joeyz Posted July 30, 2016 Share Posted July 30, 2016 from what i been reading on this topic, "nozzle vs nozzleless", i am new to rocketry and trying to figure things out. i just built my 1 ton press, following ned gorski's version using an arbor press for $45 at harbor freights and creating my own version (see picture below), and i just got my first rocket tool kit "1 lb end burner" set a few days ago from pyro direct. My first rocket CATO'd using my standard bp (75/15/10) with a dash of dextrin mix and granulated. The BP i make is mainly lift charge for my shells and came to realize that my BP is way too powerful. After ball milling for 4 days its like flash powder lol So i made a new batch of BP specifically for rockets using Ned Gorski's 70/20/10 rocket fuel screened and mixed in a plastic container by shaking it for 15 minutes. Now my 1 lb rockets are taking off normal. my question is now is if i am using the right fuel? and i am using clay nozzle and should i just do away with the nozzle? reason why i ask is because i want to start adding 2" and 3" headers on the rocket but fear that my fuel isnt strong enough to carry the weight. it appears in this conversation here that a nozzleless rocket will have more initial thrust and lift straight up. Link to comment Share on other sites More sharing options...
joeyz Posted July 30, 2016 Share Posted July 30, 2016 sorry, forgot to add the picture of my rocket press - joe Link to comment Share on other sites More sharing options...
dagabu Posted July 30, 2016 Share Posted July 30, 2016 (edited) You want to develop about 6500 pounds of force on the face of your 1 pound tooling, you have a 1 Ton arbor press which may/may not develop 2000 LPI on 1 square inch of area meaning your theoretical maximum pressure on 0.0441 of surface is 4535 LPI! This means that a 5/8" rocket can be pressed on this press but the 3/4" is just too much surface area to get the pressure you need to consolidate the black powder with this press. Also, it is highly unlikely that you are getting 2000 Loading Pounds Per Square Inch from this press, especially with that short handle. Nozzleless motors should be able to handle all BP without CATO, check where you are lighting the grain, end, middle or throat? If all the way up the throat, try bringing the fuse to the end and light one there and see if the CATO's stop. My theory is to find the most powerful composition you can make and make just that composition, make a lot at once so that you have consistency. At that point, add charcoal by weight to smaller batches to tame it down and create sparks for a tail. This way, you have a universal fuel, good for anything and all you have to do is add charcoal to dial it in for that particular use. YMMV... Edited July 30, 2016 by dagabu Link to comment Share on other sites More sharing options...
DavidF Posted July 30, 2016 Share Posted July 30, 2016 Another thing to consider is the dextrin. I don't know what a 'dash' is. But I do know that if you use 2 1/2% dextrin and fully activate it by granulating with enough water to make a 'putty ball', the grains will be very hard. Even at proper loading pressures, CATO is likely. Steve LaDuke suggests dextrin, but only moistens the propellant to a 'brown sugar' consistency- his words. From what I can see here, we are talking about an end burner. If so, there is no chance that your black powder is too hot. On a well-made end burner, regular black powder can be 'spiced up' with some whistle. That's not likely a good idea with your press setup. There is no way that you are going to lift a 3" shell with a 1lb end burner using 70-20-10 with your setup. You can easily test your lifting ability by using a dummy load. You can consolidate your (no dextrin!) 75-15-10 better on that press by using small increments, and also by granulating the hot BP with an additional 2% by weight of wax. The wax is dissolved in warm naphtha (flammable!), and distributed evenly in the propellant. It is then riced and dried. Another way to effect better consolidation at lower pressures is to add 2% additional weight of water- instead of the wax- to your 75-15-10. The mixture would need to be screened and tempered for a while to make sure the moisture is evenly distributed in the propellant. The rocket will get more powerful over a period of days as the water slowly exits. Despite everything I mention, you are still asking a lot of that press to make 1lb rockets though, as Dagabu said. Link to comment Share on other sites More sharing options...
dagabu Posted July 30, 2016 Share Posted July 30, 2016 Agreed, in an endburner, nothing is too hot and there is no such thing as too much loading pressure. https://www.youtube.com/watch?v=inVdlyuCiEo Link to comment Share on other sites More sharing options...
joeyz Posted July 30, 2016 Share Posted July 30, 2016 guys, thanks so much for sharing your expertise. sorry for asking too much and will try to tone it down to one question for each i see now has many variables. shells have been my forte in the past years and never thought i would get into rocketry until this year of lifting 3" shells with estes E-9 rocket motors (pass firing the motors) became too expensive. your experience and knowlegde explains why my first end rocket motor (nozzled) CATO on the launch, m-80 on a stick lolthe bp i used on my first 1 lb rocket was a granular batch from my lift and burst charge container for shells, very high BP and difficult to crush (press) which i think the alcohol and dextrin makes it more difficult to press, crunch, crunch. good thing i test without headers first. i will use the same concept as for when i began with shells, dummy load (baby powder, chalk, flour, etc) until i get the fuel right and my rockets are reliable. so far, in my new bp batch i used what ned gorski uses a more damp soft bp. i have shot 26 1lb nozzled rockets so far without a header, except the last 6 were with 2" ball headers. once i graduate stage 1 (right bp fuel and to nozzle or not to nozzle) i want to move up to stage 2, stronger, faster and able to carry a larger header. about the press... its the same one that ned gorski and skylighter uses on up to 5/8" rockets. i just cannot remember where i saw ned or some other creditable person video on where they said you can tenchically used the same press for a 3/4" rocket with a longer arm for more pressure/lverage. the rachet are is extendable to apply greater pressure. according to ned gorski, and skylighter, im definately with you about the surface area diameter seems to be key . so maybe i should scrub any further thoughts on pressing 3/4" or greater rockets with headers until i build another press. i just have to crack the code now in finding a 5/8" core tool kit. im a little confused on that because most sites just say bottle rocket tool kit, 1lb, 2lb, etc. some never give the actual ID. will research further. also need to research what is the maximum size/weight on a 5/8" ID rocket, correct fuel and correct press. Link to comment Share on other sites More sharing options...
joeyz Posted July 30, 2016 Share Posted July 30, 2016 ok, finally found a site (thanks to dag in another post) that revealed what is the ID of 4oz, 8oz tooling. so 4oz 5/8" universal core burner is the way to go for me for now. thanks dag! now just need to know what is safe size header i can use on a 8oz (5/8" ID) rocket. 1 Link to comment Share on other sites More sharing options...
joeyz Posted July 30, 2016 Share Posted July 30, 2016 by the way, just expirementing, i pressed two 2lb nozzled rockets on that press and flew just as nice as the 1lb. however, like mentioned here, i dont think it would handle any header and not reliable due to not having enough pressing psi to really handle a load. Link to comment Share on other sites More sharing options...
joeyz Posted July 30, 2016 Share Posted July 30, 2016 dag, forgot to mention nice vid and thanks for sharing. was that a 1lb (3/4") rocket, looks like it. was that whistle fuel? was it suppose to whistle or another option to use whistle fuel as fuel and not wanting to screech loudly, purposely muting sound? Link to comment Share on other sites More sharing options...
dagabu Posted July 31, 2016 Share Posted July 31, 2016 Yes, that was the maiden flight of Calebs 3/4" endburner tooling for special use, it was pressed by a friend in Iowa and the fuel was 100% hot sali whistle. They don't whistle in a confined space like an end burner though, the burn chamber and such destroys the oscillation that we hear. Link to comment Share on other sites More sharing options...
ddewees Posted July 31, 2016 Share Posted July 31, 2016 If you leave a gap after the nozzle, it will still whistle. http://i1149.photobucket.com/albums/o588/SaltLakeAreaPyros/MODIFIED%20ENDBURNER_zpsvwxnqonc.png 1 Link to comment Share on other sites More sharing options...
dagabu Posted July 31, 2016 Share Posted July 31, 2016 Interesting design, never thought of that before. Link to comment Share on other sites More sharing options...
ddewees Posted July 31, 2016 Share Posted July 31, 2016 I started making large fountains that way, then tried a rocket... And it works well. I've even made black powder/strobe end burners that way. [Video] Link to comment Share on other sites More sharing options...
ddewees Posted July 31, 2016 Share Posted July 31, 2016 Wrong video, that one above had whistle... This one was just black powder. [Video] Link to comment Share on other sites More sharing options...
OldMarine Posted July 31, 2016 Share Posted July 31, 2016 Both were awesome Dan! Link to comment Share on other sites More sharing options...
DavidF Posted July 31, 2016 Share Posted July 31, 2016 So many possibilities! Once I made a 1lb nozzled coreburner with sali whistle +20% charcoal. The delay portion was slow whistle with FeTi. It wasn't loud, but it did whistle. After I bragged to somebody about it, I could never do it again. I never knew why- until now. Dan's comment about the empty tube below the nozzle jogged my memory. The (borrowed) tooling I used for that rocket had quite a long standoff from the nozzle to the tube end. All my later attempts used 'regular' tooling. Also: I did experiments with strobe inserts, and found that the same logic applies. Here's the ONE that worked. Ignore the poor work on the shell.https://www.youtube.com/watch?v=U29_Ds0z5lk Link to comment Share on other sites More sharing options...
mabuse00 Posted August 2, 2016 Share Posted August 2, 2016 You want to develop about 6500 pounds of force on the face of your 1 pound tooling, you have a 1 Ton arbor press which may/may not develop 2000 LPI on 1 square inch of area meaning your theoretical maximum pressure on 0.0441 of surface is 4535 LPI! This means that a 5/8" rocket can be pressed on this press but the 3/4" is just too much surface area to get the pressure you need to consolidate the black powder with this press. Also, it is highly unlikely that you are getting 2000 Loading Pounds Per Square Inch from this press, especially with that short handle. It has been discussed over and over, but I'd like to remark that some people seem to get away with much less force. A one ton press too - but the motor is 2lb! A 3 ton arbor press would be nice... Link to comment Share on other sites More sharing options...
dagabu Posted August 2, 2016 Share Posted August 2, 2016 (edited) 2000 PSI is 3333 LPI on a 2# motor and while not a LOT of pressing force, it is more than 50% more force than 2000 LPI. Edited August 2, 2016 by dagabu Link to comment Share on other sites More sharing options...
ddewees Posted August 2, 2016 Share Posted August 2, 2016 Matt in Vermont gets away with super low pressures too, even on whistle... So it can be done. Link to comment Share on other sites More sharing options...
dagabu Posted August 2, 2016 Share Posted August 2, 2016 Must be a srcret, I can't duplicate that. Link to comment Share on other sites More sharing options...
joeyz Posted August 3, 2016 Share Posted August 3, 2016 Mabuse, thanks for finding that vid. I know skylighter says the 1 ton is capable of up to 5/8 but knew i saw elsewhere, ned gorski vid, that ned was using it for 2lb which is why i decided to make me the same cheap press to do at least 3/4 1lb rockets and get excellent results without using the arm extension for more pressure. Bp rockets flying great! Havent tried that 1 ton on whistle mix yet, waiting on chems. Link to comment Share on other sites More sharing options...
joeyz Posted August 3, 2016 Share Posted August 3, 2016 earlier in topic, saw talk about "crack in grain". im unfamiliar with the term. i assume it means that not fully compressed fuel? air pockets? Link to comment Share on other sites More sharing options...
dagabu Posted August 3, 2016 Share Posted August 3, 2016 Simple question, hard answer because nobody knows what happens. Years and yaers ago, I and others cut whistle motors apart to look at what was going on with constant CATOs, David F came up a solution as have others. What I found was a very glassy and easily broken fuel grains at the place where increments were pressed together. The tube was also compacting (again, David F found solutions) and some postulated that the tube and fuel grain "relaxes" over time causing cracks in the fuel grain, creating an over-pressure with all that surface burning at once causing a DUN! Long story-short... 1 Link to comment Share on other sites More sharing options...
NeighborJ Posted August 3, 2016 Share Posted August 3, 2016 I know it would be a PITA but it could be possible to use a wooden rammer with teeth on the end to ream off the glassy Finnish between pressings. This would allow the next increment to get a purchase on the last one. Link to comment Share on other sites More sharing options...
dagabu Posted August 3, 2016 Share Posted August 3, 2016 Yes but wood is much too soft to keep sharp teeth, better to use aluminum or SST. One of the issues that develops then is the increments become painfully small and the teeth have to be kept very shkrt, maybe 1/16". Any longer and they loosen too much comp and create soft spots in the grain. Link to comment Share on other sites More sharing options...
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