FliteFest 2022 Dawn Patrol - Sopwith Pup

[The Fopster]

Right - here goes nothing. My first WW1 plane, first biplane, biggest plane, basically it’s all new. This will be a scratch build from balsa plans, scaled up 147% to make the plane 1/6th scale to fit the Dawn Patrol guidelines.

First - why a Sopwith Pup? A few things made me pick this one: there is a full size in a nearby museum, I really like how they look, and the shapes are simple and so looked easy to replicate.

There seem to be a few challenges. First - balance. Like a lot of these WW1 bipes with rotary engines the nose is insanely short, so getting the CG far enough forward will be a challenge. To help with that I’ve a few strategies - the battery will be mounted vertically on the back of the firewall (an idea stolen from Josh Orchard’s Tumelisa) to get it as far forward as possible, and I’ll have a 3D printed dummy radial and 3D printed cowl to add some nose weight and get some nice scale detail at the same time. I’m also considering removing a lot of foam from the tail to leave a frame a bit like the balsa framing, but not cut all the way through so the outer paper is intact.
Next challenge - how to make the wings removable for storage and transport. For that I’m going for a carbon tube spar and some 3D printed magnet retainers/alignment things, again lifted from a design on here (Wilmracer for that one).

Lots to do, but we’re out of the starting blocks! Wish me luck!

 

[Scotto]

Sounds like a plan! Good luck

 

[willsonman]

You've got a solid plan and ideas for solutions to problems. Looking forward to seeing how this turns out. The pup has great lines and a very good profile for in-flight visual reference. I've seen many 1/4 scale Balsa USA versions fly and they really do look great.

 

[Tench745]

A lot of WWI pilots loved their pups. Later planes were arguably better fighters, but by all accounts the Pup was an all around nice-flying airplane.

 

[Baron VonHelton]

A lot of WWI pilots loved their pups. Later planes were arguably better fighters, but by all accounts the Pup was an all around nice-flying airplane.

Correct. The reports I've read said it was very forgiving & easy to fly!

 

[The Fopster]

Basic fuselage box is all glued together. Now need to add hard points for landing gear, lower wing and cabane fitment. The white doubler structure is the heavier - and stronger - UK foamboard. So far, so good!

 

[The Fopster]

And a speculative test print underway of a WW1 cowl off another plane - but hopefully close enough to be usable!

 

[cyclone3350]

Yes, so far so good. R U sure that it would be too much trouble to take a short trip across a pond to be @ FF? I would like to see it.

 

[The Fopster]

Yes, so far so good. R U sure that it would be too much trouble to take a short trip across a pond to be @ FF? I would like to see it.

I'd love to, but it's not a cheap trip! Some day, maybe...

 

[The Fopster]

And of course when I had a few minutes, instead of working on the undercarriage and cabane I cut out some bits for the tail so I could prop them up and make it look more like a plane. Doesn’t everyone do that?

 

[Tench745]

And of course when I had a few minutes, instead of working on the undercarriage and cabane I cut out some bits for the tail so I could prop them up and make it look more like a plane. Doesn’t everyone do that?

If they don't I'm not sure they belong here.

 

[cyclone3350]

Oh yeah, that is what I call the hump. @ first it is nothing but monotonous piece cutting & sorting out the parts. It gets so hard for me stay focused and put in the time until I get fuse & some flying surfaces pinned together. That's when the vision comes to life & the motivation sets in.

 

[Baron VonHelton]

And of course when I had a few minutes, instead of working on the undercarriage and cabane I cut out some bits for the tail so I could prop them up and make it look more like a plane. Doesn’t everyone do that?

VonHelton Build Rule No. 1:
Never attach tail surfaces until AFTER you have attached the landing gear wire/assembly.....NEVER.
(Learned this the hard way).

 

[The Fopster]

Overnight 3d print of a cowl worked ok. A few dodgy bits but usable. It's not actually the right cowl for a Sopwith Pup, but it's close enough that it'll look OK in the air - which is the level of realism I'm shooting for!

 

[cyclone3350]

Overnight 3d print of a cowl worked ok. A few dodgy bits but usable. It's not actually the right cowl for a Sopwith Pup, but it's close enough that it'll look OK in the air - which is the level of realism I'm shooting for!
View attachment 218124

Looks good to me. I was in the same situation myself. Here is the sequence of my cowl follies in 3 pics. The original plane, what I've ordered looked like when I first put it on, & how it turn out in the end. Unless U R entering a Joe Nall event, If it's close, in the end it'll look right.

 

[The Fopster]

Looks good to me. I was in the same situation myself. Here is the sequence of my cowl follies in 3 pics. The original plane, what I've ordered looked like when I first put it on, & how it turn out in the end. Unless U R entering a Joe Nall event, If it's close, in the end it'll look right.

That’s a lovely model. 👏👏👏👏👏

 

[The Fopster]

Second piece of 3d printed nose weight (and scale detail!) started. I found a nice model of the correct (I think?) Rhone rotary engine on Thingiverse. I'm in good company because it looks like the one Josh Orchard used on his Focker D.Viii.

 

[willsonman]

It's a different version than mine but still looks good. I see that I'm not the only one that has issues with retraction on those pesky cooling fins. Pro tip: you can remove them with a razor, or even a razor saw if you're careful and the blade will fit between the fins. Prints of this detail level usually require some sort of cleanup. It's just something I've come to expect.

Your cowl looks like it belongs on a Nieuport. Sometimes "close enough" will do.

 

[The Fopster]

It's a different version than mine but still looks good. I see that I'm not the only one that has issues with retraction on those pesky cooling fins. Pro tip: you can remove them with a razor, or even a razor saw if you're careful and the blade will fit between the fins. Prints of this detail level usually require some sort of cleanup. It's just something I've come to expect.

Your cowl looks like it belongs on a Nieuport. Sometimes "close enough" will do.

Having seen a few of your builds now, I can see how you'd find a way to clean up those fins. Me, on the other hand - I thought after a thick enough coat of paint no-one would notice! That prop hub you did with the locking wire represented? Just wow. I'm building a plane that might fly but you're making art!

 

[wilmracer]

Looking great! Printed cowl looks like it will fit the bill nicely!