Estes Alpha on 24MM motor and other silliness.

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Back_at_it

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Question for those of you out there with more experience with mid-power than myself. Over a couple of drinks with some rocket buddies from AZ. The discussion of how high can you go cheaply came up. This quickly turned into a challenge. We put some rules to it an what we came up with is this. How high can you go with an out of the box Estes Alpha kit. The rules are that the body tube must remain a factory Estes piece, stock length, factory plastic nose cone and it must have balsa fins and no fiberglass.

It's a given that everyone is going to show up with a 24mm Alpha. Knowing these guys, I'm guessing that they are going to stick to Estes motors and I doubt that anyone will go larger than a D. Looking through my launch box I found an Aerotech E20-7 that came from a collection that I bought a couple of months back. When I ran the SIM on this through OR I came up with 2890ft and a max velocity of 651 mph at 47G's.

Here is my question. Would an Alpha survive the flight with the E20? I tend to over build and I'm thinking of running a length of coupler for added strength and build with epoxy and possibly even coat the fins with epoxy.

I think there is a pretty good chance we'll get the rockets back as I have flow an Alpha on a C11 and D12 at the same location in the past so that's not really a concern.
 
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is papering the fins allowed? If so, could you use tissue paper and a very thin epoxy and do a tip to tip type of reinforcement? i wonder if that would be strong enough for larger 24mm motors?
 

kuririn

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Some ideas:
1. Estes E-12 motor.
2. Aerotech F32-8.
3. Cesaroni (CTI) G150.
Must add more nose ballast.
Fins will probably stay on with motor #1 if well constructed. Don't know about motors 2 and 3.
Motor 2 is single use.
Motor 3 is reload, need casing and hardware. $$$
Go big or go home. Claim your bragging rights. Choose #3. 😄
 
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Back_at_it

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is papering the fins allowed? If so, could you use tissue paper and a very thin epoxy and do a tip to tip type of reinforcement? i wonder if that would be strong enough for larger 24mm motors?
Well, no one specifically said we couldn't paper the fins. Only that they need to made of Balsa and not fiber glassed. So I'm thinking yes...

Good suggestion.
 

BEC

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Well, if you're really after max altitude, what you want to do is put about half an ounce of ballast (or a bit more) in the nose cone and use an Apogee E6.

I flew a model that was essentially a slightly lengthened Alpha in E Altitude Altimeter at NARAM last year and came in third with a flight to 1546 meters (5072 feet). Jonathan Rains beat me by nearly 100 meters with a slightly larger but very slick (literally) model. All of us used the E6 (which is a blue thunder end burner - it burns for several seconds).

However, they are $20 each.

(edited - somehow I didn't actually convert meters to feet originally.....:eek: )
 
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dhbarr

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CTI g65 plus a bunch of noseweight
 

Alan15578

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Well, no one specifically said we couldn't paper the fins. Only that they need to made of Balsa and not fiber glassed. So I'm thinking yes...

Good suggestion.
Since you specified an out of the box Alpha kit, you would have to paper the fins with the instruction sheet. You may have to limit glues and paints to those recommended by the instructions inside the box. It all sounds possible, except the G150. You might even find and old E50 and push it supersonic.
 

neil_w

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3. Cesaroni (CTI) G150.
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.
 

Nytrunner

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There is the G33 Mellow :) Same 3 grain case. I expect the CG of the motor is forward of the CP of the rocket. Shouldn't need nose weight.
Thats a negative gasrider, G33 is 29mm

A 3 grain CTI F with low thrust would be killer. Or one of the new 24/60 loads from aerotech
 

afadeev

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kuririn said:
3. Cesaroni (CTI) G150.
That would shred before it left the rod. :)
And shredding fins on the pad is your best chance of recovering that rocket! :eek:

I've toyed with an 24mm MD rocket flying on G55 or G150, and was getting simulated heights between 8-10K feet, supersonic speeds, and 40-95G at lift-off.
Without a GPS tracker, which adds a LOT of weight and space requirements for a small 24mm MD airframe, you would never see it again.
 

beeblebrox

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Question for those of you out there with more experience with mid-power than myself. Over a couple of drinks with some rocket buddies from AZ. The discussion of how high can you go cheaply came up. This quickly turned into a challenge. We put some rules to it an what we came up with is this. How high can you go with an out of the box Estes Alpha kit. The rules are that the body tube must remain a factory Estes piece, stock length, factory plastic nose cone and it must have balsa fins and no fiberglass.

It's a given that everyone is going to show up with a 24mm Alpha. Knowing these guys, I'm guessing that they are going to stick to Estes motors and I doubt that anyone will go larger than a D. Looking through my launch box I found an Aerotech E20-7 that came from a collection that I bought a couple of months back. When I ran the SIM on this through OR I came up with 2890ft and a max velocity of 651 mph at 47G's.

Here is my question. Would an Alpha survive the flight with the E20? I tend to over build and I'm thinking of running a length of coupler for added strength and build with epoxy and possibly even coat the fins with epoxy.

I think there is a pretty good chance we'll get the rockets back as I have flow an Alpha on a C11 and D12 at the same location in the past so that's not really a concern.
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.
 

beeblebrox

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And shredding fins on the pad is your best chance of recovering that rocket! :eek:

I've toyed with an 24mm MD rocket flying on G55 or G150, and was getting simulated heights between 8-10K feet, supersonic speeds, and 40-95G at lift-off.
Without a GPS tracker, which adds a LOT of weight and space requirements for a small 24mm MD airframe, you would never see it again.
If you replaced the airframe with standard high power motor mount tube (Or use Mach 1 Rocketry tubing) and used fiberglass fins... The weight of the GPS tracker isn't the problem...the extra weight would get you more altitide, due to inertia...the problem, I don't think anyone makes a GPS tracker that fits in a BT-50. You could use an Eggtimer Quark, and go dual deploy. Cross your fingers that someone sees the low altitude deploy charge go off. Use a long mylar streamer for drogue...

I flew a bt-20 sized rocket with an E82-10... Never saw it again. (Mach 1.4 at burnout, 2500' alt.
 

Walter Longburn

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If you're using electronic deployment you could use an E6-P from Dynasoar Rocketry. They only cost $13.50.
 

CalebJ

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If you replaced the airframe with standard high power motor mount tube (Or use Mach 1 Rocketry tubing) and used fiberglass fins... The weight of the GPS tracker isn't the problem...the extra weight would get you more altitide, due to inertia...the problem, I don't think anyone makes a GPS tracker that fits in a BT-50. You could use an Eggtimer Quark, and go dual deploy. Cross your fingers that someone sees the low altitude deploy charge go off. Use a long mylar streamer for drogue...

I flew a bt-20 sized rocket with an E82-10... Never saw it again. (Mach 1.4 at burnout, 2500' alt.
An Eggtimer Mini should fit.
 

Back_at_it

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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.

This is perfect. I just SIM'd it and it looks like 4375ft and only 27.9g so it should it will hold together as I've already flown an stock alpha on a D12-7 with higher MPH and G loads. Now I just need to figure out ow to get it back. Streamers will be my friend on that launch day.
 

BEC

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This is perfect. I just SIM'd it and it looks like 4375ft and only 27.9g so it should it will hold together as I've already flown an stock alpha on a D12-7 with higher MPH and G loads. Now I just need to figure out ow to get it back. Streamers will be my friend on that launch day.
Yep....when we flew E Altitude last year at NARAM we are mostly finding each other's models as we wandered about generally downwind of the pads at the IAC. Even with a shiny streamer I didn't see any of the models in the air, mine or others, once the tracking smoke stopped. But I think we all got our models back...we had to, after all, since one didn't get a score without bringing the altimeter back to the returns tent.

I did find my own model on one flight, since it landed in the parking area not too far behind where my "camp" was set up.
 

kbRocket

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I can share with you my experience of launching AP Aerotech motors in a stock Estes Alpha III.

On a Sunday morning at the end of a launch there was a cloud deck and some mist so I didn't/couldn't launch HPR rockets. I asked my son if I could borrow his Alpha 3 with the promise to buy him a new one if I destroyed it. Stock rocket. Cardboard tube with plastic (polystyrene?) fins. We used streamer recovery rather than a chute.
Alpha III.jpg


We got off 5 flights. I think two on D10 and three on D21 motors, all Aerotech. All flights were successful and recovered. After the 5th flight the cardboard was a little squishy and maybe the rocket made a humm sound during the launch. No electronics in this rocket, so no idea of how high it went. It moved fairly quickly. I bought my boy another...

I suppose I can also tell you about an experience of pushing an estes rocket too far. At our local NXRS launch in 2018 we had a competition for the highest flight on Estes pro series rockets call Shredstes. Time was tight to get one built and my hobby store only had a Trajector which isn't necessarily a good shape for high impulse motors.

est9709.jpg

I wrapped the body and did a tip-to-tip with 1 oz glass. I added a lot of nose mass to get stability.

The rocket flew beautifully on an I205 W up to 2300'. Then there was a problem with the Mach transition and pieces came fluttering down. I think that there was difficulty getting the fiberglass to adhere to the plastic fins.

Maybe the take home lesson from this is that you can probably push your alpha to E and perhaps further if you build it well. Make nice fillets. I wouldn't suggest supersonic unless you get fancy like fiberglassing it. Fiberglass should stick better to the Alpha materials than it would to plastic. Consider launching from a more distant launch pad.
 

BEC

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The Alpha III is amazingly capable. I actually wanted to base my E Altitude model on an Alpha VI (for the shiny parts) for NARAM last year but didn't like what I'd have to do to the inside of the fin can to get an E6 into it. So I just used an Alpha VI nose cone and did the rest with a piece of BT-50 and some thin carbon fiber sheet fins.

An Alpha III on a D10 (or D21) should have easily gone past 2000 feet...more like 2300-2500. The softness of the body tube probably came from the rather torch like effects of the D10/D21 ejection charges.

One can tuck a FireFly or a MicroPeak or a FlightSketch Mini up inside the nose cone of an Alpha III, which makes it relatively easy to get data from.


Too bad about the Trajector, but that one, as you recognized, was not the best choice for that particular NXRS task, even if you left off the fin tip pods, which I expect you did.
 

CalebJ

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Between this thread and the $3 shipped deal on the Mini Honest John kits yesterday at Amazon, you guys have me playing with Open Rocket simulations on switching it to 18 or 24mm motors with the appropriate nose weight. This could get interesting.
 

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neil_w

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An Alpha III on a D10 (or D21) should have easily gone past 2000 feet...more like 2300-2500. The softness of the body tube probably came from the rather torch like effects of the D10/D21 ejection charges.
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.
 

CalebJ

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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.
What's the best way to apply thin CA in that kind of quantity?
 

neil_w

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What's the best way to apply thin CA in that kind of quantity?
I used this method: https://www.rocketryforum.com/threads/summer-build-off-contest-magic-dart.134448/post-1590511

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.

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 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.
 

kbRocket

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The Alpha III is amazingly capable. I actually wanted to base my E Altitude model on an Alpha VI (for the shiny parts) for NARAM last year but didn't like what I'd have to do to the inside of the fin can to get an E6 into it. So I just used an Alpha VI nose cone and did the rest with a piece of BT-50 and some thin carbon fiber sheet fins.

An Alpha III on a D10 (or D21) should have easily gone past 2000 feet...more like 2300-2500. The softness of the body tube probably came from the rather torch like effects of the D10/D21 ejection charges.

One can tuck a FireFly or a MicroPeak or a FlightSketch Mini up inside the nose cone of an Alpha III, which makes it relatively easy to get data from.


Too bad about the Trajector, but that one, as you recognized, was not the best choice for that particular NXRS task, even if you left off the fin tip pods, which I expect you did.
The fin tip pods were not left off. The rocket needed to be just like the picture. They probably added significantly to drag and fin stress in the Mach transition. I'm not really mourning the loss of the Trajector. It isn't my present style of rocket. I'm more into minimum diameter altitude seekers than interesting looking rockets.
 

BEC

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Ah....gotcha. I'm on the NWRockets mailing list so I see stuff about NXRS go by, but I've not really tried to attend one (yet).

Well....this thread is kind of about a minimum diameter altitude seeker that just happens to start off as an Alpha (which is the second-longest running continuous production model rocket kit).
 
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