[anglin]

All,

I installed the Fenner "Power Link Plus" 3/8" spindle drive belt last night and ran some back to back tests which I recorded on video. The purpose was to measure vibration, but I decided to video them for posterity. I'm glad I did because I was shocked at how much louder then Fenner belt was than the OEM Tormach belt. This is exactly the opposite of what I've been seen about the belts here. I've condensed the video testing into a short video and put it on Youtube.

http://youtu.be/J85yuYExBXs

I have confirmed that the arrows marked on the outside of the belt are correct with the direction of spindle rotation. The spindle test was run in increasing and decreasing 1000 rpm increments from 1000 to 5000 rpm. I've got a separate project regarding spindle vibration going, so that's what the cell phone with accelerometer application was doing. This belt test is tied in with that test, but the noise was loud enough to distract me from that portion of the project for now.

Do I have too much tension on the belt? It's so much louder than the OEM belt that I'm inclined to remove it. Does the belt need to run in? I haven't read anything here that indicates that it does. Input?

Thanks.

[kevinro]

I have never been very impressed by the Fenner belting. I also bought one, based on a recommendation here, and found it to be irritating to listen to so I took it off. I assumed I had done something wrong, but your results are about the same as mine.

[GLCarlson]

Me, too. I use the Fenner on wood shop equipment and am generally happy with it, but on the Tormach, it's definitely noisier. Haven't seen an effect on cut quality yet, and having an adjustable belt size to fit my shopbuilt PDB mod is handy. Overall, it's OK, but less than I expected from reviews. For now, it stays.

[mike sr1]

The first one is the loudest, the second is quieter?? I use one on mine and like it fine. It does make a whirring noise but it helps with the vibration. Loosen it up some and check it again, they are really noisy if its too tight. I also hear the noise mine used to make before I balanced the fan, motor and spindle pulleys.
The belt will stretch and can be over tightened easily, I thought mine would slip but there is no evidence of that so far.

[tbaker2500]

That's been what I've found, too. I think what it happening, is air is being squeezed through the holes on the belt, chopping the air.

[mike sr1]

I went thru mine and balanced everything, it just makes a whirring noise that I can talk over at 4000 plus, at 5140 I have to raise my voice slightly.

I did install the pdb friday and the spindle nut isnt balanced to my liking yet which makes it a bit more noisy than it was.

[anglin]

The first one is the loudest, the second is quieter??

That's an artifact of the sound normalizing routine in the camera I recorded this video with. The Fenner belt is *definitely* louder.

I use one on mine and like it fine. It does make a whirring noise but it helps with the vibration.

That's exactly what I'm in the process of measuring with the accelerometer. I've got the data on the PC and I'll probably be spending some time on the data analysis tonight.

Loosen it up some and check it again, they are really noisy if its too tight.

I think that's part of the problem. I tightened it, uh, vigorously. I've tested it with the belt looser, but just at 1000 rpm, not with the test cycle like the video shows, so I don't really have any idea whether it actually improved the noise at all. I think I discovered a bearing problem when I did this secondary test earlier today. I'm in the process of dropping the spindle cartridge out so I can check the condition of the bearings and lubricate. I had a part come loose recently while it was being cut and it came clear of the tool and then went back into it. It just knocked the corners off the end mill, so I didn't think it was that big of a problem at the time, but now I don't know. Sounds like the a bearing might have liberated part of one of the rolling elements or there was some spalling of a race. I'll know soon.