Want a minimum weight tube with a diameter (ID or OD) close to 29 mm.

Prefer plastic but will go with plastic-coated cardboard, cardboard, aluminium or even titanium. The tube must be rigid or semi-rigid – at least as rigid as a drinking straw. It must also be evenly weighted – not heavy on one side.

Am being driven up the wall by the difficulty of getting any such tube with a wall thickness less than 1.6 mm, which is way too thick.

By way of comparison, the cardboard tubes of toilet rolls are 0.45 mm thick, the plastic of a margarine container is 0.3 mm thick.

Have even been considering increasingly desperate and unrealistic ways of making such a tube myself.

Try a model shop. They sell thin-walled Al tube. I have no idea what is their largest diameter. What length do you need?

Have a look here Moll.

http://store.visipak.com/Thin-Wall-Round-Clear-Plastic-Tubes.html

Peak Warming Man said:

Have a look here Moll.

http://store.visipak.com/Thin-Wall-Round-Clear-Plastic-Tubes.html

> 475846 1” x 4’ Thin Wall Round Clear Plastic Tube
Looks good dimensions, check price – “$132.76 USD”. Um, better price is required.

Michael V said:

Try a model shop. They sell thin-walled Al tube. I have no idea what is their largest diameter. What length do you need?

At my local hobby shop, too small a diameter.

How about an old bike pump?

>> Have a look here Moll. http://store.visipak.com/Thin-Wall-Round-Clear-Plastic-Tubes.html
> Looks good dimensions, check price – “$132.76 USD”. Um, better price is required.

Oh, I see, that’s the price for 188 metres of tube, a bit long.

> What length do you need?

I can use anywhere from 1 foot to 2 metres.

Electric cable conduit?

bob(from black rock) said:

How about an old bike pump?

That’s lateral thinking. Just checked – right diameter but wall thickness 2.25 mm is too big.

Something like the VisiPak would be ideal if I could get it in a shorter length than 188 metres – any suggestions where?

bob(from black rock) said:

Electric cable conduit?

That’s too thick a wall too.

mollwollfumble said:

bob(from black rock) said:

Electric cable conduit?

That’s too thick a wall too.

Try Alcoa, Alcan, or Comalco for aluminium tubeing.

https://www.discountrocketry.com/body-tubes—-couplers—-launch-lugs/estes-bt55-body-tube-pack-p-629.html

Discount rocketry… Didn’t know NASA had stuff for sale.

What about DWV Copper?

wall thickness for 1-1/4” ID would be about 0.04”

JudgeMental said:

https://www.discountrocketry.com/body-tubes—-couplers—-launch-lugs/estes-bt55-body-tube-pack-p-629.html

Bingo Moll, that looks like “the go”

bob(from black rock) said:

JudgeMental said:

https://www.discountrocketry.com/body-tubes—-couplers—-launch-lugs/estes-bt55-body-tube-pack-p-629.html

Bingo Moll, that looks like “the go”

Wrong diameter. BT55 diameter 33 mm is too much above 29 mm. The next size down BT50 diameter 24 mm is too small. Apogee sells both of those together with a 29 mm between the two, but doesn’t export the 29 mm to Australia. Both the 33 and 24 mm tubes are available in Australia, but I haven’t yet found anyone who will even export a 29 mm to Australia.

mollwollfumble said:

bob(from black rock) said:

JudgeMental said:

https://www.discountrocketry.com/body-tubes—-couplers—-launch-lugs/estes-bt55-body-tube-pack-p-629.html

Bingo Moll, that looks like “the go”

Wrong diameter. BT55 diameter 33 mm is too much above 29 mm. The next size down BT50 diameter 24 mm is too small. Apogee sells both of those together with a 29 mm between the two, but doesn’t export the 29 mm to Australia. Both the 33 and 24 mm tubes are available in Australia, but I haven’t yet found anyone who will even export a 29 mm to Australia.

I’ve got a US address you’re welcome to use.

stumpy_seahorse said:

What about DWV Copper?

wall thickness for 1-1/4” ID would be about 0.04”

Copper is too heavy, I think.

I may drop into a vacuum cleaner supplier to see if they have any thin-wall aluminium tube.

Did you just want a length of that aluminium pipe?

Check your local computer/electronics recycling organisation.
Either the fuser drum or the photocopier drum is thin walled alum. I have here one from the alum. bin that is 30mm dia. 0.8mm wall but is only 230mm long from an A4 copier. An A3 may just be long enough for your specs.

Molly said “Have even been considering increasingly desperate and unrealistic ways of making such a tube myself.”

Would a A3 sheet of clear acetate film from the stationery store be feasible. It’s often used to make overhead projector slides. Roll it up then twist it to get the right diameter and sticky tape the ends. Not real permanent but may suit your need.

Machined metal Is the way to go

wookiemeister said:

Machined metal Is the way to go

why not simply use a 3D printer

Tejay said:

Molly said “Have even been considering increasingly desperate and unrealistic ways of making such a tube myself.”

Would a A3 sheet of clear acetate film from the stationery store be feasible. It’s often used to make overhead projector slides. Roll it up then twist it to get the right diameter and sticky tape the ends. Not real permanent but may suit your need.

Or very thin aluminium sheet, roll up and have several layers of metal making up the wall of the tube thus formed?

diddly-squat said:

wookiemeister said:

Machined metal Is the way to go

why not simply use a 3D printer

Machined metal may well be the way to go.
Length too large for 3D printer. But good idea.

that’ll be expensive if it isn’t mass produced.

bob(from black rock) said:

Or very thin aluminium sheet, roll up and have several layers of metal making up the wall of the tube thus formed?

Alfoil crumples far too easily. Joins in home-made are a problem.

Get a regular alloy tube acid-dipped to thin it out a bit.
Some of of your work compatriots can no doubt find a way to do it.

mollwollfumble said:

bob(from black rock) said:

Or very thin aluminium sheet, roll up and have several layers of metal making up the wall of the tube thus formed?

Alfoil crumples far too easily. Joins in home-made are a problem.

Thin sheet, not Alfoil

Nakka uses thin al sheet

Have a look on his site

If you could find a way to roll 0.5 mm alloy sheet (I’ve got some here) it’s possible to TIG it together to make a tube.

I could also put the usual 1.6 mm thick wall tube into the lathe and trim it down. It’d take some time but it’s possible.

The other way could be laying down some fibre glass on a steel pipe as a mould

What is the diameter of the fatter fluorescent tubes

wookiemeister said:

Nakka uses thin al sheet

Have a look on his site

> Nakka

Rivetted join. Hopeless for diameters this small.
Roll form, that’s a possibility, I have pipe with the correct OD for form it on.
Bonded seam joint – unbalances tube too much with this small a diameter.

mollwollfumble said:

Bonded seam joint – unbalances tube too much with this small a diameter.

So alternate the seams from side-to-side.

Actually with 0.5 mm thick alloy sheet I reckon you could just about butt the edges together, use superglue to join them, then cover the lot in shrinkwrap film.
Assemble it all on a solid tube of the right diameter to match the inside of the fabricated tube. Maybe use a strip of wood or the like and make the inside tube collapsible to make it easier to remove.

> The other way could be laying down some fibre glass on a steel pipe as a mould

Did think about using an epoxy coating over a release agent over a pipe, but couldn’t rely on getting a uniform coverage.

> What is the diameter of the fatter fluorescent tubes

Will check. Measured it. OD 37 mm for superseded ones, OD 26.4 mm for more modern ones.

It’s easy to stiffen a flexible material by applying a resin coating. A sheet of paper, for example, could be coated by pouring some 5-min Araldite into the middle and spreading evenly over one surface. Roll into a tube and tape to hold.

> Actually with 0.5 mm thick alloy sheet I reckon you could just about butt the edges together, use superglue to join them, then cover the lot in shrinkwrap film. Assemble it all on a solid tube of the right diameter to match the inside of the fabricated tube. Maybe use a strip of wood or the like and make the inside tube collapsible to make it easier to remove.

That’s actually a darn good idea. All of it. I can make the inside tube with a slot in the wall so I can collapse it a bit to remove.

Glad you mentioned shrinkwrap film. I don’t know where to buy it, and would like to get some the right diameter. Not the electrical shrink-wrap.

mollwollfumble said:

Glad you mentioned shrinkwrap film. I don’t know where to buy it, and would like to get some the right diameter. Not the electrical shrink-wrap.

Model aircraft shop.

shrink wrap from packaging supplier.

How long does this tube need to be, Moll?

There’s several grades of electrical “heat ‘n shrink” tube that could shrunk onto a form of the correct size.

it is getting to the point where the easiest sounds like buying an undersize dowel and fibreglassing a spiral wound layer on it.

Rule 303 said:

It’s easy to stiffen a flexible material by applying a resin coating. A sheet of paper, for example, could be coated by pouring some 5-min Araldite into the middle and spreading evenly over one surface. Roll into a tube and tape to hold.

Make that 30 minute Araldite. I was considering (among my home-made tube options) doing that using PVA rather than Araldite. Araldite would be much more expensive but better. Went looking for paper types. 500 gsm is too rigid, would crease or crack. 250 gsm paper may or may not be too rigid to roll up this tight, has a thickness of 0.25 mm. 200 gsm paper also comes 0.25 mm thick (very porous). Normal photocopy paper is 120 gsm. Would ideally need an paper bigger than A3.

Problems with glue causing uneven tube thickness.

you can get plastic paper.

500 gsm is too rigid, would crease or crack.

well, that depends on which way you roll it. with or across the “grain”.

200 gsm paper also comes 0.25 mm thick (very porous).

well, that will depend if it is coated or not.

Normal photocopy paper is 120 gsm.

no, 80gsm. 120gsm is card.

Would be surprised if you couldn’t find something here.

https://www.google.com.au/search?q=extruded+tube&hl=en&qscrl=1&rlz=1T4GUEA_enAU550AU550&tbm=isch&tbo=u&source=univ&sa=X&ei=8AdeU9WLM4nHkgXlwoHYBw&sqi=2&ved=0CEEQ7Ak&biw=1344&bih=671

> shrink wrap from packaging supplier.

I know this exists as I’ve seen it on a product made in the USA, but the first Google hit only gives shrink wrap for diameters 2 1/2” and larger.

> How long does this tube need to be, Moll?

I can usefully use anything down to 1 foot long, but ideally want one or two lengths of one metre.

> There’s several grades of electrical “heat ‘n shrink” tube that could shrunk onto a form of the correct size.

I can’t find anything in the electrical line with a large enough diameter, and after shrinking it has an excessively thick wall.

> it is getting to the point where the easiest sounds like buying an undersize dowel and fibreglassing a spiral wound layer on it.

I’ve got the dowel ready. I really don’t like the accuracy of home made fibreglass.

The easiest is to shell out $132.76 USD for 55 four-foot plastic tubes that Peak Warming Man found. I like those very much, particularly the 0.3 mm thickness and tube quality, (also would get a kick out of the showiness of the transparency) but not the quantity.

The cheapest may be to take a 1.6 mm thickness cardboard tube (extracted from the inside of a Woolworths alfoil), impregnate it with a mixture of PVA and water, attach it to the end of a drill and hand sand the result down to thickness.

What on earth are you trying to do which has such rigid specifications in some areas and sloppy specs in others?

Michael V said:

What on earth are you trying to do which has such rigid specifications in some areas and sloppy specs in others?

I’m making a rocket, or two or three. Hence the tight constraint on weight, but loose constraints on everything else. Also, it’s a new rocket design that ensures that the tube carries no significant axial load.

Admittedly there is one other tight constraint I haven’t mentioned – it matters an awful lot if the ID is greater than or less than 1 1/8” = 28.6 mm, but that’s a design issue rather than a tube issue. The length is variable because I can use it over either the whole metre-long length, or a partial length coupled with sections of thicker-walled tube that I already have. And because I can use it for one, two or three rockets, the third rocket being up to 3 metres long.

mollwollfumble said:

Michael V said:

What on earth are you trying to do which has such rigid specifications in some areas and sloppy specs in others?

I’m making a rocket, or two or three. Hence the tight constraint on weight, but loose constraints on everything else. Also, it’s a new rocket design that ensures that the tube carries no significant axial load.

Admittedly there is one other tight constraint I haven’t mentioned – it matters an awful lot if the ID is greater than or less than 1 1/8” = 28.6 mm, but that’s a design issue rather than a tube issue. The length is variable because I can use it over either the whole metre-long length, or a partial length coupled with sections of thicker-walled tube that I already have. And because I can use it for one, two or three rockets, the third rocket being up to 3 metres long.

Can you use electrolysis to reduce wall thickness or is that likely to be uneven?

try looking on the website Inventables they might have something.. (a website I use often for interesting materials.

mollwollfumble said:

Michael V said:

What on earth are you trying to do which has such rigid specifications in some areas and sloppy specs in others?

I’m making a rocket, or two or three. Hence the tight constraint on weight, but loose constraints on everything else. Also, it’s a new rocket design that ensures that the tube carries no significant axial load.

Admittedly there is one other tight constraint I haven’t mentioned – it matters an awful lot if the ID is greater than or less than 1 1/8” = 28.6 mm, but that’s a design issue rather than a tube issue. The length is variable because I can use it over either the whole metre-long length, or a partial length coupled with sections of thicker-walled tube that I already have. And because I can use it for one, two or three rockets, the third rocket being up to 3 metres long.

Ah.

:)

Have fun with that.

Closest you will get in Ally is a drawn tube

OD 28.58 Wall 1.42

Its a 6060 T81 so plenty stiff

mollwollfumble said:

The easiest is to shell out $132.76 USD for 155 four-foot plastic tubes that Peak Warming Man found. I like those very much, particularly the 0.3 mm thickness and tube quality, (also would get a kick out of the showiness of the transparency) but not the quantity.

Darn, cancel that. Website says “We currently ship only within the continental U.S.”

> Closest you will get in Ally is a drawn tube. OD 28.58 Wall 1.42. Its a 6060 T81 so plenty stiff

I see, this or similar “Drawn Tube – 19.05 × 1.42 – 15um Clear Anodized – I.D. 16.21mm”. At 1.42 mm it’d be heavier even than 1.6 mm thick Blue Tube (plasticized cardboard), so scratch that.

> Can you use electrolysis to reduce wall thickness or is that likely to be uneven?

Aagh – runs a mile. Even sandpaper would be easier.

> try looking on the website Inventables they might have something

Interesting, but all materials seem to be only available as sheets, so unless I want to machine my own tube out of a block of urethane foam …

Am seriously considering going to a local manufacturer of cylindrical packaging products and begging.

mollwollfumble said:

Am seriously considering going to a local manufacturer of cylindrical packaging products and begging.

Got it!

Cardboard. Slightly larger ID than I wanted (31 mm) but near-perfect wall thickness 0.75 mm. Excellent price, $10 for more than 6 metres. Weight for weight, 60% lighter than the same length of blue tube even though the blue tube has an OD of only 28.5 mm. Comes to about 59 g per metre.

Luckily their website was totally misleading, suggesting that they only produced high-volume small printed exclusive items in paper, with plastic and metal foil lining, and metal. Got there and found it was just a cardboard tube warehouse, happy to sell to individuals.

Admittedly “local” meant four hours of driving, one to get there, one to get back, and another two hours to retrieve my wallet that I’d inadvertently left on their counter.

That only leaves where to find appropriately thin shrink-wrap < 1 mil = 0.025 mm thick. For comparison, cling wrap is commonly half this thickness.

Thomo said:

Closest you will get in Ally is a drawn tube

OD 28.58 Wall 1.42

Its a 6060 T81 so plenty stiff

wookiemeister has managed to lathe aluminium tube with ID 28.8 mm down to 0.5 mm thick, and it’s still strong and stiff. Nice.