Forget about a sub $100 trainer, what about a sub $100 giant scale!

Ryan O.

Out of Foam Board!
I was wondering, what is the cheapest rc giant scale plane possible? Since standard servos would need to be used, the plane would need to be 3 channel bank n yank. I couldn't think of many planes like that, but then I realized the Ercoupe had no rudder :) Again, just a hypothetical, but it might just be possible if built as frugally as possible. Also, the motor will have to be the minimum, and the wheels would have to be 3d printed to save costs. All the foam would have to be dollar tree foam board, because flite test foam would just be too expensive. The cost in printer ink for printing out the plans would also be considered, so black and white only ;) The motor and ESC will likely be from Hobbyking since they have pretty low cost motors and decent ESC's, and the prop will have to be plastic since wood is more expensive. If enough people think this is possible as well, I may do this next year as a fun project.
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mrjdstewart

Legendary member
i have been threatening to do a large scale build of a Cub. i have everything but missing 2 servos. i can either steal or buy new to replace the missing 2.

couple things for you to clarify / think about;

1- how big is big?
2- standard servos? why yank-bank only?
3- "the motor will have to be the minimum?" not sure what that means?
4- depending upon size, 3D printed wheels and gear may be time/cost prohibitive.
5- as far as plans, you need to speak to @Rasterize .
6- hobby king is prob best for cheap.
7- once again, depending upon the answer to number 1, i have ton's of wood props that were given to me. let me know and i will see if i have what you need.

i like the looks of that plane and the simplistic nature. good luck,

me :cool:
 

Ryan O.

Out of Foam Board!
i have been threatening to do a large scale build of a Cub. i have everything but missing 2 servos. i can either steal or buy new to replace the missing 2.

couple things for you to clarify / think about;

1- how big is big?
2- standard servos? why yank-bank only?
3- "the motor will have to be the minimum?" not sure what that means?
4- depending upon size, 3D printed wheels and gear may be time/cost prohibitive.
5- as far as plans, you need to speak to @Rasterize .
6- hobby king is prob best for cheap.
7- once again, depending upon the answer to number 1, i have ton's of wood props that were given to me. let me know and i will see if i have what you need.

i like the looks of that plane and the simplistic nature. good luck,

me :cool:
Bank n yank uses 3 servos, instead of the 4 for 4 channel, and that helps reduce cost. If I make this it will end up being just over 80 inches to keep it as small as possible. The motor will have to be just powerful enough for slightly beyond scale flight so that it ends up being as cheap as possible, along with the ESC being cheaper. The wheel design I've been looking at costs about 50-70 cents per print, and they only need to be scaled up by 150% 🙂
 

Ketchup

4s mini mustang
This could work depending on the plane’s size. You would have to make everything a minimum. Making the airframe too strong would be expensive, so none of that. You would have to build light to reduce the necessary motor and esc size. Also, a lighter slower plane doesn’t have to be as strong, so that works out for you. It mostly depends on electronics though. How cheap can you go there. Also, are you really going to try this? If you are, then good luck, and I will be watching that build!
 

Ryan O.

Out of Foam Board!
This could work depending on the plane’s size. You would have to make everything a minimum. Making the airframe too strong would be expensive, so none of that. You would have to build light to reduce the necessary motor and esc size. Also, a lighter slower plane doesn’t have to be as strong, so that works out for you. It mostly depends on electronics though. How cheap can you go there. Also, are you really going to try this? If you are, then good luck, and I will be watching that build!
I might make this in the future, maybe for FF 2021. If I do make it I may end up using flite test foan for longevity, and it might still be sub $100 with that as well.
 

The Hangar

Fly harder!
Mentor
I bought a 80 amp esc off of AliExpress for $15. You can get an emax GT motor for $30. Three servos you could probably get for $20. That puts you at $65 meaning you have $35 for the airframe and a receiver!
 

Ryan O.

Out of Foam Board!
I bought a 80 amp esc off of AliExpress for $15. You can get an emax GT motor for $30. Three servos you could probably get for $20. That puts you at $65 meaning you have $35 for the airframe and a receiver!
I've found metal gear standard size servos for only $9:50 a piece, so I might go for those I think the Emax GT equivalent to the monster motor is only around $35 like you said, and if I run it on 4s I save a lot money on the ESC too :)
 

The Hangar

Fly harder!
Mentor
I've found metal gear standard size servos for only $9:50 a piece, so I might go for those I think the Emax GT equivalent to the monster motor is only around $35 like you said, and if I run it on 4s I save a lot money on the ESC too :)
The $15 esc I got is rated up to 6s actually.
 

Aireal Anarchist

Elite member
Ryan
although we have never talked before Im interested in your project Id like to see you tackle this, I can see finances are an issue, I had a good month so I will buy your servos for you...... providing.............. you get all the other bits, pieces, materials and gear together for the project.
Just contact me with a shipping address when you have a photo of materials and or pledges for donated parts , and Ill have a set of servos sent to you
Good Luck hope to see your project work out


maybe others will donate a spare part to the project?
 

Ryan O.

Out of Foam Board!
Ryan
although we have never talked before Im interested in your project Id like to see you tackle this, I can see finances are an issue, I had a good month so I will buy your servos for you...... providing.............. you get all the other bits, pieces, materials and gear together for the project.
Just contact me with a shipping address when you have a photo of materials and or pledges for donated parts , and Ill have a set of servos sent to you
Good Luck hope to see your project work out


maybe others will donate a spare part to the project?
Don't feel like you need to help this😅 That's very nice of you, but I can afford to make a $100 giant scale, but I kind of want to make this design for people who can't. Thanks again, but I plan to pay for this thing myself, it only takes reffereeing a few Squirt Hockey games 😉
 

Ryan O.

Out of Foam Board!
You know what I just realized, the cost in paint would likely be too much, so if I want to keep it cheap, no paint. I think that what I'll do next year is make my first prototype for under $100, and test it until it dies. Then I'll build a waterproof and painted one for myself after the sub $100 one dies, that way I'll have the chance to get the design finalized for other people. Just a sidenote about the full scale, It had no rudder control, but was still easy to fly and practically spin proof. But, this pilot had yaw control;)
1588352078446.png
 

Ryan O.

Out of Foam Board!
I was getting worried about whether or not I'd be able to make this by FF next year because a few of my projects have been delayed due to a lack of parts, let alone be able to fit it in the car along with the Shinden and the IL-2 V2. I've come up with a way to save time, space, and cost on the Ercoupe. I'll make the wing removable with the same system as the IL-2. I'll also make the spar 2 large box spars double reinforced to the wingitps, and 5x reinforced in the center instead of shear webbed wooden ones. That means it'll be a 1 piece wing, which won't fit in my car unless I make folding wintips, which I guess I'll have to. This will also save money because finding good wood spars is expensive when ever cent counts. I'll proably only use 1 poplar spar cut in half in the center for extra strength. I'll also have to make teh vertical stabilizers foldable to prevent them from snapping in half on the long drive. I have a few ideas on how to do that, which would only add 28cents to the build. I think I'll be able to use a smaller motor than a monster motor sized outrunner since this plane will fly slowly and should have more lift and less weight than the Warbirds FT has been making.
 

OliverW

Legendary member
Love the budget giant scale idea! Thats what I'm going for on my next foam build once I finish my skyray. I'm gonna make a 90" lightweight wilga for park flying!
 

Ryan O.

Out of Foam Board!
So since I'll be busier than planned this summer, this likely won't be ready by FF'21 because of other projects taking priority. I'm aiming for the event in late summer called Warbirds and Classics Over Wisconsin where this would classify and I could fly it then. I've come up with several more cost cutting measures, so I say 80% chance I can meet my goal (receiver and battery not included since now I'm running off of 3 or 4s 2200's wired together for high capacity, which most pilots have laying around. If I can, I will make those included in the price) I've also found a great Ercoupe trim scheme which looks great:
1619571411499.jpg

I'll also be making the plans myswlf with iinkscape and fusion since I'm getting better at 2d CAD.
 

leaded50

Legendary member
I was wondering, what is the cheapest rc giant scale plane possible? Since standard servos would need to be used, the plane would need to be 3 channel bank n yank. I couldn't think of many planes like that, but then I realized the Ercoupe had no rudder :) Again, just a hypothetical, but it might just be possible if built as frugally as possible. Also, the motor will have to be the minimum, and the wheels would have to be 3d printed to save costs. All the foam would have to be dollar tree foam board, because flite test foam would just be too expensive. The cost in printer ink for printing out the plans would also be considered, so black and white only ;) The motor and ESC will likely be from Hobbyking since they have pretty low cost motors and decent ESC's, and the prop will have to be plastic since wood is more expensive. If enough people think this is possible as well, I may do this next year as a fun project.
View attachment 167515
Ercoupe had rudder! both 2 tailfins have rudder motion by a bellcrank.
But a rc model can be made without, and just using elevator and ailerons. Difficult to manouver on ground though.
 

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