setscrew/arbor loosening on spindle

wa2crk · Post by **wa2crk** » Mon Aug 01, 2011 1:39 pm

Dusty et al;
I have some of those set screws with the red dot on them and while I was still working I contacted Loctite and was told by an engineering rep that it was indeed their product but it was not generally available because it had to be cured in an oven.
I think that some of the loosening of the setscrews on older machines that have been bought used stems from the fact that the screws and the mating part have become rusted and then cleaned and reused. The rusting of the parts will remove some of the metal and this will cause a too loose condition between the mating parts and vibration will loosen them. I have solved the condition by putting a small drop of RTV on the threads of the screw and letting it cure. When the screw is put back in the hole the RTV will fill the gaps in the mating threads keeping it in place. Admittedly, this is not a permanent cure but it works for a while.
Also if there are burrs on the flat of the shaft from a previous owner using a cupped point set screw and a new flat point set screw is used, the new set screw may ride on the top of the burrs and not have enough contact area to provide a good lock. File the burrs flat.

holsgo · Post by **holsgo** » Mon Aug 01, 2011 3:17 pm

I had the setscrew loosen a few times and to fix I took Teflon tape and wrapped the threads of the setscrew. I think I wrapped the setscrew three times and then reinserted the screw and tightened. Never loosened again. Now, it may seem like it's tough, at first to rethread the setscrew into the arbor but as you proceed it will set itself tight. The Teflon tape takes up any gaps between the screw and the threads into the arbor.

robinson46176 · Post by **robinson46176** » Mon Aug 01, 2011 5:28 pm

Has anyone tried these? Or even an all brass setscrew?
http://www.lexingtonsetscrews.com/brass_tip_set_screws.html

.

pjallen · Post by **pjallen** » Mon Aug 01, 2011 5:56 pm

I have also had this problem with the arbor set screw loosing up on my while usng my bandsaw. I am wondering if my set screw is bad or the incorrect type. I am using a powerpro and I took the drive-hubs & set screws from my older 500 series headstock. As you can see in the picture the hubs don't sit very far onto the auxiliary spindle.

Are there special set screws and/or special hubs for the powerpros?
I had to replace a broken power coupler after the set screw loosened up and overheated. So this problem is becoming annoying and costly.
Phil

wa2crk · Post by **wa2crk** » Mon Aug 01, 2011 6:54 pm

Farmer
I have not tried the brass tipped set screw yet but I did acquire a few with some help kits that came with "previously owned" machines but I could not find an application for them in the various manuals. Thanks for the tip.
Bill V

JPG · Post by **JPG** » Mon Aug 01, 2011 7:17 pm

pjallen wrote:I have also had this problem with the arbor set screw loosing up on my while usng my bandsaw. I am wondering if my set screw is bad or the incorrect type. I am using a powerpro and I took the drive-hubs & set screws from my older 500 series headstock. As you can see in the picture the hubs don't sit very far onto the auxiliary spindle.

Are there special set screws and/or special hubs for the powerpros?
I had to replace a broken power coupler after the set screw loosened up and overheated. So this problem is becoming annoying and costly.
Phil

That is the normal position. Wear around the shaft is not!

The power pro will exert more torque(pulsating) than the induction motor. The setscrew 'security' is therefore more necessary. I would replace the setscrews. Make sure they are 'flat' bottomed.(no cup or serrated cup). I grind them flat(they are more commonly found).

nuhobby · Post by **nuhobby** » Tue Aug 02, 2011 3:25 am

JPG40504 wrote:That is the normal position. Wear around the shaft is not!

The power pro will exert more torque(pulsating) than the induction motor. The setscrew 'security' is therefore more necessary. I would replace the setscrews. Make sure they are 'flat' bottomed.(no cup or serrated cup). I grind them flat(they are more commonly found).

And... to pick up where member charlese has reported on the PowerPro and the bandsaw, the power-coupler needs to be a tight-fitting one. If the power-coupler is a little bit loose, then the increased backlash between headstock and bandsaw-wheel aggravates the pulsing tendencies.

michaeltoc · Post by **michaeltoc** » Tue Aug 02, 2011 7:26 am

pjallen wrote:I have also had this problem with the arbor set screw loosing up on my while usng my bandsaw. I am wondering if my set screw is bad or the incorrect type. I am using a powerpro and I took the drive-hubs & set screws from my older 500 series headstock. As you can see in the picture the hubs don't sit very far onto the auxiliary spindle.

Are there special set screws and/or special hubs for the powerpros?
I had to replace a broken power coupler after the set screw loosened up and overheated. So this problem is becoming annoying and costly.
Phil

Are you getting vibration/clanging with the bandsaw? That was loosening my set screws, and I broke a coupler because of it. A call to CS to adjust the settings may be in order.

Ed in Tampa · Post by **Ed in Tampa** » Tue Aug 02, 2011 11:13 am

I can't say I have had the set screw loosening problem myself, however I have seen more than one SS where somebody tighten the setscrew so tight that arbor shaft was gouged out.

I would guess if you tightened the setscrew that tight often enough you could actually do damage to the set screw hole in the arbor and/or the setscrew itself. I would try a different set screw and then the teflon tape.

I would be tempted to flatten the flat on the arbor shaft so there is no indent and it is smooth. Then I would only tighten the set screw enough to afix the arbor tight on the arbor shaft. You don't have to dig a hole in the metal to make it tight enough.

The SS is precision and you don't have to tighten things to point of indenting metal or gouging it out. Tight is tight not indented into metal.

My SS is almost thirty years old and there is no dent or gouge where the set screw makes contact with the arbor shaft. In fact there isn't a mark.

robinson46176 · Post by **robinson46176** » Tue Aug 02, 2011 12:57 pm

Ed in Tampa wrote:I can't say I have had the set screw loosening problem myself, however I have seen more than one SS where somebody tighten the setscrew so tight that arbor shaft was gouged out.

I would guess if you tightened the setscrew that tight often enough you could actually do damage to the set screw hole in the arbor and/or the setscrew itself. I would try a different set screw and then the teflon tape.

I would be tempted to flatten the flat on the arbor shaft so there is no indent and it is smooth. Then I would only tighten the set screw enough to afix the arbor tight on the arbor shaft. You don't have to dig a hole in the metal to make it tight enough.

The SS is precision and you don't have to tighten things to point of indenting metal or gouging it out. Tight is tight not indented into metal.

My SS is almost thirty years old and there is no dent or gouge where the set screw makes contact with the arbor shaft. In fact there isn't a mark.

The Shopsmith is a sturdy well designed machine designed for craftsman. It was not designed however for Godzilla...

When he was younger I used to fuss at my son for over tightening things.

He grew out of it.

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