RAZAMOV-SHTERN LRD-D-1....Do the fins get toasted?

[urdell99]

I've made the nose cone & boat tail for a RAZAMOV-SHTERN LRD-D-1 in a 4 1/2 inch diameter & now I'm wondering if those long, close-in fins might get charred after repeated (or one) flights. I haven't cut fins yet, so could easily use NC & aft end in something else.

Anyone have experience with one of these?

Richard Hickok

 

[nh4clo4]

:w: Great rocket.

I have been playing with this model for almost 10 years now, so I think that makes me an expert .

I have built a 3 inch version of this rocket back in 1999 and flew it on anything from F motors to the powerful single use Aerotech H125. It is a great flier, and I never had any issues with charring the fins.

Later on, I built a 5.5 inch version and flew it on J and K motors. Even with a K185 I did not experience any issues with excessive heat on the fins. I flew this rocket on J180T, K185, J540R, and K1100T. Again, it has been a great flyer.

More recently (about 2 years ago), I built a 9.25 inch version of this rocket. Only 1 flight so far, on an AMW M-1350 motor. Great boost, very straight. Unfortunately the main chute deployed right after burnout, and the rocket had a pretty hard landing. I still have it, and hope to fly it again this year on an another M motor.

I will try to dig out some pics and post them here. I have to warn you I am not very good at documenting my builds, so do not expect detailed pictures....

By all means, go ahead and build it. I have no doubts you will enjoy this rocket.

 

[urdell99]

Thanks for that very useful reply. I'll get started with cutting the fins. One thing I think that's so cool about it is that it's kinda got that retro, sci-fi movie look, but it's real scale!!

Can you recall if you tried different silver paints for yours?

Thanks again,
Richard Hickok

 

[JAL3]

Pics anyone?

 

[nh4clo4]

Can you recall if you tried different silver paints for yours?

I started with silver, but it makes the rocket very difficult to see in the sky. I ended up painting the smaller one "Russian Red" to alleviate the problem.

The 5.5 inch one has been repainted as well, but this time in black. That's the 5.5 inch one you see in the two liftoff pics.

 

[nh4clo4]

The large one (9.25 inch) flew at Three Oaks in Michigan on an AMW 1350. Beautiful boost. Unfortunately it suffered either an early ejection or drag separation at burnout. The chute was shredded into a mullion pieces, but the rocket came out of this with surprinsingly little damage. It will fly again.

I got these pics from Dave Brunsting. Thanks Dave!

 

[urdell99]

Yeah, you've got a good point about silver & visibility.....I built a Blowpipe https://missile.index.ne.jp/cgi/misearch.cgi & covered the top half of the tube with stick-on chrome sign shop vinyl (poor man's Monokote) & sitting on the pad, the chrome would just reflect the green or tan of the field & make it look like a white nose cone mysteriously hovering ~ 18 inches above the bottom half of the rocket.

Maybe I'll go with some color-changing paint (DupliColor, Krylon...Mirage, Mystique) that I stocked up on with 40% & 50% off coupons, back when Michaels & AC Moore used to carry 'em. Not as true to scale, but at least it's visible.

The way it goes......I'd recently gotten some 12" X 24" plywood & of course, these fins are a few inches longer than that. Time for either Yankee ingenuity (staggered lamination?) or a reorder.

 

[cls]

I scratch-built a BT-60 one from Alway's plans - flies on A10-3Ts, no charring.

the Mad Cow kit is just superb, flies on 24mm and 29mm, no charring, so get one of those and you are set.

 

[urdell99]

I also used Peter Alway's plan, did the math, & enlarged fin patterns on a copy machine at Staples.

Glad to hear another story of non-charred fins. Anybody even get blistering paint on fins?