die because it dissipates alot of heat during the "Startup" mode which is what mode the motor is in when stopped.
But just in case I took the rest of the motor apart. Basically your standard squirrel cage rotor with centrifugal switch. Nothing looked too bad, some of the strings of the coils were melted away, I think thats what was burning. Man those coils must have gotten hot.
So to test my theory of bad cap, I went hunting for another start cap in my house.
I found the following motors with start caps: Lathe, Grinder, old Pool Pump
The lathe and grinder ones were too big and too small. The pool pump one was close so I hooked it up to the motor. Tada!!! It started up okay!
So I went on ebay and bought the correct sized replacement and will install it soon and hopefully everythings back to normal. I will keep a close eye on the saw now in case something else goes wrong. It would be a good project to make a "stall detector" which only allows the power switch to be on and no rotation to be detected for say 5 seconds max before cutting off a relay or something.
The new cap was $17 on ebay.
I was doing some welding while the bandsaw was cutting, multitasking!
Each block takes about 3 minutes to cut. So while I was welding I heard the saw stop and saw the blade all the way down. Just like the previous 5 or 6...
I was right in the middle of welding so I didnt get up to put another block in the saw.
About 5 minutes later I finished welding and looked up at the saw.
There was smoke coming out of the motor. :thinking:
Went over and unplugged it.
Looked closer and saw the saw had not shut off. It had gotten caught on on the fixture I use to hold the piece I'm cutting because I must have installed it a little too far out.
CRAP....
So I waited for the smoke to stop coming out of the motor....5 mins later..still smoke coming out. :thinking:
Looked inside..couldnt see any flames..hmmm....
Finally after about 10 minutes no more smoke.
Tried plugging in the motor to see if it still worked..no dice. No sound no nothing. Shaft turns freely by hand...argh.
To continue the tradition of staying CHEAP with this saw I decided to try and fix the motor. BTW its definitely the original extreme-cheap-o chinese motor, not an upgrade.
First I took a look at the start cap. The plastic shrink wrap was torn open. The cap didnt smell over have liquid or any brown marks though. I wasnt sure if it was dead or just got hot or what. So I measured it and it was 27mfd while the label says 100mfg. Kind of makes sense it would die because it dissipates alot of heat during the "Startup" mode which is what mode the motor is in when stopped.
But just in case I took the rest of the motor apart. Basically your standard squirrel cage rotor with centrifugal switch. Nothing looked too bad, some of the strings of the coils were melted away, I think thats what was burning. Man those coils must have gotten hot.
So to test my theory of bad cap, I went hunting for another start cap in my house.
I found the following motors with start caps: Lathe, Grinder, old Pool Pump
The lathe and grinder ones were too big and too small. The pool pump one was close so I hooked it up to the motor. Tada!!! It started up okay!
So I went on ebay and bought the correct sized replacement and will install it soon and hopefully everythings back to normal. I will keep a close eye on the saw now in case something else goes wrong. It would be a good project to make a "stall detector" which only allows the power switch to be on and no rotation to be detected for say 5 seconds max before cutting off a relay or something.
The new cap was $17 on ebay.
