Skil worm drive problem - blade stalls but motor still runs???

[haystax]

So I grabbed the trusty old Skil saw from the shop and was in a hurry to trim some studs on a woodshed project and as I was cutting 2x4 the blade started the cut fine but then stalled out. Motor was running strong and I know I have good amperage from the cord and wall - was using other tools all day prior to this happening.

Is there a key missing in the drive somewhere? Could my monkeys in the shop have lost something when they changed the blade?

This thing has ran forever!!! I haven't had this ever happen. WTF??

Thanks!

 

[D'Animal]

Is the blade tight?

 

[KLF]

Did they knock the diamond out of the center of the blade when they installed it?

FYI: bolt for the blade is left hand thread. I got mine when the PO got frustrated trying to get a damaged blade off, he didn't realize this. He put a breaker bar on it, snapped the main shaft. I fished it out of the dumpster, and fixed it. It was about 15 years ago, but I don't remember any shear pins in the gear box. That saw is TOUGH, it will cut anything.

 

[haystax]

I only had the little Crescent wrench that I pack in my carpenters bags so I was only able to tighten it with that but it is tight. I'm sure they would have knocked the diamond out, I just got pissed and it was already late in the day so I left it. I'll see what I can find out in the morning.

I am aware that it is left hand thread, really messes with me to wrestle with the shaft lock and remember to turn the correct direction.

Gonna look for an exploded parts view and see if I can find anything, it seems like the arbor is still spinning and the blade has stopped. Makes sense that the diamond must be messed up I guess.

Thanks.

 

[KLF]

It could also be that they forgot to put the big washer back on under the blade, that has the diamond part of the arbor cast into it. It's a separate part, not cast into the arbor shaft.

 

[haystax]

It looks like the blade is too thin to get clamped sufficiently tight by the arbor bolt. Like the large backing washer needs to be thicker, because the bolt bottoms on the arbor before the outer splined washer is tight on the blade.

I tried a Dewalt blade and a Diablo with the same results. I didn't remember having any issues before with any brand of blades.

Need to look up parts and see if there is a thrust washer missing internally.

Thanks!

 

[e9999]

went to have a look at mine for you.
Besides the main outside bolt there are only 2 hand-removable parts that surround the blade: a thinner washer on the outside and a big mushroom piece with the diamond locator on the inside that goes in into the housing.
These 2 parts are actually touching when there is no blade so the blade would indeed be clamped tight.

 

[haystax]

went to have a look at mine for you.
Besides the main outside bolt there are only 2 hand-removable parts that surround the blade: a thinner washer on the outside and a big mushroom piece with the diamond locator on the inside that goes in into the housing.
These 2 parts are actually touching when there is no blade so the blade would indeed be clamped tight.

So you're telling me that there is no free play (backspace) behind the inner "mushroom" piece? For some reason my saw doesn't seem to get tight enough.

Thanks!

 

[e9999]

So you're telling me that there is no free play (backspace) behind the inner "mushroom" piece? For some reason my saw doesn't seem to get tight enough.

Thanks!

yes, when I tighten the bolt, there is no axial play in the mushroom at all, even without blade.

there is some sort of fixed bushing in the main hole that the mushroom fits in. But the outside lip of that bushing shows no wear so it's not riding against the mushroom. OTOH, there is either a raised ridge or a washer (not sure which) at the bottom of the well, surrounding the driveshaft, that is shiny and I think is where the mushroom is riding. Have a look and see if you have that. I tried to remove mine in case it is a washer but was not successful. May be part of the casting.

The mushroom which has the diamond locator and is therefore keyed to the blade is free rotating. Only the outside washer with the square hole fitting the square driveshaft end is rigidly "keyed" to the shaft. IOW, the blade is rotating with the shaft only by friction between the blade/mushroom and the outside washer. Of course, you'd expect some sort of clutch effect to prevent explosive breakup, but that suggests that the whole drivetrain to blade torque is predicated on -and limited by- some sort of precise clamping effect. Which is probably what you are dealing with.