yvariro Posted February 20, 2013 Posted February 20, 2013 (edited) Hi all! yesterday i shot a my first 1LB rocket!,with a 200 Gr (~1/2 pound) dummy head and a little bp report for see the high and the delay, the fuel was 62/28/10(ballmilled 3hours)and 4 extra parts of 30meshs charcoal,I put granulated bp in the core for make a quick start but it not seemed to work. The dummy shell consisted of a 3" can shell filled with flour and a 2"ball shell filled with bp for make the report http://www.youtube.com/watch?v=yS5UsVLbKCc so you can see the trust and the delay are not good,so my next motor will have a 64/26/10 fuel with no extra part of charcoal,I hope it will not cato I hope lift some 3" shell in the future Edited February 20, 2013 by yvariro
nater Posted February 20, 2013 Posted February 20, 2013 (edited) Nice successful flight. 60/30/10 is the most common ratio for a standard core burning BP motor. I suspect your fuel without the extra charcoal would fly just fine though. In the future, please use something to guide the stick as it picks up speed rather than pushing the end of the stick in the ground. A 4' length of PVC pipe stuck in the ground will work and is easy. Stick rockets don't have much stability at liftoff and need a little help. Edited February 20, 2013 by nater
yvariro Posted February 21, 2013 Author Posted February 21, 2013 thanks you I hope lift 300-330 Gr in the futur so i must have a good fuel,I've re-ball milled the fuel for make the extra part charcoal finer Thanks you for the idea,I'm going to buy one,or see if my mortar can do the job
nater Posted February 21, 2013 Posted February 21, 2013 Once your fuel is dialed in, you should have no trouble lifting a 3" or 4" ball shell on a 1 lb motor. With fuel that was known to be good, we were able to have a group of first time builders lift 3" shells on their first attempt. The fuel was simply 60-30-10 BP, ball milled using Alder charcoal. (which is pretty hot). Only one rocket CATOed that day and he didn't ram it hard enough. Everyone else had great flights. As for the mortar, that works fine for small rockets, but larger ones I prefer a good launch tube that supports the entire length of the stick. Some have build real nice racks to display flights, others just drive a pipe into the ground. One club member makes metal spikes with section of bar welded like a cross, so you can drive it into the ground. The non sharp end is long enough a piece of pipe can be slid over top and you have a portable launch tube.
nater Posted February 21, 2013 Posted February 21, 2013 (edited) I also want to add, you don't NEED to ball mill BP to make a rocket. I use screen mixed only for my own and they work just fine. Since I don't use a standard BP spindle, I need to use a little hotter fuel than you will, but the concept is the same. I like being able to screen mix and granulate fuel on shoot sites where we can build. If you time it right and get good weather I can arrive on site with raw materials and have plenty to shoot that night. Everything for this rocket was made in one day, with no ball milling. I should have waited until it was a little darker and cut the stars a little bigger, but I was happy with it. That header probably weighed about 300g and was the soft break was intentional. Edited February 21, 2013 by nater
yvariro Posted February 21, 2013 Author Posted February 21, 2013 Thanks you for all of you experimented advice!I use my ball mill because my charcoal and my potassium nitrate,they are 30meshs fine,and my ball mill is a little lortone rock tumbler,so the powder is milled but not too much,maybe your chemicals are already pre milled?Your rocket was very nice!! for a 300gr shell,it flew very quick!I will make some fuel without the extra part of charcoal,and see the result,and do an other test,but with 300 Gr this time
nater Posted February 21, 2013 Posted February 21, 2013 I do think you will need to mill those chemicals until they are airfloat. My charcoal is airfloat, and I mill batches of KNO3 by itself so I always have fine material ready when I need it. The coarser charcoal does give a prettier tail but less thrust, always a trade-off.
yvariro Posted May 25, 2013 Author Posted May 25, 2013 (edited) Hi all,Some news of my rocket study Here is a rocket with the same fuel that i shot my a 1/2Lb dummy head,with a 2" cylindrical shell on the top,stars was D1,I was happy with the result but I did not put enough boosting charge,so the break was not big enough http://www.youtube.com/watch?v=uS8cDeIhSoE Recently I've tried a news fuel with a300gr dummy head,The rocket did not flew right to the sky,I think it's due to the stick,the video is really bad,sorry of that,and yes not enough visco( I realized that the burnrate of my visco changed a little bit ) http://www.youtube.com/watch?v=5xtHtrGh59U Fuel was 65/25/10,ignition at the top of the core,I will shoot soon a farfale and inserts cylindrical shell,and a 3.5'' brocade spider-web to yankies flashings stars (wich weigt 330Gr,I hope it will lift it to a good height,I will maybe try another fuel type,this time with 67/23/10 ) (both are made) My final intention is to lift 400Gr max. to a good height I've some question to ask, Does granulating the fuel worth it ? I don't mind about the dust when I ramm,all my motors are made outside, I tested a little nozleless R-candy motor (3/4" ID 3" long fuel was just 60/40 with 1% Fe203) the results realy surprised me http://www.youtube.com/watch?v=xEwwef61FKk A 1LB motor test with a better fuel is an obligation ! I will check the result here Yvariro Edited May 25, 2013 by yvariro
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