dagabu Posted June 17, 2011 Posted June 17, 2011 I posted this picture elsewhere but I wanted to share with you all what a proper rocket fuel increment looks like on the outside of the casing. This is a 1# (.75" or 3/4" ) rocket motor, 7" long with a clay nozzle and 12 increments of BP. The fuel portion of the rocket motor is 4.5" long and each fuel increment is about .375". That makes for 1/2 ID for each increment which will give you the best consolidation vs efficiency rate for reliable motors. I cut my tubes long so that I can add a report, coupler or whatever I wish without any hassle. http://www.pyrobin.com/files/100_2351_1.jpg -dag
Juiceh Posted June 17, 2011 Posted June 17, 2011 This is a 1# (.75" or 3/4" ) rocket motorYou forgot 19mm. Endburner or Coreburner? I'm guessing endburner based on the 4.5 inch fuel grain. Pretty cool pic. I can't see the increments that clearly on the outside of my tubing. Minus the photoshopping later on, how did you get the increments to show so clearly? Almost looks like you rubbed it with some pencil lead.
dagabu Posted June 17, 2011 Author Posted June 17, 2011 You forgot 19mm. Endburner or Coreburner? I'm guessing endburner based on the 4.5 inch fuel grain. Pretty cool pic. I can't see the increments that clearly on the outside of my tubing. Minus the photoshopping later on, how did you get the increments to show so clearly? Almost looks like you rubbed it with some pencil lead. I press my tubes into a support and press them out again. The aluminum support leaves the dark marks on the tubes as it rubs the walls. I am using Universal Tooling, it's a core burner with a spindle length of 4.3" (?) inches. -dag
PersonGuyDude Posted June 17, 2011 Posted June 17, 2011 I posted this picture elsewhere but I wanted to share with you all what a proper rocket fuel increment looks like on the outside of the casing. This is a 1# (.75" or 3/4" ) rocket motor, 7" long with a clay nozzle and 12 increments of BP. The fuel portion of the rocket motor is 4.5" long and each fuel increment is about .375". That makes for 1/2 ID for each increment which will give you the best consolidation vs efficiency rate for reliable motors. I cut my tubes long so that I can add a report, coupler or whatever I wish without any hassle. -dag Ah I was thinking about proper fuel increments too. What is the proper size of an increment measuring spoon? I was thinking maybe 1.5 tsp. Ill be ramming my BP rockets.
dagabu Posted June 17, 2011 Author Posted June 17, 2011 Ah I was thinking about proper fuel increments too. What is the proper size of an increment measuring spoon? I was thinking maybe 1.5 tsp. Ill be ramming my BP rockets. I don't do it that way, I use a copper cap on a handle and put a full scoop into a casing and measure the increment, I then cut off some of the copper and make another increment, repeat, repeat till the increment is exactly 1/2 ID. This is done in an empty tube with no spindle mind you. BTW- Every fuel is different as well, BP compresses a lot so I hold it at 6500LIP for 30 seconds while whistle compacts immediately with no dwell. -dag
PersonGuyDude Posted June 17, 2011 Posted June 17, 2011 I don't do it that way, I use a copper cap on a handle and put a full scoop into a casing and measure the increment, I then cut off some of the copper and make another increment, repeat, repeat till the increment is exactly 1/2 ID. This is done in an empty tube with no spindle mind you. BTW- Every fuel is different as well, BP compresses a lot so I hold it at 6500LIP for 30 seconds while whistle compacts immediately with no dwell. -dag O ok interesting. To the hardware store! Haha, been doing that alot lately!Thanks for the help.
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