usapyro Posted January 9, 2012 Posted January 9, 2012 (edited) In the beginning with hand rolled/rammed tubes I had so many problems until I developed this reliable method...http://i41.tinypic.com/juaed2.gifThese tubes are SLICK inside like Al tubing or PVC! Make sure to ram the nozzle well or it will get blown out. You can also reinforce the area outside the nozzle with a type of stiff non flexible tape before compacting it. This method has worked smoothly and reliably for me. And as a last note...I use the larger 8x16 sheets of paper nowadays. Other tricks and tips... You can omit the aluminum tape on the top inch and ram the plug into that end. It gives it a little better grip and less risk of blowout. Feel free to add your own methods and tips to this thread if you do/have done any hand rolling! Nothing more fun than building a successful rocket COMPLETELY from scratch! Edited January 9, 2012 by usapyro
usapyro Posted January 9, 2012 Author Posted January 9, 2012 I.D. = Inside Diameter, which will automatically match the dowel diameter on rolling.I.D. = Outside Diameter.
Col Posted January 9, 2012 Posted January 9, 2012 Grain direction is the most important thing when it comes to rolling tubes. Problem is, all the kraftpaper i`ve come across on a roll has the grain running in the wrong direction so you have to cut the paper and roll it across the width. With that in mind, its best to buy a roll width that divides nicely into the length of paper you need for the tube otherwise you`ll end up with more cutting and lots of offcuts. My 3/4" rocket tubes use 3m of 50lb virgin kraft, the best roll width`s are 500mm, 600mm or 750mm.
usapyro Posted January 9, 2012 Author Posted January 9, 2012 (edited) I have always just used sheets of normal white paper. I just looked at it with a flashlight shining through it... I don't think this stuff has a grain direction. It's pretty cheap stuff and works perfect with my technique. The real key with my technique is the Al tape. That makes for a nice smooth tube on the inside which makes the powder compact easily. Ramming long grains is no problem. Edited January 9, 2012 by usapyro
Col Posted January 9, 2012 Posted January 9, 2012 (edited) The best way to test the grain direction is to cut a square of paper and wet one side, it should curl up or down across the grain. The good thing with having a grain is the paper will elongate more in one direction than another as the glue soaks in. Rolling the tube in the direction of the elongation (at right angles to the grain) will result in a much stronger tube. The paper contracts as it dries and that tightens it up, much like the pasting on a shell. If you have a hydraulic press with a gauge you can compare different tubes. For a 3/4" id tube, press 20g of clay until the tube splits and note the pressure on the gauge. If it handles 6000psi unsupported its not a bad tube. This one failed at 5390psihttp://i770.photobucket.com/albums/xx341/colinspyro/2011/tubetest.jpg Edited January 9, 2012 by Col
madmandotcom Posted January 10, 2012 Posted January 10, 2012 sorry, i meant in thicknesswhat is the wall thickness for these?
usapyro Posted January 10, 2012 Author Posted January 10, 2012 Whatever you want it to be. I vary it depending if I want a smaller higher pressure nozzle or if it's going to be a lower pressure core burner, etc... The number I put up is the minimum number of sheets really.
dan999ification Posted January 10, 2012 Posted January 10, 2012 normal A4 copy paper wont have a grain nor will most recycled papers, forget about rolling tubes with al tape, roll proper tubes get proper results, simples, i dont see what benefit this has, the first turn on the tube needs to be the strongest bonded one,lining with al tape wont make your tube stronger nor will it help you with ramming, if the fuel is gripping the tube and crushing it you need smaller increments,stronger tubes and or a support sleeve, the grain is more prone to being spat out like this paper grips it better, the plug to help is also a mystery i never had a problem with tubes splitting while ramming motors, seems like a lot of extra unnecasary work to me. dan.
usapyro Posted January 10, 2012 Author Posted January 10, 2012 (edited) This works for me. Cheer up man! In Soviet Russia, paper rolls you!!! The Al tape makes the increment ramming smooth and easy. Leaving Al tape out of the nozzle section gives that area a good grip. I do that every time now. I try to use the minimum amount of paper possible. My end burners reliably burn through their casing near the end of flight and give a little extra show with a glowing paper cylinder falling back to earth. The Al tape does seem to insulate the paper a tiny bit and help delay the burn through a bit longer. Love having zero fire danger in winter... I am wayyy too impatient for small increments and using tons of paper is a waste. In my opinion you only need just enough paper for the internal pressure of the motor during burn. Less wasteful that way. I could care less about having great PSI strength in every tube. Core burners need like a quarter of the tube strength of an end burner. I am however going to buy some NEPT tubes from hobbyhorse and some custom tooling in a while. I might be moving to a different part of the country for a bit though and will have to pause pyro. We shall see... Meh... I wish I could get NEPT tubes with aluminum inside... So much for pressing increments!!! LoL... Slick enough with a +2% mineral oil BP and you could probably press a third of a rocket in one increment! Edited January 10, 2012 by usapyro
Col Posted January 10, 2012 Posted January 10, 2012 Core burners need like a quarter of the tube strength of an end burner. Sounds like a spiral wound tube should be more than plenty for a 1lb coreburner..not My 1/2" coreburners go from 0 - 3.6kg in 67milliseconds, a weak tube wouldn`t take the strain.
guntoteninfadel Posted January 10, 2012 Posted January 10, 2012 Less wasteful that way. I think hes becoming a tree hugger..........
Col Posted January 10, 2012 Posted January 10, 2012 (edited) sorry, i meant in thicknesswhat is the wall thickness for these? If its standard 80gsm (50lb) white printer paper, 8x A4 sheets would be around an 1/8" wall on a 1" tube. You`d get 62 tubes from a ream (500 sheets) Edited January 10, 2012 by Col
dagabu Posted January 10, 2012 Posted January 10, 2012 USA, you didnt mention glue. Do you glue each sheet together first and stack them of just glue the calendar together? -dag
usapyro Posted January 10, 2012 Author Posted January 10, 2012 i just wrap the outside in a spiral of tape.
Col Posted January 11, 2012 Posted January 11, 2012 A dry rolled tube will be incredibly weak compared to one thats fully glued. You`ve got me curious now, i`ll make one and do a test to see how much pressure it can take.
usapyro Posted January 11, 2012 Author Posted January 11, 2012 (edited) One thing about my rockets... I really like making very large and short rockets that make tons of smoke. I really like the cool look of slow launches and longer duration high smoke flights. It's all about the look for me. High TI/Charcoal nozzleless core burners are pretty awesome if I need to lift something, but core burners for the most part don't really appeal to me because of the flight time is too fast to enjoy and there isn't enough smoke. I can tell you these tubes work just fine for HOT BP core burners though... They hold up to launches that are so fast I can't even see the rockets go... My favorite rocket at the moment is my hybrid sugar end burner with a +2% mineral oil BP core. I like the hybrid core design so well I am thinking about buying some custom tooling for it in a while. I am falling in love with lower pressure whistle mix end burners too. They leave smoke trails through the sky like nothing else!!! The whistling is a tad annoying though. The absolutely coolest rocket I can remember making was a 2" sugar rocket core burner that was only 5 inches long that made it to only like 75' up. It was multi stick stabilized and the amount of smoke was EPIC!!! That was a couple years ago. Edited January 11, 2012 by usapyro
Col Posted January 19, 2012 Posted January 19, 2012 Quick update, a 1" id tube using 8x 80gsm sheets of printer paper and no glue failed just shy of 1200psi. Seems borderline seviceable for bp if you use a support sleeve, but i wouldn`t trust it for hot fuel, hybrid or whistle rocket use.
usapyro Posted January 30, 2012 Author Posted January 30, 2012 (edited) Yep, that sounds about right... Did you follow mine exactly with the internal aluminum tape and the overlapped way of rolling? People need to chill out in here... This design is not supposed to make the highest pressure high performance rocket possible. It's just to make a reliable tube that gets a rocket off the ground nicely all by hand with the minimum effort possible from common HOUSEHOLD items. Not everyone has the luxury of NEPT tubes, hobby paper rolls, hardeners, and etc... Still lots of kids around with only stump remover KNO3 and paranoid adults that won't order from pyro suppliers. In the old days I use to get certain "hazmat" items shipped to a duplex condo... LoL!!! Wonder what the manager there would have thought of the black powder and other lovely stuff I was storing. I have driven across the entire US twice through border check areas near mexico with the back of my car full of giant plastic boxes of oxidizers, fuels, tubes, and etc. I'm not that paranoid... Little more paranoid nowadays that the IRS is looking through my bank statements. Ha... Edited January 30, 2012 by usapyro
asilentbob Posted January 30, 2012 Posted January 30, 2012 I've always just used heavy weight brown kraft paper and thinned wood glue with some wax paper wrapped around the dowel rod to reduce sticking when removed. The Wax paper stays on the dowel and the moist tube slides off. A un-glued tube is likely to have more trouble with fallout than a glued one. This gets into the whole surface area thing. Individual sheets of paper stacked up, or sheets with glue in between them. Granted aluminum foil tape on the inside should reduce that... but its also less grippy for the nozzle and any rough material in the fuel. If you have fallout concerns you could always bind with sodium silicate for rock hard tubes. Pun intended. Or a bit of sodium silicate in the center where the fuel is and transition to wood glue as you roll.
nater Posted January 30, 2012 Posted January 30, 2012 I have rolled servicable tubes from manilla folders and a few wraps of recycled kraft postal paper, glued with diluted wood glood and using a wood dowel as a mandrel. All household products and a few minutes of time. No need to aluminum tape which raises the cost. Do whatever works best for you, though. I dont see anyone who has posted in this thread that needs to "chill out"
allrocketspsl Posted February 2, 2012 Posted February 2, 2012 I have rolled servicable tubes from manilla folders and a few wraps of recycled kraft postal paper, glued with diluted wood glood and using a wood dowel as a mandrel. All household products and a few minutes of time. No need to aluminum tape which raises the cost. Do whatever works best for you, though. I dont see anyone who has posted in this thread that needs to "chill out" I totally agree with nater,all just seem to give there perspective.I to roll all my tubes no need for any special anything.I simply brush wall paper paste on the cut pieces Im using for a tube of any size.I let it soak a bit so the tackyness is gone.Then I roll the first pice that I have only 3/4 wetted so the the dry untreated part is going around the dowel one time.This way the tube slides off easily with absolutely no effort. Let dry two days.Done! All
allrocketspsl Posted February 2, 2012 Posted February 2, 2012 In the beginning with hand rolled/rammed tubes I had so many problems until I developed this reliable method...http://i41.tinypic.com/juaed2.gifThese tubes are SLICK inside like Al tubing or PVC! Make sure to ram the nozzle well or it will get blown out. You can also reinforce the area outside the nozzle with a type of stiff non flexible tape before compacting it. This method has worked smoothly and reliably for me. And as a last note...I use the larger 8x16 sheets of paper nowadays. Other tricks and tips... You can omit the aluminum tape on the top inch and ram the plug into that end. It gives it a little better grip and less risk of blowout. Feel free to add your own methods and tips to this thread if you do/have done any hand rolling! Nothing more fun than building a successful rocket COMPLETELY from scratch! all mine are scratch built the last five years.No ball mill even.My powder takes three weeks to dry fully.
allrocketspsl Posted February 17, 2012 Posted February 17, 2012 looks like I need to do a tutorial on expertly rolled glued tubes.I have been rolling these for 5 years the same strong way!Rock hard not spongy to!Wall paper paste!!Cheap easy to use!!! All
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