Amateur and Model Rocketry Avionics Page

The Origins of the "Grudge Match".

Max Qruiser 0.1 was my attempt to beat the formidable opposition in the Boost/Rocket Glider Competition at the 1997 Scottish Rocket Weekend.

Having picked up tips at a number of previous Scottish Rocket Weekends, I thought it was time to enter the fray - my entry was to be a vehicle which was a cross between a Pegasus rocket and BOMARC missile, only with a large vertical tail and canards, and a large underslung duct. The plan was to fit the vehicle with radio control, and then control the pitch through the canards. The whole thing was to launch on a Rocket Services G30 Comet motor, and then to fly for a while on a Rocket Services Tutu motor mounted in the duct.

A number of 2 inch diameter poster tubes were bought for body tubing, along with a few sheets of 2mm thick plasticard and a model aircraft spinner for the nosecone. The plasticard was cut out to form a delta wing. This was then glued on with araldite at the C of G. A smaller delta was also glued on with araldite at the rear, with a large vertical tail also attached with araldite. The duct was then glued on ...not surprisingly, with araldite.

I arrived on the Friday, quite sure that I would beat Bobby Wark, who constantly mocked my design (The whole weekend was a constant friendly psychological war between the both of us). Some simple glide tests showed that my rocket would glide ....badly - but with the radio gear inside, the canards were to be my trump card - I had however left my transmitter at Jim Macfarlane's place previously, and had asked him to bring it up. Quelle surprise, he forgot !

The day before the event Kevin Cave showed me his boost glider entry - I was gutted. This thing was awesome, and obviously flew much better than mine. A rapid retreat to the Rocketry Pavilion followed, followed by much scavenging of Catherine Procter's balsa and Jim Macfarlane's duct tape. The rather improvised result was a balsa delta wing with more than double the wing area of the original, and reinforced with large amounts of duct tape. The result was promising, it actually flew - which rather surprised me, as well as many others.

I had by now managed to persuade Pete Barrett of HART to lend me the radio gear from his radio controlled helicopter. I was also sure that I could borrow Rick Newlands radio gear if the worst came to the worst.

The morning of the competition, disaster. My radio gear sources bottled out - both of them. This left me with a rocket which was able to glide steeply. I left off the canards, and rethought the idea of using the Tutu motor. Suddenly, an 8 second burn motor on an uncontrollable rocket was not such a good idea. So it was all down to the G30 and a bit of luck.

Jim Macfarlane thought I was completely mad, and feeling sorry for me, helped me trim the rocket for gliding. It needed a pound of stones as nose weight to trim it - there may be trouble ahead...

We got out to the launch site, and the main opposition launched. First Kevin Cave with his scratch built delta winged boost glider, then Julie Ince with a Quest Flat Cat kit, then Dave Edgar with some awesome polystyrene thing. Oh dear. There was no way I could match their flight durations. However, as long as I could beat Bobby Wark, I would be happy - otherwise, I'd have a year of teasing ahead of me on email !

Bobby Wark's glider launched, looped and crashed - all in about 2 seconds. While this was hilarious, it was also sad, since I hoped he really would give me something to aim to beat.

A rather nervous looking John Bonsor went over the details with me, and Rick Newlands moved the crowd back (O ye of little faith), expecting it to go horribly wrong.

The launch was perfect, it shot skyward with the flame of the G30 visible all the way up to motor burnout. It coasted to apogee fairly rapidly, and then the nose pitched down ...vertically.

Its rate of descent was, how shall I put this, ....rapid. When I retrieved it, I was amazed to find it didn't core sample,

but the nose was completely smashed, the front half of the body tube was completely mangled, and the wing had come off (the wing was still intact, mind you).

Bobby Wark came up to me afterwards, to tease me, and said he didn't think my flight should count because it didn't glide. I said, neither did his.

Conclusions

1. The rocket was way too heavy.
2. Aralditing plasticard to cardboard tubes is not a good idea.
3. You can never have enough wing area.

I have now started work on one of next year's entries (yes, I'm entering a number of them). Not giving too much away, the flagship entry, (whose sole purpose is to beat Bobby Wark), uses carbon fibre (No embarassing overweight rocket glider this time !), has more wing area, and does not use plasticard. Using the G30 Comet motor, it should still be pretty light.