dynomike1 Posted March 16, 2017 Share Posted March 16, 2017 I rammed my first rocket today. The rammer set came from Cannon Fuse, since i had some other stuff ordered to.The rocket i built is a 1/2" 4oz. end burner, with 70-20-10. The question is how much or about how much pressure should i have? My camera messed up on me and it looks like i had around 1.17oz. of pressure. Link to comment Share on other sites More sharing options...
Mumbles Posted March 16, 2017 Share Posted March 16, 2017 Are you talking about a thrust measurement from burning the rocket? Link to comment Share on other sites More sharing options...
lloyd Posted March 16, 2017 Share Posted March 16, 2017 (edited) IF you're talking about force on the spindle -- Ummm... 1.7 OUNCES of pressure on the rammer? No... for a 1/2" motor, you'd be 'in the range' if you put about 315 POUNDS of force on that spindle! If you're talking thrust, we usually strive for about 2.5-4x in force times the mass of the total load to be lifted. Lloyd Edited March 16, 2017 by lloyd Link to comment Share on other sites More sharing options...
dynomike1 Posted March 16, 2017 Author Share Posted March 16, 2017 (edited) I Guess i failed to say thrust. From what Lloyd said i need to change to 75-15-10 i guess. Seems like 2.5 ounces of thrust would be light. I cant really find anything on here on 1/2" endburners. Ok test 2 I screened my BP fines and rammed another tube, well that didnt go over to good either. It blew the nozzle out right off the bat. So i think i might be getting somewhere. Edited March 16, 2017 by dynomike1 Link to comment Share on other sites More sharing options...
OldMarine Posted March 16, 2017 Share Posted March 16, 2017 My fuel isn't too hot and I'm getting about 6.5 lbs of thrust from my ½" nozzle-less rockets. If I put a nozzle in them they turn into firecrackers. Link to comment Share on other sites More sharing options...
dynomike1 Posted March 16, 2017 Author Share Posted March 16, 2017 I just granulated some 70/20/10. I think i missed something on Ned's video i thought you were supposed to dampen the comp before you ram it, like Go getters. So i went back and re read and granulated it. Link to comment Share on other sites More sharing options...
Mumbles Posted March 16, 2017 Share Posted March 16, 2017 For end burners, you probably want to use as hot of BP as you can make. There's so such thing as too hot of BP for end burners, just not enough compression or consolidation. This is true if you have good tubes at least. I wasn't totally confident about what you said about granulating. Just to clarify, granulation is helpful and makes it nicer to work with, but isn't absolutely necessary. I personally granulate my comps for this, but that's for convenience and processing. After you wet it with a few percent water and granulate, you do need to let it dry first. That was the part that wasn't entirely clear to me if you were doing. A 4oz end burner will probably give off 1lb of thrust if I had to guesstimate? Maybe someone with an ACME stand or other measurement device will chime in with number that aren't totally guesses. 1 Link to comment Share on other sites More sharing options...
dynomike1 Posted March 16, 2017 Author Share Posted March 16, 2017 I will try another 72/20/10 tomorrow and another 75/15/10 tomorrow. The thing about the 75/15/10 is that it has Dextrin in it, that may be where consolidation may possibly have played a part. Link to comment Share on other sites More sharing options...
calebkessinger Posted March 16, 2017 Share Posted March 16, 2017 Dyno..For what it's worth..I've tried and tried to hand ram 1/2in. endburners and NEVER got one to work with those harder tubes. The nozzle can't lock in properly and always came out. They might make it 20 or so feet up and then boom.. woosh.. arrrrrr! many many many many... attempts ending in frustration. I finally made a support and pressed one and they started working. I saw those sets on there with the tubes and wondered how long till we start hearing the sad stories of rockets that just won't fly. Someone might be able to hand ram an endburner in a nept style tube.. I just haven't met em yet. 1 Link to comment Share on other sites More sharing options...
dagabu Posted March 17, 2017 Share Posted March 17, 2017 I've made hundreds of them using NEPT tubes and clay nozzles and an 8oz plastic hammer. https://youtu.be/dtNZ57B1Q8U Link to comment Share on other sites More sharing options...
dynomike1 Posted March 17, 2017 Author Share Posted March 17, 2017 (edited) I've made hundreds of them using NEPT tubes and clay nozzles and an 8oz plastic hammer. Dave maybe you wouldn't mind sharing your secret with us. Cable thats why i kinda didnt want to start fooling with rockets, seems like every move i make i have to buy something. Now i have to modify me press and buy a tube support. Edited March 17, 2017 by dynomike1 Link to comment Share on other sites More sharing options...
calebkessinger Posted March 17, 2017 Share Posted March 17, 2017 See... now I've met 1 Maybe I was having beginners luck.. Wiley Coyote luck that is. Hard tubes and hand ramming usually creates a problem. I'll stick with that. It's hard to get the nozzle "locked" in unlike in a softer tube where the nozzle rips the inside layers of paper creating a c clip of sorts. Don't feel bad Mike..All I wanted to do was make tools for myself and look where I ended up, and I still don't have a large stack of stuff for me. Link to comment Share on other sites More sharing options...
dynomike1 Posted March 17, 2017 Author Share Posted March 17, 2017 (edited) That would be a good feeling. Making money instead of spending money.You probably dont have a support for these tubes yet? Edited March 17, 2017 by dynomike1 Link to comment Share on other sites More sharing options...
Sparx88 Posted March 17, 2017 Share Posted March 17, 2017 Getting the nozzle really pressed in good worked for me early on. Tube support is king. Then work in a short core. Link to comment Share on other sites More sharing options...
dynomike1 Posted March 17, 2017 Author Share Posted March 17, 2017 (edited) I got my press updated and pressed some nozzles. I rammed 2 motors and the problem i have with that is flaring on one end. Edited March 17, 2017 by dynomike1 Link to comment Share on other sites More sharing options...
DavidF Posted March 17, 2017 Share Posted March 17, 2017 (edited) Here's an end burner I pressed on my 1 ton arbor press with a torque wrench at 127FP. Acme says it would lift a rocket weighing 8 ounces to 210 feet with a 2" ball on it. The tooling was from a small girandole kit I bought a long time ago. I used an unwaxed NEPT tube, bentonite nozzle, and a split PVC support. EDIT: That monocopter was grrreat! Edited March 17, 2017 by DavidF Link to comment Share on other sites More sharing options...
dagabu Posted March 18, 2017 Share Posted March 18, 2017 I posted my Monocopter tutorial in 2011, here it is again for you all. The tubes I used at PGI were hand wound but its all exactly the same for NEPT, Marshall or hand wound. MONOCOPTERS Link to comment Share on other sites More sharing options...
dynomike1 Posted March 18, 2017 Author Share Posted March 18, 2017 Pretty cool.tutorial Link to comment Share on other sites More sharing options...
dagabu Posted March 18, 2017 Share Posted March 18, 2017 Thanks DM! Link to comment Share on other sites More sharing options...
dynomike1 Posted March 20, 2017 Author Share Posted March 20, 2017 (edited) I dont have the fancy equip at hand, so i found some good charcoal left in the bag last night so i milled a batch of 75-15-10 and granulated it with Denatured alcohol no Dextrin it seemed to be pretty hot so i rammed a motor today and thought i was doing pretty good. So i done a test on it and this is what i did. Motor 5" long i rammed 3.5" of comp, burn time was 5sec. peaked out at 7oz. I had to ram it because my 1T Arbor is not tall enough yet. I guess maybe i have enough pressure for a Dola anyway. Edited March 21, 2017 by dynomike1 Link to comment Share on other sites More sharing options...
Wiley Posted April 9, 2017 Share Posted April 9, 2017 Maybe I was having beginners luck.. Wiley Coyote luck that is. Did someone say my name? Link to comment Share on other sites More sharing options...
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