Author Topic: Rocketry Warehouse Lil Rascal HED  (Read 8993 times)

Offline RKeller

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Rocketry Warehouse Lil Rascal HED
« on: November 22, 2015, 06:40:25 PM »
monday at LDRS34 AMW was having a killer sale. They not only had the AMW kits but a pretty good selection of Madcow kits as well as Rocketry Warehouse kits. I couldn't resist and picked up a RW Lil Rascal in fluorescent yellow and a madcow 2.6" patriot. This Lil Rascal kit is pretty nice for the price, especially on sale! The kit includes a FW fiberglass nosecone and 6" coupler. I know these things need a bunch of nose weight so I'm going to build it with HED (head end deploy) and have some fun with 3 grain 38 and 2 grain 54mm motors! I still have to order the bulkplates and switch band from Rocketry warehouse but I got started on the back end. I'm using 5/16th tubular kevlar as a Y harness to the motor tube. after washing and sanding, the top centering ring was notched and glued on with a little JB weld.


here is a pic of the nice nosecone these come with now.
Riley Keller
URRG
TRA#15415
L1 25 Oct 2014 Estes MDRM CTI H133
L2 25 June 2015 Rocketry Warehouse DYOK, CTI L1030RL 14.7k ft mach 1.57

I'm addicted to building stuff, rockets are just a way to get high

Offline RKeller

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Re: Rocketry Warehouse Lil Rascal HED
« Reply #1 on: November 22, 2015, 06:42:01 PM »
This yellow fiberglass, while radioactively awesome, is very translucent. I'm going to go a little non traditional for Riley on the build at this point. normally I would slather some epoxy into the tube and stuff the motor tube and centering ring in there, but that would leave a big ugly visible ring where the centering rings are. so... I just tacked the ring and motor tube in with a dot of CA at each fin slot. I will do nice internal and external fillets as well as epoxy the centering rings to the edges of the fins, just not to the body tube. it will be plenty strong, I promise.
I also drilled and installed rail buttons with flange nuts. I use these on just about everything. https://www.rocketarium.com/Build/Rail/Delrin-Rail-Gudes/1010-Airframe?cPath=19_133&

but, due to the see thru body tube I chucked them up in the drill press and filed them down to the same diameter as the rail button.

glued them in with a very light coating of JB weld on the face of the flange nuts.

Riley Keller
URRG
TRA#15415
L1 25 Oct 2014 Estes MDRM CTI H133
L2 25 June 2015 Rocketry Warehouse DYOK, CTI L1030RL 14.7k ft mach 1.57

I'm addicted to building stuff, rockets are just a way to get high

Offline RKeller

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Re: Rocketry Warehouse Lil Rascal HED
« Reply #2 on: November 22, 2015, 06:44:00 PM »
marked, masked and sanded the the body and fins for epoxy. also put a 45 degree bevel on the fins. useful? not really... next I need to print the fin guide on payloadbay.com and glue it to cardboard. I've found this to be a great way to get the fins aligned perfectly.


Riley Keller
URRG
TRA#15415
L1 25 Oct 2014 Estes MDRM CTI H133
L2 25 June 2015 Rocketry Warehouse DYOK, CTI L1030RL 14.7k ft mach 1.57

I'm addicted to building stuff, rockets are just a way to get high

Offline RKeller

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Re: Rocketry Warehouse Lil Rascal HED
« Reply #3 on: November 22, 2015, 07:08:21 PM »
I printed out the fin guide from payloadbay.com on 11x17 paper, used the kids glue stick to glue it to thin cardboard from some toy thing, and cut it out.

then I injected some JB weld through the slots onto the motor tube and front centering ring.

I warmed JB weld by putting the tubes in a baggie under some hot tap water. this lets it flow a lot more so it can run down and form internal fillets.

This is where I always fail with pictures. I like to do lots of steps at once so I forget to take pictures. once I stuck the fins in I injected JB at each joint letting it run all the way down to the front centering ring. I use a stick when needed to move the JB weld around. This time I had to be careful not to get it on the body tube beyond where the external fillets will be because it will show. once I'm happy with the fillets I glue on the rear centering ring and retainer. then use rubber bands to hold the fins in tight while it all cures.

Riley Keller
URRG
TRA#15415
L1 25 Oct 2014 Estes MDRM CTI H133
L2 25 June 2015 Rocketry Warehouse DYOK, CTI L1030RL 14.7k ft mach 1.57

I'm addicted to building stuff, rockets are just a way to get high

Offline RKeller

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Re: Rocketry Warehouse Lil Rascal HED
« Reply #4 on: November 22, 2015, 07:11:25 PM »
time to decide how long of a switch band to get...


used up lots of tape and rocketpoxy...


Riley Keller
URRG
TRA#15415
L1 25 Oct 2014 Estes MDRM CTI H133
L2 25 June 2015 Rocketry Warehouse DYOK, CTI L1030RL 14.7k ft mach 1.57

I'm addicted to building stuff, rockets are just a way to get high

Offline RKeller

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Re: Rocketry Warehouse Lil Rascal HED
« Reply #5 on: November 22, 2015, 07:12:36 PM »
This project sat for a while, but I'm back at it. I ended up going with a 2" vent band and recessing the aft bulkplate 1" making room for a 54mm 3g CTI and 1280 AT case. here's the av bay, which is not done yet. I still have to drill the three vent holes but I'm waiting till I know where the screw switches will be...
I had to bevel the edge of the bulkplate so it didn't stick in the nosecone

The other side, I'll have to plug that hole in the middle and add an eye bolt off to the side to make sure there is room for the motor.

rocketpoxy fillet on the inside

all the parts

what it looks like


The nose is drilled and tapped for 3 2-56 nylon screws. the coupler to body tube will be friction fit. inside will be an eggfinder TRS and a TBD backup altimeter.
Riley Keller
URRG
TRA#15415
L1 25 Oct 2014 Estes MDRM CTI H133
L2 25 June 2015 Rocketry Warehouse DYOK, CTI L1030RL 14.7k ft mach 1.57

I'm addicted to building stuff, rockets are just a way to get high

Offline RKeller

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Re: Rocketry Warehouse Lil Rascal HED
« Reply #6 on: November 22, 2015, 07:14:03 PM »
still debating with myself regarding how much weight to add. adding no weight = 0.2 cal stability. if you add a 3:1 0 mass nosecone to simulate base drag stability goes to 1.0. this picture is with 8oz in the nose which is what I think I'm going with. stability is around 0.5 to 0.6 depending on the motor and ~1.3 with the base drag.
Riley Keller
URRG
TRA#15415
L1 25 Oct 2014 Estes MDRM CTI H133
L2 25 June 2015 Rocketry Warehouse DYOK, CTI L1030RL 14.7k ft mach 1.57

I'm addicted to building stuff, rockets are just a way to get high

Offline RKeller

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Re: Rocketry Warehouse Lil Rascal HED
« Reply #7 on: November 22, 2015, 07:14:46 PM »
got all the doohickeys and wires and battery things mounted...

Riley Keller
URRG
TRA#15415
L1 25 Oct 2014 Estes MDRM CTI H133
L2 25 June 2015 Rocketry Warehouse DYOK, CTI L1030RL 14.7k ft mach 1.57

I'm addicted to building stuff, rockets are just a way to get high

Offline RKeller

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Re: Rocketry Warehouse Lil Rascal HED
« Reply #8 on: November 22, 2015, 07:16:33 PM »
I added 4oz to the nose. to attach the weight and shock cord I drilled a hole into the epoxy tip inside the nosecone and tapped it with 1/4-20. I found a 1" piece of brass rod and cut it to 1.25" long and drilled and tapped that for 1/4-20. threaded that onto a long eye bolt and screwed it all into the nosecone.
here it is in the nose


also did some ground testing. I calculated I needed 0.7g of BP in the nose and around 1g for the body tube. testes went well. pulled the 20ft 1/4" kevlar shock cords mostly straight but did not pull out all the z folds that were taped up.
https://goo.gl/photos/rJmmwfAutYfEvTyNA
https://goo.gl/photos/T286PGHvSb7rpdjt8
« Last Edit: November 22, 2015, 09:32:24 PM by RKeller »
Riley Keller
URRG
TRA#15415
L1 25 Oct 2014 Estes MDRM CTI H133
L2 25 June 2015 Rocketry Warehouse DYOK, CTI L1030RL 14.7k ft mach 1.57

I'm addicted to building stuff, rockets are just a way to get high

Offline RKeller

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Re: Rocketry Warehouse Lil Rascal HED
« Reply #9 on: November 22, 2015, 08:15:09 PM »
first flight, CTI I212 Smokey Sam to 1800ft. super windy but it flew great! Thanks Dizwolf for the great pictures!




Riley Keller
URRG
TRA#15415
L1 25 Oct 2014 Estes MDRM CTI H133
L2 25 June 2015 Rocketry Warehouse DYOK, CTI L1030RL 14.7k ft mach 1.57

I'm addicted to building stuff, rockets are just a way to get high

Offline RKeller

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Re: Rocketry Warehouse Lil Rascal HED
« Reply #10 on: November 22, 2015, 08:15:54 PM »
so this is why they tell you to use a drogue on HED... totally forgot to, I never use a drogue. next time I will. I haven't pulled the data off the TRS yet to see how fast it came down.
Riley Keller
URRG
TRA#15415
L1 25 Oct 2014 Estes MDRM CTI H133
L2 25 June 2015 Rocketry Warehouse DYOK, CTI L1030RL 14.7k ft mach 1.57

I'm addicted to building stuff, rockets are just a way to get high

Offline RKeller

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Re: Rocketry Warehouse Lil Rascal HED
« Reply #11 on: December 05, 2015, 08:19:02 PM »
2nd flight was black friday on an AT I435. great flight to around 3500ft. got there in a hurry!
Riley Keller
URRG
TRA#15415
L1 25 Oct 2014 Estes MDRM CTI H133
L2 25 June 2015 Rocketry Warehouse DYOK, CTI L1030RL 14.7k ft mach 1.57

I'm addicted to building stuff, rockets are just a way to get high

Offline dbmccann

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Re: Rocketry Warehouse Lil Rascal HED
« Reply #12 on: December 05, 2015, 08:45:11 PM »
That thing left dodge in a hurry....wow.