Flite fest 23 barnstormer challenge p26

[FlyerInStyle]

This is for the first ‘23 barnstormer challenge. I am planning on making a p26 peashooter but add 2 scale lego mini figures from foam on the wingtips to add to the barnstorming realism. Hopefully I can install some servos for moving arms, and heads? Maybe? I got a new tx16s and want to use as many of its may channels and features as possible on this build. Looking forward to making this a reality. I will be posting progress as soon as it happens. It will be a master series style build.

 

[Ligbaer]

Cant wait to see this next year.

 

[FlyerInStyle]

Cant wait to see this next year.

I hope it will be a reality. Still deciding on a wingspan. I want something big but I still want it to fit nicely into an suv

 

[Ligbaer]

I hope it will be a reality. Still deciding on a wingspan. I want something big but I still want it to fit nicely into an suv

Maybe 1/5 scale with removable wings would be good. at this size i would'nt put to many features into the lego figures (or anything TBH) as it would add a lot of weight and be very complex and probably be hard to maintenance with having that many things go into the receiver. If you keep it simple with just the plane and then at most flaps with the lego figures static i think you would have a great flying plane.

 

[FlyerInStyle]

Maybe 1/5 scale with removable wings would be good. at this size i would'nt put to many features into the lego figures (or anything TBH) as it would add a lot of weight and be very complex and probably be hard to maintenance with having that many things go into the receiver. If you keep it simple with just the plane and then at most flaps with the lego figures static i think you would have a great flying plane.

Ok. Should work. 67” wingspan doesn’t sound too big (that is 1/5 scale) 9g servos for moving arms wouldn’t add that much weight though would they

 

[wilmracer]

Ok. Should work. 67” wingspan doesn’t sound too big (that is 1/5 scale) 9g servos for moving arms wouldn’t add that much weight though would they

Exellent! Looking forward to seeing it! If you need reference shots let me know. There is one down the road I can grab pictures of if you need them.

 

[FlyerInStyle]

Exellent! Looking forward to seeing it! If you need reference shots let me know. There is one down the road I can grab pictures of if you need them.

those would be really nice. is there any chance you could recommend a propeller size from the real one? that is the only problem that I have right now. also I am slowly learning cad so this might take a while

 

[wilmracer]

those would be really nice. is there any chance you could recommend a propeller size from the real one? that is the only problem that I have right now. also I am slowly learning cad so this might take a while

Lol... gonna be impossible to get close enough to measure. She is hanging from the ceiling at the air and space museum

Here is what I found with a little google-fu https://www.bombercommandmuseum.ca/collection/aircraft-engines-pratt-whitney-wasp-1340/

One of the most successful aircraft engines ever designed, 34,966 R-1340 Wasp’s were built between 1925 and 1960.
The engine powered numerous aircraft, the most well known in Canada being the North American Harvard. The distinctive roar of the Harvard comes from this wonderful radial engine coupled to its nine foot Hamilton Standard propeller. Even today its distinctive growl overhead never fails to spark memories in those who heard it many decades ago.

Most of the P26s built had the R-1340-27. IDK if they were outfitted with the exact same prop as the Harvard but it seems reasonable. That puts you in the 21-22" range.

Given that they appear to have been outfitted with metal props you might look at Xoar's PJM-E line. (https://www.xoarintl.com/rc-propellers/electric-props/PJM-E-The-Sword-Electric-Beechwood-Propeller/). You might want to keep an extra APC prop or two for actual "events" and save the nice Xoar for less risky flights. They can be a bit pricey but they preform amazingly.

 

[FlyerInStyle]

Lol... gonna be impossible to get close enough to measure. She is hanging from the ceiling at the air and space museum

Here is what I found with a little google-fu https://www.bombercommandmuseum.ca/collection/aircraft-engines-pratt-whitney-wasp-1340/

One of the most successful aircraft engines ever designed, 34,966 R-1340 Wasp’s were built between 1925 and 1960.
The engine powered numerous aircraft, the most well known in Canada being the North American Harvard. The distinctive roar of the Harvard comes from this wonderful radial engine coupled to its nine foot Hamilton Standard propeller. Even today its distinctive growl overhead never fails to spark memories in those who heard it many decades ago.

Most of the P26s built had the R-1340-27. IDK if they were outfitted with the exact same prop as the Harvard but it seems reasonable. That puts you in the 21-22" range.

Given that they appear to have been outfitted with metal props you might look at Xoar's PJM-E line. (https://www.xoarintl.com/rc-propellers/electric-props/PJM-E-The-Sword-Electric-Beechwood-Propeller/). You might want to keep an extra APC prop or two for actual "events" and save the nice Xoar for less risky flights. They can be a bit pricey but they preform amazingly.

Of. Those are too expensive for me and it would be too expensive to find a motor for that so what I am thinking is i have some 11” props so I put them on the wings and have that powering it while having a dummy prop in the front

 

[wilmracer]

Of. Those are too expensive for me and it would be too expensive to find a motor for that so what I am thinking is i have some 11” props so I put them on the wings and have that powering it while having a dummy prop in the front

IDK... If what you've got are setups for 11" props I'd rethink building it with a 67" span. Build it @ 36ish inches and call it a day. The peashooter doesn't really lend itself to wing mounted motors. You'll have a hell of a time getting the CG right and a big freewheeling dummy prop is going to act like a huge brake. SO much more drag. Just my 2c though

 

[bwarz]

those would be really nice. is there any chance you could recommend a propeller size from the real one? that is the only problem that I have right now. also I am slowly learning cad so this might take a while

based on scale drawings, the prop would have been about 28% of the wingspan, or just under 19" for a 67" span if you're shooting for scale.

 

[FlyerInStyle]

IDK... If what you've got are setups for 11" props I'd rethink building it with a 67" span. Build it @ 36ish inches and call it a day. The peashooter doesn't really lend itself to wing mounted motors. You'll have a hell of a time getting the CG right and a big freewheeling dummy prop is going to act like a huge brake. SO much more drag. Just my 2c though

I might just ignore the front prop and why doesn’t it lend itself to wing mounted motors? I wanted this to be a big build so that is why I was aiming for 67”

 

[wilmracer]

I might just ignore the front prop and why doesn’t it lend itself to wing mounted motors? I wanted this to be a big build so that is why I was aiming for 67”

There are a LOT of reasons, some of which I've already noted.

• CG will be a PITA to get right
• The wing profile is very thin. Even at 1/5th you'll be hard pressed to hide the motors in the LE of the wing. You'll likely end up with nacelles of some sort and that will completely throw off the lines of the P-26
• Wiring will be loads of fun. If you have any chance of balancing it you'll need your batteries (probably a lot of them if you're thinking 3S 2200 mAh or similar) as far forward in the nose. You're talking about a removable wing so you might end up wanting to extend the battery leads rather than the motor wires, but extending battery leads is generally the wrong call and leads to electrical issues. You would probably need to install the ESCs in the nose as well (for weight and wiring) and then reconnect the extended motor wires each time.

Here is a set of free plans for 1/5th scale balsa version of the P-26 (https://outerzone.co.uk/plan_details.asp?ID=6078). The plans actually look pretty easy to convert to foam building techniques a la the process laid out by @willsonman. Even without the main prop it is a draggy profile and I don't see something less than a 60 sized electric pulling it around well.

Again, just my 2c.

 

[FlyerInStyle]

There are a LOT of reasons, some of which I've already noted.

• CG will be a PITA to get right
• The wing profile is very thin. Even at 1/5th you'll be hard pressed to hide the motors in the LE of the wing. You'll likely end up with nacelles of some sort and that will completely throw off the lines of the P-26
• Wiring will be loads of fun. If you have any chance of balancing it you'll need your batteries (probably a lot of them if you're thinking 3S 2200 mAh or similar) as far forward in the nose. You're talking about a removable wing so you might end up wanting to extend the battery leads rather than the motor wires, but extending battery leads is generally the wrong call and leads to electrical issues. You would probably need to install the ESCs in the nose as well (for weight and wiring) and then reconnect the extended motor wires each time.

Here is a set of free plans for 1/5th scale balsa version of the P-26 (https://outerzone.co.uk/plan_details.asp?ID=6078). The plans actually look pretty easy to convert to foam building techniques a la the process laid out by @willsonman. Even without the main prop it is a draggy profile and I don't see something less than a 60 sized electric pulling it around well.

Again, just my 2c.

Ok. I guess it is time I experience the expensive side of rc. Also do you recommend where to get such large electronics? Thanks for the balsa plans. I might convert them to foam in cad.

 

[Ligbaer]

Ok. I guess it is time I experience the expensive side of rc. Also do you recommend where to get such large electronics? Thanks for the balsa plans. I might convert them to foam in cad.

You could maybe get away with putting a 4020 620kv and then keep it light, the spacewalker i built (haven't flown it yet as i need to do linkages)
has a 60in wingspan has a 3536 and has alot of thrust on 3s the only reason i suggest a 4020 is because youre doing master series style and that would be a bit heavier. also emax has an "affordable" 4020 for sale.

 

[FlyerInStyle]

You could maybe get away with putting a 4020 620kv and then keep it light, the spacewalker i built (haven't flown it yet as i need to do linkages)
has a 60in wingspan has a 3536 and has alot of thrust on 3s the only reason i suggest a 4020 is because youre doing master series style and that would be a bit heavier. also emax has an "affordable" 4020 for sale.

I will look into it. Thanks Al’s would a 3548 do? It is bigger than 3536 and even more than 4020. Also cheaper

 

[FlyerInStyle]

so after lots of thinking and plannng i have decied to chnge this to a boxy p26 from my original idea of making it master series. the cowling will be 3d printed with an inbuilt mtor mount. i didnt scale up the tail from scale as i usually do asthe p26 hd a large enough tail as is. The cowling wil be 9 inches in diameter with a 12 inch prop. it is scaled dwn but hat is the biggest my 3d printer can 3d print and big enough in my opinion. I do not know how I will design the wings though. i do not want to use predesigned wings like i did for my other design. any reccomendations? anywas that is a summary of the progress of this project for the last 2 months. also as note i am tiling th fuselage and tail now. hopefully I can upload pictures soon. I am also thinking about how i will make the wing r
emovable.

 

[FlyerInStyle]

I finished the fuselage. Weighs 1.36kg or 3 pounds with a hefty 4s 5200 batt. The power my motor can provide is 900w and I am aiming for at least 100w per pound. I should be under my weight limit. Any tips on making removable wings would be helpful.

 

[Piotrsko]

First question: when do the wings need to be removable? I had some that were jettisoned mid flight, some jettisoned after straining through tree branches, others after early landing in knife edge flight.....

Otherwise, 100lb velcro, 2 piece plug in spar wings that fit the fuselage sides, the tired and true rubber bands. For the longest time I used brass tube guides on a 1/4 steel rod

 

[FlyerInStyle]

First question: when do the wings need to be removable? I had some that were jettisoned mid flight, some jettisoned after straining through tree branches, others after early landing in knife edge flight.....

Otherwise, 100lb velcro, 2 piece plug in spar wings that fit the fuselage sides, the tired and true rubber bands. For the longest time I used brass tube guides on a 1/4 steel rod

ok. thanks. they need to be removable for transport. I am planning on using magnets for proper alignment but other than that those tips help. thanks. I have a single thickness of foam fuselage, so how would you recommend reinforcing it so the spars that go through the fuse just dont rip it apart ocmpletely.