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motor heating up

Posted: Wed Mar 21, 2012 3:18 pm
by jakest
I was ripping some pine 4X4's on my 510. The motor bogs down constantly, and it took forever. After a couple dozen cuts, I felt the motor pan, and it was smoking hot. Like prolonged touch hurt a bit...so not water boiling hot, but pretty darn close.

I recently bought the saw on CL, so I am not really sure what to expect. Off the top of my head a couple potential issues come to mind.

1. I am expecting too much of a 1.25 hp motor and a hot motor is really just standard operating conditions.
2. The headstock needs to be rebuilt (the quill doesn't retract by pure spring tension is one thing that needs to be address, but that shouldn't affect the motor loading. It may be symptomatic of a head that needs rebuilding)
3. dull blade (the blade came with the saw, but it seems to cut okay with minimal tearout in pine and none in oak.)

Can you guys cut 4X4's with minimal issue, or is it a serious pain with the 510?

Posted: Wed Mar 21, 2012 3:52 pm
by trainguytom
A couple of things come to mind. (I've not tried to rip 4x4's, but I have ripped 2" oak without a problem, so here's me 2 cents worth.

Are you using a rip blade? Even if a blade is sharp, if it's not a ripping blade it will clog/bog in lumber that thick. Also, pretty sharp isn't the same as sharp, especially in stock that thick.
Next, it's a good idea to go through the headstock top to bottom checking belts & bearings, since you don't know the use & service of the machine.
You didn't mention blowing any breakers, so that's good news. & now I'll bow out because there are a ton of guys here who can get you through the best ways to check out all the headstock components.

Posted: Wed Mar 21, 2012 4:16 pm
by beeg
Was your feed rate slow? What speed setting were ya using?

Posted: Wed Mar 21, 2012 5:42 pm
by jakest
Slow doesn't cover it, I think molasses flows uphill faster in the winter than my feed rate. I could easily stop the blade mid cut if I upped the feed rate. My speed setting was on the saw speed indicated on the dial. I could have turned it down, I don't know why I didn't think of that. You get more torque the slower you go I suppose.

I think a Sharper rip dedicated blade would have helped a lot over my mediocre combination blade. The heat of the motor was alarming though. I don't want to fry the windings...

Posted: Wed Mar 21, 2012 6:21 pm
by dusty
jakest wrote:Slow doesn't cover it, I think molasses flows uphill faster in the winter than my feed rate. I could easily stop the blade mid cut if I upped the feed rate. My speed setting was on the saw speed indicated on the dial. I could have turned it down, I don't know why I didn't think of that. You get more torque the slower you go I suppose.

I think a Sharper rip dedicated blade would have helped a lot over my mediocre combination blade. The heat of the motor was alarming though. I don't want to fry the windings...

Cutting a dry pine 4x4 should not be a significant challenge for a Mark V. However, that assumes a proper blade, a sharp blade, a well lubricated and properly aligned machine and a properly aligned rip fence.

A properly aligned machine would by my way of thinking include proper belt tensions.

If this has all been done and you still have a heating issue, I would suspect bad bearings.

Posted: Wed Mar 21, 2012 8:36 pm
by robinson46176
I don't see any mention of the kind of circuit it is plugged into or if it is running on 800' of extension cord. :)

Always begin at the beginning...


.

Posted: Wed Mar 21, 2012 8:50 pm
by JPG
robinson46176 wrote:I don't see any mention of the kind of circuit it is plugged into or if it is running on 800' of extension cord. :)

Always begin at the beginning...


.

Indeed, and by stop, do you mean the saw blade stopped, or everything(including the motor) stopped.

If the latter, I have to assume the ripping was slowing down the rpm's of the entire power train including the motor. = Recipe for warming the motor!;)

Same thing if long extension cord is causing a low voltage to the motor.

IMHO ripping a 4x4 with a combo blade will tax the system. Add not sharp and things really heat up.

Adjusting the speed slower will help and may even allow feed rate faster than molasses.:rolleyes:

Truth be told, a sharp RIP blade is the 'answer' IMHO! Until you rip with a rip blade you cannot appreciate the difference!

Posted: Thu Mar 22, 2012 3:32 am
by billmayo
All of the above suggestions should be checked. I have found a few Shopsmith motors that became sawdust/crud clogged that overheat quickly. I found I had to remove the motor from the motor pan to fully clean the motor. Normally the fan sheave end motor bearing needed replacing too.