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This "dragster", was fabricated with a 30" length of 2" SCH40 PVC pipe. The nose is a 2" Cap and the engine is held in place with a short length of 1" SCH40 PVC pipe, using a 2" x 1" Reducer in the rear.
<div align="center"><img src="http://img117.imageshack.us/img117/6664/rc1dm1.jpg"></div>
Power is delivered by a single Estes rocket engine (E9-P). These type of engines produces a maximum thrust of 5.6 lbs. , with a thrust duration of 2.8 seconds.
The rear fin is more for looks, than function. It was fabricated out of a sheet of 1/8" plastic. The wheels are 100mm (4" diameter") Scooter wheels, with abec-5 bearings. The axles are simply a length of 5/16" allthread.
<div align="center"><img src="http://img124.imageshack.us/img124/8315/rc4td2.jpg"></div>
<div align="center"><img src="http://img123.imageshack.us/img123/5624/rc2ls1.jpg"></div>
The axle struts were made out of solid rod, with 3/8" I.D. Bushings welded to the ends. - They also, are more for aesthetics than a necessity. The two of them together, weigh close to a pound, which I'm sure drastically reduces the acceleration of the dragster.
<div align="center"><a href="http://www.youtube.com/watch?v=_rYHUXLFbns">Short Video of first Test-Run</a></div>
Last edited by DR on Thu Dec 04, 2008 6:14 am, edited 1 time in total.
Really fine work DR. Looks really speedy. Does it remain stable during a full run...ie. not crash?
Did you have some motivation like a competition of some sort to pump this puppy out?
Shame about the round nose
No seriously, nicely done there DR - have you tried it out yet? If so, some sort of video would be appreciated Also - since you're American and all what - what, just one rocket?
Did a little research about nose-cones for rockets and found out that a round nose is more efficient on vehicles are subsonic. Also, pointy noses do not fair well, when smacking into a curb!
Edited my post and included a short Test-Run video.
Future plans are for shortening the vehicle length, adding new lightweight axle struts, and running a D12-0 Booster engine, which will ignite the E9-P engine.
No dry lake beds in your are then
Why not keep the length but cut down on body diameter? Or does the rocket engine diameter not allow this?
Is it really lit by a fuse?
"If at first you dont succeed, then skydiving is not for you" - Darwin Awards
There's an easy pyrotechnic way to ignite more than one rocket engine at a time, but I can't talk about it and you probably already know it.
Unless you have a license for larger engines?
The video answered my question about stability over the full run. Any even slight yaw in the placement or thrust hole of the engine could cause directional problems.
Also it's possible that the fin isn't as effective as it could be, being somewhat forward of the rear wheels, it's going to tend to steer the car rather than straighten it. I believe a placement slightly behind the rear wheels will be more effective.
Why can't you talk about it? Standard Estes igniters can be used for multiple engines, just wire'm in parrallel and power with a 12V gel battery.
Or, cheaper yet, get a couple hundred 1/8 watt 10 Ohm resistors for $10 and use them in place of the Estes ignitors.
BTW, looks good DR. I suspect the shape of the nose is darn near perfect for this application.
I meant the dirty pyrotechnic "meal pan" way of igniting multiple engines at once. Cheap, simple, and somewhat effective if done correctly.
There was some girl on the Discovery channel a few years ago who managed to launch around 50 (I think) D engines completely using the method.
But the electronic igniters work good as well.
I like it, but befor I got into this hobby I endulged a little in model rocketry (my dad has a friend that works at NASA)
The Estes engines are ok, but you could do much better if you make your own. I probably cannot discuss this on this form so PM me your email me your email address and I will email you the formula I found to work best.
if you live in Ohio join the Ohio Spud Gun and BBMG Association at http://www.ohiosga.webs.com
Very clean DR! Good to see you still got the skills and haven't quit the PVC game.
BTW I don't have a pointy nose myself, and that is probably why I can't run supersonic...
Cool stuff, looks really nice. I'm just waiting for the part where you say 'screw this!' and launch it out of a cannon
No it's fine. It's a commerical rocket motor and even if it wasn't, you're not shooting it out of a cannon
How in the hell, did someone post a reply... under MY screenname??? and was it mark11?
Oh, duh! - Guess someone deleted my entire last post. Ah, well!
Last edited by DR on Thu Dec 04, 2008 6:49 pm, edited 2 times in total.
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