Spitfire76's Build Log of Ben's PT17 Stearman

[Spitfire76]

I've been meaning to build Ben's P17 Stearman for sometime and finally made a start. It will be my first foam board bi-plane.

Link to original thread

PT-17 Stearman

SP0NZ submitted a new resource: PT-17 Stearman - PT-17 Stearman Free Plans, Designed by Ben Harber PT-17 Stearman Design by: Ben Harber Plans by: Dan Sponholz Ben Harber designed this amazing 1 : 9.65 scale Boeing PT-17 Stearman built from ADMAS Readi-Board (a.k.a. Dollar Tree Foam Board)...

forum.flitetest.com

 

[Spitfire76]

3 out of 5 foam boards cut with the TimSav and 3d printed all other parts with Sunu PETG filament.

 

[AIRFORGE]

3 out of 5 foam boards cut with the TimSav and 3d printed all other parts with Sunu PETG filament.

Nice prints, Spittie!

 

[Spitfire76]

All 5 foam board sheets cut. Modified the servo cut outs to fit the 3d printed mounts.

Likely going with the US Navy colors and markings - “Yellow Peril”.

Boeing-Stearman Model 75 - Wikipedia

en.m.wikipedia.org

 

[Spitfire76]

I had a bit of a problem when folding the top wing as I did not make sure the top and bottom trailing edges lined up.



I made a better job of the other top wing half.

 

[Spitfire76]

Here is a rough draft of my steps for the bottom wings as its slightly different from the build video.

Score red lines
Cut leading edge bevel
Remove paper from designated area
Remove foam from trialing edges
Bend wing tip

First dry fit then glue...

3d printed servo mount to servo doubler.
servo doubler to wing.
spars to wing
Trailing edge (A fold, use table as your friend)
Fold wing making sure trialing edges line up
Thin bead of glue on bevel, good bead on spars and top of trialing edge.
Cut bevel on aileron
Thin bead on aileron bevel
Glue wing tip

 

[Spitfire76]

Making progress - both wings done, landing gear wire bent and working on the fuselage.

I re-cut the top right wing as I was not happy with the way the edges did not line up. I suspected it was due to me using a 3d printed tool cutter to cut the bevel edge and while it cuts a perfect 45 degree edge I found it aligned better just cutting it with a knife.

As noted in the build video the landing gear wire has to be inserted into the fuselage front bottom before gluing on the gear plates.

 

[Mr Man]

Making progress - both wings done, landing gear wire bent and working on the fuselage.

I re-cut the top right wing as I was not happy with the way the edges did not line up. I suspected it was due to me using a 3d printed tool cutter to cut the bevel edge and while it cuts a perfect 45 degree edge I found it aligned better just cutting it with a knife.

As noted in the build video the landing gear wire has to be inserted into the fuselage front bottom before gluing on the gear plates.

View attachment 252761

Nice 👍. I personally don’t like how the Elevator and Rudder servos go. I wonder how they’d work farther back?

 

[Spitfire76]

Nice 👍. I personally don’t like how the Elevator and Rudder servos go. I wonder how they’d work farther back?

I haven't got to that part yet but I am a bit confused with the cut out for the control horn on the elevator as its very small.

 

[Mr Man]

This: https://forum.flitetest.com/index.php?resources/short-control-horn.293/

 

[Spitfire76]

This: https://forum.flitetest.com/index.php?resources/short-control-horn.293/

Thanks.

As there is a very small area of foam board between elevators I think something like this is needed.

Part - FT Scout XL Elevator Support and Control Horn

FT Scout XL Elevator Support and Control Horn This replaces the Popsicle stick on the elevator, plus adds the control horn. It can be printed flat in PLA or PETG with no supports. Be careful not to use to much hot glue with PLA so as not to...

forum.flitetest.com

Unless there is one already developed for the Stearman I'll design one.

 

[Mr Man]

Thanks.

As there is a very small area of foam board between elevators I think something like this is needed.

Part - FT Scout XL Elevator Support and Control Horn

FT Scout XL Elevator Support and Control Horn This replaces the Popsicle stick on the elevator, plus adds the control horn. It can be printed flat in PLA or PETG with no supports. Be careful not to use to much hot glue with PLA so as not to...

forum.flitetest.com

Unless there is one already developed for the Stearman I'll design one.

I used the good ol’ popsicle stick. 😂😂😂

 

[Spitfire76]

I used the good ol’ popsicle stick. 😂😂😂

That works but I made a 3d printed support and glued on the control horn. I also noticed that when dry fitting the tail there is very little clearance of the control horns.

 

[Mr Man]

That works but I made a 3d printed supported and glued on the control horn. I also noticed that when dry fitting the tail there is very little clearance of the control horns.

Add photos

Yup, I forgot about that…

 

[Spitfire76]

Yup, I forgot about that…

After installing the tail control rods and horns it worked just fine. I just need to have the linkage stoppers on the servo arms rather than the control rods which is what I normally try to do these days.

 

[Spitfire76]

I bit rough in places but its assembled apart from electronics as I plan on painting it first.

 

[Mr Man]

Looks great!

 

[Mr NCT]

I bit rough in places but its assembled apart from electronics as I plan on painting it first.

View attachment 252820

If you end up needing nose weight I made a radial that you can print with different percentages of infill to vary the weight

Part - Pratt & Whitney Wasp(ish) 9 cyl. Radial

I needed a larger radial for my golden age planes and was inspired by @SP0NZ radials. This one is in two pieces - the case & cylinders that allow for a motor with X mount to be attached from the front and the cover then snaps over the top. It's...

forum.flitetest.com

 

[Spitfire76]

The power pod is a really tight fit but I think it still needs securing somehow.

 

[Spitfire76]

Its now painted - well just the yellow, I need to add blue to the rudder, gray for the wheel fairings and some black on the dummy engine.