contractor saw belt vibration

Page 1 of 2  
How much vibration is normal in the belt of a contractor saw? The saw/belt is about eight years old but has rarely been used. The belt appears to be in excellent condition, but the up/down vibration of the belt as it comes of the pulley appears to be bit excessive. How much is too much?
Best, Christopher
Add pictures here
<% if( /^image/.test(type) ){ %>
<% } %>
<%-name%>
Add image file
Upload
On Thu, 5 Nov 2009 11:41:07 -0800, "Christopher Glaeser"

Can you balance a nickel on edge? If not, check the tension or how much the belt deflects when firmly pressed with one finger--you can actually measure this accurately using a cricket guage. There are many other things that can cause vibration, loose bolts, pitch buildup/damage on blade, damaged pulley, bent shaft, change in natural frequencies, etc. Inspect everything, time for a tuneup.
Add pictures here
<% if( /^image/.test(type) ){ %>
<% } %>
<%-name%>
Add image file
Upload

What is the recommended delfection tolerance?
If a saw is stored for extended periods of time, should the belt be removed to avoid uneven stretching?
Best, Christopher
Add pictures here
<% if( /^image/.test(type) ){ %>
<% } %>
<%-name%>
Add image file
Upload

Typically a contractors saw belt thightness is not measured in deflection because the weight of the motor provides the tension. As the belts stretches or shrinks the tension is going to be different. Industrial belts, the type normally used on this type saw are pretty bad about taking a set and creating vibration.
To remedy this situation either up grade the belt to an "automotive" belt which is designed to fun at much faster rpm's with much less vibration or go with a link belt. The link belt is going to be considerable more expensive but will work the best.
As far as the automotive belt is concerned you want one that has the notches on the inner side of the belt. The notches run from side to side. The notches permit the belt to bend around a tighter/smaller radius pulley.
Don't confuse this with the serpintine automitice belts that have 8-10 groves on the inside perimeter of the belt.
Add pictures here
<% if( /^image/.test(type) ){ %>
<% } %>
<%-name%>
Add image file
Upload
Christopher Glaeser wrote:

I bought a saw that sat for many months. The belt had taken the shape of the pulleys... it had a memory kink, if you will. It has a heavy vibration at slow down, which I suspect is caused by the kinks in the belt.
Once I replece the belt with a new, round one, or one of those "link" belts, I bet it runs smooth as butta.
--

-MIKE-

"Playing is not something I do at night, it's my function in life"
  Click to see the full signature.
Add pictures here
<% if( /^image/.test(type) ){ %>
<% } %>
<%-name%>
Add image file
Upload

Yeah, I think I'll do that. I don't use it much and it sits for long periods, so I'm guessing it has a memory kink. Thanks!
Best, Christopher
Add pictures here
<% if( /^image/.test(type) ){ %>
<% } %>
<%-name%>
Add image file
Upload
Christopher Glaeser wrote:

...
I hear folks claim that but I've never seen it in 40 years or so--once a tool runs for a few minutes at most any belt I've ever had has had no apparent belt "memory kink".
Go to the Gates Rubber or other major belt manufactuer's site for tips/guidelins on v-belt tensioning/applications. I also personally don't think there's any significant difference between an "industrial" belt as opposed to "automotive" for small-sized belts (4L, typically) as used on woodworking equipment. Electric motor rpm of 3450 vs 2-3000 typical cruise rpm for automotive applications is pretty much overlapping. Somewhat higher torque loadings, but most belt spec's far exceed those anyway.
I suppose _perhaps_ some of the more recent Chiwanese stuff may use some really inexpensive belt that has some of these problems but certainly everything I've ever had it's never been an issue.
I'd look at whether the pulleys are truly concentric machined pulleys or cheap cast-zinc hardware store varieties, whether they're really tight on the shafts (motor and driven) and aligned properly as primary culprits.
If it is a saw w/ more than a single drive belt, be sure to get matched pairs/triplets depending on number required. These days Gates adds a suffix number at the time of manufacture that indicates those that are within a specified tolerance instead of the old "hunt and measure" days or buying actual sets.
$0.02, imo, etc., etc., ...
--
Add pictures here
<% if( /^image/.test(type) ){ %>
<% } %>
<%-name%>
Add image file
Upload
dpb wrote:

Mine must be a pretty cheap belt. I marked the kinks, and they are still in it, after running the saw many times.
I'm not saying it *is* the issue, just saying it's something to check out before you go taking the saw apart.
--

-MIKE-

"Playing is not something I do at night, it's my function in life"
  Click to see the full signature.
Add pictures here
<% if( /^image/.test(type) ){ %>
<% } %>
<%-name%>
Add image file
Upload

I have not yet had a chance to pick up a new belt, but I did remove the old belt for inspection. Major kinks from the two pulleys, apparently due to sitting idle for long periods with little use. Thanks again for the assistance.
Best, Christopher
Add pictures here
<% if( /^image/.test(type) ){ %>
<% } %>
<%-name%>
Add image file
Upload
Christopher Glaeser wrote: ...

OK, ya' got me curious...can you find a vendor/manufacturer name on that puppy?
The PM-66 is 30 or so and has never had a new set and certainly has sat far more in those years than run and there's certainly no indication of any problem w/ them. Same w/ jointer, bandsaw, etc., etc., etc., ...
--
Add pictures here
<% if( /^image/.test(type) ){ %>
<% } %>
<%-name%>
Add image file
Upload

The belt is CAT NO 49-034.
I purchased this Delta about ten years ago and is rarely used. In hind sight, if I had removed the belt when not in use, I expect it would be running just fine. There are no visible signs of age or wear, just two strong kinks. I'll confirm when I pick up a new belt (which will be removed when not in use).
Best, Christopher
Add pictures here
<% if( /^image/.test(type) ){ %>
<% } %>
<%-name%>
Add image file
Upload
Christopher Glaeser wrote:

I still dunno'....one would think 30 years would have done it if were going to do so. I just don't see the same problem.
Go figure...
--
Add pictures here
<% if( /^image/.test(type) ){ %>
<% } %>
<%-name%>
Add image file
Upload
scrawled the following:

Do an experiment. Gauge the vibrations from one of your current machines which uses belts. Now put on a link belt. I'll bet the vibration level is lower with the link belt on it.
-- "To compel a man to subsidize with his taxes the propagation of ideas which he disbelieves and abhors is sinful and tyrannical." -- Thomas Jefferson
Add pictures here
<% if( /^image/.test(type) ){ %>
<% } %>
<%-name%>
Add image file
Upload
Larry Jaques wrote: ...

...
I've have seen 'em tried on quality sheaves and heavy gear and I'm sure it won't make enough difference on anything I have to make it worth the time (and especially the expense; they're d-d proud of those puppies from what I've seen.
If one has a lightweight contractor saw w/ the pot metal cast out-of-true pulleys or the like, perhaps it'll cover up/mask some of the inherent problems.
--
Add pictures here
<% if( /^image/.test(type) ){ %>
<% } %>
<%-name%>
Add image file
Upload
scrawled the following:

I think I got 4' of it for $17 from Harbor Fright when I bought mine. I don't think I've spent less than $20 on a belt (serpentine) in the past decade, though. How much are v-belts going for nowadays? Hmm... http://www.mcmaster.com/#6230k17/Nnn1b 35.5" for $11.05? Less than I thought. Still, the lower vibration and ease of use for the link belt makes it a winner in my book, even if the price is $6 higher.

Yeah, variances in machinery quality and style will make a difference.
-- The Smart Person learns from his mistakes. The Wise Person learns from the mistakes of others. And then there are all the rest of us... -----------------------------------------------------
Add pictures here
<% if( /^image/.test(type) ){ %>
<% } %>
<%-name%>
Add image file
Upload
Christopher Glaeser wrote:

Yes, please report back with the results.
--

-MIKE-

"Playing is not something I do at night, it's my function in life"
  Click to see the full signature.
Add pictures here
<% if( /^image/.test(type) ){ %>
<% } %>
<%-name%>
Add image file
Upload

I replaced the original kinked belt with a new v-link. The blade now sings. Sweeter than pie. Thanks.
Best, Christopher
Add pictures here
<% if( /^image/.test(type) ){ %>
<% } %>
<%-name%>
Add image file
Upload
Christopher Glaeser wrote:

Hate to say I told you so, but..... no wait a sec. In this case, love to say I told you so. :-)
--

-MIKE-

"Playing is not something I do at night, it's my function in life"
  Click to see the full signature.
Add pictures here
<% if( /^image/.test(type) ){ %>
<% } %>
<%-name%>
Add image file
Upload
Is it OK to run the motor without belt or load to test the balance of the motor and pulley?
Best, Christopher
Add pictures here
<% if( /^image/.test(type) ){ %>
<% } %>
<%-name%>
Add image file
Upload
On Sat, 7 Nov 2009 19:59:05 -0800, "Christopher Glaeser"

Table saw motors are designed to run with a load on them. I'd say that it changes the mechanics of the situation. You might even damage the motor. It's the balance of the motor and pulley running together that you should be concerned with.
Add pictures here
<% if( /^image/.test(type) ){ %>
<% } %>
<%-name%>
Add image file
Upload

Related Threads

    HomeOwnersHub.com is a website for homeowners and building and maintenance pros. It is not affiliated with any of the manufacturers or service providers discussed here. All logos and trade names are the property of their respective owners.