Table Saw Making a Cunking noise

[Jesse Wilson]

My JTAS10 just started making a clunking sound that speeds up with the revolutions of the motor. Nothing significant happened before the sound started. I pulled out the insert and it sounds like the noise might be coming from the arbor. I am going to take the belts off the pulleys and see if the noise continues or not. Obviously if it does then it's the motor and if it doesn't then it's probably the arbor bearing if I am guessing correctly.

Does anyone have any input or something I might not be thinking of?

Few questions for those who can help:

How much is a new arbor? Are they universal or am I going to have to find one specific to this saw? How is it removed, I's not going to need a press am I?

TIA


Jesse

[David G Baker]

My clunking sound started prior to my finding out that the screw on the arbor pulley had started to loosen and the pulley would occasionally spin on the shaft.

[Lee Schierer]

A number of years ago my Craftsman TS made a slight clunking sound as it would slow down. I put a couple of drops of oil n the bearing shield closest to the arbor flange, the noise went away and has not returned and my arbor has no end or side play.. YMMV.

[David Thompson 27577]

If you remove the belt and the clunk goes away, it might be the belt. Or it might be one of the pulleys. Or it might be an out-of-balance blade. Or a bearing........

[Ray Newman]

Periodically, my Uni-saw makes the "'thud-on-start-up". Some say this is normal due to motor design.

I checked the belts, pulley alignment, set screws, etc., and all seemed normal and tight.

Then I noticed that it usually occurred if the saw has been sitting for awhile. The belts on my Uni-saw are the original belts -- approx. 23 years old -- and they may take a set when not run periodically. Lately, I have been running the saw more than normal and the "thud-on-start-up" has not occurred.

In any case, it is wise to check the saw just to make sure. Preventive maintenance goes a very long way.

If you think the bearing(s) may be bad, use a shop-fabricated stethoscope. Unplug the saw; remove blade and belts. Then take a 1" dowel about 2-3' long and place one end to your ear, the other end on a bearing while hand turning the arbor. If the bearing is bad, you’ll hear a very distinct noise. And if one bearing is bad, I suggest that you replace all of them as the worn/bad bearing(s) just may have caused premature wear on the others, which could lead to their early failure.

You can take the saw apart and have the bearing(s) replaced at a machine shop. The price difference between good/OEM and the best quality bearings often times is not that much.

An arbor press is needed to remove/install the bearings. Bearings, unless a very unusual size are commonly available.

[Paul Atkins]

I'm guessing loose pulley set screw.

[Jesse Wilson]

Winner winner chicken dinner...

Arbor pulley set nut was loose. Thanks everyone for your help. It went rather smoothly, I even left a bolt out "on purpose" so that I could take it apart once I had it all back together and redo it. :o



Jesse

[Alex Leslie]

I had the same problem with my 5hp JTAS. I replaced all the pulley setscrews with new ones as the factory ones would periodically loosen and cause a low, rumbling vibration. No problems since installing the new.

The factory motor also shelled out after about 8 years of intermittent use. Dust had been sucked through the motor, causing the windings to short out. Blew the whole house breaker! It was about a $400 rebuild at a local shop.

[Jesse Wilson]

OK so I got it all back together and started using it this evening. As soon as I used the dado set on it the sound came back. It appears that the dado set is causing the set screw to come loose.

Come to think of it that's when the sound started the first time, right after I started using my Oshlun dado set for the first time. I am sure it has something to do with the added weight of the additional blades.


Any ideas/suggestions?

What would happen if I used the saw a little bit with one of the pulley set screws loose just in case I have to order something?

[Andrew Nemeth]

Any ideas/suggestions?



I use loctite 242 (threadloc) on mine.

[Myk Rian]

If there is room in the hole, you can put another lock screw on top of the first one. The 2 screws will lock each other in. Like using 2 nuts on a shaft.

[Ray Newman]

Your 3 HP JET -- a Uni-saw clone --should easy swing an 8" dia. dado which is heavy, even a 6" dia. has some heft, but I don't think that either would normally loosen pulley set screws.

I looked on the JET web page and found the owner's manual: http://content.wmhtoolgroup.com/manuals/708715PK_m.pdf

From what I read there, the saw is a three belt model and the arbor and motor pulleys have two set screws and a key each.

First see what Alex Leslie posted. Sounds like that may be your answer.

While installing the new set screws, I would also:

--Remove the belts and check for any wear. Bad belts can cause vibrations, which the weight of the dado blades will increase.

-- Remove the pulleys and see if the set screw threads are damaged.

-- After removing the pulleys check the "keys" for damage. Too much torque applied tightening down the set screws can damaged the key and prevent it from tightening up properly.

--If all is well with the keys and pulleys' threads, check the pulleys that they are co-planar. If for some reason, the pulleys are not co-planar, that will cause vibrations, which the weight of the dado blades will increase.

-- Could be that the bearings are starting to go. Since you gone this far, might as well check them.

How old is this saw and did you buy it new or used?

[Jesse Wilson]

Your 3 HP JET -- a Uni-saw clone --should easy swing an 8" dia. dado which is heavy, even a 6" dia. has some heft, but I don't think that either would normally loosen pulley set screws.

I looked on the JET web page and found the owner's manual: http://content.wmhtoolgroup.com/manuals/708715PK_m.pdf

From what I read there, the saw is a three belt model and the arbor and motor pulleys have two set screws and a key each.

First see what Alex Leslie posted. Sounds like that may be your answer.

While installing the new set screws, I would also:

--Remove the belts and check for any wear. Bad belts can cause vibrations, which the weight of the dado blades will increase.

-- Remove the pulleys and see if the set screw threads are damaged.

-- After removing the pulleys check the "keys" for damage. Too much torque applied tightening down the set screws can damaged the key and prevent it from tightening up properly.

--If all is well with the keys and pulleys' threads, check the pulleys that they are co-planar. If for some reason, the pulleys are not co-planar, that will cause vibrations, which the weight of the dado blades will increase.

-- Could be that the bearings are starting to go. Since you gone this far, might as well check them.

How old is this saw and did you buy it new or used?

I bought it used a few months ago to have something to use until the 1023RL comes out.

I pulled it apart again and checked the belts and they looked recently replaced. The arbor bearing has no play whatsoever and the threads on the pulley and the set screw looked good.

Here is what I did.... I purchased 1/2" 1/4-20 set screws to replace the 3/8" that came from the factory. I lined up the pulley by rotating the belts around a few times then I installed them with some blue Locktite. They filled up almost the entire depth in the pulley thread. The combination of the Locktite and more grip provided by the 1/2" set screw length should hopefully keep them secure.

Incidentally now that I have had a saw with the 50" extension I think I am going to change my order for the 1023RLW to the 1023RLX. I didnt think I would have the room because I am just using one car of a 2 car garage for a workshop. However I find myself using the extension for a workbench 80% of the time and I can store it lengthwise in the garage unless I am cutting long sheets.