Return-Path: Received: from sccrmhc11.comcast.net ([204.127.202.55] verified) by logan.com (CommuniGate Pro SMTP 4.2.5) with ESMTP id 564381 for flyrotary@lancaironline.net; Sun, 12 Dec 2004 10:54:53 -0500 Received-SPF: none receiver=logan.com; client-ip=204.127.202.55; envelope-from=kenpowell@comcast.net Received: from 204.127.205.142 (sccrwbc58.attbi.com[204.127.205.158]) by comcast.net (sccrmhc11) with SMTP id <2004121215543801100f01r4e>; Sun, 12 Dec 2004 15:54:38 +0000 Received: from [166.102.160.133] by 204.127.205.142; Sun, 12 Dec 2004 15:54:37 +0000 From: kenpowell@comcast.net To: "Rotary motors in aircraft" Subject: chain drive for Kolb Date: Sun, 12 Dec 2004 15:54:37 +0000 Message-Id: <121220041554.27145.41BC69BC00031AF400006A09220588636004040A99019F020A05@comcast.net> X-Mailer: AT&T Message Center Version 1 (Nov 22 2004) X-Authenticated-Sender: a2VucG93ZWxsQGNvbWNhc3QubmV0 MIME-Version: 1.0 Content-Type: multipart/alternative; boundary="NextPart_Webmail_9m3u9jl4l_27145_1102866877_0" --NextPart_Webmail_9m3u9jl4l_27145_1102866877_0 Content-Type: text/plain Content-Transfer-Encoding: 8bit You guys know that I am not an engineer -with that being said take this with a grain of salt. I was looking at buiding a chain drive (motorcycle chain) for my minimax (40HP Kawasaki) and found that chain does not like high centrifugal loads. When you use a large enough crank/drive sprocket (13 -15 tooth) to minimize the turn angle you end up with a fairly large driven sprocket (39 - 45 teeth); thus the chain loads around the larger sprocket are suprisingly large. I no longer have the calcs or I would share them. I would love to find out that I made a mistake though. Remember that a motorcycle has a primary gear reduction to reduce this RPM before the final drive. It is intersting that some motorcles use a chain primary reduction - however, on my Maico dirt bikes these were somewhat short lived (200 to 300 hours). Anyway, please run the numbers before doing this. Lastly, I suspect that this would work OK with a short chain that was changed often (only experimenting will determine how often) and I may yet attempt this if more research were to show a higher chance of success but my initial research was not promising. Ken Powell -------------- Original message -------------- He uses a racing motorcycle chain up to a propeller shaft in pillow block bearings up where the engine is supposed to be. Charlie Thanks Charlie. For some reason, I never thought of that, but it does seem easy, and I agree with the 3:1 ratio. I'd sure hate to think of that chain coming off and going through the prop though. I mentioned the chain to my wife, and she reminded me of all those Junkyard Wars episodes we've seen. On that show, anyone who uses a chain to drive anything is destined to lose. I would hope that I could exceed the average Junkyard Wars standard of quality though :-) Thanks, Rusty (something else to think about) --NextPart_Webmail_9m3u9jl4l_27145_1102866877_0 Content-Type: text/html Content-Transfer-Encoding: 8bit

You guys know that I am not an engineer -with that being said take this with a grain of salt. I was looking at buiding a chain drive (motorcycle chain) for my minimax (40HP Kawasaki) and found that chain does not like high centrifugal loads. When you use a large enough crank/drive sprocket (13 -15 tooth) to minimize the turn angle you end up with a fairly large driven sprocket (39 - 45 teeth); thus the chain loads around the larger sprocket are suprisingly large. I no longer have the calcs or I would share them. I would love to find out that I made a mistake though. Remember that a motorcycle has a primary gear reduction to reduce this RPM before the final drive. It is intersting that some motorcles use a chain primary reduction - however, on my Maico dirt bikes these were somewhat short lived (200 to 300 hours). Anyway, please run the numbers before doing this. Lastly, I suspect that this would work OK with a short chain that was changed often (only experimenting will determine how often) and I may yet attempt this if more research were to show a higher chance of success but my initial research was not promising.

Ken Powell

-------------- Original message --------------

He uses a racing motorcycle chain up to a propeller shaft in pillow block bearings up
where the engine is supposed to be.

Charlie

Thanks Charlie. For some reason, I never thought of that, but it does seem easy, and I agree with the 3:1 ratio. I'd sure hate to think of that chain coming off and going through the prop though.

I mentioned the chain to my wife, and she reminded me of all those Junkyard Wars episodes we've seen. On that show, anyone who uses a chain to drive anything is destined to lose. I would hope that I could exceed the average Junkyard Wars standard of quality though :-)

Thanks,

Rusty (something else to think about)

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