Looking for 2 stage BT-80 kit

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I like the Lil Augie for its unique design, the ripstop nylon chute the basswood fins . The only thing I dont like about the Riproar is the balsa fins. I can scratch build one similar to the RR but with custom basswood fins for under $40 but I need to decide whether to scratch build or kit? Hmmm??? The Augi's diameter is listed at 2.75". Is this an exclusive Semroc size?
 
captbk said:
I like the Lil Augie for its unique design, the ripstop nylon chute the basswood fins . The only thing I dont like about the Riproar is the balsa fins. I can scratch build one similar to the RR but with custom basswood fins for under $40 but I need to decide whether to scratch build or kit? Hmmm??? The Augi's diameter is listed at 2.75". Is this an exclusive Semroc size?
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Most of the Dynastar kits, including the Rip Roar, are built to be lightweight using balsa fins and thin wall tubing. The philosophy is similar to the Launch Pad's: Build mid power kits that are light for maximum performance using smaller 24mm engines.
The SLS Lil Augie is an upscale loosely based on this design:https://www.spacemodeling.org/jimz/eirp_10.htm
It is a unique design using ducted propulsion. A two stage rocket without a drop off booster.
The LT-275 tube is carried by erockets, which acquired Semroc some years ago. Semroc tubes are based on the old Centuri classification system. Great for cloning the classic Centuri kits.
https://www.erockets.biz/lt-275/
 
captbk said:
The only thing I dont like about the Riproar is the balsa fins.
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You could use the kit and paper the fins. The kit has a proven track record with the balsa, paper makes them significantly stronger if that makes you feel better (as it would me) and adds very little weight.
 
Hmm.. Maybe ARS will have to release a 2 stage BT-80 kit........

What if I made an upgrade to the new ARS K-08 Crazy Cluster, and added the option to get a booster?
It could be a BT-80 cluster 2 stage rocket.



I'd have to run some sims before going any further into this idea, though


Thanks,
 
I forgot about papering the fins. All my rockets are fiberglass, but these cold winter days got me wanting to build something out of wood and paper for a change. Is there a good/better/best paper to use when papering fins?
 
That's the advice I've always heard. I've only tried it once and totally screwed it up. Too much glue. (Since I had to cut new fins from scratch, I made them out of basswood, and that meant I could forgo the paper.)

Here's a random thought; has anyone tried this? When papering fins, leave extra paper hanging past the root edge to make tabs, then bury the tabs in the fillets. I know this is a normal technique with glass cloth in high power; maybe not tabs made this way, but cloth bridging from fin to airframe within the fillets. It seems like it might be a good light weight strengthening measure for mid power up to L1 rockets built with otherwise lower power construction techniques and materials.
 
kuririn said:
Just throwing some thoughts out here: Instead of pyrogen coated igniters, would a quick burning safety fuse work just as well, if not better? One end wedged into the BP motor nozzle and the other end going through the bleed hole in the ejection well and directly contacting the delay element. Might reduce the delay gap and improve reliability. I know AT makes 24mm F reloads with a 3 second delay.
Capt, feel like experimenting? Thought/comments?
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I've been experimenting with these fuses https://www.skylighter.com/collections/firework-fuse I have the fastest 4 speeds (about .3 sec/ft to 10 sec/ft). They light BP motors directly and will light composites by dipping the end in your favorite pyrogen about 1". Wrap the part inside the motor but below the pyrogen with masking tape to prevent ignition of the bottom of the grain.
 
I've been thinking for a long time that something like this might allow for the supposedly impossible composite motor direct staging. I'm happy to here someone beat me to the experiments and is getting good results.
 
Years ago I built a Fat Boy with Fat Boy booster, from plans in Sport Rocketry. Neat rocket - 4 18mm in the booster, with the center motor a C6-0, lighting a 24mm in the sustainer. The other motors in the booster were C5-3s, that, along with giving a strong boost off the pad, deployed three parachutes. Props to the author of this (whom I can't recall).

Basically you bought two Fat Boys and chopped them (and accessories, like tube coupler, centering rings, balsa separators) into the plan spec.
 
The primary aim of my experiments is to replace Thermalite for airstarting outboard motors in clusters. I used fuses to light 4 motors at the last Camden launch.
38/2G motor lit with 4-5 sec/ft fuse. About 7" long.

38/3G motor lit with 4-5 sec/ft fuse. About 7" long.

38/4G motor lit with 1-2 sec/ft fuse. About 10" long.

Fuse testing .3, 2, 4, 10 sec/ft.
 
Rocketjunkie said:
he primary aim of my experiments is to replace Thermalite for airstarting outboard motors in clusters. I used fuses to light 4 motors at the last Camden launch.
38/2G motor lit with 4-5 sec/ft fuse. About 7" long.
Click to expand...
None of your videos are viewable.

They all say Unavailable
 
Fattbank64, Can you give any personal insites on US Rockets kits? I did enough research to find out materials used like ply fins but thats about it.
 
captbk said:
Can you give any personal insights on US Rockets kits? I did enough research to find out materials used like ply fins but that's about it.
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U.S. Rockets kits use balsa nose cones, Kraft paper tubes, and plywood or balsa fins. Overall, their products that I have seen in person, or personally used, over the years ( since the mid-1980's ), have all performed well.

There is a long, convoluted "history" with story of U.S. Rockets ( that I will not go into here ). There is information available online.

I have NOT had any experience with, nor seen in person, any of their kits, 4" in diameter or larger . . . Do your research, before purchasing !

As for the availability of all of their products, or who their Dealers are, I can't say with accuracy.

https://www.usrockets.com

https://v-serv.com/usr/instaship-visual.htm

https://v-serv.com/usr/kits.htm

Dave F.
 
captbk said:
Fattbank64, Can you give any personal insites on US Rockets kits? I did enough research to find out materials used like ply fins but thats about it.
Click to expand...
I bought the Two The Limit kit from Apogee last year. My observations/opinions are based on that particular kit.

I dry fit booster and sustainer fins and there was neither a straight edge nor proper alignment. I showed the fin configuration to a friend and he said, "You paid money for that?" He does woodworking on the side and he figured out a method to get each fin in alignment.

Second, instructions are nth generation photocopies with half-printed letters, cutoff words, and incomplete sentences. I guess the hand drawn illustrations are nostalgic. Luckily, someone posted a copy online.

Third, most of the recommended motors are OOP. Instructions have not been updated because TTL cannot be flown using present-day BP motors in its original configuration. The complete kit is too heavy for motors BP motors. It can be flown either as single-stage with payload section or as 2-stage without payload section. I had to call Apogee to get that info.

Finally, one has to understand the origins of the company. It is one of the pioneers for HPR. A NAR letter frowning upon their actions is posted on their website. Several kits are designed using either multi-stage or cluster motor configuration. Designs are cool but haven't been updated to use larger/composite motors. The company is entrenched in the 1980s.

I've attended enough launches and realized most people fly Wildman, LOC, Madcow, Estes, and others. No one has flown a USR rocket.

I apologize for the long winded response.
 
Fattbank64 said:
I dry fit booster and sustainer fins and there was neither a straight edge nor proper alignment. I showed the fin configuration to a friend and he said, "You paid money for that?" He does woodworking on the side and he figured out a method to get each fin in alignment.

Second, instructions are nth generation photocopies with half-printed letters, cutoff words, and incomplete sentences.
Click to expand...

I agree with the above. I fell victim to the ‘dual 18mm rear eject’. Instructions were bogus and body tube cuts were a wreck. Couplers were way too small and had to be replaced. Uggh
 
I just decided to scratch build something. I used BT80H so it's a little heavier than I hoped. Right now I have it set up with 24mm E size mounts in each section but I was thinking of building another booster section but with a 29mm mount. Its the one one the left, the others were just to combat the winter blahs.
thumbnail.jpg
 

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