Table Saw Vibration

I finally decided it was time to investigate my tablesaw vibration. The saw is a Grizzly G1023S and is 8 years old. It has had a noticeable vibration on and off for the last two years. Lately it has been more pronounced and my rips have been at least 1/32 wider than the scale on the fence - it had been nearly perfect.

I noticed considerable radial movement on the arbor and disassembled the arbor. The bearings inside race spun on the arbor. Normally, the race is tight on the shaft (the spinning portion) and loose in the housing (the non-spinning portion).

I am considering how to assemble without causing a bearing defect. The bearings have to be assembled in such a way to be sure you are pushing on the tight fitting race - not across from one race throught the rollers to the tight fitting race.

I am thinking about installing the bearings in the housings on the saw - then putting the arbor in the freezer overnight to shrink it. This should allow the arbor to slide right through the inside races of the bearings. The bearings are 6203 sealed and shielded - they are not very big. I am not sure about condensation.

I ordred the arbor shaft from Grizzly which should arrive by next weekend. I would have reverse engineered it and had a machine shop make it, but there is the flange for the blade that would be a problem. The bearings I will have tomorrow from one of our power transmission distributors (Motion Industries).

You might consider getting dry ice to shrink the shaft I have used it before & its quicker to do what you want you should be able to slide the shaft in after just a a few minutes. Make sure you are all set up because as you probably know its difficult to get a second chance at doing it right.

Consider the dry ice, like Bart suggested. Not only is it quicker, but it's much colder - something like minus 234°F, as I recall. It'll give even better shrinkage than just putting it in the freezer.

Thanks for the response guys. That is a better idea. We have used dry ice at the paper mill for shrinking large dia shafts (7" in one case) into hubs on pulper rotors. The first time we used it, the shaft shrunk 0.007" in 15 minutes. It went together like it was a slip fit. 7 years later, it took about 80 tons to pull it apart.

This job will definitely require well insulated gloves.

One other question. I havent taken the table top off. I am starting to think this might be a good idea. I was looking to avoid the hassle of realignment, but it might be worth the hassle - Bart, your comment about being ready has me thinking this way.

Don't do like the highly paid Einsteins I used to work with. A fixture got stuck in an aluminum gun barrel housing and they figured a couple inches of liquid nitrogen and a sharp rap with a hammer would free it up. It kind of worked. When they hit it with the hammer you would have swore a plate glass window shattered. The fixture was made from 1/2" steel. I haven't had a good laugh like that in years.

Rich

We used dry ice to shrink dry liners for diesel engine cylinders when we rebuilt engines. I just hope you can completely position your shaft by hand. We had to use a press to finish pressing the cylinder liner into place.So we allowed the liner slide in until it stopped & then pressed it the rest of the way.

In my experience with dry ice, I have not had to use a hammer. However, it is usually much larger diameter shafts and bores that are involved.

Maybe I am better off taking the whole thing apart and using a bearing press to put the bearings on. I have the issue of the sheave in between the yoke where the bearings mount. I can invision getting the shaft stuck in the sheave because there is a key involved. At that point, I would be taking it apart. I will not hammer on the bearings - that is from one race through the rollers to the other race.

I pulled the trunion out of the saw. The saw is going to have to be tuned anyway after I get through the bearing change, so this will make life easier.

There was paint in the bearing bores. Not all the way around, but just in a few areas. I am going to mic the bores as they are to see how out of round they are. Then, I am going to clean bores with emory cloth to remove the paint and check them again.

Two possibilities for root cause are 1) paint in the bores cause the bores to be out of round and 2) the bores had paint because the bores were machined out of round.

I emailed Grizzly to see if they will tell me the bore tolerances and the arbor tolerances. I will keep you posted.

I measured the bearing fit with the paint and it was very tight where the paint was in the trunion bores. The places where it was bare metal gave a few ten thousands press fit. I cleaned the bores with emory cloth 600 grit - it took a lot to get the bores clean. The bores were very round, which is good for the bearings. The arbor shaft was 0.001 smaller than the bearing bore, so basically put the bearings, shaft, spacers and sheave on with my hands - no pounding and surprisingly enough, no use of the puller tools that I rigged up. I had a few sockets that were the right size for the outside races of the bearings - with a bolt, washer and nut, you can pull the bearing into the housing without "loading across the rollers". I used the sockets and pushed to push the bearings in by hand - using my weight as well (I am not very big).

The saw is basically together now, except for the extended fence rail on the outfeed side of the blade. The lag bolts pulled out of the table between the extended rip rails and I forgot to repair it until now.

I had to try a narrow rip to make sure my fence scale is in the proper position. The saw is super smooth.

Maybe that is the problem with my vibrating Jet 6" jointer .... I'll have to tackle that next.

Rich Aldrich said:

Thanks for the response guys. That is a better idea. We have used dry ice at the paper mill for shrinking large dia shafts (7" in one case) into hubs on pulper rotors. The first time we used it, the shaft shrunk 0.007" in 15 minutes. It went together like it was a slip fit. 7 years later, it took about 80 tons to pull it apart.

This job will definitely require well insulated gloves.

One other question. I havent taken the table top off. I am starting to think this might be a good idea. I was looking to avoid the hassle of realignment, but it might be worth the hassle - Bart, your comment about being ready has me thinking this way.

Click to expand...

If you pull your top mark each shim at the bolt position. These look like washers but are a specific thickness to mount your table flat.

Rich...

Thanks for sharing that info. My saw is a Grizzly G1023SL, and Sunday it's coming apart for cleaning, maintenance, and trying to figure out why the flange part of the arbor isn't running true (the attached flange, not the loose one). The arbor itself seems fine, but the dial indicator is showing a deflection of .005 give or take at a particular spot on the flange. This seems to be transferred to the blade, which shows the same behavior...can't get a rip without excessive blade marks (Forrest and a TS2000 both behave the same). Hopefully I don't have to get into disassembly to the extent you did, but nice to know I can get some questions answered if I do.

Glenn...I understand what you're saying about the shims, but don't understand flat...with respect to what? I've been looking over the parts list for my saw for the above reason, and don't see any shims there. Help.

Cheers.