How to roll pyro-tubes

[paplik]

What's in the home glue? Dextrin, starch and flour?

I thought that someone invented an automatic machine for paper tube .

I'll have to get a plastic stick to it. I use aluminum alloy rod, but the paper sticks to it and then it will not come off. Paper stick sticks even if there is only a little more glue. I use dextrin

[Col]

Its a blend of dextrin,casein and sodium silicate, 62.5% dry solids with a viscosity somewhere between SAE 40 motor oil and castor oil. Its possible to push a 2ft tube from an aluminium mandrel using the simple tool i mentioned in the earlier post. I dont have glue on the first turn of paper but it can still partially stick if glue finds its way out of the flap onto the mandrel.

A machine will roll a tube in seconds but its only worth it if you need a lot of tubes.

 

 

 

 

[ivars21]

Col, your machine looks nice, can you take some more photos, or perhaps a video?

Cheers

[jessoman]

I originally used aluminium rod when rolling tubes and it didn't have much tolerance to the glue, the paper just sticks. I experimented with a few different mediums and I emailed the manufacturer of my paper so I can know what sort of paper I'm dealing with (haven't heard back).

Personally I use PVC and change it over when it accumulates too much scoring from cutting tubes. But it works extremely well. I can pump out a few good quality tubes in a short time. I enjoy doing it strangely enough.

 

I have my roll on a dowel with a stand to unroll freely. Then use a big brush to paste as I go when dealing with thicker walls as I found dealing with long sheets of paper to be testing. Very primitive set-up, but functional.

 

http://youtu.be/kU5ZFN2q9DI there's a few of my tubes. I use Aquadhere (for you Aus people) 50/50. I don't have the tools to test the strength of the tubes but would be happy to send a few to any locals to test.

 

Kind regards,

Jess

[Col]

Rolling the paper straight from the roll onto the former makes it a lot easier but there is a tradeoff if you`re after the strongest tube possible from the paper.

To get maximum beam strength you need to cut the paper and roll the tube across the paper width so the grain is running parallel to the former. I`ve tested 3 grain orientations; former parallel to the grain, former right angle (aka perpendicular) to the grain and using multiple sheets rotating the grain at right angles similar to how plywood is made.

Former parallel to the grain produces much stronger tubes (>1000psi difference) in each case whether they are made from pure or recycled kraft. No paper has equal strength or stretch in both the machine direction (MD) and cross direction (CD), its always measurably stronger in the machine direction with more stretch in the cross direction.

Edited December 9, 2013 by Col

[patsroom]

@ Col, I have a few questions for you if you do not mind. First what are the sizes of tubes you role, to each size how long is the sheet of paper and what weight of paper do you use. Thank................Pat

[jessoman]

Truly Col, thats fascinating. I haven't read or come across any documentation with anyone claiming to do that. So I will look forward to trying it myself. For thicker wall sizes, is there any particular method of joining sheets as you would have to use multiple cuts. Joining sheets doesnt ruin the integrity? Or would you pre-glue multiple sheets then roll. Very interesting!

[Col]

Hi Pat, i mostly roll 1/2" and 3/4" tubes but can do any size from 1/2" to 1-3/4" id and od`s upto 2.25".

I use 4ft wide rolls of 90gsm virgin kraft and tailor the number of sheets to the wall thickness. 1/2" id x 1/8" wall tube takes one sheet, 3/4" id x 4mm wall takes 2 and a 1.5" id x1/4" wall would need 6 sheets. There`s a limit to how many sheets you can use so the wider rolls provide more length and leeway. You can roll a 1/2" x 1/8 wall using 2ft wide rolls (2 sheets) but it wouldnt work for 6lb`ers as you`d need 12 sheets to get a 1/4" wall. You do need to consider the number of turns, 1/8" thick card stock only needs 2 turns for 1/4" wall but it wouldnt be very strong

 

Hi Jessoman,

You make a good point about the paper jointing method. Winding the individual sheets in series creates weak points in the tube wall as each sheet is reliant on a single turn bond. If they break loose you`ll have several loose tubes telescoped one inside another. Winding the sheets in parallel solves the problem. I havent had much success calendering the sheets together to form a thick sheet and then rolling the tube, you`ll find the damp sheets tend to delaminate because each sheet travels at a different speed, ie; the top sheet in the stack has further to go than the bottom sheet. I tried a calender roll to compress the sheets together at 250psi and allowed the sheets to dry before rolling but you cant get enough tension on the resulting super thick kraft.

The method that works best is to combine the individual sheets right at the mandrel so they can all pull independantly without sticking to each other.

Edited December 9, 2013 by Col

[jessoman]

Okay Col, my apologies for needing reiteration: So calendaring the paper would be to sandwich and glue. That I understand. In series would be; wrap one sheet then the next. To achieve the wall size required. Now how is parallel different? Or do you mean wet all sheets together and wind all together at the same time, as you would one sheet?

[leedrill]

yeah thats what he means just with a staggered starting point for each sheet like lllllll then ending like lllllll but had never thought about the problem col brought up about this method in theory the calendar method sounds great but i can see what you mean when you say it can be the cause of de-lamination is hard for me to picture how severe it could be by hand but with a machine like yous col i can see it being an emphasised problem

[Col]

It happens when handrolling multiple sheets too, if the glue is tacky the sheets cant slide and you`ll get major creasing. If you put plenty of glue on to ensure the sheets can slide, you`ll shoot yourself in the foot as the excess glue between each sheet will build up in front of the mandrel and force the sheets apart

Use a high solids glue that will dump just enough water into the neighbouring turn to force it to tack on contact. That way, the tube will be halfway dry and dimensionally stable by the time you push it off the mandrel.

Edited December 9, 2013 by Col

[jessoman]

Great, I look forward to experimenting. I stumbled across some heavy weight kraft paper at work today. Looking forward to trying it out. Would love to see your technique on video Col

[asdercks]

Its a blend of dextrin,casein and sodium silicate, 62.5% dry solids with a viscosity somewhere between SAE 40 motor oil and castor oil. Its possible to push a 2ft tube from an aluminium mandrel using the simple tool i mentioned in the earlier post. I dont have glue on the first turn of paper but it can still partially stick if glue finds its way out of the flap onto the mandrel.

A machine will roll a tube in seconds but its only worth it if you need a lot of tubes.

 

rm4.jpg

rm5.jpg

rm2.jpg

 

 

 

Col did you make your machine o did you buy it? if you made it will you be interested in selling or sharing the plans to make one

Edited December 22, 2013 by asdercks

[Col]

Its not a machine the average pyro would consider building. I dont have plans but the design is loosely based on the chinese convolute tube machines you find on you tube. Its all home built apart from the side roller mounts (steel arcs) and mandrel bearing plates that i had laser cut from 6mm steel plate to ensure accuracy.

 

Here`s a quick rundown to give you some idea of what you`re getting yourself into

The machine has a fixed mandrel supported by a bearing at each end and 3 rollers equipped with both radial and thrust bearings for zero play. The rollers are mounted on a carriage that is raised and lowered by a pair of scissor jacks linked together. The carriage itself runs on vertical ball-raced slides so it can only move up or down, there`s no side or end play.

 

The 2 outer rollers are mounted onto steel arcs which have radial bearings pressed in at the pivot points, the arcs are attached to mounts made from 60mm x 30mm unequal steel angle bolted onto the carriage.

The bottom (center) roller mounts are made from 6mm thick steel flat and they run between 2 pairs of radial bearings which act as guides for up/down movement only. The bottom roller mounts are also equipped with compression springs. The bottom roller makes contact with the underside of mandrel when the carriage is raised, locking the paper between the bottom roller and the underside of the mandrel so it cant move. The springs keep the bottom roller in firm contact with the mandrel as the carriage continues upward ( the springs compress). The two side rollers track around both sides of the mandrel to wrap the 1st turn and tuck in the end.

The pic shows how the rollers move in relation to the paper.

 

Thats the rolling machine, but you`ll also be needing a glue applicator to evenly apply glue to the full width of the paper.

Another fun project

Edited December 23, 2013 by Col

[Bobosan]

Very interesting! Nice piece of engineering Col.

[asdercks]

Its not a machine the average pyro would consider building. I dont have plans but the design is loosely based on the chinese convolute tube machines you find on you tube. Its all home built apart from the side roller mounts (steel arcs) and mandrel bearing plates that i had laser cut from 6mm steel plate to ensure accuracy.

 

Here`s a quick rundown to give you some idea of what you`re getting yourself into

The machine has a fixed mandrel supported by a bearing at each end and 3 rollers equipped with both radial and thrust bearings for zero play. The rollers are mounted on a carriage that is raised and lowered by a pair of scissor jacks linked together. The carriage itself runs on vertical ball-raced slides so it can only move up or down, there`s no side or end play.

 

The 2 outer rollers are mounted onto steel arcs which have radial bearings pressed in at the pivot points, the arcs are attached to mounts made from 60mm x 30mm unequal steel angle bolted onto the carriage.

The bottom (center) roller mounts are made from 6mm thick steel flat and they run between 2 pairs of radial bearings which act as guides for up/down movement only. The bottom roller mounts are also equipped with compression springs. The bottom roller makes contact with the underside of mandrel when the carriage is raised, locking the paper between the bottom roller and the underside of the mandrel so it cant move. The springs keep the bottom roller in firm contact with the mandrel as the carriage continues upward ( the springs compress). The two side rollers track around both sides of the mandrel to wrap the 1st turn and tuck in the end.

The pic shows how the rollers move in relation to the paper.

roller operation.jpg

 

Thats the rolling machine, but you`ll also be needing a glue applicator to evenly apply glue to the full width of the paper.

Another fun project

wow! thanks for sharing, I'll try to make one as soon as I finish with a shell pasting machine that I'm working on right now, it sure will be a fun project to work with

[Col]

Its worth making a 4ft or 6ft version (if you have space) as the main cost is in the bearings, plates and hardware which are the same for any length of roller.

A few other details that may be useful when you design it.

Each tube id requires a mandrel and 2 bearings (2-bolt flange type), the slots in the steel end plates are geared to accomodate the range of bolt spacings (0.5"-1.5" bearings). The mandrel is driven by an old drill press mounted horizontally, the 1/2" chuck is equipped with a 50mm watchmakers lathe chuck with a straight arbor to accept large od mandrels. The drill presses normal up/down plunge motion translates into a horizontal pull/push which is used to pull the mandrel from the outboard end support bearing. The end plate and bearing hinges down out of the way so the finished tube can be pushed off the mandrel through a large hole in the end panel.

Edited December 23, 2013 by Col

[asdercks]

Its worth making a 4ft or 6ft version (if you have space) as the main cost is in the bearings, plates and hardware which are the same for any length of roller.

A few other details that may be useful when you design it.

Each tube id requires a mandrel and 2 bearings (2-bolt flange type), the slots in the steel end plates are geared to accomodate the range of bolt spacings (0.5"-1.5" bearings). The mandrel is driven by an old drill press mounted horizontally, the 1/2" chuck is equipped with a 50mm watchmakers lathe chuck with a straight arbor to accept large od mandrels. The drill presses normal up/down plunge motion translates into a horizontal pull/push which is used to pull the mandrel from the outboard end support bearing. The end plate and bearing hinges down out of the way so the finished tube can be pushed off the mandrel through a large hole in the end panel.

Col, once again thanks for sharing more info, I've been watching some videos of different homemade tube winding machines and in most of them you have to manually roll the first turn of paper on the mandrel, but seems that your machine does the job itself

[Col]

Trying to accurately align and roll a 2ft wide piece of paper onto a mandrel manually is tricky at best, especially if your fingers get stuck to the glue

I slide the paper in under the mandrel (handling only the dry side) so its square to the rollers and the correct distance in. The bottom roller traps it in a vice-like grip so it cant move or get skewed. The side rollers wrap the first turn up both sides of the mandrel simultaneously and force the leading edge into the nip point of the side roller and the mandrel. Its not possible with handrolled tubes unless your part octopus.

[asdercks]

Trying to accurately align and roll a 2ft wide piece of paper onto a mandrel manually is tricky at best, especially if your fingers get stuck to the glue

I slide the paper in under the mandrel (handling only the dry side) so its square to the rollers and the correct distance in. The bottom roller traps it in a vice-like grip so it cant move or get skewed. The side rollers wrap the first turn up both sides of the mandrel simultaneously and force the leading edge into the nip point of the side roller and the mandrel. Its not possible with handrolled tubes unless your part octopus.

Col, I appreciate all the info and comments you're posting,not a lot of people is willing to share ideas especially when it comes to building machines, I'll keep them in mind when I try to build my machine

[shouldnoteatindat]

that is very interesting

[MWJ]

Very cool! I'm making some today! Thanks VikingP

[BrainDamage]

very nice tubes keep the videos coming good job

[Extrarius]

I've thought about making something like this 'newspaper rolling machine' http://www.youtube.com/watch?v=x3sR9ywfcZs to make pyro tubes. If your glue isn't too tacky, the only neccessary modification I see would be inserting a former of the right diameter so the tube will come out the right size.

Edited March 4, 2014 by Extrarius

[Col]

Adding a former to the newspaper roller wont do the trick as the former/mandrel needs to be the driven shaft