BrianS

I've got an older contractors model table saw from somewhere in the early to mid 50's. The pulley on the motor keeps working loose and sliding into the end of the motor. The shaft of the motor has a square key in it and the allen screw in the pully tightens against the key.

Any ideas why this might be happening, or what the best solution would be? I'm leaning towards coating the allen screw with blue loctite and seeing if that might stop it coming loose.

Thanks
Brian

__________________
A married man should forget his mistakes. There's no use in two people remembering the same thing!

Advertising

__________________
This advertising will not be shown in this way to registered members.
Register your free account today and become a member on Router Forums

gregW

Brian,
If you flatten the end of the allen screw it may seat better against the key. You could use a grinder or a file to make it flat.

Greg

bobj3

Just one more way to fix this type of error..

Find some plastic tubing and make a spacer, hvy.wall PCV works well , also on the set screw you can get a CONE point or grind the one you have to a cone and it will hold well BUT it will put a spot on the key that makes it hard to get off if you need to....
It's called staking the key..

__________________
Router Tables plans FREE, plus more
http://www.absolutelyfreeplans.com/W...p_projects.htm

Router Tip Archive
http://www.routerworkshop.com/router_tip_glossary.html

Calculators
http://www.routerforums.com/dynamic-calculators/

gregW

Hi Bj,
The spacer is a GREAT idea!

We used to use a punch to stake both ends of a keyway to keep the key from slipping on a shaft, but the single contact point of the set screw would sometimes allow the pulley to slide on the key, grinding a flat bottom on the set screw would usually solve the problem.

Greg

bobj3

Hi Greg

That's true sometimes but most good set screws come with a cup point and a knurl edge around the the cup and if it's removed it will let the pulley slip just a bit but the cone point will deform the key that's to say push the steel out and lock the pulley in place the norm the best way I found is to heat the key up to a nice red and put it in place then push the pulley over it and torq. the set screw down....

Not to sure why the pulley is moving over but my guess would be a bad belt or out of line ....most V-belts will keep the pulley in place without a set screw that's torq. down.

__________________
Router Tables plans FREE, plus more
http://www.absolutelyfreeplans.com/W...p_projects.htm

Router Tip Archive
http://www.routerworkshop.com/router_tip_glossary.html

Calculators
http://www.routerforums.com/dynamic-calculators/

kp91

Is the set screw backing out? sometimes putting 2 set screws in (one on top of the other) works well, but the hub has to have enough threads to allow that. Field service removable loctite works well (I can't remember which color it is right off the top of my head).

I had a '73 craftsman saw that started running real rough, vibrating and shaking the motor mount bolts loose. At first I thought it was the belt, because it had sat idle for a long while, but swapping the belt out didn't fix it. It turned out that the motor end bells had worn down in the way of the bearings, and the shaft could move too far axially. Picked up a 2 hp motor at HF for $75, and the saw ran great. Took the motor apart later and added some shims under the bearing to move it back into place, it's a workable spare.

You can also check out surpluscenter.com and find motors and pullies for cheap if you find you need more than a quick fix.

__________________
Doug
1 John 1:9

challagan

Well it's either too loose or too tight I had to get a gear puller to line up my pulley to the arbor pulley. It was on there!

Corey

__________________
My Carving Website: The Iowa Woodcarver
http://iowacarver.tripod.com/

My Shop Website - Woodshop 51503
http://woodshop51503.tripod.com/

BrianS

Hmmmm.... intersting concept. This was my Dad's saw, and I can't remember him ever complaining about this pulley coming loose on him, but he did run it with a v-belt. My brother had it for several years after Dad passed and he upgraded the v-belt to a link belt.

As for it being out of line, that's a real possiblity as the motor is mounted on a rod to allow it to move back and forth. This is necessary as there is also a 4" jointer mounted on the saw stand that is driven by the same motor. Kind of a neat setup in my opinion, take the belt off and move the motor into position to drive the jointer. But, since alignment is done by eye, misalignment is certainly possible.

Brian

__________________
A married man should forget his mistakes. There's no use in two people remembering the same thing!

BrianS

Thanks for all the ideas. Think I'll try the spacer and the flat/cone setscrew (one at a time to see which works) and the blue loctite. I'm told the blue stuff will come loose without heat, where the red stuff needs to be heated to break it loose.

Brian

__________________
A married man should forget his mistakes. There's no use in two people remembering the same thing!

harrysin

Yet another method would be to drill and tap another hole opposite the existing one, I did this some time ago on my lawn mower, I also fitted longer screws with lock nuts, it's still working fine about ten years on.

__________________
Harry