Alert: owners of older Grizzly 1023 TS
This is a continuation of an earlier thread, and concerns the Grizzly 1023 TS model and similar models that have pulleys on the arbor shaft that are not secured with set screws.
I recommend that you check the tightness of the drive pulley to the arbor assembly; wear may have occurred due to loose fitting pulleys. You may need to replace the arbor and pulley to eliminate the problem.
The attached photo shows the pitting and wear found on a ca. 1991 model 1023 TS. This saw has been used heavily during the past two years, but only lightly before that. During routine maintenance, I discovered the drive pulley was loose on the arbor shaft. Loose pulleys will cause increased vibration, noise, and poorer quality cuts.
You do not need to disassemble the arbor assembly to determine if you have this problem. To see if this problem affects your saw, do the following:
1) UNPLUG THE SAW. Removing the saw blade after this step will also help.
2) It helps greatly to remove the saw top, but it may not be necessary. I have not done this with the saw top in place.
3) Lift the motor slightly to remove the three drive belts from the pulley on the motor.
4) Remove the belts from the top (arbor) pulley.
5) Grasp the arbor pulley and try to move it. If you can move it in any direction, you have a problem. If the pulley can be pulled away from the arbor (namely, in the direction tangential to the arbor axis), you have the same loose fit that I found on my saw.
If you examine the attached photo, you will see the wear/pitting on the arbor that can happen when the pulley is loose. I measured the arbor diameter with a micrometer in several spots, and found no detectable difference. This means the loose fit is not due to wear, it is due to a design flaw that will result in wear and eventually cause more damage than just more noise and vibration.
Grizzly recommends(and I agree) to replace the arbor and pulley with the newer model that includes set screws to make sure the sucker doesn’t get loose. If you go this route, you should also replace the bearings. The bearings on my saw are shielded: I will be replacing them with higher quality sealed bearings (I get my bearings from McMaster-Carr).
One disclaimer, this note is not a Grizzly service directive, and it nor I have any tie to Grizzly (other than I am a Grizzly customer). This is an “in my humble but very firm opinion” kind of note!
Replies
Paul,
That was good advice and no quibble here just a design opinion.
The way these machines are designed today, they all use set screws, for various reasons. Fundamentally, your old Grizz was a better pulley design, but they missed some of the fundamental basics in the fit tolerance, which is why you had this problem.
Using set screws as a pulley fixture on a shaft is a cheap way out, for design, assembly, and it does not offer much precision. Anything above 3 hp, this problem is magnified.
Good design allows for a press fit, with tolerances which allow the pulley to never work loose. This means more complex design and assembly, or disassembly, and more precision during manufacturing.
I'm in the same boat and make it a monthly chore, to check that those set screw are tight. If they work loose, you can loose the shaft and pulley in no time. Locktite is not a solution, as the screws don't necessary turn loose, but rather the indentations they make in the shaft, become bigger due to compressive yield and the pulley gets loose.
I would also suggest getting some knurled cup point set screws, catalog page 2910, and Loctite 242 from McMaster-Carr. The first thing I do is replace the set screws on a new machine, the OEM supplied set screws are usually too short. I like stainless steel knurled cup point screws and I use some Loctite 242. I have not had a set screw problem since I started the above replacement procedure.
Life is what happens to you when you're making other plans .
Thanks for the advice, I'll get some better set screws. The ones on the collars that hold the worm gears in place were so soft that they "stripped" pretty quick.
I also agree with the previous comment about a press fit. Unfortunately, the fit for this TS wasn't anywhere close (much >0.01"). Recommending the use of "Hide Signatures" option under "My Preferences" since 2005
Jerry -
I noticed McMaster also sells nylon tip set screws, which are supposed to be good at reducing noise and vibration. Have you any experience with these, or do you know of a reason to stick with the knurled cup screws? I was thinking of trying the nylon tip ones.
PaulRecommending the use of "Hide Signatures" option under "My Preferences" since 2005
I would stick with the knurled cup set screws as they really make a secure bite into the shaft and key. This is very important to prevent the problem that you have encountered. I have used the brass tipped set screws in less severe situations. Most of the vibration you get is because of a solid belt vibrating. Try a link belt and you will be pleasantly surprised on the smoother cut your TS will produce. Also, because of less belt vibration the pulleys will be less likely to work loose. McMaster-Carr has link belts available by the foot.
Life is what happens to you when you're making other plans .
Thanks, I'll stick then with the knurled cup screws. I'll also bite the bullet and spring for some link belts.
I got a kick out of your previous post with the "nickel" and "dime" tests. Before starting this tune up, my saw vibrated so badly it would vibrate a crescent wrench off the extension table...Recommending the use of "Hide Signatures" option under "My Preferences" since 2005
Paul, check out this message for a description of what I also encountered when switching to link belts on my Unisaw and Grizzly G0543 jointer.
http://forums.taunton.com/tp-knots/messages?msg=23939.47
Life is what happens to you when you're making other plans .
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