Not sure if this is an edf or a ducted prop project, but for a while Ive been thinking about this rather radical 1970's design as a foamie. This delta winged, shrouded fan plane was built by Rohr as a direct competitor to Cessna's dominance of the small plane market. Financial troubles eleswhere in Rohr meant that it got cancelled before it went into production.

From the little Ive found though it appeared to fly well, and now Ive scaled up a 3 view for a 36" span depron version. The wing span resulted from scaling the duct for a suitable prop.

I considered making it a KF wing, but in the end Ive gone for simple 6mm plate wing to replace the original symetrical one.

So far Ive cut out the wing and much of the basic fusalage shape. Im waiting delivery of the UH HXT28-26-CQ 1300Kv Brushless Outrunner that will be fitted with a 7x4 prop inside the duct and hopefully this will arrive this week and then progress can continue

Richard

Edit after posting this was the piece that got me intersted in this plane as a foamie

http://massflow.archivale.com/2_175.htm

Different and interesting, hope it works out for you.

This is cool, you gonna draw up some plans?

Some more pictures and info - ROHR 2-175

Originally Posted by Beemus

This is cool, you gonna draw up some plans?

Yes of course - I usually like to complete a prototype before publishing just in case there are errors - or it doesnt fly!

Richard

Originally Posted by eflightray

Some more pictures and info - ROHR 2-175

Thanks - I found that one a few days ago

Richard

Originally Posted by RJPIoW

Yes of course - I usually like to complete a prototype before publishing just in case there are errors - or it doesnt fly!

Richard

Sweet! This looks like a neat little plane. With the right motor it could be quite a screamer!! I just added this thread to my subscribe list!

Originally Posted by Beemus

Sweet! This looks like a neat little plane. With the right motor it could be quite a screamer!! I just added this thread to my subscribe list!

Ive planned it around a 7" prop. The duct is 7 1/4" ID which is scale

The motor Ive chosen from United Hobbies was about the best thrust I could find with a 7" prop

Model: HXT28-26-CQ Kv: 1300
Thrust: ~500g ESC Required: 18A
Weight: 33g
Suggested Prop: 3cell:7x4.

Ill fit a lightweight 18A Esc and use a 1000mah 20C LiPo with two 8gm servos on the elevons and a 4.3gm on rudder.

Just working out the likely AUW - but I need the motor to build any more - it was shipped a week ago .......

Richard

The motor arrived and Ive fitted it. A few photos attached to show progress so far. Hope to have a reasonable plan ready soon.

Richard

More progress - hopefully maiden flight this weekend

Richard

I am loving the wheel housings! How are you going to keep the duct from warping during flight? I mean, how will you stiffen the foam ring, or are you going to try it as is first?

Cool. I asked about this a while back and got "it won't work" from RCG members. I kept at it and found that using an actual fan from a ducted fan or even using 2 props (4blade) made quite a difference in speed. Couldn't find that one prop that would give both speed and thrust. 2 6x3's cut down to 4in spin up nicely and still make a good amount of thrust for low amps.

good luck.

BTW mine was a MIG 15 with a big ole tube for a fuse.

Originally Posted by Beemus

I am loving the wheel housings! How are you going to keep the duct from warping during flight? I mean, how will you stiffen the foam ring, or are you going to try it as is first?

Try it first was my plan, although its pretty stiff now and Im going to add a layer oor several of cross weave tape on the outside of the duct

Plan B was to add 1mm CF spokes just behind the prop.

Undercarriage now attached and fuslage sheeting being attached

Richard

Wow. Nice build you got here. Good luck on the maiden flight.

Richard,
Really interesting plane and a great looking build! Wonder if that big ol' rudder will give you any issues? Also, what are your thoughts on elevons only? Undercarriage looks too nice to land on!

Sterling