Gentlemen,

re: In-Line Thrust

How do model builders get the correct thrust from the rear engine? As odd as it sounds.........is the engine spinning backwards [sm=lol.gif]or is a reverse pitch prop employed? Comments? Thanks in advance.

GDJ

reverse pitch prop employed

The prop manufacturers make PUSHER PROPS

Honorary Professor

This grasshopper has searched..............................and searched...............could you please be more specific. Thanks

GDJ

http://www.zingerpropeller.com/Pusher.htm

Honorary Professor

Thankyou for your help.................cheers.

GDJ

There are two ways. Either use a reverse (lefthanded) prop, or let the engine run "backwards". Latter engines need to have the ignition pickup modified, so contact your supplier if he can do that.

There are two ways to do it with the normal RC glow engine. The first is to use a prop where the blades are pitched in the opposite direction (the reverse or left handed prop as Pe said) and the engine runs the normal way. The second way only applies to an engine where the front housing is removeable (and to some rear induction engines) when you turn the front housing 90 degrees anti-clockwise. This allows the engine to run in the reverse direction as well as it would the usual way. With this system you use a normal propellor but put it on the crankshaft backwards.

Correct me if I'm wrong Pe, but I think you were talking about large reed valved ignition engines?

Also several manufacturers, such as Fox, maybe OS sell reverse rotation crankshafts for a number of their engines. Changing the location of the ignition pick-up on an ignition engine would work on reed valve engines.

why make it so hard, everyone knows you just put the prop on backwards..







*yes, i'm kidding!*

It is best to use a reverse pitched prop on the rear engine, that way with the engines both turning in "Normal" roataion the torque cancels. If the rotation of the rear engine is reversed to use standard pitch propellors the torque is additive.

Bill.

I became interested in this design while perusing Model Airplane News', on-line plan, Double-Trouble. I wasn't immediately taken with the idea but by-chance got reading up on a full scale German WWII fighter designated the Dornier 335...........the Model Airplane News plans by Tony Newsom immediately germinated. A query to RC UNIVERSE resulted in several members replying that they had hacked kits or scratch built sport planes with spectacular results. Hmmm.....maybe something interesting here, eh? The advantages are in-your-face, ie, clean wing, low drag, little torque, etc, etc................and of course out-of-the-ordinary at the field (hee hee). Al Masters has an interesting web cite for those folks interested in how he constructed a scale, Do 335 model

http://www.wingsontheweb.com/vhangar...o335_proj.html

My ambitions are far more mundane than Al's ship (GREAT web page Al). Anyway, as always RC Universe has provided a wealth of common sense, suggestions and fellowship...........what a great tool for the enthusiast.

GDJ