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Building Tips and technical articles. => 1/2 A building. => Topic started by: John Rist on October 21, 2008, 01:49:33 PM
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I would like to build a twin engine DO 335 German fighter. It has a push pull, fore and aft motor setup. I would like to use a pair of TD 049 that will not run backwards. Can you buy a 3 bladed 1/2A pusher prop? ???
Or a 2 bladed pusher will do.
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Yes.
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Sorry for my smartalec answer, John...I thought someone else would jump in and give you a real one.
AFAIK, pusher props are still available from Cox, don't know of other brands. I have a 6x2 2-blade pusher I acquired free for nothing, I could forward it on to you since you have a more immediate need for it than I do.
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As an alternative, there are some left-hand crankshafts that were made for Tee Dees. They were popular in speed flying. Haunt E-Bay and you may get lucky!
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As an alternative, I have a left-handed crankshaft for the TD .049/.051, which might be a more flexible solution. New. $20 including shipping. PayPal or Personal Check.
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Zinger makes left hand props down to about 7 inch diameter. It does not take much effort to cut them down to 5.5 to 6 inches, do some cleanup on the airfoil shape and refinish the things with finishing resin. Do the same thing with the regular Zinger props and you will have a nice matched pair.
Where and how are you goint to mount that rear engine?
Keith
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This might help.
http://stores.ebay.com/Model-Engines-and-Parts-Warehouse_Cox-Propeller_W0QQcolZ2QQdirZQ2d1QQfsubZ200584017QQftidZ2QQtZkm
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Thanks one and all. All good stuff. I have decided to to use one of Cox product engines as the pusher on this project. It will run backwards. I will pick up a hand full of props from the EBAY site sugested by jamtx. All good stuff. H^^
Thanks!!!!
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John,
It will still be interesting to know how you plan to mount the rear engine.
Is this going to be a profile fuselage or will it have a full scale cross section? Is the engine going to be mounted mid-fuselage like the full size version, or are you going to have it mounted somehow on the tail end of the airplane. The Do 335 design represents some interesting "challenges" because that rear propeller is right behind and on the center lines of the vertical and horizontal tails.
Keith
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John,
It will still be interesting to know how you plan to mount the rear engine.
Is this going to be a profile fuselage or will it have a full scale cross section? Is the engine going to be mounted mid-fuselage like the full size version, or are you going to have it mounted somehow on the tail end of the airplane. The Do 335 design represents some interesting "challenges" because that rear propeller is right behind and on the center lines of the vertical and horizontal tails.
Keith
All TRUE on the challenge. It is 1/2 A profile. The big problem is mounting the Cox in frount of the tail and getting the prop aft of the tail. It looks like it will take a 2" extension on the prop shaft. Fortunatly I have a machinest frend with a home machine shop that should be able to fix that problem. The other problem was how to mount a Bee style Cox with its tank on the rear. The Bee runs backwards making it a good pusher. However I found a LH crank for a Madalion. That should work great with its beam mount. Just cut a square hole and drop it in, add 4 screws and done. Any way, as time goes on I will start a new thread with pictures. Should I put it in 1/2 A or scale? By the way it looks like there is a surge in Twin 1/2 a fun scale. That is why I am building a twin. I heard about it a this years Broken Arrow Stunt and Scale contest, St Louis MO. ~> #^ H^^
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Make sure you have a steel washer between the aluminum prop driver and crankcase when you setup a pusher configuration, otherwise the two aluminum pieces may gall when pushed together. I don't recall if one is standard.
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Make sure you have a steel washer between the aluminum prop driver and crankcase when you setup a pusher configuration, otherwise the two aluminum pieces may gall when pushed together. I don't recall if one is standard.
True, will do. Thanks
John Rist