Pirotex Posted January 20, 2015 Posted January 20, 2015 (edited) 25 mm sorbitol rocket with 70 mm can shell" Golden crown with magenta rubies" Rocket engine:Nozzleless 25 mm with standart sorbitol fuel 65/35 + 1% red iron oxide.Core lenght - 150 mm http://savepic.ru/5505464m.jpg Shell:4 layers golden glitter stars (15*12 mm, 40 stars in shell) + 6 mini shells with magenta starsBurst - BP on sawdust + 1.5 g. perchlorate flash. http://savepic.ru/5562811m.jpghttp://savepic.ru/5556667m.jpghttp://savepic.ru/5554619m.jpghttp://savepic.ru/5553595m.jpg VIDEO: https://www.youtube.com/watch?v=QBvcLoAUhrE&feature=youtu.be Edited January 20, 2015 by Pirotex 2
mabuse00 Posted January 20, 2015 Posted January 20, 2015 (edited) A very nice one Great that you found your way to this page, I guess many people here have been watching your channel for a long time.Apart from the nice rockets I also like the fact that you share many details in your videos. I intended to copy your motor design for some time now but never had the time. I was under the impression that KNSB needs high pressure to reach useful burn rates, making it unsuitable for pyro uses. However, you even use it nozzleless, with a rather short core (compared to "normal" BP rockets) - wow. May I ask how heavy that shell was?Have you ever tried to use a longer core to increase payload capacity? Edited January 20, 2015 by mabuse00
Pirotex Posted January 20, 2015 Author Posted January 20, 2015 (edited) mabuse00Q: May I ask how heavy that shell was?A: 330 g. Q: Have you ever tried to use a longer core to increase payload capacity?A: No, maybe in future I try this Edited January 20, 2015 by Pirotex
a_bab Posted January 21, 2015 Posted January 21, 2015 Nice to see you here Pirotex. As said before, I'm sure many admire your work.You clearly don't have access to "good" supplies, so you roll your own tubes and find alternatives for fuels. The stars are very impressive - I would have never though about making a Mg/Na nitrate star for instance.Other Russian addicts are really good with tool making, and generally speaking you greatly contribute to the scene. Welcome !
mabuse00 Posted January 25, 2015 Posted January 25, 2015 One more question: How do you cast these?I just tried to melt cast KNSB on a normal BP tooling set, by pouring the fuel around the spindle instead of pressing/ramming.It seems to work nicely, but extracting the spindle is somewhat difficult.Would you rather wait until the fuel hardens, and maybe also contracts, or remove the spindle while the grain is still soft?My spindle teared a little amount of fuel sticking to it out of the motor. The core is a little rough now, I canot see any bigger voids though.It seems like your coring tool/spindle is covered in paper, can you explain that?If you pull the rod out, I would assume the paper to stay inside the core...?
dagabu Posted January 25, 2015 Posted January 25, 2015 A very light coating with a silicone gel or oil will stay on the spindle when casting the grain but wax will melt off. Yes, the spindle is very hard to remove, if you let it cool (wrap it well and stick it in the freezer until the spindle gets cold) then the spindle will come out easier.
Ericz Posted January 25, 2015 Posted January 25, 2015 Nice rocket !!But...How much composition of kno3/sorbitol is there in the motor ?Your core is 150 mm long.... do you use any of the same composition as a delay ? Maybe 1 or 2 cm ?Is there bentonite clay on top of the fuel ?And how much Ti did you add to the fuel ?Greets and thanks !Iam really known with 6-3-1 coreburners from 10 mm to 40 mm. But this is a new thing for me.... awesome
Pirotex Posted January 25, 2015 Author Posted January 25, 2015 mabuse00Spindle covered in paper + scotch tape + oil.Look here: http://serge77.rocketworkshop.net/nozzleless4/nozzleless4.htm Ericz~ 150 g. composition. In delay I use glued BP tracer 50/40/10 + 5% Ti
dagabu Posted January 25, 2015 Posted January 25, 2015 Thats pretty darn clever of you! I like the paper getting turned to collapse the former...
dagabu Posted February 1, 2015 Posted February 1, 2015 I like the all thread for compressing the grain as well. I imagine that if one were to use an epoxied phenolic or graphite nozzle, that would make a nice 1-n-done motor. http://serge77.rocketworkshop.net/nozzleless/nozzleless.htm
stix Posted February 1, 2015 Posted February 1, 2015 Great stuff Pirotex. It's the sort of thing I've always wanted to do with sugar rockets myself, ie. have some sort of pyrotechnic header. I've never been able to work out how to do a delay without using BP and therefore just stuck to "rockets". I really like your ingenuity using the "collapsible cardboard spindle" - If there's a will there's always a way <thumbsup>. My method is pretty much the same as Dagabu, I use silicon spray on my spindle then put it in the freezer (to contract the metal) then twist and pull out with a vice. Cheers.
dangerousamateur Posted February 1, 2015 Posted February 1, 2015 Cool stuff! Pirotex, do you first pour the fuel in the tube and squeeze the spindle in there? Or do you pour the fuel in with the spindle fixed in the motor?
Pirotex Posted February 1, 2015 Author Posted February 1, 2015 (edited) dangerousamateur, first pour the fuel, spindle after that..Photo: http://cs623724.vk.me/v623724122/1163f/8-60HbLF6pc.jpg Edited February 1, 2015 by Pirotex
dangerousamateur Posted February 1, 2015 Posted February 1, 2015 That sounds very simple. In this case the fuel does not need to be so liquid. But I dont understand how you get all the paper and tape out of there, it must stick to the sorbitol like hell and tear apart? What kind of scotch tape is that exactly? Did you ever have any catos with your sorbitol engines? Many people only show working stuff, but do not show the 10 other rockets that exploded On the other hand nozzleless is often very easy to get reliable. And the delay, how do you put this in there? Wet with a binder?Because I think you cannot put pressure on or ram the casted sorbitol grain, it might crack, or am i wrong?
dagabu Posted February 2, 2015 Posted February 2, 2015 That sounds very simple. In this case the fuel does not need to be so liquid. But I dont understand how you get all the paper and tape out of there, it must stick to the sorbitol like hell and tear apart? What kind of scotch tape is that exactly? Did you ever have any catos with your sorbitol engines? Many people only show working stuff, but do not show the 10 other rockets that exploded On the other hand nozzleless is often very easy to get reliable. And the delay, how do you put this in there? Wet with a binder?Because I think you cannot put pressure on or ram the casted sorbitol grain, it might crack, or am i wrong? EZPZ: Turning the paper to pull away from the grain should release just like shown. Looks to be a plasticized paper like a magazine. http://serge77.rocketworkshop.net/nozzleless4/IMG_3456-1.jpg 1
dangerousamateur Posted February 3, 2015 Posted February 3, 2015 (edited) Yes, i've seen the pictures. But I still think the sorbitol must adhere to the paper, or does it not? Especially when soaked in oil? Because if the paper ruptures and keeps adhering to the core, maybe somewhere in the upper section of the core, it must be a pita to reach there and get it out... Pirotex, can you say something about pressing/casting the delay on top? Edited February 3, 2015 by dangerousamateur
stix Posted February 3, 2015 Posted February 3, 2015 Yes, i've seen the pictures. But I still think the sorbitol must adhere to the paper, or does it not? Especially when soaked in oil? Because if the paper ruptures and keeps adhering to the core, maybe somewhere in the upper section of the core, it must be a pita to reach there and get it out... Pirotex, can you say something about pressing/casting the delay on top? Experimentation is the only way to answer that question. Pirotex has his method and it works for him. There are various methods for making "Sugar Rockets". Casting and removing the central pin is obviously the main game - but there's always room for improvement. Cheers.
Pirotex Posted February 4, 2015 Author Posted February 4, 2015 dangerousamateur, delay - it's glued BP tracer with slow burning compositionWood dummy:http://cs408718.vk.me/v408718122/3385/RkCyGIkVu6s.jpgTracer here:http://cs408718.vk.me/v408718122/338e/0fPR0o5B9to.jpgParameters: http://cs609417.vk.me/u29674122/docs/15b79659686c/tracer.png?extra=XcojeMWHvKrb9ZaqWswX-RQ4EmIa8OnbCeWly4-_sgHpGaXD-9pXIDGRU0_HCe9fPe_3ggcCCLvfGvr_gJvo1ey3iIg1yA
dangerousamateur Posted February 4, 2015 Posted February 4, 2015 I see. So your sorbitol fuel has nothing to to with the delay at all, the core is going all the way through, right? The delay burns right from the beginning when you ignite the motor? With that small hole I rather call it a second stage endburner. This is a cool concept, I like it.
Pirotex Posted February 4, 2015 Author Posted February 4, 2015 The core is going all the way through, right? The delay burns right from the beginning when you ignite the motor? yes
dagabu Posted February 5, 2015 Posted February 5, 2015 Yes, i've seen the pictures. But I still think the sorbitol must adhere to the paper, or does it not? Especially when soaked in oil? Because if the paper ruptures and keeps adhering to the core, maybe somewhere in the upper section of the core, it must be a pita to reach there and get it out... Pirotex, can you say something about pressing/casting the delay on top? There seems to be a good layer of transparent tape all the way around the length of the spindle, it should de-bond without coming off on the propellant. Why would the core rupture?
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