quorneng
Master member
This build came about via a rather disjointed route.
The AN2 makes an interesting model. A biplane with flaps on both wings and a huge radial driving a 4 blade prop.
There are no many 'electric' 4 blade props around but I found a nice 10x7.
At scale size this would give a wing span of 50" (1270 mm)
After 2 years of designing and printing lightweight structural components I wanted to make a scale 9 cylinder ASh 62 (a licence built P&W Cyclone) to go inside the cowling so that was the first task and only if practical would construction take place. Find the prop and then build a plane to match.
The basic 9 cylinder actually printed in silver and black PLA to avoid having to paint the very fine closely spaced cylinder fins.
A suitable motor to drive the 10x7 four blade from a 2200 mAh 3s would fit completely inside the crankcase.
It then followed on to print a mount that would support the motor and the 9 cylinder in the correct place directly from the scale firewall.
The ASh-62 in the AN2 has a substantial exhaust collector ring.
It then seemed logical to print the cowling as well.
Only a single wall print so for rigidity it would have to be glued in position once the air frame was complete.
The engine is virtually a 'kit' as it is made up over 60 individual printed part glued together.
So far so good so now onto actually building something.
I found this highly detailed 3 view which included some fuselage cross sections.
With a bit of interpretation it was possible to create a suitable number of intermediate sections for the required 10 fuselage formers.
The AN2 fuselage is quite portly so should provide more than sufficient strength and stiffness from just its 3 mm Depron skin so why not simply 3D print the formers like this?
Each former becomes a 'U' channel beam to support the skin. This section is light and easy to print with diagonal bracing to add stiffness.
The full set of 10 fuselage formers.
Although quite adequate for purpose 3D printing is not really a practical way of making a set of formers as the time to design and print is considerable. It would be much quicker to simply cut them out of 6 mm Depron unless of course you intended to build several identical AN2s.
Now finally actual building can start.
The AN2 makes an interesting model. A biplane with flaps on both wings and a huge radial driving a 4 blade prop.
There are no many 'electric' 4 blade props around but I found a nice 10x7.
At scale size this would give a wing span of 50" (1270 mm)
After 2 years of designing and printing lightweight structural components I wanted to make a scale 9 cylinder ASh 62 (a licence built P&W Cyclone) to go inside the cowling so that was the first task and only if practical would construction take place. Find the prop and then build a plane to match.
The basic 9 cylinder actually printed in silver and black PLA to avoid having to paint the very fine closely spaced cylinder fins.
A suitable motor to drive the 10x7 four blade from a 2200 mAh 3s would fit completely inside the crankcase.
It then followed on to print a mount that would support the motor and the 9 cylinder in the correct place directly from the scale firewall.
The ASh-62 in the AN2 has a substantial exhaust collector ring.
It then seemed logical to print the cowling as well.
Only a single wall print so for rigidity it would have to be glued in position once the air frame was complete.
The engine is virtually a 'kit' as it is made up over 60 individual printed part glued together.
So far so good so now onto actually building something.
I found this highly detailed 3 view which included some fuselage cross sections.
With a bit of interpretation it was possible to create a suitable number of intermediate sections for the required 10 fuselage formers.
The AN2 fuselage is quite portly so should provide more than sufficient strength and stiffness from just its 3 mm Depron skin so why not simply 3D print the formers like this?
Each former becomes a 'U' channel beam to support the skin. This section is light and easy to print with diagonal bracing to add stiffness.
The full set of 10 fuselage formers.
Although quite adequate for purpose 3D printing is not really a practical way of making a set of formers as the time to design and print is considerable. It would be much quicker to simply cut them out of 6 mm Depron unless of course you intended to build several identical AN2s.
Now finally actual building can start.
