Estes Alpha on 24MM motor and other silliness.

The Rocketry Forum

Help Support The Rocketry Forum:

timb

Well-Known Member
Joined
Apr 25, 2006
Messages
127
Reaction score
6
Here is what you want: Low thrust long burn, won't shred balsa fins as long as you use some decent fillets. Carefully remove the glassine layer where the fins will attach, about 1/16" wider than the fin root thickness.
Bonus: lower speed means lower dynamic drag and should produce higher altitudes. Thrust curve says the E6 burns for 5.8 seconds. The closest to that is the Estes E9 at 3.1 seconds.

To the OP
I would add that epoxy is not stronger than wood glue when joining wood to paper (it's also heavier). You want some weight though for inertia (difference between throwing a baseball vs a wiffle ball sort of thing) but you want that up front not aft for balance too. Keep running sims and find that optimum weight.
 

afadeev

Well-Known Member
TRF Supporter
Joined
Sep 21, 2017
Messages
1,154
Reaction score
456
Actually I did it slightly differently: I dribbled some thin CA into the end of the tube, and then mopped it to spread it around. Caution: thin CA will roll right down the tube and out the other end before you even realize it. Gary's method of soaking the sponge first might have worked better.

I did not perceive any brittleness to the treated tube; the CA was not soaked all the way through. YMMV. Practicing on a scrap tube could be worthwhile.
Great advise.
One more point to consider - wood glue (e.g.: TiteBond II) works best when it can soak into the fibers of the two surfaces you are gluing. Once you CA the inner tube, you should us epoxy (and no longer the wood glue) to attach the motor mount. Same goes for any other elements (harness anchor, etc) that you might have otherwise attached with TB2.

Otherwise, I always treat the ends of the tubes with thin CA on low-power (Estes) rockets. Pour some around the perimeter, spread around with a napkin, and wipe of any excess.

Also, a body tube is like a fume cannon: keep your face away from the top end, despite your desire to see what you're doing. If I were doing it now I'd use my BSI SuperGold which has no fumes at all, and gives an extra few seconds to work with as well.
I've noticed that the rougher / the lower quality the tube, the more it fumes up when exposed to epoxy.
Not sure about the causation, but the correlation is pretty strong.

+1 for BSI SuperGold to minimize the irritating fumes:
 

mbeels

Yes balsa
TRF Supporter
Joined
Feb 9, 2019
Messages
2,039
Reaction score
930

HVArcas

Well-Known Member
Joined
Oct 25, 2016
Messages
232
Reaction score
80
we bored out a super alpha to fit 29mm, no record breaker but tons of fun

the body tube imploded on a medium-speed motor and was replaced to the same spec, but then the whole deal got a light fiberglassing
 

heada

Well-Known Member
Joined
Jan 18, 2009
Messages
3,112
Reaction score
497
Location
Indianapolis, Indiana
This is where I would speculate that applying a coating of CA to the inside of the BT would give it some measure of protection against both ejection blasts and subsequent moisture absorption.
Sodium silicate aka water glass. Much easier to apply than CA and gives the same effect.
 

neil_w

Hunkered down and slowly going crazy
TRF Supporter
Joined
Jul 14, 2015
Messages
8,811
Reaction score
2,222
Location
Northern NJ
Sodium silicate aka water glass. Much easier to apply than CA and gives the same effect.
Interesting. Does the water in the solution not harm the tube before it evaporates?
 

RobertH3

Active Member
TRF Supporter
Joined
Apr 18, 2020
Messages
29
Reaction score
23
Location
Central Indiana
I flew an Estes E2X Generic with a D10-7W. I stripped every gram off of that thing I could - the 1" long heavy green centering ring replaced with lightweight rings, motor hook removed, etc. App. 38 grams painted - best I could get with plastic fin can and cone, no nose weight required. I also air foiled the plastic edges. Thought about removing some fin span too, but didn't in the end. That thing got it, you are gonna laugh, Alpha is WAY lighter. I did have some tube damage directly above the motor mount. Got a suggestion from Apogee that it is a rare issue, and that it might have been possible that I used too much wadding, holding in the charge for too long. I don't specifically remember how much wadding I used. Either way, CyA is light. I used the plastic fin can to help get the thing back, it is durable enough to allow a 4x40 mylar streamer and the ground thump, and thus easy to see. I can snap a pic if you are interested. If you are really paranoid, JB Weld pro thinned with lacquer thinner or tech grade isopropyl may also work. I am not going to worry about it unless it happens again.

Cheers / Robert
 

heada

Well-Known Member
Joined
Jan 18, 2009
Messages
3,112
Reaction score
497
Location
Indianapolis, Indiana
Interesting. Does the water in the solution not harm the tube before it evaporates?
Not that I've seen. I use it to fire-proof paper mortars in fireworks. I dunk the tube in a tub of it, pull it out and set aside to dry. Hardens the tube and makes it fire-proof, or very fire-resistant. Cures with CO2.
 

mrwalsh85

Well-Known Member
Joined
Apr 30, 2012
Messages
911
Reaction score
85
I've flown a Mini Fat Boy on an AT G55W and G110T. Both were a hoot. Lost it on the G110T flight. 15/10 would do again. Oh wait - I have another one built and ready to go :)

I did a simple layer of 2oz tip to tip on the fins, but that was the only reinforcement I did. I might pick up an Alpha just to do the same thing - because, why not? :) Maybe paper the fins and let it rip. I will see if I can squeeze a tracker in the cone. I did just get a TeleMini the other day. :)
 

BABAR

Builds Rockets for NASA
TRF Lifetime Supporter
TRF Supporter
Joined
Aug 27, 2011
Messages
5,816
Reaction score
1,219
That would shred before it left the rod. :)

I definitely agree with papering, and using the instruction sheet should work fine.

You could even do something like tip-to-tip with the paper, which should help the fins stay attached.
The face card comes “in the bag”, and the launch set comes in the cardboard box. Thus using the face card or the box to “paper” the fins might be within the rules, and likely stronger than using the instruction sheet.
 

Attachments

f.geiger

New Member
Joined
Mar 2, 2020
Messages
3
Reaction score
0
Water glass solution is sodium silicate dissolved in water, is it not?
Weigh solution when done boiling. Only water has evaporated, based on laws of mass. No quantum calculations here.
So you can safely subtract 500 grams from 1100 (if you used 600 grams of water) to find your water content and therefore the solution dilution.
Sorry about that, My mistake .
Frank
 

dcastle

Well-Known Member
Joined
Jan 24, 2009
Messages
394
Reaction score
4
This is reminding me of a few years back when I built an Estes Wizard (bought a bulk pack just for this purpose) and flew on a D21. I was trying to see if I could go supersonic on a D; per Rocksim I couldn't get there but was in the transonic region anyway. I can't remember how many G's it was pulling off the rod, but it held together (fins were papered) and the last I saw of it at the CMASS launch where this was flown was the sparkle of the mylar streamer way up in the sky but not a chance of recovering it.
 
Top