P-38 Lightning (BT-60/BT-55 + 3D printed Parts + Plywood Wings/Fins)

[Cape Byron]

So do you just throw the rocket without the nosecone and see if it glides? I have not done enough [any] gliders...

I’d put it into the condition you want it in to glide: no nose cone, expended motor: and throw it around a bit. Trimming gliders is a bit of an art, but you’ll get the hang of it.

Okay throw it around a bit is flippant, but essentially true. Some gliders hare easy to trim (Edmunds) and some are difficult (like lifting bodies). Lots of trial and error, but great Zen too.

Consistency of your throw is important, as is smoothness. Tiny pieces of clay to trim. Translating these pieces of clay into design changes will be the real challenge and the finalised design will probably still require clay to trim.

The only glider I have designed to date required trimming after every flight at one field and then caught a thermal and flew away straight out of the box at another.

But, the rewards are big. Search Fake Wulf on this forum for one of the most (IMHO) brilliant gliders of the last 20 years.

 

[BigMacDaddy]

Had a good flight today with the P-38. I think I was just overthinking this quite a bit and the two launch lugs were causing issues. Mounted a pair of aligned launch rail buttons on the bottom and it launched great (and no issues with pulling off launch buttons/lugs).

Couple of ideas for final revisions of the model -- including connecting rail buttons / lugs to motor mount as @Richard N (and maybe others) suggested. Thank you everyone for suggestions for getting this to work.

Interesting that the traction motor with a big tail like this has no issue flying straight with a 10 degree cant...

 

[Bowman]

Had a good flight today with the P-38. I think I was just overthinking this quite a bit and the two launch lugs were causing issues. Mounted a pair of aligned launch rail buttons on the bottom and it launched great (and no issues with pulling off launch buttons/lugs).

Couple of ideas for final revisions of the model -- including connecting rail buttons / lugs to motor mount as @Richard N (and maybe others) suggested. Thank you everyone for suggestions for getting this to work.

Interesting that the traction motor with a big tail like this has no issue flying straight with a 10 degree cant...


View attachment 564970

Cool project

 

[Daddyisabar]

The angle between success and failure in high end rocket science is slight! Living on the edge with silly warbird oddrocs! Good job!

 

[BigMacDaddy]

Cool project

thank you!

 

[BigMacDaddy]

The angle between success and failure in high end rocket science is slight! Living on the edge with silly warbird oddrocs! Good job!

That is why we avoid 3fnc...

 

[BigMacDaddy]

@burkefj

Frank (not sure if you have time but I wanted to tap into your glider experience). If you can make it out in the launch video the rocket (after nosecone ejection) is coming down more or less flat (and quite slow). Does that suggest that a bit more forward weight might help it get into a glide? Obviously without the nosecone there is a big draggy hole in the front so maybe this is not possible but figured I would ask.

 

[BigMacDaddy]

Made the propellers that are intended for static display. I am hoping to see someone experiment with launching with these in place (they are free-spinning) since I don't know if I will have time.

 

[Richard N]

This is Swordfish, a research P-38 built for airfoil testing.

 

[BigMacDaddy]

I wonder which paint schemes we will see first... I hope this is like the F-104 and inspires a bunch of really beautiful finishes.

 

[BigMacDaddy]

Jake P. shared his build of the P-38 kit over on the Radical Rocketry FB page. I thought it was a plastic model till I clicked on it and saw it was one of my kits... Amazing!

 

[BigMacDaddy]

Great picture of the P-38 taking off at CMASS in Acton MA. Photo by Curtis Heisey and I think this is @BruceS 's rocket launching

 

[Daddyisabar]

Warbirds and midcanted motor(s) rock!