Estes Javelin #2005 PSII UPSCALE

As mentioned in the other thread, the #2005 Javelin would make a good upscale. I am now pretty much set on attempting a 2.5" upscale using parts I have on hand from a Partizon.

My goal for this one is to build it light enough to fly on Fs, yet stout enough to handle a small I at 600mph. Basically the full range of 29mm motors.

The build on this probably won't happen until June. But I would like to be ready when I do. I have put together an initial draft of what I think would work and would like some input on it. Is there anything I haven't considered or should do differently?

View attachment Estes Javelin #2005 2.5in PSII upscale.ork

This mission is a go! Parts are on the way. Going to use 3/16 plywood for the fins, u-bolt anchor with #1500 kevlar leader. Otherwise stock Estes PSII materials. Going to be painted the same color scheme as my original in 1989.

All I need to get started on this is the fin stock. So I went to my local Michael's to pick up some birch ply and found that they only have 1/8" or 1/4", no 3/16" I bought the 1/4" so the trip wasn't for nothing. I'm sure I'll find a use for it.

Now I'm thinking the dreaded WHAT IF...

1/4" (5-ply) would leave plenty of room for airfoiling, I could even sand it thinner a bit. That would be a lot of fin though for the PSII tubing. So why not try glassing it?

Sorry in advance for the multitude of questions as glassing is all new to me.

My goal for the more stout configuration would be to have it hopefully light enough to barely fly on an E30, yet strong enough to handle a mid-H to a half-mile in alt. Which weight of cloth would be ideal? How many layers?

Now, my somewhat local HS is very RC-centric so they have plenty of fiberglass cloth and resin. They have: 1/2oz, 3/4oz, 1.5oz, 2oz, 5oz and 6oz. Do those weights refer to the actual weight of 1 square yard?

How much Bob Smith Finish Cure would I need, for example, for 2 layers of 30" of 2.5" tube?

Finally, so that I can sim somewhat accurately, what would the density per inch of a glassed 2.5" PSII airframe be? I'm guessing 6g/in?

Here's an OR screenshot of what I have so far. Stability is getting close at 1.5 cal.

weight of the cloth, also the amount of resin per yard(roughly). I note that I have seen stock PS2 (builders kits) fly on the I200 motor...to over 3k, with that said, good luck on your build.
Rex

you might want to consider making your fins about 80 - 90% of the upscaled size, Estes low power birds tend to have fins that are somewhat over sized and are HUGE after up sizing .
Rex

Rex R said:

... I note that I have seen stock PS2 (builders kits) fly on the I200 motor...to over 3k, ....
Rex

Click to expand...

That's good to hear. I haven't personally seen PSII kits fly on more than a baby H. So... does that mean if I glass it, keep the 1/4" airfoiled fins, swap the motor mount to 38mm, I could go for a mile high on a 5-grain CTI I125 long burn? Yet light enough still to fly nicely on an F40?

I guess this is just all ballpark until I actually start making parts. Inspiring though. This will make a good first winter build.

op:op:

Going to start a build thread soon. I think I have the .ork file set now so I'll update that here and get crackin'. 2.5", 38mm MMT, glassed, 1/4" ply fins, and kevlar recovery harness. "HPR-ified"?

Here's the "final" .ork file, looks like I should have everything set. I'm planning on using Madcow-type motor retention along with an adapter for the 29mm motors. This file has the body tubes as wrapped in 1 layer of 5oz glass and enough nose weight to keep a 1.2cal of stability with a heavy I(J?) motor in there. Feel free to critique. I'm open.



View attachment Estes Javelin #2005 2.5in upscale_V3.ork