Over on the CEF, we’d been rehashing the old debate about practical mounting for the Testors pipe bomb engines.  I made my own mount using scrap 3/32” ply and spruce.  The thread is here:
http://www.coxengineforum.com/t8062-fun-with-generic-non-threatening-title






To test the engine mount, I needed a plane to test fly it in.  Since the little Testors engine pod I’d come up with wouldn’t fit any on hand plane I already had, I needed a new plane.  But, since this is just an experiment and a curiosity, I did not need a plane that needed to last a long time, nor one with much money and time invested.  Just something to test out the engine mount.  The obvious thing would to be to make a coroplast plane.  And the easiest plane for that would be the coroplast PT-19 replica .  That Keith Morgan, what an actor…

So I whipped up a quick fuselage with some on hand coroplast.  It’s basically Keith’s design, but I made a couple of changes.  The front firewall is replaced by the engine crutch, and I didn’t bother with the rear former.  It’s sturdy enough as it is.  I used different tail surfaces to save time and effort.  Instead of a stabilator, I made a stab/elevator with a slotted hinge.  I just cut a slot in the fuse and slid it in, then glued it in place.    It’s actually easy to build a straighter plane this way.  If your wing saddle follows the flutes, and the stab follows the flutes, you’re guaranteed to have 0 degrees incidence on both.  I didn’t make a new wing, I just took one from one of the previous coroplast PT-19’s I built.

It’s not pretty, and I didn’t bother with any trim, but it’s functional.   It is what it is.  It is the Pipe Bomb Special.






Mark

Mark, Looking good as always!!   

What are you using for elevator hinges these days?

RkFlyer

Wow, I didn't know that PT-19s had one-wheel landing gear!

It all depends on who the previous student pilot was.  I just finished it yesterday, and the weather's not cooperating.  Hopefully I'll get to fly it next week.

Richard, for the hinge I just cut the plastic away from one side of a flute (channel), and then on the other side I cut strips out so that there were only five remaining pieces of 1/2" plastic tying the stablizer to the elevator.

You call them that to see if big brother is watching and will send the swat team and b++b squad to your door!

I believe they got that name because some of them had a metal crankcase (mine does). They were also sold as the Testor's 8000 (.8cc) with a prop, attached tank, wrench, and needle extender.

   Most of those types I saw had some sort of plastic (glass/nylon, I think) crankcase, and a very strange nylon metering valve - which wasn't a needle. It was cylindrical with an L-shaped groove in it. My experience was generally negative. Most of then started and ran OK when new, but after 10 or so flights, something would happen (probably got some crud somwhere) and then it acted like it couldn't get any fuel, and turning the "metering" valve didn't seem to have any effect. We took it apart to clean it but never got them to work again.

  Of course, this was all something like 45 years ago, and my overall skill level and attention to detail was perhaps not entirely up to the task. I do recall visually with near perfect clarity, as is my gift/curse.

    Brett