My First Hybrid Rocket

astroboy · Postby **astroboy** » Thu Sep 20, 2007 8:34 pm

Back on topic to the Astrobee D.
Over the last week I have glassed the airframe and redesigned the electronics bay to allow dual deployment as I want the rocket to be able to be flown on H (or maybe an I200??) composites too.

The glassing job was done with a layer of 25g cloth and West-Systems epoxy. I cracked out the automatic tube turner I made from bits of a plotter to stop epoxy gathering on the underside of the tube while it cured. I made this up to glass my Aerobee 150 Hi scratchie and it has gathered dust in the back of the shed. I found it to be very easy going with only minimal sanding and filling required to get a nice smooth finish. The trick I have found is not to put on too much epoxy. If you weigh the required amount of cloth, you only need that much epoxy to do the job. Too much epoxy or runs in the finish = heaps of extra work!

I will post a few pics when I can.

astroboy · Postby **astroboy** » Wed Oct 10, 2007 2:07 pm

I have completed the airframe and all that remains to be done is to rig the recovery harness and fit electronics.
As the rocket has been designed to suit the RATTWORKS H70, I had to put a port in the airframe to insert the tank vent. All I did was put a hole in the side of the motor mount that lines up with one in the airframe. I am going to get a screw that fits the vent and drill a hole axially and silver solder in a short piece of brass tube. That way it goes in easily and can be removed to withdraw the motor.

Just needs to be painted, but that wont stop me flying it!

Hey Spacelaunch, when is your GSE getting to Qld? I'm keen to fly this bird.

spacelaunch · Postby **spacelaunch** » Wed Oct 10, 2007 9:42 pm

astroboy wrote:Hey Spacelaunch, when is your GSE getting to Qld? I'm keen to fly this bird.

Astro - should have the rig here by 2nd week November, it will be on show at University of Adelaide Expo till then.

astroboy · Postby **astroboy** » Wed Oct 10, 2007 9:49 pm

Cool, I'll have to russle up some nitrous! :lol:

october sky · Postby **october sky** » Thu Oct 11, 2007 2:07 pm

Just a thought guys : Spacelaunch, what are the chanses of getting it here by 11.11 launch ??

It sounds like it's going to be fairly popular day ( here's hoping ).

astroboy · Postby **astroboy** » Thu Oct 11, 2007 3:03 pm

This will not be flown at a public launch ARi.

october sky · Postby **october sky** » Thu Oct 11, 2007 7:22 pm

Didn't mean it to be flown, but "on show". It is something special.

spacelaunch · Postby **spacelaunch** » Fri Oct 12, 2007 10:41 am

october sky wrote:Just a thought guys : Spacelaunch, what are the chanses of getting it here by 11.11 launch ??

It sounds like it's going to be fairly popular day ( here's hoping ).

Possible, as long as Adelaide get it in a box to me straight after the school expo, which is on 4/11.

october sky · Postby **october sky** » Fri Oct 12, 2007 2:05 pm

Sounds possible then. Thanks Spacelaunch.

astroboy · Postby **astroboy** » Mon Feb 25, 2008 10:03 am

Finally finished the Astrobee. WooHoo!!

All glassed out and finished with Export paints after a couple of paint compatibility problems :oops:

. Its not a scale paintjob its my design, also the decals are not scale placed.
A homebrew mercury switch triggered 556 timer with continuity and timer check has been fitted. On composite flights the drogue will be fired by the motor and the main will be by timer. Lower altitude flights on a Rattworks H70 will be single deployment only.

Heres a shot. Note the timer bay door is not fitted in this photo

By Satans_Bollocks

Sumo310 · Postby **Sumo310** » Mon Feb 25, 2008 10:14 am

Very cool! Can't wait to see it fly on the Ratt motor - they sound mean!

astroboy · Postby **astroboy** » Mon Feb 25, 2008 1:46 pm

Gonna have to wait a bit first...cert and GSE required!

I am thinking as the MMT is extra long to take the the H70, I will have to fit a tube up in the head end when I fire it on composites. This will prevent the tube being fouled and potentially causing problems when the ratt case is being installed.

cody1382 · Postby **cody1382** » Wed Sep 17, 2008 9:47 pm

just wondering how you where going with the ratt works ignition system?
What are you planning to launch yours on?
are you happy with the rat works system?
ive been looking at the skyripper system too they dont look to bad
its just the ignition system thats got mee buggered
id go hypertech but id like 29mm gear

PK · Postby PK » Wed Sep 17, 2008 10:18 pm

Some input from someone with a bit of experience with EX hybrids:
GSE for small hybrids is trivial. Either buy a Burket direct acting solenoid. Valve, or rig a 1/4" ball valve with a gearhead motor, (built one of these this week) ,pm me if your club is serious about hybrids.
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My First Hybrid Rocket

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