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General control line discussion => Open Forum => Topic started by: frank williams on March 21, 2012, 12:47:03 PM

Title: Carbon Fiber Pusher Prop 13x4.5 Available
Post by: frank williams on March 21, 2012, 12:47:03 PM

All,

Mejzlik Modellbau in the Czech Republic has produced a carbon fiber PUSHER prop (13x4.5).  The blades are extremely thin, under-chambered, stiff, and accurately pitched.  The prop weight is very light, ~25 grams.  The finish of the props is superb.

I am selling the prop for $40.00 each.  There is a $5.00 mailing charge for 1-4 props (US only).  PayPal is the preferred method of payment.  Lonestar_77062@Yahoo.com.

The fact that the blades are stiff and do not “flex-in” extra pitch when loaded, means that the required RPM for typical stunt flight is slightly higher than what was used for the thin 4.5” pitch props in plastic.  Typically the RPM required is about 10.1K to 10.3K.   In my opinion, the flight performance with these props at this pitch is superior.  The props can be re-pitched by the user for lower RPM’s if desired.  These props have a robust hub area for both electric and IC engines.

Order at lonestar_77062@yahoo.com while supply lasts,
Frank Williams

Title: Re: Carbon Fiber Pusher Prop 13x4.5 Available
Post by: Joe Yau on March 21, 2012, 07:45:48 PM

Hi Frank,

Do they also make a 12" or 13" CF 3-blade pusher?

Title: Re: Carbon Fiber Pusher Prop 13x4.5 Available
Post by: frank williams on March 21, 2012, 09:17:15 PM

Hi Joe,
Not yet ..... they wanted to see the response to a two blade pusher before they tried a 3 blader.  I plan to check with them again soon.  What would be the best diameter and pitch for a three blade pusher?
Frank

Title: Re: Carbon Fiber Pusher Prop 13x4.5 Available
Post by: Tim Stagg on March 22, 2012, 06:32:28 AM

Frank,

Just sent you some money for one, cant wait to try it.

Thanks

Tim Stagg

Title: Re: Carbon Fiber Pusher Prop 13x4.5 Available
Post by: Joe Yau on March 22, 2012, 10:09:13 AM

Quote from: frank williams on March 21, 2012, 09:17:15 PM

What would be the best diameter and pitch for a three blade pusher?
Frank

I think something like a 12" X 5.5 or 5.25 3-blade might be in the ballpark.. (approx 9000rpm @ 55mph)  and some 12.5"-13"  for the 4-strokes (approx 8300rpm @ 55mph).  hard to come up with the precise pitch not knowing how efficient the prop really is, and along with the undercambered blades.   

Title: Re: Carbon Fiber Pusher Prop 13x4.5 Available
Post by: Bob Reeves on March 22, 2012, 10:44:05 AM

I would go for a few 13-5.5's, The old Stalker 3 blade 13-5.5 works well on a Saito 62 and could be trimmed a little for the 56. A reverse pitch version of it would be wonderful.

Title: Re: Carbon Fiber Pusher Prop 13x4.5 Available
Post by: James Strickland on March 23, 2012, 10:36:25 PM

Hey guys,
Please excuse my ignorance as I've never owned or even ran a 4 stroke model engine. I am mildly familiar with their construction layout though, so how do you get one to run backwards? Is the demand great enough that companies are making some reverse rotation crankshafts/ camshafts for the 4 strokers?

James

Title: Re: Carbon Fiber Pusher Prop 13x4.5 Available
Post by: Bob Reeves on March 24, 2012, 06:42:41 AM

Hi James, you need to visit the 4 stroke section..

http://stunthanger.com/smf/index.php?topic=22426.0

Also might want to check the two articles I wote on Saitos on the Gluedobbers web site.

http://www.tulsacl.com/Engines.html

Title: Re: Carbon Fiber Pusher Prop 13x4.5 Available
Post by: frank williams on March 24, 2012, 06:17:50 PM

The reverse cam is an easy mod for the 4 strokes.  Someone should try an OS VF 40 or 46 and rotating the front housing 90 deg to the left.  This yields perfect timing for reversing a two cycle engine.  Easy to do with a bolt on front end or a rear intake engine.  Just a thought.