- This topic has 13 replies, 4 voices, and was last updated 15 years, 7 months ago by
MikeS.
MikeS.-
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edward
1% does a very good job of accelerating the burn rate. I’ve found that you get a much more conistent propellant if you ball mill some KNO3 until it is very very fine, almost flour like. You then mix that 1/3 flour to 2/3 regular by weight and then add your sugar and iron oxide. You get a smoother burn and it is much more consistent.
I would not go above 1% – but I know that measuring just a gram can be hard. I used to mix my sorbitol and iron oxide in a premix and then mix that with my KNO3. I would measure out 990 grams of sorbitol and 10 grams iron oxide. Mix them in a ball mill for a couple days and you get a very nice uniform product. Then mix that with the potassium nitrate.
What internal geometry are you using? If I remember I used 1″ PVC, a washer that had a 5/16 hole in the middle for a nozzle and then a 3/8″ aluminum rod that was turned 5/16″ on one end for a core. I used to make them about 5″ long.
Edward
MikeS
Mine is pretty much the same.
I use an arrow for the core.
You can get wind chime parts at ‘Hobby Lobby’ in many differant
sizes that work well also.Mine is 1- 8″ to 9″ grain. poured into the PVC. if I was to go larger,
I would make individual grains making a three or four grain.I have made a few grains. With the idea of putting them into a
premaid case (RMS / LMS)I purchased some LMS kits to try making some 29mm motors.
Have not tried that yet.MikeS
Tried a new forward closure today. Took less work and was a little
less involved in construction.NNOOOTTTT 😳
With the help of My friend Carl with a countdown, It faild
almost immediately.Glad it was in a test stand and not in a vise or a rocket.
I will go back to a closure that has not failed.
More Gooder.MikeS
latest tests. Went perfect. Everything works right. They are ready
to put in a rocket someday.Thank You Carl for the countdown and commentary.
edward
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