Madcow Avlanche

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I'm flying at LUNAR. Got a bunch of stuff for this Saturday.

On the BAR-None at 40oz rocket weight with no motor, a G76G goes to 986' and 45 F/s off the pad. I think that's passable for SARG. I would definitely go bigger on mine at LUNAR like you said. Can't wait to get these flying. Is there a BAR-None race planned for LDRS? Are you going to drag race the Avalanche?

Toby, you need to come fly at SARG one of these days. I realize it's a trek from Mtn. View, but we're friendly, and I always have donuts. Will see you at LUNAR this weekend. And I'll be happy to drag race all of these with you and Eric at a future launch, just not LDRS. I won't have them done in time, and you already know I've got scout commitments that weekend. :( Maybe I can add a rocket event at the Ninja Warrior.
 
Opened my Avalanche today. Two issues. First two of the fins were stuck together and took some doing to separate them, leaving some adhesive residue. How to remove? Second two of the fin slots are too small. Do I enlarge the slots and how or sand the fins to fit?
 
Opened my Avalanche today. Two issues. First two of the fins were stuck together and took some doing to separate them, leaving some adhesive residue. How to remove? Second two of the fin slots are too small. Do I enlarge the slots and how or sand the fins to fit?
My fins were stuck. They usually tape them together for cutting. Isopropyl alcohol will clean it up easy. Sounds like your fin slots were like mine. One of them was wide enough, almost sloppy, and the other two were tight. You have to sand the slots a little until the fins fit.
 
My fins were stuck. They usually tape them together for cutting. Isopropyl alcohol will clean it up easy. Sounds like your fin slots were like mine. One of them was wide enough, almost sloppy, and the other two were tight. You have to sand the slots a little until the fins fit.

It was not a tape issue with the fins, there was/is large swath of adhesive across the middle of two fins, not where the tape had been. They were literally stuck together.
 
It was not a tape issue with the fins, there was/is large swath of adhesive across the middle of two fins, not where the tape had been.
It's from tape. They tape them together for cutting so they are all the same. Then they take it off and tape 3 fins together for shipping. IPA will take it off. Not the beer kind but you should have one while you work on it. Acetone probably works well too. Maybe Goof-Off. Whatever you can get.
 
It's from tape. They tape them together for cutting so they are all the same. Then they take it off and tape 3 fins together for shipping. IPA will take it off. Not the beer kind but you should have one while you work on it. Acetone probably works well too. Maybe Goof-Off. Whatever you can get.

Noticed that mine also didn't fit. The slots were actually about 1mm too short. I will use a drill dremel to open them up.
 
Got my assembly off to a good start. I used acetone to remove all the tape residue. Ed boyfriend slots we're actually a couple mm too long but one of them did need to be widened just a little bit. The Aeropack retainer I order with the kit was made for thin wall. 30 minutes of hand sanding later, it fit nice. Limited to what I have in the hotel room for a couple more weeks. Ready to add the Rocketpoxy fillets.0415182122.jpg0415181758.jpg0415181757.jpg0415181754.jpg0411181631.jpg

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Got my assembly off to a good start. I used acetone to remove all the tape residue. Ed boyfriend slots we're actually a couple mm too long but one of them did need to be widened just a little bit. The Aeropack retainer I order with the kit was made for thin wall. 30 minutes of hand sanding later, it fit nice. Limited to what I have in the hotel room for a couple more weeks. Ready to add the Rocketpoxy fillets.View attachment 342864View attachment 342865View attachment 342866View attachment 342867View attachment 342868

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Did that fin alignment jig come with the kit?

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For those building the Avalanche with HED deployment, what size/manufacturer chute are you planning to use? Not a lot a room in that NC!
 
For those building the Avalanche with HED deployment, what size/manufacturer chute are you planning to use? Not a lot a room in that NC!
James Dougherty ran a bunch of sims for the drag race page (https://ldrs37.org/ldrs37-avalanche-competition/) and recommends/suggests this rocket should weigh about 6 pounds built. Plugging 6 pounds into a calculator indicates the need for a 72" round parachute to slow to 15 F/s descent. A 72" parachute is pretty big. I think a high quality alternate like Fruity Chutes Iris Ultra Compact toroidal parachute can go down to 48" for a similar performance. $168 is pretty steep but there's a lot at stake here.
 
Even a 45” TFR is tight in a 17” NC. Would like to see you try that 70”.
Doesn't sound easy. But Eric says skip the motor ejection, go for dual deploy, and put the drogue in the nose cone, and the main in the sustainer.
 
I do plan on running the drogue in the nose. With a backup altimeter I feel safe not using motor ejection. Are any of you guys getting 2" of coupler engagement into the nose cone?
 
Plugging 6 pounds into a calculator indicates the need for a 72" round parachute to slow to 15 F/s descent.

I'm looking at the Descent Rate Guide at Top Flight. It shows that a 45" standard TFR chute is appropriate for 5-7 pounds (a 70" is stated to handle 12-18). A 72" chute has 2.5x the surface area of a 45". Any idea why the two recommendations are so different?
 
I'm looking at the Descent Rate Guide at Top Flight. It shows that a 45" standard TFR chute is appropriate for 5-7 pounds (a 70" is stated to handle 12-18). A 72" chute has 2.5x the surface area of a 45". Any idea why the two recommendations are so different?

Perhaps field conditions? I shoot for 20-25 fps on a sod field. My Punisher of similar size/weight uses a 45” TFR.
 
Mine is finished. Was planning on putting a K660 in it this weekend but unfortunately launch site is under burn ban.
IMG_4414.jpg
 
You painted it Gator colors... YUCK!

Just kidding, Tim. It looks pretty good. Did you end up swapping the main and drogue or did your main fit in the nosecone?

That was all the paint I had & I'm no fan of UF. Really didn't want to paint it at all but a white rocket doesn't show up too well with clouds in the background!
I was able to fit a 50" TFR in the NC. It's snug but pulls out with no resistance at all.
 
That was all the paint I had & I'm no fan of UF. Really didn't want to paint it at all but a white rocket doesn't show up too well with clouds in the background!
I was able to fit a 50" TFR in the NC. It's snug but pulls out with no resistance at all.

Curious what your finale weight is?
 
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