FTFC’25 MS Design SR - 71 Blackbird by Houndpup Rc

[Houndpup Rc]

Okay, so I have never designed anything before so no promises that this will work out but what's the harm in trying!!! (IF I do get it designed it will fly or I will die trying! lol)

 

[LitterBug]

Can I have A-12 and M-12 variants please?

 

[Mr Man]

Can I have A-12 and M-12 variants please?

Just a nose change and some ventral fins, correct?

 

[Houndpup Rc]

So The first crook is is it possible to form that much foam backward....This will probably be "Expert" build skill level.

 

[Houndpup Rc]

There! Got my first former done!

 

[Burnhard]

So The first crook is is it possible to form that much foam backward....This will probably be "Expert" build skill level.

If you remove the paper from both sides of the foam, that should be no problem. Once you are done you can skin it with a new layer of paper.

 

[Houndpup Rc]

If you remove the paper from both sides of the foam, that should be no problem. Once you are done you can skin it with a new layer of paper.

Yes.....But that will make it weaker.....maybe a heat gun on the back to help make the foam stretch. I will have to experiment both ways. Thanks for that idea! (More ideas welcome!)

 

[Burnhard]

Yes.....But that will make it weaker.....maybe a heat gun on the back to help make the foam stretch. I will have to experiment both ways. Thanks for that idea! (More ideas welcome!)

Hence the idea to add back the paper later. Good luck with the heat gun. My foam never liked that.

 

[Houndpup Rc]

Hence the idea to add back the paper later. Good luck with the heat gun. My foam never liked that.

Maybe a LOT of elbow grease!! LOL

 

[noahangel11]

I did my SR-71 with fillets instead of trying to bend foam backwards. It worked out well

 

[Mr Man]

If you remove the paper from both sides of the foam, that should be no problem. Once you are done you can skin it with a new layer of paper.

Yes.....But that will make it weaker.....maybe a heat gun on the back to help make the foam stretch. I will have to experiment both ways. Thanks for that idea! (More ideas welcome!)

Maybe forget about adding paper at all, just add some extra reinforcement and you should be good. And be a whole lot lighter too.

 

[Houndpup Rc]

Maybe forget about adding paper at all, just add some extra reinforcement and you should be good. And be a whole lot lighter too.

Maybe remove all paper and Minwax it to give it a smooth finish!

 

[Houndpup Rc]

I did my SR-71 with fillets instead of trying to bend foam backwards. It worked out well

Looks great! I am trying to going more for the Master series look. (Not to mention that this is a MS design challenge)

 

[Houndpup Rc]

Some guidance:
1: EDF size and (3s 4s,6s), how long are you going to fly it, weight of all electronics including approx of plane stuff, determines the area of plane. You also need to place everything in location(do you need LG?) so balance of CG, battery's and location of EDF's will blend into shape.
Where CG of your shape? Are you putting spikes in inlet of duct or it doesn't need it?

So yeah, that leads to what I have been wondering.....How do you figure out where your CG is? I think I will be doing this one around 2306 motors/50 or 60mm edfs.

 

[Mr Man]

So yeah, that leads to what I have been wondering.....How do you figure out where your CG is? I think I will be doing this one around 2306 motors/50 or 60mm edfs.

Hmm, I’ve heard of cg calculator’s before. Or just a good ol‘ fashioned glide test can work too.

 

[Houndpup Rc]

Hmm, I’ve heard of cg calculator’s before. Or just a good ol‘ fashioned glide test can work too.

Well, I need to know where to put the battery box.......roughly

 

[Mr Man]

Well, I need to know where to put the battery box.......roughly

Cg should be near the front of the nacelles.

 

[Houndpup Rc]

Cg should be near the front of the nacelles.

Okay thanks!

 

[Houndpup Rc]

I have a cool idea for the battery hatch!.......I have to think on it to see if it will work though...

 

[Houndpup Rc]

Getting some good progress tonight!