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vacuum impregnating tubes


MadMat

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Col, very nice, but... A spring-loaded paper-guide? I mean, considering the craftmanship of the whole machine, integrating a guide to make it fully automated (at this step) should be fairly easy for you. I imagine a very light spring pressure, or even just gravity, holding a couple of metal strips in place should do the trick.

 

Thanks for sharing, your work is always... amazing. Wish i could reproduce it.

B!

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Automating that part wasnt a high priority and it`d only save a couple seconds :) I dont need to use them for larger diameter mandrels. The smaller the mandrel diameter, the less space you have available as the gap between the rollers is related to the mandrel diameter and the height of the side rollers after they`ve been raised. As the roller height changes with mandrel diameter i had to fit adjustable limit switches to control the up/down travel range.

The roller diameter effectively sets the range of tube id`s the machine can roll. If i used 4 rollers instead of 3, the smallest mandrel od would be half the roller od, eg 1/2" for 1" rollers or 1" for 2" rollers.

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One of these days you really need to give us your blueprint for this thing. I cant even wrap my head around how it's built. Freaking amazing.

I wish i could roll 1" and up reliably, and without so much manual labor, but currently i'm stuck with using tubes machined to size, and hand-rolling. Trimming the edges after they dry, and wishing for the best, so to speak. (using tubes since they save weight. It turned out to cost more to get solid rods then tubes. might be since i made the mandrels out of stainless.)

B!

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Hi B

Most of my machines are fairly easy to make, i dont have the worlds best equipped workshop ;)

I doubt anyone would build a rolling machine like mine as its the best part of 4ft long. A glue machine is a must have for rolling tubes, its slightly shorter than the tube roller but weighs more, around 30kg.

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I got around to making a tube rolling machine, and Ill post some pics of it when I get a chance. I'm honestly a bit proud of it. The rolling mandrel actually a metal pipe with a flexible, heavy duty acrylic tube fit pretty tight around it. I start the first few turns on it by hand, then pressurize the tube so it expands slightly against the paper, holding it very tightly and pressing out any tiny flaws in the first few turns. That lets me actually drive the whole system from the mandrel without it slipping, which I had lots of trouble with because how I have it set up. The paper crosses over itself several times to provide tension and abrade the surface slightly. If I am not careful, it will actually tear the 2 foot craft paper.

 

It's not nearly impressive as yours, though. It looks rather... ragged.

Edited by StevenRS11
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Hi B

Most of my machines are fairly easy to make, i dont have the worlds best equipped workshop ;)

I doubt anyone would build a rolling machine like mine as its the best part of 4ft long. A glue machine is a must have for rolling tubes, its slightly shorter than the tube roller but weighs more, around 30kg.

Glue... I use one of these:

Holly crap that was a big picture. Which made me change my mind, and instead of hotlinking it, it's here.

 

Its really intended for wallpaper, but with my manual rolling, it works well enough.

For wallpapers it's apparently not even a good one, and leaves a spotty application, unless you pretty much overfill the glue reservoir.

For my paper rolling needs it is more like the other way around, it get a bit messy with excess glue. But thats all right, i roll a bunch of tubes at once, set them to dry, and clean my workplace. I can deal with that a few times a year. My main problem is tube consistency. I scrap tubes for not being round after drying, finding that they dried unevenly causing bends, and so on. Part of the problem probably is that regardless of how i try, i cant seam to get the tubes (reliably) consolidated enough to give a perfect end result.

And of course, even a great handrolled tube still has uneven ends, so i waste a bit of paper cutting the ends of the tubes, before cutting them to size.

 

I got access to a few different good workshops, CNC plasma-cutting robot, 5-axis CNC mill, with a 12 tool shifter-magasine (i think it's 12) a couple of CNC lathe's with toolmags, 8-16 tools and so on. In reality i cant do much with what i got access to, since i cant program them. But i could hand a set of blueprints fro a one of, and get parts back, if i try and sweeten the deal with the operator(s) by tossing in some coffe-treats, and don't push them to hard about when it should be done. They'll pop it in when ever they have a slow day, if i don't run around and bug them, to much.

 

Having access to all the tools in the world doesn't help, if you cant use em. And thats me. I can tell what end of the mill that does the work, and, i could run a manual mill, but these CNC things? Way out of my comfort zone, and i'm not going to start practicing with a working workshop, and their equipment.

Anyway i didn't mean much by the previous statement, sure blueprints would be nice, but im not convinced there are any. You built a one of, (and a great one, by the looks of it) not sure why you would need blueprints.

B!

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Mine works on the same principle as the gear driven wallpaper pasting machines. It was hijacked for hanging wallpaper not so long ago :)

Sounds like that machine may benefit from a doctor bar to control the glue thickness. Shouldnt take much to mod it :)

 

@StevenRS11

Sounds great. it doesnt matter what it looks like as long as it does the job.

Edited by Col
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  • 2 weeks later...

Here`s a pic comparing 2 tubes.i destroyed in the press.

The one on the left had localised deformation from the pressure on the clay and split from the inside out and clearly from the bottom of the tube upwards.The top of the tube is largely unaffected so it wasnt sharing the load. Looking at the pressure guage, the tube failed in defined stages as the wall initially deformed, expanded and finally split..

The tube on the right has less localised deformation. The split shows the pressure was being distributed over the length of the tube. This tube didnt fail in stages, it hung onto the pressure until it couldnt take any more, and then it failed instantly.

 

post-10522-0-53822500-1445448689_thumb.jpg

 

 

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Sorry Mumbles, should have said both tubes were identical in every way apart from the glue. The tube on the left used pva adhesive and the tube on the right used casein/dex.

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Anyone know where I can find 2 oz tubes other then sky lighter ?

Which it pretty expensive. Been doing some heavy research and can't find 3/8 in. Tubes. How time consuming is it to roll your own. And what kinda glue?

Edited by FLpyroBP
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I think Phil had some at one time.

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Precocious Pyrotechnics (www.pyro-pro.com), has some similar sized tubes. Nothing quite long enough to make 2oz rockets from. I figured I'd mention it just in case that wasn't an issue. Skylighter used to sell uncut 2oz rocket tubes that were much more reasonably priced. In fact, I used them for spolettes a few times without batting an eye. I'm not really aware of any other sources.

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Yea I'm looking for 2 oz rocket tubes. I'm thinking I need 3 1/2 length. I seen Phil has .380 tubes will that fit wolter 2 oz rocket tool. How much of a difference is .375 and .380 Edited by FLpyroBP
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