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Building a Plastic's Forming Vacuum Table

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Been annoyed with the organisation of my tool cabinet / display for some time..... Needs to be bigger and better organised. Particularly where mates are concerned lol they seem to be able to get tools from the cabinet all good but they seem to get returned to random locations and some don't make it back.... so I want every tool to have a place that is at least difficult to fit another random tool lol and so I can check at a glance 

To this end I've been looking at cutting closed cell foam (camping mat) and have bought some sets of tools in foam inserts for work.... I found they got damaged rather quickly and are a prick to keep clean compared to the old blow mold organizers. One rain off day I was on the net trying to find a harder version of foam and stumbled on Vacuum forming.... a day of U tube later I've decided to give it a go

I'm going to build it here at work, trial it at our workshop and kit out my work tool kit.... possibly build some stuff for my home tool kit and then throw it in my backpack and it can fly home with me.... so it has to be small enough to fit yet big enough to form up to 300x300mm stuff.... this is a good size for me and is about as big as I can fit in an house hold oven ( I plan on fitting one into my shed "when/if" its built ) that way I don't need to concern myself with a heating setup. I also want it to be resumably compact and able to store away.... I have enough tools etc and I want to keep space open in my new shed

So I'm thinking of building the vacuum base out of a sheetmetal box with a shop vac attachment, with a double angle iron frame that I can seal to the top of the box that clamps the plastic sheet  

This is going to be a learning curve lol so if any of you have played with this please pipe up 

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Interesting.....


Will follow with great interest.

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Posted (edited)

I've just sold one as I had all these great ideas but never really used it. It was a small commercially made machine, it would do a bit bigger than A4 size. A bar heater above the plastic then once it was soft and droopy you raised the parts up into the plastic then turned the vacuum on to suck the sheet down onto the parts. For a deep pull you could blow instead of suck so that it ballooned the plastic, this thinned the material so when you sucked it down you didn't get really thick base and sides then paper thin corners. Then you raised your parts and sucked down with the vacuum as usual.

To make your tool inserts you need to lay them on a sheet of wood and put either a block of wood either side of it for finger holes so you can lift it out or part bury the part so it's only half in the plastic. Then you need to drill a load of small holes around the part so that the vacuum can pull the plastic down. Or use a board with a lot of small holes already in it. If you get the plastic too tacky it will get sucked under say a hammer head and you won't be able to get the part out so you either need to do it when the plastic is a little stiffer or put some bluetac or playdough or something around it so the plastic can't suck under. Finally to get the tray to sit flat in the tool box and not rock around you need to build a lip around the edge so that it has a flat edge to sit on... and drill loads of small holes around that so that it can suck the plastic in the corners. 

I'm sure it'll be fun, good luck!

These are a couple of things I did just messing around trying to get the hang of it, the two spanners failed because when I lifted the parts into the plastic the tray didn't latch in place properly so when I turned the vacuum on it sucked the whole try back down. But it also shows how it doesn't get around the part very well without the holes at the edge for the vacuum. The other part you can see the mould for and the holes around the edge so that the vacuum could get into the corner. This was a deep pull so needed to blow first, without down this the corners just tore, you can see a crease at the edges where it couldn't get the material back in. 

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Edited by Cynic-al
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Adam Savage has mentioned his home-made one a few times:

 

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Elbekko,   thats one of the vid's I watched..... was impressive how deep that buck he used I would have thought not a chance 

Cynic-al,  Thanks for the advice about blowing it.... I hadn't seen anything about that on Utube or any of my research, my uncle has pressure formed acrylic to make airplane canopies and that was alot of trail and error because of optic distortion.... it came down to the shape of his clamp area and then adjusting the base once the canopy was blown

Any recommendations on what material to play with 

My bucks for the most part (for the tool box) will be no more than 45mm high.... I was planing on using the tools and plasticine to round off and stop the plastic sucking under and to form pickup points 

 

I've designed this so I have 50mm around a 300x300mm buck I'm sort of guessing this will give it enough to suck down the edges, so its a 400x400x75mm box with a handle one end to and a tube for the shop vac poking in one side about as simple as i can think of lol 

This is what I've got done so far lol I'm not doing this again any time soon!..... hand formed bends on the end of the bench with a nylon mallet then over 600 holes marked center punched and drilled with one drill bit surprisingly 

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When I get some time I'll fold up the other part of the box and hand roll a tube to fit the shop vac then its simple enough to make a frame to hold the plastic 

 

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That looks fantastic work! 

I found ABS sheet easy enough to use. 

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The only drawback I can see is that the sheet thins out as it's drawn down, starting at the edge of the shape, and that edge tends to be a weak point and fracture prone.

You may want to experiment with thicknesses of sheet to get best results.

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8 hours ago, JohnnoK said:

The only drawback I can see is that the sheet thins out as it's drawn down, starting at the edge of the shape, and that edge tends to be a weak point and fracture prone.

You may want to experiment with thicknesses of sheet to get best results.

Watch that Adam Savage video.... it is way more than I thought you'd be able to form, Cyniic-als suggestion to pre stretch it would give it a lot more uniform thickness, since I'm using an oven to heat with I'd have to do this by hand with gloves at a guess...... from what I've seen online in videos and other threads on this, 1/8th sheet seems to be the limit using a shop vacuum

My plan (feel free to speak up if you've done this before lol) is start with 2mm sheet until I get to know and anticipate that thinning out stretch, I'll also get some 1.5mm as well when I get the plastic just incase I can't form the contours I want ..... my plans for the tool boxs are pretty much along the lines of this 

teng-tools-mega-bite-circlip-plier-set-9

In fact I'll it is this and a combination of what I can build for those tools that arn't Teng and I'll be using there clip together organisational system 

Oh and found out last night plasticine might not be the go a melting point of 175F given I need the sheet at 300F to form I don't think this will work lol might try modeling clay 

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I don't think this'll cause you a problem, but then again I didn't think it would cause me one -a vacuum draws it's input partly through the motor, where there are sparking brushes, a good ignition source. If you are pulling highly inflammable fumes, they may ignite. My experience was with one applied to an exhaust system pulling residual petrol through with surprising results. Just saying.

Nigel

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I wouldn't worry too much about melting the forming material as the thin plastic cools very quickly so I doubt you'll get enough heat transfer. Maybe window putty or something might be an alternative.

Or build a CNC router instead and hack it from foam :D

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lol I've considered building something cnc a few times...... catch is I need to finish some vehicles first lol the tool box is something I can do after hrs while I'm away with work 

I'll give it a play with the plasticine it won't cost me much to find out and its a nice product to work with.... ordered the plastic today 20 sheets of 2mm and 20 sheets of 1.5mm in black and white 

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Back at the work workshop, stayed late one night and finished the base 

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No pretty welds on this one lol we fix trenching gear here so the lightest welding wire was 1.2mm trying to weld galv sheet metal with that wasn't pretty I had the welder wound down that low it was stuggling to strike and I still played chase the hole.... but shes done the plastics guy has my ABS sheet in but hasn't cut it yet.... been doing a bit more research and I'm going to try it in Polystyrine sheet as well and learned a few tricks to do with deep draw forming (where the opening on the die is less than 75% of the depth ) something I'm going to have a bit of when I get onto making parts containers 

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For all my patience bending and welding this I did get a few issues but they are minor enough.... the hammer forming on the bends has left me slightly off square so my clamp frame only fits one way .... not a biggy lol and I got a little weld warpage that pulled the middle of an edge down so I have 3mm dip on one side but the felt seal will deal with that 

I've had to step it up a notch...  turns out my home oven is a bit fancy and bigger than the norm.... I can't fit the plastic clamp in any oven I've got access to at work lol  So I've bought a Radiant Patio Heater 2400W and I'm going to have to build a colapseable heating box 

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