Heinkel P.1076 Build

[saiga556]

Heinkel P.1076.

Build will be non-swappable and built about the same size as the ft mustang. Powered by a suppo 2217/7(for now) and a hurc 30 amp esc. Plan to spin an APC 8x6 prop unless someone can suggest something that will pull faster without getting everything too hot.

 

[saiga556]

Prototype wing:

8 degrees of forward sweep and some dihedral (whatever looked good). I used a tapered spare(16mm - 7mm) and I like the way the wings taper down.


Here it is compared to my beat up FT Mustang

Definitely less wing area. I think she's gonna want to fly fast. The root and tip of the wing were both stretched by 25mm so I could gain some more wing area. The wing cube loading with the scale measurements was not looking good, I think I might still be pushing it. Lets hope I can keep the weight down.

Any suggestions about dealing with forward swept wings or other stuff are very welcome.

 

[earthsciteach]

Cool build! You might be able to spin a 9" prop with that motor. Not positive, though.

 

[Foam Addict]

FSW are fun to work with. Be forewarned, they often need really big vertical stabilizers to fly well in our scales, and suffer from some odd yaw coupling with large aileron throws. Still, I see no reason why this won't fly well as planned. It looks like a sound design.

 

[saiga556]

You might be able to spin a 9" prop with that motor

I have been running several different 9" props with that motor on my ft mustang for sometime now with no problems.

I would like to get a higher kv motor for this plane and use a smaller prop maybe somewhere around 1500-1700kv with a 7x6 prop?

 

[willsonman]

Your FSW CG calculation will be the normal method. Typically 25-33% MAC (mean aerodynamic chord). If your tail planes come to be further toward the wing then that may push forward. I would HIGHLY suggest you make a box spar. FSW design is a tricky devil. Since they are designed to have the root stall at the tame point as the tip there tends to be a lot of aerodynamic twisting forces on the wing. With the "FT under camber tip" you will highly exaggerate this effect. While it will prevent tip stalls in normal wings I think it may lend to more abrupt stalls on your landing approaches. If it were me I would not do the under cambered tips first. Those flat sheets of foam are just begging to be warped and cause instability.

 

[saiga556]

With the "FT under camber tip" you will highly exaggerate this effect. While it will prevent tip stalls in normal wings I think it may lend to more abrupt stalls on your landing approaches.

I wondered about that. I built the wing with 50mm of under camber. I plan to make some pieces that are easily attached an removeable to go in the under cambered space. This being a prototype wing I can then test which is best. That is part of the reason that I moved my servos inboard to almost the inside of the ailerons.

 

[willsonman]

You may just do a glide test before you put a real motor in. Just see how it glides. If it abruptly plops when it loses airspeed you will know.

 

[saiga556]

Permanent motor mount. I should have a decent amount of room in this fuselage. Getting rid of the power pod just opens up so many possibilities.

 

[saiga556]

Mocked up all the pieces. That vertical stabilizer looks huge without the turtle deck.



I think it's looking pretty good. It's really turning out much better than I thought it would. I have used no real prior planning for this build, just taking measurements off of a 3 view and hoping for the best. I did try making a set of plans using sketchup but decided That it would be easier to grab a ruler, pencil, and protractor. So far designing on the fly is working out.

Keep in mind many of the details have been left out. This is just a test bed to see how the wing performs. If it works well I will try to make a more detailed version.

 

[saiga556]

size comparison with FT Mustang






Its definitley smaller and will be much lighter because i'm not going to tape it all up like the mustang. My beef motor has been running an APC 9x6E prop just fine on the mustang. I'm thinking about trying out this GWS HD 9X7.5 prop that I have laying here.Im going to be running a 30A ESC but I have a 35A if this combo pulls to many amps.

Anybody have any idea how many amps the suppo 2217/7 1250kv with the 9X7.5 prop will pull?

 

[Foam Addict]

in a word, too much, around 30 amps. I'd recommend the GWS 9x5 HD for this build, those are some of my favorite props, and would draw around 22.5 amps, right on the limit of the motor, but still very usable. The other one would probably smoke the motor after a few flights.

 

[saiga556]

Maybe I need to step up to the Suppo 2814/6 1400kv motor. With a n 8x4 prop I think it would pull around 25 amps which would be acceptable with either esc I have. Would the plane be faster than the motor I have with a 9x6 prop?

If I buy a new motor then I will have 2 beef motors that can go into a p-38 build or something. Win win.

I would like to use either the 30a or the 35a esc I already have. Any better motor suggestions? I prefer to order from somewhere like altitude hobbies or headsuprc.

 

[Foam Addict]

I'd still go with the original motor to start with. It will have more thrust to pull you out of trouble.
That being said, my mustangs fly excellently on a 1400kv 2217 with a GWS 9x5 cut down to 7.5x5. Maybe a higher KV motor would be a good upgrade.

 

[saiga556]

my mustangs fly excellently on a 1400kv 2217 with a GWS 9x5 cut down to 7.5x5. Maybe a higher KV motor would be a good upgrade

If I cut down the prop will it give me a noticeable increase in speed with less thrust or will it just be the same speed with less strain on the motor/esc?

 

[Foam Addict]

It would give a higher speed in theory with a much lower load on the motor. As the motor is "unloaded", its RPM increases, so the same pitch will yield a higher pitch speed.

 

[saiga556]

I need to get a tachometer and a watt meter. I have seen some cheap watt meters but does anybody have a suggestion on a cheap tach?

 

[saiga556]

Made some progress. Remade the vertical stabilizer and glued some things up also got the joint of the wings taped up along with the leading edge. Basically ready to add the formers and cut my battery hatch as well as installing the elevator servo.



Sorry if you don't like lots of pictures but I do. I hate reading threads with no pics

 

[Christopher14]

Sorry if you don't like lots of pictures but I do. I hate reading threads with no pics

I like lots of pictures, great job.

 

[saiga556]

A start to the turtle deck.


Battery hatch removed.


The hatch itself.


I am trying to figure out how to make the canopy. The aft side of said canopy is right at the back of the battery hatch. The former that butts up to the hatch is taller by 6mm. Some tricky folding is going to have to go down.

Any ideas? I don't want a clear canopy.