Cox TD .049 Powered Russian Style Combat Plane
09-05-2024, 09:10 PM
#1
Cox TD .049 Powered Russian Style Combat Plane
I took a PDF of the Believ F2D plane [They fly all .15 size combat] and had the PDF drawing that had a nominal size of 16 inch span blown up 170% to produce this copy that turned out right at 26 inches.
What you see framed up so far weighs 4 ounces.
The perimeter frame work is 1/8" thick balsa [except the trailing edge is a mixture of balsa and spruce].
That's a 1/16" thick plywood bellcrank riding on a 3/32" aluminum welding rod axle and a Goldberg plastic bellcrank bearing.
This model is using .045" piano wire for a push rod which is as light as I dare go.
I plan on no leadouts...just make up 35 foot long lines that are permanently tied to the bellcrank.
The aluminum engine mount beams act as a heat sink and reduce vibration but I believe are heavier than similar sized maple.
The airfoil I kept constant thickness...1 1/8" thick, so the airfoil is only 11% thick at the center rib but ended up over 20% thick at the tips
I'm trying to make this one come out lighter and a better all around flier than my "boot leg" version of a Lil Satan.
The Lil Satan is OK but not what anyone would say is outstanding.
To be fair, the factory original Lil Satan is probably lighter than the one I just built and that would really help.
What you see framed up so far weighs 4 ounces.
The perimeter frame work is 1/8" thick balsa [except the trailing edge is a mixture of balsa and spruce].
That's a 1/16" thick plywood bellcrank riding on a 3/32" aluminum welding rod axle and a Goldberg plastic bellcrank bearing.
This model is using .045" piano wire for a push rod which is as light as I dare go.
I plan on no leadouts...just make up 35 foot long lines that are permanently tied to the bellcrank.
The aluminum engine mount beams act as a heat sink and reduce vibration but I believe are heavier than similar sized maple.
The airfoil I kept constant thickness...1 1/8" thick, so the airfoil is only 11% thick at the center rib but ended up over 20% thick at the tips
I'm trying to make this one come out lighter and a better all around flier than my "boot leg" version of a Lil Satan.
The Lil Satan is OK but not what anyone would say is outstanding.
To be fair, the factory original Lil Satan is probably lighter than the one I just built and that would really help.
09-06-2024, 09:08 AM
#3
The "TD Product Engine" runs pretty good with the Kamtech head / Nelson plug.
APC 5x3
first model I've ever built where the wing tip weight ends up on the inboard panel. I noticed during construction that 1 panel was heavier.
I think the lead outs are too far back...the model "hinges away" during tight turns.
The fat airfoil might contribute to sensitivity during level flight. I think it's time to switch to a handle with tighter spacing.
You can really feel the difference in weight between this one and the "Not So Lil Satan"
Here is another TD / Product Engine hybrid that runs even better...22,500 with a 5x3 which is OK for even a purebred TD.
APC 5x3
first model I've ever built where the wing tip weight ends up on the inboard panel. I noticed during construction that 1 panel was heavier.
I think the lead outs are too far back...the model "hinges away" during tight turns.
The fat airfoil might contribute to sensitivity during level flight. I think it's time to switch to a handle with tighter spacing.
You can really feel the difference in weight between this one and the "Not So Lil Satan"
Here is another TD / Product Engine hybrid that runs even better...22,500 with a 5x3 which is OK for even a purebred TD.
Last edited by combatpigg; 09-06-2024 at 08:18 PM.
