captainG Posted January 11, 2015 Posted January 11, 2015 Can anyone suggest a good place to buy sticks thanks
pyrojig Posted January 11, 2015 Posted January 11, 2015 Try a garden supply for bamboo. Or if you have a local place growing some , you may have a free source . Some smaller rockets may use the window shades bamboo rolls . Also if you have a table saw , you could custom make your own to fit your needs .
captainG Posted January 11, 2015 Author Posted January 11, 2015 (edited) Ahhh I just happen to have a bunch of bamboo growing on my property. ....not any more lol.....great idea thanks! Don't really knowv blackthumb was thinking of trying some rcandys about 1/2-3/4" about 4-5" long suggestion on length? And supplier? Edited January 11, 2015 by captainG
nater Posted January 11, 2015 Posted January 11, 2015 (edited) Blackthumb sells sticks. So does Midwest Wood Specialties and Hobby Horse. You can also be really careful with a table saw and rip your own. Stick size is a debated topic. It needs to be sturdy enough to not break when the rocket launches and provide just enough drag to keep the rocket pointed the right direction. Heading weight and shape compared to the power of the motor also makes a differnece. With the rockets I make, I typically use the following: 1/4" SBR - 12" long bamboo BBQ skewer1/2" BP or Whistle - 18" long 1/4" square dowel3/4" BP or Whistle - 36" long 3/8" square stick1" BP or Whistle - 40" - 50" long 1/2" square stick. Edited January 11, 2015 by nater
captainG Posted January 11, 2015 Author Posted January 11, 2015 Ok so I procured some free bamboo from the backyard score! I'm guessing narrow diameter on rocket fatter on bottom
captainG Posted January 11, 2015 Author Posted January 11, 2015 (edited) Ok so another question I made a 60/40 dry mix is it safe to hammer and hand drill that? I saw a guy on you tube do it but like everything on there I'd like to get a second opinion from someone who i can trust. also another question the dry mix seemed to be easier to mess with and make is there a big difference in using it dry and cooking it down?thanks cap. Edited January 12, 2015 by captainG
ddewees Posted January 12, 2015 Posted January 12, 2015 (edited) Just buy as many as you can afford from Midwest Wood Specialties, best sticks I've ever seen. Plan ahead too, sometimes you may have to wait a little bit. Edited January 12, 2015 by ddewees
Col Posted January 12, 2015 Posted January 12, 2015 In the long run it`d probably work out cheaper to buy a used tablesaw or bandsaw. They`re handy for all kinds of stuff.
stix Posted January 12, 2015 Posted January 12, 2015 (edited) Ok so another question I made a 60/40 dry mix is it safe to hammer and hand drill that? I saw a guy on you tube do it but like everything on there I'd like to get a second opinion from someone who i can trust. also another question the dry mix seemed to be easier to mess with and make is there a big difference in using it dry and cooking it down?thanks cap. I assume you're talking sugar rockets. It's a bit of a long read, but you should be able to glean some useful info from this recent thread.http://www.amateurpyro.com/forums/topic/10324-substitute-for-fuse/ Cheers. [EDIT] Ok so I procured some free bamboo from the backyard score! I'm guessing narrow diameter on rocket fatter on bottom No need for that - a straight stick is just fine. . . .It needs to be sturdy enough to not break when the rocket launches and provide just enough drag to keep the rocket pointed the right direction. Agreed nater, but stability is mainly due to the 'balance' ie. centre of gravity not just drag. In general, after temporarily attaching the stick, try to balance the rocket on your finger positioned approx. 1xMotor ID, behind the nozzle (where the stick joins the rocket). If it swings down on the motor end, that means the stick should be longer, or alternatively you can add a bit of weight to the end of the stick - I've use a bit of solder wrapped around then sticky taped. If it swings the other way toward the stick, then it should be stable. If it balances perfectly, then that should be relatively optimal stability without adding extra weight. Edited January 12, 2015 by stix
Col Posted January 12, 2015 Posted January 12, 2015 None of mine balance, no sense using a 5ft stick if a 3ft`er does the job. Balance is likely more important for slow rising rockets than quick ones.
stix Posted January 12, 2015 Posted January 12, 2015 True Col, no sense in adding extra weight. I agree with you, and in my experience, you can get away with much shorter sticks if you have lots of g's and fast takeoffs. Best though to err on the side of caution when starting off and not you're not sure how your motor is going to perform as seems to be the case with the op. Cheets.
Col Posted January 12, 2015 Posted January 12, 2015 Best thing to attach to an unknown motor is a set of kitchen scales. They`ll let you know if it can lift the stick
stix Posted January 12, 2015 Posted January 12, 2015 (edited) Yep! and that's exactly what "I" did Col - I tested many motors before launching one.But somehow I don't think that's the op's modus operandi ... whoops, I meant btw. spring scales (video'd) is really good advice for anyone starting out - they can be picked up cheaply from op shops or markets etc.. Edited January 12, 2015 by stix
captainG Posted January 12, 2015 Author Posted January 12, 2015 Ok so I can't really figure out this quote thing. so yes stix sugar rockets. I appreciate that link, i read it all, I had browsed it the other day but being it was fuses it wasn't really info I cared to read at that point. but as many of the threads do it changed to a fascinating topic quickly. so that video was basicly my model i was using I guess since nobody adressed the issue of him hitting it with the hammer I'm assuming that's safe? Someone even suggested it was safe enough to use a metal hammer on? As far as the scale goes ill look for the plans to build one sounds like a good test. I taped one to about a 3# metal thing yesterday and it moved it so I'm fairly confident I have no problem with lift. I was waiting for the rain last night and will test one attached to my bamboo today I balanced it a little tail heavy in fact its 630 in the morning and the grounds wet sounds like a good time for a launch I'll try to video it
captainG Posted January 12, 2015 Author Posted January 12, 2015 Also I have seen several people talk about the re crystalization method as being the best I went to yawns site but didnt really see a clear explanation or recipe is there a thread on here? I couldn't find one.also opinions on that method ? Seems as though the powdered is not the preferred method....sure was easy though
captainG Posted January 12, 2015 Author Posted January 12, 2015 (edited) Ok so 3 highly successful launches,went completly out of site, these things are bad! But after hearing the thud of these things hitting I think ill be moving to cardboard tubes as if this falling pvc tube hit someone or something ...not good.but gonna stick with 3/4" seems to be a good size.....I'm hooked! Edited January 12, 2015 by captainG
stix Posted January 13, 2015 Posted January 13, 2015 (edited) Click on the "Quote" button in the r/h bottom corner of the post you wish to reply to. It will take you to the "Reply to this topic" input box. Type away. You can also "multiple quote" and then try "more reply options". Ok so I can't really figure out this quote thing. so yes stix sugar rockets. I appreciate that link, i read it all, I had browsed it the other day but being it was fuses it wasn't really info I cared to read at that point. but as many of the threads do it changed to a fascinating topic quickly. so that video was basicly my model i was using I guess since nobody adressed the issue of him hitting it with the hammer I'm assuming that's safe? Someone even suggested it was safe enough to use a metal hammer on? As far as the scale goes ill look for the plans to build one sounds like a good test. I taped one to about a 3# metal thing yesterday and it moved it so I'm fairly confident I have no problem with lift. I was waiting for the rain last night and will test one attached to my bamboo today I balanced it a little tail heavy in fact its 630 in the morning and the grounds wet sounds like a good time for a launch I'll try to video it There's no problem ramming with a hammer providing you are not using sparking metal like steel as your rammer in contact with other metal that could potentially cause ignition whilst you're holding it You're drilling out the core? - so that won't apply in this case, but be careful when drilling. I don't feel comfortable with drilling so I use aluminium tooling to mould the shape. I believe It was me that suggested a metal hammer for the simple reason that rubber is not a good Idea. You need the motor on a solid base and strike with a solid hammer - a 'dead blow' rawhide or nylon capped hammer is best - my suggestion of a std. metal hammer is not great because it will ruin your rammer after a few motors. Anyway, the purpose of ramming is to make the fuel more compacted which is what you want. Also I have seen several people talk about the re crystalization method as being the best I went to yawns site but didnt really see a clear explanation or recipe is there a thread on here? I couldn't find one.also opinions on that method ? Seems as though the powdered is not the preferred method....sure was easy though I think he re-organised his site. Try this.http://www.jamesyawn.net/skillet/large/index.html He uses a few other sugar type additives - you don't really need to. The accepted standard mix for r-candy KNO3/Sucrose (KNSU) is 65/35. It's safer to start off with 60/40 until you're satisfied with your methods. There are various methods - these are my general explanations and opinions (IN SUMMARY), and happy for others to comment. 1. Dry Powder (your current method): The powdered ingredients (fine as possible is best) are combined and rammed or pressed into the tube. A shop press gives better results. Pros: If hammer rammed, it's quick and easy to get something workable off the ground in a reasonably short time frame (as you pointed out)Cons: Substandard performance unless you have a decent press. It takes longer because of the incremental pressing and waiting between presses (when using a shop press). 2. R-Candy re-crystalised (dissolved): The ingredients are dissolved with water in an electric skillet/frypan. KNO3 and Sugar don't have to be a fine powder as they both will easily dissolve. The temperature is increased until the water is driven off and the KN+SU will begin to re-crystalise. The resulting candy/toffee can then be cast into a mould. Pros: Excellent incorporation of the ingredients makes reasonably consistent burning and high performance.Cons: Difficult to cast at times and more hazardous dealing with hot melted sugar. ouch!. Also hard to determine when the water is driven off completely which can result in slower burning - this can lead to inconsistent results. 3. R-Candy (melted): The ingredients are finely powdered (fine as possible is best, ie. ball-milled) then placed in an electric skillet/frypan. The temperature is increased until the sugar melts (the KNO3 won't melt). The melted sugar will coat the KNO3 particles. The resulting candy/toffee can then be cast into a mould. Pros: Similar to no.2, Excellent incorporation of the ingredients makes consistent burning and high performance.Cons: Difficult to cast at times and more hazardous dealing with hot melted sugar. More consistent results that no.2. due to no water. 4. R-Candy (Riced/Grated/Granulated): I don't know too much about this method but as far as I'm aware it uses a combination of the above methods. The melted mass if formed into a solid, then when cool, grated with a cheese grater or similar into granules. Pros: The granules can then be stored and used later.Cons: The hard granules have to be pressed under great pressure otherwise cavities will form resulting in boom booms. 5. Stix's Plasticine R-Candy Balls (might have to re-word that!) There is some good info in this thread worth your reading.http://www.amateurpyro.com/forums/topic/10059-rcandy-not-working-properly/ Pros: Less heat when casting and can be cast over a longer periods (ie. 1hr or more) without overcooking or going hard. No need for a press.Cons: Takes a while to make. Potential to leave minor cavities if not formed correctly. Please remember that these are only my general observations and experiences. There is a lot of detail left out. Whatever other methods you decide to experiment with, please make sure you read up, ask questions and pay attention to any potential safety hazards. Also check the temperature scales being discussed, ie. fahrenheit or celsius/centigrade. Ok so 3 highly successful launches,went completly out of site, these things are bad! But after hearing the thud of these things hitting I think ill be moving to cardboard tubes as if this falling pvc tube hit someone or something ...not good.but gonna stick with 3/4" seems to be a good size.....I'm hooked! Great to hear about your successful launches - Yes, it's very addictive I think that whether you use pvc, thick cardboard or aluminum (like me) it's more about potential shrapnel if the rocket cato's, than where it might fall, because you are letting them off in an open safe area away from people and property aren't you? Stay Safe, Cheers. Edited January 13, 2015 by stix
dagabu Posted January 13, 2015 Posted January 13, 2015 If I may offer an observation? The quote from Stix below isn't quite correct, the riced or grated R-candy is grated on clean dry paper while the mass is still warmed and is re-warmed slightly before pressing in small increments of no more than 1/2 the motor diameter. There are no boom booms when done this way. 4. R-Candy (Riced/Grated/Granulated): I don't know too much about this method but as far as I'm aware it uses a combination of the above methods. The melted mass if formed into a solid, then when cool, grated with a cheese grater or similar into granules. Pros: The granules can then be stored and used later.Cons: The hard granules have to be pressed under great pressure otherwise cavities will form resulting in boom booms.
dagabu Posted January 13, 2015 Posted January 13, 2015 (edited) I assume you're talking sugar rockets. It's a bit of a long read, but you should be able to glean some useful info from this recent thread.http://www.amateurpyro.com/forums/topic/10324-substitute-for-fuse/ Cheers. [EDIT] No need for that - a straight stick is just fine. Agreed nater, but stability is mainly due to the 'balance' ie. centre of gravity not just drag. In general, after temporarily attaching the stick, try to balance the rocket on your finger positioned approx. 1xMotor ID, behind the nozzle (where the stick joins the rocket). If it swings down on the motor end, that means the stick should be longer, or alternatively you can add a bit of weight to the end of the stick - I've use a bit of solder wrapped around then sticky taped. If it swings the other way toward the stick, then it should be stable. If it balances perfectly, then that should be relatively optimal stability without adding extra weight. Man, it sure sounds like this is the "pick on Stix " day, I am sorry that this is two in a row but I just want to add a few observations in addition to your post if that is OK? Coreburners: I encourage anybody that is making stick rockets to look closer at balance, using a full and fused motor for balance will push the CG so far back that you will have to add a significant mass to balance the rocket. However, this CG is only present for a few microseconds as the propellant is burned off in the initial stage of lift, well before the "G's" fully kick in to stabilize the rocket. Look closely at stick rockets lifting off from the launching tube, the thrust pushes against the stick since the stick is providing drag and lacks the same inertia that the motor has. This causes the stick (really, any length or weight) to bend until the inertia "catches up", the thrust lessens and only then, the rocket flight straightens. For core-burners, this occurs well after the thrust peak ends. Not only does the bending of the stick deflect the flight path but so does the drag on the stick surface. If a stick is made from steel key stock (unrealistic example) v.s. Balsa, the weight becomes almost irrelevant to stability. Lets look at a fantasy example of a few different rocket stick set ups. -0.75" one pound core burner, black powder, nozzleless, 18 pounds of thrust at peak, burn time (useable thrust) is .5 seconds, single stick 3/8" square and are all just as "stiff" as each other. 1.) Stick is Basswood, knot free, clean wood, 50g at 40" of length. 2.) Stick is White Oak, knot free, clean wood, 50g at 20" of length. 3.) Stick is Pine, knot free, clean wood, 50g at 30" of length. 4.) Sticks are Basswood, knot free, clean wood, cut into three sections, one 20" long, two 10" long, each mounted 120° apart, total weight 50g. Which of the four will most likely have the straightest flight? The 2012 PGI convention brought Dianne Hauschild to the manufacturing chair position and she brought the tri-stick to the forefront with her competition rockets. Using a regular basswood stick, she cut steep angles in the stick ends to streamline them, glued them 120° apart and flew them with fantastic results. In order for balance and CG to mean anything, weight, friction (drag), flexibility, thrust, durability and mounting all must be taken into consideration. Just to throw the whole thing on it's ear once again, here is a video of two rockets, end burners, they have NO sticks or guide rods, they just sit on the ground and launch out over the lake. Do they balance at all? Nope, the CG is almost dead center due to the clay bulkhead. https://www.youtube.com/watch?v=036YqxmkXIA I await your feedback on the four rockets above, which of the above was the second most stable in flight? Edited January 13, 2015 by dagabu 2
captainG Posted January 13, 2015 Author Posted January 13, 2015 Great info thanks for taking the time to give such detailed answers guys!
stix Posted January 15, 2015 Posted January 15, 2015 If I may offer an observation? The quote from Stix below isn't quite correct, the riced or grated R-candy is grated on clean dry paper while the mass is still warmed and is re-warmed slightly before pressing in small increments of no more than 1/2 the motor diameter. There are no boom booms when done this way. 4. R-Candy (Riced/Grated/Granulated): I don't know too much about this method but as far as I'm aware it uses a combination of the above methods. The melted mass if formed into a solid, then when cool, grated with a cheese grater or similar into granules. Pros: The granules can then be stored and used later.Cons: The hard granules have to be pressed under great pressure otherwise cavities will form resulting in boom booms. Thanks for that info Dave - I'm always interested to gain more knowledge and may give this method a shot. When you re-warm the granules, how exactly are you re-warming? Also, are you hammer ramming or pressing? I would have thought the granules would get cold too quick. Do tell. . . . Man, it sure sounds like this is the "pick on Stix " day, I am sorry that this is two in a row but I just want to add a few observations in addition to your post if that is OK? . . . I await your feedback on the four rockets above, which of the above was the second most stable in flight? Hmmm "Pick on Stix Day" has a certain ring to it. All good though Dave - it was only twice in a row, if it was three then I may have thought vendetta. At least you were polite or were you holding back? I didn't quite grasp what you were getting at re the video. They both looked very stable to me - the 2nd I couldn't really tell though as it took off so quick. I liked them. Most of the rockets I've ever made have been 'model rockets' with fins & nosecones launched using a launch rail. the rest were static tests and only a few with sticks attached to save time. Cheers.
stix Posted January 15, 2015 Posted January 15, 2015 Great info thanks for taking the time to give such detailed answers guys! No probs - please take note of the additional correct info posted by Dagabu: 4. R-Candy (Riced/Grated/Granulated) Hope it all helps. Cheers.
captainG Posted January 15, 2015 Author Posted January 15, 2015 Was doing some more research and seen a fellow doing it in a fry daddy anyone have experience with that? looks like its in a nice self contained nonstick package. Thoughts?
dagabu Posted January 15, 2015 Posted January 15, 2015 Too deep and not enough surface for even heating.
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