contractor saw belt vibration

Page 2 of 2  
snipped-for-privacy@teksavvy.com wrote:

Where did you hear this? I don't think it's a problem.
--

-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
wrote:

I didn't hear it anywhere and could well be wrong about it. However, tablesaw motors are built to run with saw blades being driven by them putting a load on the motor. It seems sensible that's the optimum condition for them to be running when you're looking to correct any issues. And yes, I have seen and experience a motor that turns and builds speed fine, but stalls when the belt is connected.
You can confirm a car motor runs fine at idle, but I'd prefer my car to be passed under test conditions when the car is actually moving or perhaps on a dynometer when the motor is under stress. Again, that's what seems logical.
Add pictures here
<% if( /^image/.test(type) ){ %>
<% } %>
<%-name%>
Add image file
Upload
snipped-for-privacy@teksavvy.com wrote:

I didn't question about any of that, which is why I cut it out of my reply.
You said it might damage the motor. I can't say for certain, but I don't think it would. That's why I asked for more info.
--

-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
wrote:

Sure, you could be entirely right. No argument there. My knowledge of electric motors doesn't extend to whether they might have governors for speed or the bearings might be subject to suffering from too much heat that might be generated from a motor running without load.
It's not my motor, so unless someone asked me specifically to find out and that person was a friend, then I'm not going to spend what might take me considerable time to find out. Guess that's a little selfish, but if I acceded to all similar requests, I'd never get anything done for myself.
Makes me think of the guy who has been asked to shorten a metal exterior door. Much of my decision for a job like that, (if I felt I was capable of doing it) would revolve around my relationship with the person who asked me. Unfortunately, there's any number of people, (friends can sometimes fall into that category too) who will take advantage of you every chance they can. For me anyway, close friends fall into the opposite category and treat me well despite my flaws and weaknesses.
Add pictures here
<% if( /^image/.test(type) ){ %>
<% } %>
<%-name%>
Add image file
Upload

That could be the case if the motor was "series wound" as without a load they can just keep getting faster and faster. I don't think any power tools would be purely series wound.
Add pictures here
<% if( /^image/.test(type) ){ %>
<% } %>
<%-name%>
Add image file
Upload
Scatter wrote:

Series wound. Does that mean what I think it means? As opposed to parallel wound? Or something totally different?
--

-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
wrote:

It means that the armature and field are wired in series.

As opposed to shunt wound.
Motor characteristics: http://www.elec-toolbox.com/motorchar.htm
Add pictures here
<% if( /^image/.test(type) ){ %>
<% } %>
<%-name%>
Add image file
Upload
krw wrote:

Cool info. Thanks.
--

-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

Correct, and I forgot to say that it would only apply to DC or universal motors - ones with brushes. Perhaps angle grinders are series wound - I really don't know though (they're probably compound wound instead - sort of a combination of both series and shunt).
Add pictures here
<% if( /^image/.test(type) ){ %>
<% } %>
<%-name%>
Add image file
Upload
On Sun, 08 Nov 2009 00:25:06 -0500, the infamous snipped-for-privacy@teksavvy.com scrawled the following:

Optimal, yes. What is there on a normal motor to destroy? The RPM is self-limiting by design, with 1,725 and 3,450 being the 2 norms.
And what makes you think that they would run any slower (more than 1 percent?) with the blade and belt attached?
Steam and internal combustion engines are the only power plants which really need loads (flywheels, etc.) AFAIK.

There's a whole lot more moving mass changing directions in an auto engine, suh.
-- 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
On Sun, 08 Nov 2009 08:51:42 -0800, Larry Jaques

The unloaded limit would be the synchronous speed (1800 or 3600). An induction motor can't turn faster than the AC line feeding it. When loaded fully the motor "slips" to 1725/3450, or whatever is on its plate.

Note that a saw turning a blade is not fully loaded. In fact it takes very little power to just turn the blade. Hogging out a 3/4" wide 2" deep dado in Oak takes a little more.

The flywheel, in this case, is only needed to force rotation to the next cycle, not as a governor. That is, to maintain rotation not to maintain integrity. ;-) A steam (or nuke) power plant and turbine generator are better examples.

A car has a whole lot wider RPM range than a table saw, too.
Add pictures here
<% if( /^image/.test(type) ){ %>
<% } %>
<%-name%>
Add image file
Upload
On Sat, 07 Nov 2009 23:13:52 -0500, the infamous snipped-for-privacy@teksavvy.com scrawled the following:

Hmm, "damage the motor"?!? I doubt 'er.
And how -else- would you discern whether it was the motor/pulley combo or the arbor/blade end which was bad when troubleshooting or tuning, eh? I wouldn't hesitate at all in running any woodworking machine motor alone, with or without a pulley, even.
Unless you have seen warnings on specific combos and can refer us to them, I wouldn't worry Christopher about it. I know of no such warnings on any U.S., Taiwanese, Japanese or Chinese machines from any century.
Thinking back, I do seem to recall some toys with universal motors on them which would blow themselves up with no load, but nothing in the tool area comes to mind.
Got cites?
-- 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. That's a good way to rule out some sort of motor mount problem.
--

-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
On Sat, 7 Nov 2009 19:59:05 -0800, "Christopher Glaeser"

Table saws (real ones anyway ;) use induction motors. Unloaded they'll spin only a few RPM faster than a loaded motor so it's not going to hurt a thing to run it unloaded. The motor doesn't require the load for cooling (as a fan might) so heat isn't an issue either. Go for it.
Add pictures here
<% if( /^image/.test(type) ){ %>
<% } %>
<%-name%>
Add image file
Upload

Thanks. It's running smooth with the new belt, but was curious to observe without the belt.
Best, Christopher
Add pictures here
<% if( /^image/.test(type) ){ %>
<% } %>
<%-name%>
Add image file
Upload
dpb wrote:

I think it certainly could have something to do the with manufacture/material of different belts and their intended purpose.
Someone else mention automotive belts being designed for tighter turns and faster speeds.
Just thinking out loud here, but I could see a belt that is reinforced with steel being more prone to developing kinks than one reinforced with fiberglass, for example.
--

-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
-MIKE- wrote:

I'm a believer in Gates which is, afaiaa(ware) what everything in the shop is (as is most everything on everything from the passenger cars to the largest tractors/combine/field equipment (JD-branded stuff is also afaik). Replacements for shop stuff are replacement-sized at NAPA which carries Gates as well as store brand (which I don't know what theirs is; I tend to pay the extra dollar there altho tend to use housebrand for most anything else--seems as good as any other).
I don't know who Delta or others use; it could be a problem there of trying to hold down cost too much, perhaps. I also don't have a piece of ww'ing stationary equipment that's much under 30, either... :) In fact, thinking, the Model 66 is the last new piece I have--the more recently acquired shaper is an old Walker-Turner from an ODU cabinet shop auction and the big jointer I found at a TVA surplus sale (held at a TN nuclear site but they had hauled stuff in from all over the TVA system plus a lot of other federal sites including a bunch of military shops) is unknown vintage but has to be WW-II era at newest. It does have lubricated bearings (not sealed, but not poured, either, so isn't truly ancient).
--

--

Add pictures here
<% if( /^image/.test(type) ){ %>
<% } %>
<%-name%>
Add image file
Upload
dpb wrote:

Ditto, except most of my belts are 50 or so years old. I put a new belt on my jointer when I built a new cabinet for my Tsaw/Jointer and needed a different length belt. I went to an auto parts store for a fan belt and when he asked what car it was for, and I told him, he said I needed a machine rated belt, and sold me a bit heavier belt? I wasn't too concerned. The new belt certainly was stiffer than all my old belts. They tend to loosen up bit after billions of revolutions....
--
Jack
Got Change: General Motors =====> Government Motors!
  Click to see the full signature.
Add pictures here
<% if( /^image/.test(type) ){ %>
<% } %>
<%-name%>
Add image file
Upload

Heed the advice given elsewhere in responses to your question and invest in a link belt. It makes a world of difference - less vibration, less noise, better cut (IMHO). HFT sells them and sent out a 15% off coupon that makes them the best buy!
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.