Bensmith Posted December 5, 2012 Posted December 5, 2012 Thought some of you guys may find this interesting. I posted a simple tutorial for making KBenz whistle fuel and manufacturing a white tailed whistle rocket. These are the latest in a long line of how-to guides on the drawing board. You can view both tutorials on my website if you like. www.firesmithtools.com -Ben 1
Col Posted December 7, 2012 Posted December 7, 2012 I`m not brave enough to use ti-sponge in whistle rockets even in the delay
Bensmith Posted December 7, 2012 Author Posted December 7, 2012 No bravery needed. Working with Ti bearing fuel above the spindle is quite a bit safer than if the Ti was around the spindle. Plus, with the petroleum jelley (or mineral oil as some guys use), really desenitizes the fuel. Should you not want to use Ti, substitute 5% coarse aluminum. Really, the key to working with whistle (or any fuel) in the safest manner possible is to avoid metal bearing fuels around the spindle and also clean the rammer bores after each increment. I've been around two accidents (one right next to me and one about 5 minutes before I got there) and they both involved rammers that had plugs of fuel crammed in the bores. Keep the bores clean and the probability of an accident greatly diminishes.
WonderBoy Posted December 7, 2012 Posted December 7, 2012 Ben, I know that you developed the Super BP spindle through your own testing, but is it similar to the H-U spindle? Have you tried hotter benz whistle with it? WB
Bensmith Posted December 7, 2012 Author Posted December 7, 2012 The Universal spindle is a bit shorter and fatter than the Super BP. My Universal spindle is a bit different than the version developed by SLD as well. However, about the only time I use my Universal setup anymore is when I'm making a BP rocket with a nozzle. With my Universal spindle I can use hot 75:15:10 BP and a clay nozzle. This fuel would be too hot with a nozzle for the Super BP spindle. Once you switch to nozzleless motors, though, a taller & skinnier spindle is more desirable in my opinion. Oh... yes the Super BP works even better on NaBenz fuel. I made a few rockets using Dan Thames' Super Whistle fuel and they flew like a scalded cat. When I finally run out of KBenz I'll be switching over to the NaBenz fuel (I've got a huge drum waiting for me).
WonderBoy Posted December 7, 2012 Posted December 7, 2012 (edited) I agree about the taller and skinnier spindle for nozzless. I don't make many, but when I do, for 1lb motors, I use a 5/16x 5" spindle. I've been running straight 76 perc- 23 NaBenz- 1 CuOxy - 3 mineral oil on my 1lb "BP" spindle which is about .375" at the base and about 4.75" long. I bet you could leave out the charcoal and make a real kick butt motor. I've posted this before, but here is an example of a 1lb whistle, the heading weighs just under a kilo: http://youtu.be/M_TCWH32Fto I may bring one to the next MPA shoot and see how much weight I can toss up with it. Did you get one of those big drums from Jeff? I'm jealous, I just don't have enough storage space to have a 60gallon drum hanging around. WB Ps. Those are very nice tutorials. Edited December 7, 2012 by WonderBoy
nater Posted December 8, 2012 Posted December 8, 2012 (edited) I have posted these before too, using Ben's Universal spindle I get 36 pounds of thrust from a 1 pound motor made with NaBenz Super Whistle fuel. This easily lifted a 2 break 3" cylinder a little too high. I can't complain about the results at all. This summer I plan on finding the limits with this setup. Edited December 8, 2012 by nater
psyco_1322 Posted December 8, 2012 Posted December 8, 2012 I think, with a well tuned spindle and fuel, we could some day be shooting 2 kilo loads on 1lb motors. Giving that the tube stays together, it should not be much a challenge, just a lot of work. It might not be the altitude for multi-break headers, but maybe singles or salutes. We tried this year at PGI to get closer to finding out the answer to the lingering question of brute powerful thrust vs slow building thrust....but data was not well retrieved, to say the least. I posted this in another thread, but it's one of my favorite little combos. I think this header was around 440g, but I've have some well over a pound, before they even got onto the rocket. They get to about 2 stories, which is just right IMO.
AlexPyro66 Posted December 10, 2012 Posted December 10, 2012 With a 3lb Universal spindle wich is the max weight it would lift and with what composition?
Bensmith Posted December 11, 2012 Author Posted December 11, 2012 Yeah, I do wonder where the limit with these motors really is. A buddy in our club was playing around with a really high impulse fuel this year that made whistle fuel look slow. I'm unable to shed any light on what he was using but I'm sure he'll be posting something in a bulletin article down the road a bit. I tend to skew my motors towards reliability a bit more than absolute performance. With my 1lb motors, lifting a 5" ball shell is plenty good for me. The vid's posted above are really cool! I am very impressed! I do have a design in mind for a "Super Nozzleless" core burn set I'll be testing when things get back to normal around here. It should really scream on any of the benzoate fuels. Alex; motor power is really a combination of tools, fuel and manufacturing technique. As such, overall power can vary quite widely. With the benzoate whislte fuels and either the Universal or Super BP spindles, you will be able to lift a 6" ball shell on a 3lb rocket without much issue at all. Heck, even simple BP fuel will do this with a 3lb rocket. As you get your motors dialed in a bit more I have absolutely no doubt you could lift even more. But again, get your motors working reliably before attempting to lift a bunch of weight.
nater Posted December 11, 2012 Posted December 11, 2012 (edited) Ben, I am hoping to get a handful of people together and test various motors on thrust stands and find their limits. With different chems, tooling, and techniques it won't be completely accurate but I want to compile average performance from each common motor. From there I also want to see what relationship their is in performance with each size of motor with the same tooling dimensions and fuel. One person is on board already and I have not asked anyone else yet. Once winter gets under way and we get close to Spring I will see what I can get done. I am happy with the performance I get with the H/U spindle with Dan Thames' Super Whistle and SLD's hybrid fuels on my one pound set. I will start with a 6 on the 3# size and want to see if I can lift an 8. Edited December 11, 2012 by nater
AlexPyro66 Posted December 11, 2012 Posted December 11, 2012 I have heard that a 3lb hybrid rocket can lift a 10 inch shell is that possible?
Bensmith Posted December 11, 2012 Author Posted December 11, 2012 I'm sure "anything" is possible.... but that doesn't sound terribly realistic. I've seen 6lb motors lift 10" & 12" shells, though.I've found the easiest way to lift a 10" shell is a pound of 2F ;-).
Mumbles Posted December 11, 2012 Posted December 11, 2012 3lb rockets under the right conditions can definitely do 8" shells. 6lb rockets under the right conditions can definitely do 10 and 12" shells. I've heard rumors of a test 10" shell on 3lb motor, but I don't know if they ever happened. There were some concerns over distances from what I recall. You'd have to talk to the guys who do these sorts of rockets to get all the details. I'm not even entirely sure if they're using a stock tooling set. You really need to dial these things in before attempting to lift anything serious. A rocket CATO is one things, but strapping a large shell on top takes it to a very new level for safety concerns.
MrB Posted December 12, 2012 Posted December 12, 2012 A rocket CATO is one things, but strapping a large shell on top takes it to a very new level for safety concerns.You ca say that again. A couple of years ago a CATO triggers the shell above it, causing a 3" shell to go of at 3-4meters. Burning stars sizzled past me where i stood wondering what the hell just happened. I don't wanna imagine what it would be like if the stars were graded by inch rather then mm's when the shell was built.B!
AlexPyro66 Posted December 12, 2012 Posted December 12, 2012 You ca say that again. A couple of years ago a CATO triggers the shell above it, causing a 3" shell to go of at 3-4meters. Burning stars sizzled past me where i stood wondering what the hell just happened. I don't wanna imagine what it would be like if the stars were graded by inch rather then mm's when the shell was built.B!I have been more lucky than you when i had a cato on a 1lb bp rocket with a 3'' header the header didnt ignite that was weard
nater Posted December 12, 2012 Posted December 12, 2012 A few months ago, someone had a 3/4" BP motor CATO with a 3" commercial color shell as a header. They cut the time fuse as short as possible before mounting it as a header. The CATO lifted the shell to a low, but still safe height before it broke. I bet they couldn't do that again if they tried.
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