Power Station vibration tamed!

[dusty]

I think that I have a rough dimensioned sketch of the brackets around here somewhere. I'll see if I can find it. I'm working on learning basic Sketchup skills, so perhaps I could produce a decent drawing -- it would be good Sketchup practice in any case.

I don't have the right equipment to make the brackets efficiently, so it was pretty time-consuming. But it would be child's play for a fabrication house. They'd use CNC machinery cut the bracket outlines out of heavy sheet metal, and also to put in the holes. Then they'd form a 90 degree bend. I'd estimate the cost per bracket at less than $5, but only after paying several hundred dollars in setup charges.

This could me a money-making opportunity for the Mother Ship. Improve the product at low cost, and also sell stiffener upgrade kits to the installed base. The exact same business model as their planer dust-collector upgrade, with which I was very pleased.

So anyhow, I'll try to get a decent drawing and hardware list posted here, and then maybe someone can make another prototype or two. If the results are as good as mine were, perhaps someone will want to make them for resale.

It could also be a big disappointment. I am not certain that we all have the "same noise" problem. Yes, the Power Station is inherently noisy but I have two and they do not rattle at all the same. Furthermore, if simple vibration was the universal source of noise, that noise could be altered by just clamping a piece of wood or steel across the top of the stand.

I just did that with mine (which is very noisy) but it changed the noise level not one little bit.

You have me curious, however, I am going to tinker a bit when I get the time and this will not be low on my list of priorities. I am going to remove the Power Station transmission from the stand and run it (bolted to my work bench) to see how much of the noise comes from within the transmission.

[dusty]

Outstanding fix Dennis! I have a power station that makes the racket. It seemed to be a resonance thing but never investigated. I wonder if aluminum angle purchased at the box would work? Not nearly as heavy duty but if changing the resonance point is all that is needed it seems the aluminum angle would also do that and could be machined a little better.

If you can workup a Sketchup drawing with dimensions I will give the aluminum a go. Will give me the opportunity to lube my motor as well.

Thanks
Jack

If you do this, Jack, I am real anxious to hear about the results.

[BuckeyeDennis]

Outstanding fix Dennis! I have a power station that makes the racket. It seemed to be a resonance thing but never investigated. I wonder if aluminum angle purchased at the box would work? Not nearly as heavy duty but if changing the resonance point is all that is needed it seems the aluminum angle would also do that and could be machined a little better.

If you can workup a Sketchup drawing with dimensions I will give the aluminum a go. Will give me the opportunity to lube my motor as well.

Thanks
Jack

You've got a deal. This weekend was crazy, what with my daughter's high school graduation, her boyfriend's Eagle Scout ceremony, doing tons of home landscape maintenance for the upcoming graduation party, and lastly scoring a very nice Ringmaster 730 off of Craigslist for the whopping sum of $20! But that's a whole different story.

Tomorrow is back to work, so I can finally slow down and think deep thoughts about woodworking. Well, at least during coffee breaks.

I suspect that the aluminum angle will be adequate .. its gotta be way stiffer than the stock flat sheet metal. I'll also look up the ordering info for the link belt that Bill Mayo recommended. I never did test the stiffener brackets with the original belts, so it might be that my results are due to a synergistic combination of the link belts and stiffener brackets.

[BuckeyeDennis]

It could also be a big disappointment. I am not certain that we all have the "same noise" problem. Yes, the Power Station is inherently noisy but I have two and they do not rattle at all the same. Furthermore, if simple vibration was the universal source of noise, that noise could be altered by just clamping a piece of wood or steel across the top of the stand.

I just did that with mine (which is very noisy) but it changed the noise level not one little bit.

You have me curious, however, I am going to tinker a bit when I get the time and this will not be low on my list of priorities. I am going to remove the Power Station transmission from the stand and run it (bolted to my work bench) to see how much of the noise comes from within the transmission.

And I'm curious to see how your bench-mount experiment works out. If nothing can move, no acoustic noise can be generated. That experiment should help determine what is moving.

I think we can all agree that a sound generator requires an excitation-energy source. In this case, the obvious suspects are the drive belts, although a bad pulley or motor shaft runout could also be the culprits.

On my Power Station, the headstock (a.k.a. variator) only rattles when the speed-adjust clamp, or whatever that large wing-nut thing is called, is loose. When tight, it clamps the pulley slide (ways?) nicely so that it cannot rattle. In the Youtube video, I cheated a smidge by loosening it only just enough to let the speed lever move. Had I loosened any further, the variator slide would have rattled while changing speeds.

But anyway, on mine, the variator components do not rattle when the clamp is snug. So you may be fighting an issue that I have not had to deal with. Pre-stiffening, however, my sheet-metal belt guard rattled like crazy when the structure hit a resonant frequency.

In any case, I'm very glad that you're on board.

[claimdude]

Dennis,

I checked mine last night and my belt cover shakes considerably. At times it reaches resonancy and then makes the noise I and referring to. I also found that I can apply slight pressure to the motor head housing and it quiets down some which indicates to me it should take much to change the level at which the resonance occurs. Mine has the original SS belt.

Jack

And I'm curious to see how your bench-mount experiment works out. If nothing can move, no acoustic noise can be generated. That experiment should help determine what is moving.

I think we can all agree that a sound generator requires an excitation-energy source. In this case, the obvious suspects are the drive belts, although a bad pulley or motor shaft runout could also be the culprits.

On my Power Station, the headstock (a.k.a. variator) only rattles when the speed-adjust clamp, or whatever that large wing-nut thing is called, is loose. When tight, it clamps the pulley slide (ways?) nicely so that it cannot rattle. In the Youtube video, I cheated a smidge by loosening it only just enough to let the speed lever move. Had I loosened any further, the variator slide would have rattled while changing speeds.

But anyway, on mine, the variator components do not rattle when the clamp is snug. So you may be fighting an issue that I have not had to deal with. Pre-stiffening, however, my sheet-metal belt guard rattled like crazy when the structure hit a resonant frequency.

In any case, I'm very glad that you're on board.

[dusty]

Jack, if you suspect the belt cover why not check with the cover removed. What sort of noise level do you have without the belt cover; that will quantify the covers' contribution.
.

[JPG]

Tightening the speed control lever reduces 'rattle', but internally the slide which the variator shaft slides on is floppy. The shaft will wobble front to rear and the slide gear rack presses on the control spur gear by belt pressure and gravity alone. The belt tension will vary due to set in the belts and the motor belt is pulling down while the output shaft belt is pulling up. Add to that the center(movable sheave) is loose also. I believe this is where most of the 'rattling' comes from.

Add base 'plate' flexing and belt cover singing and we have a multi voice acoustic generator.

I have attempted to reduce the slide flopping by shimming.

As Dusty has said re belt conditioning(reduces belt set) 'it helps but . . .' .

On mine which was essentially in storage by the PO the belt conditioning really helped. I have not been inside it yet so I do not know if it is sloppy. My first one has new slide etc. - minimal improvement!

P.S. That motor mount sucks! I added fender washers between the screw head and top nut and that reduced flexing. Angle iron has to be an improvement.

[BuckeyeDennis]

Tightening the speed control lever reduces 'rattle', but internally the slide which the variator shaft slides on is floppy. The shaft will wobble front to rear and the slide gear rack presses on the control spur gear by belt pressure and gravity alone. The belt tension will vary due to set in the belts and the motor belt is pulling down while the output shaft belt is pulling up. Add to that the center(movable sheave) is loose also. I believe this is where most of the 'rattling' comes from.

Add base 'plate' flexing and belt cover singing and we have a multi voice acoustic generator.

I have attempted to reduce the slide flopping by shimming.

As Dusty has said re belt conditioning(reduces belt set) 'it helps but . . .' .

On mine which was essentially in storage by the PO the belt conditioning really helped. I have not been inside it yet so I do not know if it is sloppy. My first one has new slide etc. - minimal improvement!

P.S. That motor mount sucks! I added fender washers between the screw head and top nut and that reduced flexing. Angle iron has to be an improvement.

It's been quite a while since I messed with it, but IIRC the slide on mine locks down tight, and does not contribute to the rattle. If so, that could be a key difference. I had it completely disassembled when "enhancing", so there's also a chance that I reassembled it in a non-standard way. I'll check it tonight and let you know what I find.

[JPG]

It's been quite a while since I messed with it, but IIRC the slide on mine locks down tight, and does not contribute to the rattle. If so, that could be a key difference. I had it completely disassembled when "enhancing", so there's also a chance that I reassembled it in a non-standard way. I'll check it tonight and let you know what I find.

Run it with the cover off. The shaft flops from front to rear, The slide 'tenon' is smaller than the outer rails. I have only observed the first one, and it was 'reassembled' by the po from a pile of parts. Extra/missing parts etc.

Our favorite SS CS person refers to the slide parts as 'very sloppy'. Gotta give him credit, the new parts did not improve things much.

[billmayo]

I found a large 1/2" thick aluminum plate bolted in many places under the platform really helped eliminate flexing and noise on my Mark V Power Station.