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Skyrocket with cannister heading


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#1 moonshot

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Posted 23 June 2007 - 08:42 PM

This is a way that I came up with to build a cannister shell onto a rocket motor. The motor I'm using is 5" (130mm) long 5/8" (17mm) ID and 1" (25mm) OD but you can adapt this technique to different sized motors. The first thing I do is make the shell casing. I use the spiral cardboard roll from the center of a paper towel roll. 1 3/4" (140mm) OD x 1 9/16" (137mm)ID.
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this one has a stiff 1/8 (3mm) wall thickness. You can use thinner ones but you will have to paste them more to get a good break. Cut a length of tube 3" (75mm) long and then mark a line around it 3/8" (9mm) from one end, Doesn't matter which :D . Then trace the ID of the tube onto some stiff poster board or cardboard.
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Cut out the circles to make the end discs.
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Now take your scissors and cut small triangles down to the line on the tube
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Bend the tabs in and out to make them flexible.
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Now take one end disc and push it down 1/8' (3mm) below the tabs.
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#2 moonshot

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Posted 23 June 2007 - 10:19 PM

For the next step I use a piece of steel round stock inserted into the tube to back up the end disc but you can use PVC pipe or whatever. heat up your hot glue gun and cover the end disc with hot glue. Push the tabs in and press the glued end onto a piece of wax paper untlil the glue sets up.
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This forms a very stiff end cap.Posted Image
Now take The other end disc and center one end of your rocket motor on it and trace the OD on it.
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Now cut the center out using a razor blade or x-acto knife to make a cardboard washer.
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Press the washer onto the top end of the motor and hot glue it.
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Now load up your shell with whatever you have.This one gets TT stars with some white leaf fuse.
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Press the rocket motor firmly into the shell.
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Now make another cardboard washer tracing the OD of the shell casing and the OD of the rocket motor.
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Cover this with hot glue
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And slide the washer on and press it firmly until the glue sets.
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Here is the unpasted rocket
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I paste the header using kraft paper with stars.
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Here is the rocket with pasted header
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Press the kraft paper in at the top and bottom to form a crimp.
I spike the header using cheap garden twine.
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And lastley glue on the stick
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here is the finished rocket
http://i107.photobuc...icture127-1.jpg
http://i107.photobuc...icture128-1.jpg

#3 Aquarius

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Posted 24 June 2007 - 02:46 AM

Hi Moonshot, nice tutorial. Hope you get to film this!
The only thing I could think of, is the lower end of the cannister shell. Is it strong enough?
My suggestion is that you could try the sam split 'n fold method as used on the upper cap, if it breaks uneaven.

But as said, looks very good!

#4 fight fire with fire

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Posted 24 June 2007 - 08:07 AM

Nice looking rocket, clean construction. Just wondering in the 12'th picture showing the passfire hole are you using a wooden endplug?
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#5 moonshot

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Posted 24 June 2007 - 11:11 AM

Yeah Aquarius, I think the lower disc will be strong enough especially with the spiking but your suggestion of using the split crimp on the lower disc is a good one. It will make it even stronger. I'll try that on the next one :D . It's hard to find a place to shoot these on a regular basis around here due to the fact that it's frowned upon by the local constabulary :angry: ,so my research and development process is pretty slow. Anyway I'm hoping to have a few of these ready for the July 4th holiday. Thanks for the positive input!

#6 moonshot

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Posted 24 June 2007 - 11:42 AM

Nice looking rocket, clean construction.  Just wondering in the 12'th picture showing the passfire hole are you using a wooden endplug?

No Fight Fire, the end plug isn't wood. I use a product called Durhams Rock Hard Water Putty. It's a powder like plaster. I take a small amount of the powder, mix it with a few drops of water to form a thick putty then, just using my fingers, I press the putty into the space at the top of the tube above the propellant to form the plug. Then I dip my finger tip in water and rub it over the top to smooth the putty out. The stuff dries quickly, you can drill your pass fire hole after 45 minutes. I like it because it doesn't crumble when you drill it and I haven't had any problems with blow outs. Only drawback is it takes a bit longer than just ramming kitty litter but I'm in no big hurry anyway :P . Thanks for the feedback! (sorry about the double post).

#7 shagaKahn

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Posted 23 April 2011 - 03:48 PM

Am assuming that core of kraft paper inside your canister is for the break powder.

What did you use for break? In the snap it just looks like riced BP--but is it spiked with a little flash?

This thread's nearly four years old so I hope someone's still monitoring it.

Thanx for the attention,
s

#8 Mumbles

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Posted 23 April 2011 - 05:41 PM

I'd put my money on straight BP. In comparison to the BP used to fill in between the stars, they look the same, and there isn't a lot of reason to put flash on the BP out there. If your bursts are lacking, you can certainly add some booster though.
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#9 dagabu

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Posted 23 April 2011 - 06:31 PM

Considering the size of the cannula, I dont see why he would need a booster or flash. I use a 1/2" cannula (left in) and fill it with 2FA and 1 gram flash. These are 4" canisters weighing upwards of 500g and they break just fine.

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#10 NightHawkInLight

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Posted 24 April 2011 - 12:11 PM

I like it, very nice. Very precise construction technique, that's respectable work.




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