Run in stand/dyno build.

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dwilfong

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I have seen a dyno that some one in Sweden built with a belt drive to the wheel. Thy run RS.91 on them to test.
Ever think about using a belt drive to reduce the RPM of the wheel?
 

Terry Keeley

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This one?


Yup, thought about it a lot.

A year ago, lol.

The way it starts I don't think he's using a clutch...
 

Steve White

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Thanks much, so no big issues with binding I take it.

Rudy, my Consigliere? He's the best!

A dirty picture for you Ray.

This one has been nagging me for a week or so. I gotta ask - why a hole saw over a fly cutter? I see the results look good and that speaks for itself. Even chucking it up on the lathe and boring it was an option.

You took "down and dirty" and made it work nicely. What did you lube it with? The hole saw arbors I have use drive pins so the cutter floats loosely on the threaded arbor and chatters and walks. I suppose that's the difference, having a good solid mount of the saw to the arbor?

What RPM did you use? Hole size cut?

Well done by the way.
 

Terry Keeley

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This one has been nagging me for a week or so. I gotta ask - why a hole saw over a fly cutter? I see the results look good and that speaks for itself. Even chucking it up on the lathe and boring it was an option.

You took "down and dirty" and made it work nicely. What did you lube it with? The hole saw arbors I have use drive pins so the cutter floats loosely on the threaded arbor and chatters and walks. I suppose that's the difference, having a good solid mount of the saw to the arbor?

What RPM did you use? Hole size cut?

Well done by the way.

I used it just to rough out the holes, my boring head finished them to size.

2 1/2" hole saw, slow rpm to start then sped up, lots of cutting fluid and brushing the chips outta the teeth. This one has a drill in the center to help guide it.
 

Steve White

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^^^ Rough-in, that makes sense. I was really struggling to connect the nice looking holes and fit to a hole saw hack job. :)
 

Terry Keeley

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I filled the previous hole in and added a new full width tungsten weight right at the point that the clutch engages.



Also cutting a bunch of slots in the bell housing to cool things down, lots of chatter from the 1/5 buggy guys about heat and "clutch fade".

Just for you Ray. :D

 

Brad Christy

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Terry,

Cold Air Gun

Kinda spendy, I know. But probably well worth it in the long run.

Lesser spendy options available. I found some on Ebay.

Thanks. Brad.
Titan Racing Components
BlackJack Hydros
Model Machine and Precision LLC
 
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Terry Keeley

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How the heck do distributors justify their prices?

I'm looking at a Ringspann FZ 6202 PP one way bearing, 29.39 euros on their site which is US$35.50:


I talked to the N. American distributor and they have stock but don't sell direct, here we go.

Get a quote from Motion for US$201.39. Shopping Cart

It gets better. One distributor here in Toronto (Wajax) quoted C$348.54 (US$276.26) and another (Canadian Bearings) said C$462.33 (US$366.45). :eek:

Bend over Rover!

A huge thank you to Joachim Ruess who got me one of these in Germany and is sending it over.

We are all part of an awsome community, thanks again Joachim!
 

Terry Keeley

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Just an update, I haven't given up by any means.

I'm still fighting the issue of the one-way clutch bearing slipping. I've done a bunch of reading and even talked to a couple bearing engineers and it seems that single cylinder two stroke engines are the absolute worst when it comes to this. The engineers call it "torsional vibration", this is what it looks like on an rpm plot. This is one second of engine and dyno wheel rpm while the bearing is still hooked up!




What happens is when the rpm of the motor drops below the wheel rpm the bearing lets go but when it increases back above the wheel speed the sprags in the bearing can't react fast enough and it slips.

I tried a quality German "Ringspann" bearing (6202) but it did the same as the cheapo unit. I then tried a bigger cheapo bearing (6302) and it still slipped. I've now got a German GMN 6302 to try then it's needle bearing time. For the needle bearing I'll have to make an A-2 sleeve, harden then finish grind it to spec. I owe my Consigliere big for consulting time, lol.





If none of these work I'll try to dampen the fluctuations with either this FSR type coupling I got from Dave Marles or the small Lovejoy coupling.





If none of these work I'll make a ratchet as posted before...
 
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Ken Retallick

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Terry, I had read that the one way bearings were troublesome with the fluctuating power loads that a single cylinder engine produces with each revolution, so i didnt even try one.

I built a 50mm Dia multiplate clutch pack, i think it had 5 friction plates all up. Never had any issues with it. Belleville spring clamped it together. released with a lever. Friction lining was same as used in torque converter lock-up clutches.

Easy to start engine with it released, slowly moving lever to engage clutch got the flywheel spinning with the engine. End of a run throttle back and disengage clutch at the same time. Apply brake and do another run within mere seconds!
 

Steve White

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Terry, sitting here pondering alternative solutions while waiting for dinner.

Have you considered using a collet with flex cable with a shear pin at the flywheel end?
 

Terry Keeley

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Terry, I had read that the one way bearings were troublesome with the fluctuating power loads that a single cylinder engine produces with each revolution, so i didnt even try one.

I built a 50mm Dia multiplate clutch pack, i think it had 5 friction plates all up. Never had any issues with it. Belleville spring clamped it together. released with a lever. Friction lining was same as used in torque converter lock-up clutches.

Easy to start engine with it released, slowly moving lever to engage clutch got the flywheel spinning with the engine. End of a run throttle back and disengage clutch at the same time. Apply brake and do another run within mere seconds!

A miniature Top Fuel clutch! Any chance you'd have a photo of it?

My main concern with something that's manually operated only is if the motor seizes, you'd need a shear pin in there somewhere for sure. Didn't you use a short piece of flex cable? IIRC Lohring and Mike used a 1/4" square key.


Terry, sitting here pondering alternative solutions while waiting for dinner.

Have you considered using a collet with flex cable with a shear pin at the flywheel end?

That might be another option...
 

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