old question from different pt of view - saw blade wobble

[gk777]

What is an acceptable wobble of the 1.5 inch arbor saw blade. Today I measured mine by keeping my dial caliper (actually digital calipers) at the edge of the saw blade just inside the outside circle. I did not move the calipers they were locked in place and measure the distance the blade travel left to right. My blade travel on average .032" or I believe this would be 32 thousandths. I thought Nick was only getting .005" or less but he was moving from back to front of table. I did not move my measuremnt point so that it would be a constant (no variable)

1) is this normal?

2) If not, How can I correct it? Is it the mounting on the arbor or the quill or just maintenance to be done? Or is there something wrong with my arbor or blade?

I have a 2006 Mark V 520.

[Nick]

I'm not aware that we have a 1.5" arbor saw blade. Sounds like a tiny little bugger. Especially since the arbor hole is 1.25". Also, I wasn't measuring the runout in the video to which you refer -- I was measuring the alignment.

To measure runout on a blade, rest your dial indicator on the blade just inside of the gullets and slowly spin the blade. Watch the needle move back and forth -- the range over which the needle travels is equal to the runout. Most blade manufacturers try to holds this to +/- .005", although this will depend on the type of steel used in the blade body, the blade application, whether or not it has set teeth or carbide teeth, and, of course, the diamter of the blade. At 1.5" diameter, you shouldn't even be able to measure the runout.

With all good wishes,

[gk777]

oops your right i goofed 1.25 arbor. The blade is mounted to this and I am measuring the blade movement.

[dusty]

Yes, .032" of wobble (runout) is definitely excessive.

Given my own experience with the Shopsmith and my total faith in its quality and reliability - I will be very surprised if you would determine the problem to be caused by the "Shopsmith" - not a 2006 Mark V 520 - not even - never.

A defective arbor (not very likely), a bent blade (not perfectly flat), a sawblade installed with crud between arbor and blade.

I'd take the blade and arbor out of the picture. Install the sanding disk, after cleaning it very well. Repeat your test and compare results.

I would also take that pair of calipers out of the pictures. Fall back on the alignment procedures in the manual. If after doing that, you still have a .032" of wobble - you might have a problem worth calling customer service about.

BTW - How did all of this come to be? Had you recently done anything out of the ordinary with the Shopsmith?

[gk777]

Nick and Dusty thanks for the quick responses

Nick,

The blade is the shopsmith blade that comes when you purchase the machine. This is the first time the blade has been used. I am measuring as you describe. I am measuring about 4.4" from center, not at the tip of the teeth nor near the gullet but on the smooth steel of the blade body. I recorded the min and max several times and that is were I came up with the number of .032" average, Max number was .038 and min was .28. These numbers are, of course, from subtracting the largest reading from the smallest reading while spinning the blade. Just want to make sure its ok and figure out what I am doing incorrectly before I use it.

Dusty,

I to think it is operator error, thats what I am trying to figure out. What I did wrong. Actually my arbor does have a problem it has burs on the threads because I have to use wrenches to get it all the way off. (Posted this on another thread) Usually, with most arbors, you can loosen it with the wrenches and then loosen the rest of the way with your hands. I can only do this for a few turns, then I have to put the wrenches back on to get it past the 'bad spots'. If I had a tap and die I am sure it could be fixed really quick. I do 'think' the arbor is tight on the blade body I have tried to move it side to side and it does not deflect and I do not think the arbor is the issue. I think my installation is the issue. but I will take it apart and verify no 'gunk' is causing the issue and check it with the sanding disk and redo the manual set up.

Today is the first time I 'tried' to use the SS in table saw mode. I have used all the other modes with no issues. When bringing it up to speed, I felt and heard a vibration and it did not sound like Nick's on the sawdust session. So I stopped it and started to investigate before using it. It is time for a headstock maintenance in the near future but I don't 'think' (there's that word again) that that is the issue but trying to reduce the issues branches so I can resolve the problem quicker.

I will investigate further on Saturday. Thanks for the help.

[charlese]

Today is the first time I 'tried' to use the SS in table saw mode. I have used all the other modes with no issues. When bringing it up to speed, I felt and heard a vibration and it did not sound like Nick's on the sawdust session. So I stopped it and started to investigate before using it. It is time for a headstock maintenance in the near future but I don't 'think' (there's that word again) that that is the issue but trying to reduce the issues branches so I can resolve the problem quicker.

I will investigate further on Saturday. Thanks for the help.

Simply because you asked the question - Yes, it is time for a lube job! Remember to run it up to high speed before putting 5 to 6 drops of 10W non-detergent oil into the control shaft and a couple drops on the motor shaft. Also lube the speed control quadrant and the worm gear. Then clean out any sawdust or dirt from the inside of the headstock and check the condition of the drive belt and the poly V belt. This should be done every 10 hours of running, or if the machine has set idle for a long period, like several months.

You shouldn't be hearing and feeling vibrations that were not there when the machine was brand new. After years of use, you may get some new noises, but not on a new machine like yours.

About your original question, You got excellent advice from Nick and Dusty. Personally, I'd either get that arbor working smoothly or replace it. Your problem sounds like a warped blade to me. Probably caused by irregular pressure from the arbor.

[Ed in Tampa]

Okay here is what I would do.
I would mark the high spot with an H and the low spot with an L on the blade.
Then I would mark both the blade and arbor with a straight line.
Then I would loosen the arbor and shift the blade about 90 degrees to the mark and then check the blade.
If the high and low spots moved I would say the arbor is warping your blade.
If the high and low spots remain in the same place but increases or deceases in magnitude then possibly you do have a warped blade and/or arbor but you may be able to adjust it into .005 tolerance by shifting the blade in relation to the arbor.

If the high low spots remain the same I would remove the blade from the arbor and lay it flat on the sturdy table and smack it. It may be sprung by the arbor and smacking it may relieve the tension. Remount the blade making sure your line on the blade and arbor are about 90 degrees out and test again. If the runout is about the same in the same places you probably have a bent blade.

I suspect the arbor is bad and is warping your blade.
Do those tests and let us know what you find.

[hardway]

I had a new 1 1/4" arbor early this year that was bad. I immediately notice the rough cut and the wide kerf when I did my first cut. I do not have a dial gauge but, instead use the miter gauge with the allen wrench (as per the SS alignment section instructions) to determine the wobble. Since I had a second arbor, I switch the blade to the other arbor and the wobble immediately disappeared.

I could find no visible flaws on the arbor threads even when examined under a magnified light and using 0000 steel wool across the threads. Even the slightest flaw or burr on the threads will catch on the steel wool. SS replace the arbor with no problem. The replacement arbor was perfect and I am using both of my 1 1/4" arbors regularly.

[gk777]

maintenance I do not believe was the issue. Yes that is past tense I have solved the problem. I did maintenance anyhow because I keep track of my shop time and do it per the schedule. I actually probably do it more often than necessary because the machine is not running all the time that is counted towards the time it is running.

Gunk was about 7 to 10 thousands of the problem. I cleaned the arbor and the blade and the new measurements were reduced by about that amount. Don't understand how it got there since it was supposable new, never used, as in the whole machine was never used. I bought the machine used not directly from shopsmith, just to make that clear.

The rest of the error is operator assembly. It looks like one of the burrs must of been near the end of the shaft on the arbor nearest the blade body. I took the parts to a auto/machine shop and he ran a tap and die set through it for me. I could not find tap and die large enough in any of the stores I went to yesterday.

Reassembled and remeasured. Now the readings are 6-7.5 thousandths and I am going to say part of that is measurement error with my method.

The best part is now the machine sounds like the beginning of the sawdust sessions. So I believe that I am good to go. Amazing how you hear a sound over and over you can tell when its not working right. Sometimes things you do not even think are helpful, like the beginning of the sawdust sessions can turn out to be helpful. Thanks for those they help me greatly.

Thanks for the help:p going to go cut wood.

[billmayo]

This may sound far-fetched but I have found a few 1 1/4" saw arbors that the person back out the set screw just enough to hit the nut and cause the set screw, nut and arbor threads to be somewhat mangled/destroyed while they continued to remove the nut. Replqcing the arbor was the only solution.