pyrogeorge Posted June 11, 2009 Posted June 11, 2009 Hi,I plan to make a comet pump.My tube has got 67mm I.D (2.63").So the O.D of comet what size must be? Also i must make a core to comet for better burning time?
Bonny Posted June 11, 2009 Posted June 11, 2009 (edited) Hi,I plan to make a comet pump.My tube has got 67mm I.D (2.63").So the O.D of comet what size must be? Also i must make a core to comet for better burning time? Make the comets about 2.25"- 2.375" max. Personally, I'd make them 2.25" OD... to leave room for fusing and/or priming. You can always paste a layer or 2 of paper if needed to tighten the fit, or add more lift. As for the core that would depend mainly on the comp's burn speed. I would't bother, just change the height of the comets, or prime all over to increase burn speed if needed. Edited June 11, 2009 by Bonny
firetech Posted June 11, 2009 Posted June 11, 2009 A core could cause a swimming effect depending on the speed of the comp. you are using.
Bonny Posted July 7, 2009 Posted July 7, 2009 what's a swimming effect? I think it would be the same as a "jetting" effect, where the comet essentially acts as a rocket (unguided) and shoots in a random direction from the thrust generated by the core.
Bonny Posted July 7, 2009 Posted July 7, 2009 Isn't it called a go getter ? Or I'm wrong ? I believe the effect is the same, but with a go-getter it is intentional.
pyrogeorge Posted July 17, 2009 Author Posted July 17, 2009 My new 2,5'' comet pump from strong plastic.
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