In the market for some centering rings...
Was looking at 1/8" plywood to center a 29mm H motor mount... also for shock cord mounts fore and aft....
Total weight of model fully loaded will be 1lb...
Yeah thats right...I'm modding a Estes Executioner to fly on
I don't know if it's lighter, but .062" G-10 will certainly do the job. I have built a couple of rockets comparable in size to Executioner with .062 G-10 fins, and it woks just fine. It's funny you mention a 29MM Executioner, because I'm bashing mine to 29MM as well. I am going to use the stock fins though.
-- Joe Michel NAR 82797 L1
Joe: what about the weight? I'm getting awful close to the 453g/16oz limit..
stock Estes Executioner = 8.1 oz 230g Dr.Rocket/AT 29/180 casing 88g H128W reload = 3.35 oz 95g
Thats 413 grams of the 453 leaving me with 40 grams....for strengthing... getting close to the edge..
I was only thinking of using .062" G10 for the fins and CR if it would save me some weight while not compromising strength....or just keep the ply fins and use G10 for the CR?
shockie B)
Shockie, I'm willing to bet that the stock fins would be lighter. When I did TTW .062" G-10 fins for my Maxi-Alpha 3, they weighed about 4oz for the three of them. I of course had a full length TTW tab, which made it a little heaver. The rocket was built with G-10 fins, three 1/8" centering rings, and heavy wall tubing. It weighed about a pound dry.
I made lightweight centering rings for my 29MM Executioner. I used 2 sets of stock Estes centering rings, and used wood glue, and sandwiched some 1/8" balsa between the two, cured under pressure. Then I buzzed the hole in the center out for a 29MM tube with a Dremel and a sanding drum.(messy!) I have used this technique before and it works well. Of course I don't intend to fly my Executioner on anything stouter than a G-80. The rings probably hold up to the H-128 as well.
You get binaries? I could post a couple of pics of it.
-- Joe Michel NAR 82797 L1
joe: thanks for the info... I notice that the TTW fin tab on these stock Executioner fins are not full length on the fin chord....so what I was planning on doing is gluing 2 rectangular tabs lengthwise between the CR...such that the TTW fin tab fits in the slot between the 2 tabs...does that make sense? overkill?
I have a stock Estes Executioner Rocksim(6.9) along with a modified one if you would like either....
Are you planning on using any nose weight with that G80? My Rocksim with a H128W sims to almost 3000ft at 16oz.....
sure I get a.b.m.r.. post away...
every little bit helps a newbie......I'm going for my L1 in a model rocket !!!
shockie B)
strengthing...
Probably overkill. I good set of epoxy internal and external fillets where the BT and fin meet will give you strength you desire without the extra complication.
I have not got that far yet,( as you will see) but I don't anticipate having to use any nose weight. I want a lightweight Executioner for a different reason than you do. I want it light so I can fly it on a D-12-3 as well G-64's and G-80's. I don't know if it will work out though.....I have to see when I get finished.
I'll snap some pix and get them posted....
Oh boy, that will be a long walk. :)
-- Joe Michel NAR 82797 L1
With all the mods you're going to end up with, you're better off buying, say LOC parts and using an extes nose cone on top. That gives you a thicker wall tubing to take the extra power, and will still leave you under a pound, so you can fly HPR with no waiver.
BTW, I've got a THOY Hornet that so far has flown on the D13-4 reload up to the H238 reload and many in between. I can't remember, but I think it's under 453g...
Bob Kaplow NAR # 18L TRA # "Impeach the TRA BoD" >>> To reply, remove the TRABoD!
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