Here are plans for a profile Sukhoi Su-31 aerobatic 3D model. Like my other designs, it features the same type of simple tabbed construction for a quick and easy build. The dimensions for slots and tabs are made for 6 mm depron.

I've marked out the slot for the motor, but you might want to adjust the slot to fit your particular motor and mount.

This is quite a large model and it is intended to be flown outdoors. Make sure to user proper reinforcements on the wing and elevator, like stiff carbon fiber rods.





Data

Wing span: 105 cm (41 inches)
Length: 98 cm (39 inches)
CoG location: 5.7 cm (2.2 inches) behind wing leading edge

Build instructions
Not available.

Plans

Plans for this model in PDF, Google Sketchup, and AutoCad formats, can be downloaded from http://rc.tomhe.net/su-31. The tiled plans are intended to be printed centered at 100 %.

Consolidated information

Consolidated information on this model is available on my website.

Great ! Loving it already
Any estimates/suggestions for weight and powerplant/propsize ?

Originally Posted by Segunda

Great ! Loving it already
Any estimates/suggestions for weight and powerplant/propsize ?

I believe it will weigh in somewhere around 500 g (17-18 oz.) with a 2.2 Ah battery.

I'm planning to use this motor: Above All 2813-18. 240 W with 1200 V/RPM. Perhaps with a 10x5 prop.

I forgot to include the template for the motor mount in the plans, but I have added it to the list of files for the Su-31.

WOW! That will be my next outdoor foamie!

Soon finished my EDGE 540. http://www.rcgroups.com/forums/showt...light=edge+540

/Micke

start to build it since yesterday... maybe snap few photo..

Anybody ever figure out where the CG is on this foamie?
Thanks Ray

Here's some pic on progress..

CG?
CG?
CG?
Ray

Originally Posted by raythomas

CG?
CG?
CG?
Ray

Sorry Ray, I haven't built this plane yet. My guess though, is that the CoG will be in line with, or slightly in front of the aileron hinge line.

Originally Posted by tomhe

Sorry Ray, I haven't built this plane yet. My guess though, is that the CoG will be in line with, or slightly in front of the aileron hinge line.

That seems "WAY" back doesn't it?
I wish somebody here had built and flown one of these and could tell us the
CG.
I'm dying to build one, but won't cut mine out yet till I hear some flight reports.
Thanks Ray

Got busy a bit now.. but the plane already glued well and it only wait for electronics and motor.. plus time to fly.. hahah

I'm working on a 3D bipe right now, but this will be on the to do list next! I have a 3D su-29, but I'm new to 3D flying so I would rather crash one I can rebuild rather than buy parts to fix!

I Just got done building this plane. (Cut out the foam and glued together)

Then I realized, there is no manual, I was looking for the CG as well lol.

I guess, once I get it all up I will be the test pilot

I'm going to be running a 1800 mah, 2200kv and not sure on which prop yet.

I'll post pics soon.

Looks nice, It has a long tail moment, with very large control surfaces on the tail. The long tail will make it stable. The large surfaces wil make it responsive. A conservative cg at 25% of root chord with lots of throw on the elevator and rudder with 40% expo would be where I would start. This would be on the nose heavy side IMHO. The nose is on the longish side for a foamy, so I would leave plenty of room to move the batt back. I believe the neutral cg will be closer to 30%, but 25% will be a safe starting point. That motor and battery are on the heavy side for un reinforced 6mm depron, so you may want to beef up the nose a bit. It's nice to finally see Su-31 3 views, I've been looking all over the web with no luck. Until now the best I've found was a front and top view, with no side view. IMHO the long moments will favor smooth pattern type flying with good wind tolerance. I bet it will roll like it's on a string. Nice looking plane, good luck.

Jeff