Is vibration at shut down a real problem?

[Christopher Morgan]

I recently bought a Ridgid R4511 table saw (no, not during the current sale, but I did get the price reduction:D). After spending some time getting it all set up, I turned it on. That part went OK. But then when I turned it off, it performed a shut-down shimmy -- a very noticeable shuddering of the whole cabinet as the motor slowed down.

From what I have read, this might be caused by a poor quality belt, or sheaves that are not centered properly on the arbor. What I know is that when I turn the belt by hand, I can see the motor move up and down.

So I am wondering: Is this something worth investing time, energy and/or $ to try to solve? The saw runs smooth enough after start-up and before shut-down that a nickel will stand on edge. Since I will only be cutting wood with the saw running, should I just chalk up the shimmy to one of the (largely aesthetic) compromises of buying a $299 saw? Or is it something that could have practical consequences?

Thanks,

Christopher

[Myk Rian]

Was the belt already installed? It might have a set to it. Run it awhile to loosen it up.

[Gary Muto]

My saw (Delta Cabinet saw) does something similar. I think it may be related to the belts taking a set if the saw isn't used for a while. I just finished a project and plan to tension the belts to see if that has an effect.

I'm curious as to what others will have to say about this problem.

[Adam Strong]

I have the R4511 and had the same issue. I replaced the belt with a higher quality one from McMaster-Carr and that helped quite a bit. The remaining problem is the pulleys (sheaves) being out of balance on the shaft. The only way to really fix it is upgrade them. I still have minor shimmy at wind down, but find it to be of no concern. The only worry is that if the vibration is too much it could throw something on the table into the blade.

[Scott Hildenbrand]

Chances are the belt has a predisposition to be in an oval shape, as you say the motor moves up and down when you spin it over.. This is enough to cause a shimmy when it slows down past a certain RPM.

A shimmy at shutdown isn't anything bad, so long as it's not doing it while running and affecting your cuts.. I know my stock blade SUCKS and has a slight wobble to it (bent) so the saw resonates while on. [WeeeEEEERRRRRrrrrrrr-- WeeeEEEERRRRRrrrrrrr-- WeeeEEEERRRRRrrrrrr]..

Now THAT problem is an issue and causes bad cuts. I've got a WWII standing by, but I have yet to make a cut that I feel warrants a $100+ saw blade... Soooo... I'm gonna pick up a good Delta cheap on eBay.. :)

So... If it annoys you, pick up a new [better] belt... If not, no biggy.

I can not recall the belt source, but the post about the R4511 belt is over at the Ridgid forum.

[Cliff Holmes]

My jointer had a very similar problem with shuddering when the motor brake kicked in. Turned out to be a loose setscrew in the pulley.

[Galip Guvelioglu]

I have Steel City 35920 which is manufactured by the same company as I know with R4511. I had the same issue as you mentioned, spent a little time researching and it looks like it is related to the type of motor as it is shutting down the shaft does not rotate at the center and at certain rpm when slowing down it vibrates everything.

I also got the McMaster belt as previous poster mentioned and it does help. I looked into getting the powertwist belt but unfortunetly pulleys need replacing and could not find a 2" grove pulley with 5mm key for the motor side. and at top arbor needs a thin pulley or granite needs modification to maintain all the blade movement.

I checked the pulleys they seem to be pretty good and but the motor shaft when not under power has significant runout 0.007" to 0.01" but it seems like under power it rotates pretty center as vibration is not significant. If I knew a means to measure runout when it is spinning I could give numbers.

[Lee Bidwell]

Guys, thanks for the posts on the 4511 "shimmy." I was beginning to think I got a lemon. Mine shakes bad enough on shutdown to concern me. Adam, could you post which belt you found to replace the OEM one?

Also, regarding runout, I am measuring about .005 at the blade rim (and this number is consistent with a couple of different blades). The cut quality is OK, but not perfect (some saw marks, but not bad enough to burn). So would you worry about .005 of runout at the blade, and could this contribute at all to the vibration? Thanks for your help. This is my first real table saw.

Lee

[Myk Rian]

You can always use a file to true up the collar washer. I believe there was a post here about someone doing that.
Use a dial indicator to find the high spot and file it down a smidge.

[Christopher Morgan]

Guys, thanks for the posts on the 4511 "shimmy." I was beginning to think I got a lemon. Mine shakes bad enough on shutdown to concern me. Adam, could you post which belt you found to replace the OEM one?


I had the same concern about getting a lemon -- so it is good to hear that I am not alone.

The belt that was referred to on the Ridgid forums is McMaster-Carr's Part #9003K16 -- Ultra-Flex J-Section Neoprene Belt 6 Ribs, Trade Size 300J6, 30.5" Outer Circle.

I have ordered it; I'll post back to say whether it helps.

[Bob Haskett]

My R4511 does this as well. I never thought anything of it until this post. I think I am going to leave the stock belt on, the shimmy is not really all that bad on only happens for the last ~1-2 sec before the blade stops.

[Adam Strong]

The belt that was referred to on the Ridgid forums is McMaster-Carr's Part #9003K16 -- Ultra-Flex J-Section Neoprene Belt 6 Ribs, Trade Size 300J6, 30.5" Outer Circle.

That's the one! It is a little softer, and more pliable than the stock belt. As I said, it helped quite a bit with the shimmy, but did not eliminate it.

As for the blade run out... Have you checked the arbor run out as well? If the arbor has any run out at all it is magnified on the edge of the blade. If it is not the arbor itself, then checking and truing the collar should be a fairly simple fix. If it is the arbor, call Ridgid and get a replacement.

[Lee Bidwell]

Adam and Christopher,
Thanks for the belt info. I'll definitely be ordering one. Also, checking the arbor runout is the next thing on my to do list. I just haven't had any shop time this week. Thanks for the advice.

Lee

[Chris Friesen]

I suspect what's happening is that the blade/arbour/belt/motor assembly is simply hitting a resonant frequency as it slows down.

[John Harden]

My jointer had a very similar problem with shuddering when the motor brake kicked in. Turned out to be a loose setscrew in the pulley.

+1 on this advice. You might want to check this. I used to have a PM-66 and every few years, the set screws on pulley attached to the motor would work loose and the pulley would vibrate. Eventually, I got smart and used some blue locktite on them and they stayed put.

I also agree with the advice others are giving you about the belts. That's a likely culprit too.

Regards,

John

[Christopher Morgan]

Well, I did get the new belt and put it on. I does seem to help some. It is certainly a more flexible belt. I do not regret spending the $17 (after shipping), as it does seem to help some. But it is not an overwhelming improvement.

What I think did make a big difference is that it is now considerably warmer up here in NY than when I was putting the saw together. It was down in the single digits at night during that time, and my unheated shop never got above freezing (you know it's cold in your shop when the vapor from your breath freezes on your new saw.) I think the cold made the OEM belt very stiff, and though it had only been on the saw a couple of days before I first tried it, I think it did have a bit of a set to it that made the problem considerably worse at first. So I think Myk and Scott were right on this one.

At any rate, I have been using the saw recently and really like it. I had been looking at much more expensive saws, but I think this one will do me just fine for awhile.

Thanks for the help, everyone.

[Kevin Gregoire]

im also glad i am not alone on this problem but i have a craftsman cabinet saw Model 152.221240
and it has a pretty hard shimmy on shut down. do the motors have some kind of breaking system?
after hitting the off button it starts slowing down and then after a few seconds it really starts slowing down
and then the vibration starts and the machine rumbles to a stop.

it would be nice if its as simple as replacing the belt and maybe the pulleys. are a new set of stock pulleys good
to use or where do you find a good set of machined rib pulleys?

[Josiah Bartlett]

im also glad i am not alone on this problem but i have a craftsman cabinet saw Model 152.221240
and it has a pretty hard shimmy on shut down. do the motors have some kind of breaking system?
after hitting the off button it starts slowing down and then after a few seconds it really starts slowing down
and then the vibration starts and the machine rumbles to a stop.

it would be nice if its as simple as replacing the belt and maybe the pulleys. are a new set of stock pulleys good
to use or where do you find a good set of machined rib pulleys?

The motor shunts the start winding and the run winding together when the shaft speed slows enough to trip the centrifugal start switch, and this does provide some braking action. Coupled with a belt that is now transmitting power in the wrong direction it changes the slack in the belt and tends to make it slap and jerk. This isn't necessarily a problem as long as it runs smoothly when on, but if it really bothers you than balanced pulleys and a good belt alleviate the symptom somewhat.

[Joe Kaufman]

The motor braking action will cause a Freud P410 Premier Fusion Blade to wobble and enlarge a ZCI (Zero Clearance Insert) after a few shutdowns. I exchanged the blade and the second blade has less wobble on the shutdown, but still chews on the side of a new ZCI.

Joe

[Josiah Bartlett]

The motor braking action will cause a Freud P410 Premier Fusion Blade to wobble and enlarge a ZCI (Zero Clearance Insert) after a few shutdowns. I exchanged the blade and the second blade has less wobble on the shutdown, but still chews on the side of a new ZCI.

Joe

Is your arbor or one of the brackets loose? Maybe use a blade stabilizer?

[Joe Kaufman]

Is your arbor or one of the brackets loose? Maybe use a blade stabilizer?


Talking to the Freud rep, the blade has a lot of laser cuts designed to allow some flexibility to the blade so it will straighten out any inaccuracies at speed. The sides of the teeth burnish the cut so the blade needs to run true for maximum smoothness of cut. The blade performs great, it's just during the period of the motor braking that it vibrates/wobbles enough to enlarge the ZCI. Don't think blade stabilizers would make any difference as most of the laser cuts would be outside of the stabilizer O.D. I have several Freud thin kerf blades that don't exhibit the same problem.

[Josiah Bartlett]

Talking to the Freud rep, the blade has a lot of laser cuts designed to allow some flexibility to the blade so it will straighten out any inaccuracies at speed. The sides of the teeth burnish the cut so the blade needs to run true for maximum smoothness of cut. The blade performs great, it's just during the period of the motor braking that it vibrates/wobbles enough to enlarge the ZCI. Don't think blade stabilizers would make any difference as most of the laser cuts would be outside of the stabilizer O.D. I have several Freud thin kerf blades that don't exhibit the same problem.

Theres probably nothing you can do about it then, except for trying to make the thing run smoother.

[Kevin Gregoire]

i took a crappy little video of my TS to show you the wobble on shut down
i didnt have a nickle on me to try that test so i used a nail.
watch the video and tell me what you think?
(there is a little extra vibration because cam is sitting on saw)

http://www.youtube.com/watch?v=my_YOTAnAlw

[Jeff Miller]

i took a crappy little video of my TS to show you the wobble on shut down
i didnt have a nickle on me to try that test so i used a nail.
watch the video and tell me what you think?
(there is a little extra vibration because cam is sitting on saw)

http://www.youtube.com/watch?v=my_YOTAnAlw



Your saw is fine but you have too much time on your hands............. go cut some wood:D



JEFF:)

[Gary Muto]

I just adjusted my belt tension last night and the vibration went away. My belts were loose since I have never checked them in over 3 years.

[Kevin Gregoire]

i have severe arthritis in my knees so i cant get down on the ground to check my belts.
when i first got the saw a friend from wood club helped tune up the saw and i thought
he said the weight of the motor held the belt tight so i dont know if there is a bolt to
tighten or if its just dead weight?

[Scott Hildenbrand]

If it's an R4511, the motor hangs as dead weight and keeps pressure on the belt. No need to tighten.

[Terry Welty]

I concur with Jeff

[John Petsche]

great info here.