loose disc plate in belt/disc sander

[Carlos Alden]

Hey all:

I have a Delta 4' belt/6' disc sander. The disc wobbles after a few minutes' of run time, and gets loose. I have tightened the set screw to the shaft multiple times but this happens regardless of that.

I am wondering if I somehow have tightened the set screw too tight at one point and it has deformed the threads in the collar in the disc - it is aluminum - which would cause it to not hold fast against the shaft.

Any ideas? I have thought about putting some lock-tite in there. The disc doesn't really need to come off again. I have also thought about drilling a little dimple in the shaft where the set screw touches it, thinking that might help lock it in place.

Or maybe it is time to get a new replacement disc.

Thanks in advance...

Carlos

[Rick Potter]

If the set screw has deformed the aluminum, my suggestion would be to find a larger setscrew, drill out the aluminum collar, rethread it for the new screw, then dimple the shaft and reinstall. Locktite optional. Should be fairly simple to do.

You mention the disc wobbling. Check to see if the disc has been galled by the shaft. If so, it is possible to drill it out and put a bronze bushing in. More difficult, but workable.

Hope this helps,
Rick Potter

[Bill White]

Don't be afraid of Locktite. I use the Locktite RED compound. I find that it holds better. Check all that was mentioned above as well. Just remember that the alum. is probably pretty soft. Be gentle.
Bill

[Carlos Alden]

Thank you Bill and Rick. It does outwardly appear that the threads in the aluminum disk are deformed. I will try the Loctite and put a dimple in the shaft. IF that does not hold it I will go to step two and drill out and retap the hole with a larger set screw.

When it is tightened up it functions fine, but after maybe 10 minutes of spin time the whole disk starts to loosen up. I have taken the disk off and been only using the belt, which is 90% of the usage anyway. However, It would be nice to have the thing function as it is supposed to, and there are times when I can use the disk for more precision sanding jobs that need the right-angle rest.

Carlos

[Gary Kman]

AS long as you have your tools handy, add a second setscrew at 90* to the first.

[michael veach]

AS long as you have your tools handy, add a second setscrew at 90* to the first.

.
+1 on the second set screw. also look at the set screw in it now. If does not have a good sharp cup, replace it.