TYRONEEZEKIEL Posted June 23, 2014 Posted June 23, 2014 What is the purpose of this post? Are you asking for the formula, do you plan to share it, or do you want to discuss its characteristics?
burnie Posted June 23, 2014 Author Posted June 23, 2014 Want to make my own reloads, I have made apcp using this formula that works very well AP 65% Al 10% silicone rubber 25% iron oxide .05% Using 24mm parts from rocketmotorparts.com and cored by pushing a 4oz spindle into it before it sets up. I know for a delay mix to either add 15% baking soda to basic black powder, or uping the charcoal content, or not ballmilling the black powder, just curious I guess. Please correct me if I am wrong about a delay mix
TYRONEEZEKIEL Posted June 23, 2014 Posted June 23, 2014 Ammonium perchlorate is not compatible with coming to contact with nitrates. Im not entirely sure if the rubber would inhibit the reaction by coated the AP, however there are delay mixes that don't use KNO3. I also think you are going to have a hard time using a powdered delay with a rubber setup fuel. You could not get the powdered delay consolidated onto the rubber fuel enough to be effective. I know that APCP motor geometry is a pretty big deal. good APCP formulas really output quite a bit of pressure inside the motor casing. Thats why they use aluminum and graphite nozzles instead of paper tubes. I am not entirely sure what the effect of using a 4oz BP spindle would do in regards to giving the optimum burning surface area. Do you plan on making a nozzle? For a delay, why not use a passfire with a piece of time fuse or visco?
burnie Posted June 23, 2014 Author Posted June 23, 2014 I am using the 24mm RMS hardware, and yes, a molded glass/phenolic nozzle .104" and all the other components of an Aerotech reload from rocketmotorparts.com, but using the propellant I made. I just ignited a piece of apcp and it ignited a D1 star touching it?
TYRONEEZEKIEL Posted June 23, 2014 Posted June 23, 2014 Hmm. Try this for making a delay. I do know that Win 39j is a very popular delay formula. If you have a similar glitter formula try that as well. Make a very thin comet with the same OD as your fuel grain. Dab one end of it in some KP based prime. This will act as a barrier for the AP/KNO3. (I don't know if it is necessary, but I imagine if you store the motors you could have potential problems if you didnt use the prime) Just stack the comet once it is dry on top of the propellant grain. Then seal it up and test it. I am sure you will have to play with the dimensions or the comp in order to get the delay timing just right.
burnie Posted June 23, 2014 Author Posted June 23, 2014 Can I ask if you have any experience assembling and using Aerotech hardware and reloads? Will work on posting some pics.
TYRONEEZEKIEL Posted June 24, 2014 Posted June 24, 2014 I do. I was L1 certified a few years ago, but fell off to pyro. Its been quite awhile since I've built a reload of theirs
burnie Posted June 24, 2014 Author Posted June 24, 2014 Here is a reminder, this is a D9-4W, there is a spacer that inserts into the delay that faces the fuel, so the delay doesnt touch the fuel grain in a 4, so it must pass the fire, it might touch in a 7 as it gives a longer delay time and thus is longer.
taiwanluthiers Posted June 24, 2014 Posted June 24, 2014 (edited) Generally you don't assemble a reload until right before a launch, so nobody is really going to store it. I'd be careful about making your own reloads however, it is against NAR safety codes and only allowed in TRA experimental events. It also goes without saying that Aerotech doesn't exactly sanction this... Edited June 24, 2014 by taiwanluthiers
TYRONEEZEKIEL Posted June 24, 2014 Posted June 24, 2014 Oh that's right. Thanks for the reminder. So for the reload, just use a similar liner tube and fill it with your glitter formula. I am pretty sure that the high pressure will affect the linear burn rate, so you may need to do some experimentation.
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