david200mph

Hello speed freaks, I need a little help. I am building a 90 size pusher jet. I need a pusher prop around 10X10, 11X10, 12X10. (pitch is speed). APC only make a 10X7, 11X7 and Graupner makes an 11X8 (the most pitch I have found so far). Does anyone know of a manufacturer who makes a pusher prop with more pitch? Or, perhaps a company who can make them for me? If not I guess I will have to go with the 11X8.
Thanks
David200mph

No1pylon

Why dont you make your own maybe out of carbon fibre

david200mph

I wish I knew how to. But I dont have a clue? [&o]

hattend

My Feedback: (20)

Zinger has an 11-10 Pusher

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

Don

david200mph

Thanks Don, I really appreciate the help. My jet will really move now.

bob27s

My Feedback: (19)

Dave, what aircraft are you building ? G&P Hornet ? Something else ?

A while back Dub built a reverse-rotation SJ-120 for someone - was using it on a pusher design. Works out great that way, since you can use 'regular' rotation props - thus all the sizes you might want are available.

Bob

hattend

My Feedback: (20)

Bob,

Is it an extra cost option? If so, how much and how long do you have to wait for the modification?

Don

david200mph

You are good Bob, nice guessing! I am building the G&P sales Hornet, Dubb is building the engine as we speak. It is the BSE F.I.R.E. 90 engine with a straight bolt on header with a Macs tuned pipe. Looks like it will be tuned for an 11X10 prop slightly cut down. It should make the hornet move out fairly nice, I hope. I still have some tank issues to deal with because I dont really like the 14 OZ tank mounted at the rear next to the engine. (this will make the plane really nose heavy when the fuel is gone). I will probably put the tank on the CG and run a 2 OZ hopper tank at the engine. Do you have any suggestions on he fuel system set-up? I dont want to drill this engine for pump pressure!

David200mph

bob27s

My Feedback: (19)

Its a good plane .... flys well..... but it has a lot of drag. But once the gear is up it gathers speed and energy fairly quickly. Flys sorta like a ducted fan.

You have the right engine there. If Dub is tuning it for a clipped 11x10 (or 10x10) you will be good. Chances are you will receive it set up in the LX configuration. That APC 11x7 pusher might be the prop you want to start with - Engine will enjoy it, and you will have pleanty of power for the first few flights. Allows the engine to turn way up - which it likes. The 11x8 graupner is not bad either.

Keep in mind, the pipe will deterimine an "rpm range". Dub will identify this to you. Your prop selection will be made to keep the engine running in that range on the ground.

nah... no pump. It will drive you nuts.

Keep the main tank just aft of the CG, and the 2oz header will do the trick.

Bob

bob27s

My Feedback: (19)

Don,

Special crank or setup is usually a $15 upcharge. Would be in this case. Dub noted that he has not yet made a SJ-90L reverse crank, but it would be easy enough to do.

Bob

hattend

My Feedback: (20)

Thanks Bob,

I just bought one of the EAM Velocity ARFs with the "Firewall aft" kit. It comes with a Webra Speed 1.20 and it's good to know that there is an engine manufacturer out there who does special work to make things easier for us modelers. A reverse running engine will make prop selection so much easier.

The Velocity is a ways off in the build list but I may have to think of putting the Jett reverse 1.20 in there and putting the Webra on something else.

Cool
Thanks
Don

david200mph

Thanks Bob for the info. Its nice to know I am off in the right direction. I will keep the reverse crank option for another plane.
Im also glad this plane flys somewhat like a ducted fan. Im using it as a stepping stone to ducted fan models I am working on. I have not flown a ducted fan yet.

Thanks Again
David200mph