1/12/04 - After rebuilding a modified version of my bike spoke burn chamber, I tested two new formulas for burn rates. The first two are from my MBR hot formula (modified version of TT) and the last two are of my new blue formula. Here are the results from the burn chamber that now has 4 break wires.
10/05/03 - I finished working with the MBR green formula 7 inch strand burn after verifying the case would hold pressure. Since I was able to burn the 7 inch stick without a problem, I got the burn rate data points and was able to come up with A and N numbers. The pressure held just fine at 1230 psi. The MBR Green A=.0167 and the N=.374. Here are some windaq files:
- MBR Sky Blue test 1
- MBR Sky Blue test 2
- MBR Sky Blue test 3
- MBR Sky Blue test 5
- MBR Sky Blue test 7
- MBR Green test 3
- MBR Green test 5
- MBR Green test 7
- MBR SunRise Hot test 1
- MBR SunRise Hot test 2
10/04/03 - I setup the burn chamber to test the MBR Blue and MBR Green formulas. My setup was three, five and seven inch sticks of propellant that I had packed into McDonald's soda straws. They work very well and are consistent in size for better sampling of data. The first was the 3 inch blue which worked well. It got up to 460 psi and I got two good data points. The second was the 5 inch blue that reached 1051psi. The 7 inch was building pressure but one of the bike spokes that did not have enough epoxy (must of had a bubble inside) started leaking so the sample was no good. I whipped up some 30 minute epoxy to fill the hole and let it cure. After a while I came back and set up the 3 inch green. I got good data and it reached 395 psi. The second test was the 5 inch green which made it to 664 psi before the same bike spoke burst out again. This time I had to fix it right. With the data gone for the 5 inch stick, I took apart the closure, drilled out all the bad epoxy, rethreaded the hole and scuffed up the bike spoke to stay put. I used a syringe to insert the epoxy into the hole to make sure it was completely filled. I was able to get a much better seal on the closure. I let it sit over night to make sure it was cured.
09/05/03 - I built a new burn chamber to help get A and N number to better dial in my motors