Vacuum-forming or heat-forming styrene sheet ???

[BKLN]

Dallas,
I think you would save a lot of time by just browsing any packaging for pens, school supplies, anything that comes with a vacuum formed cover. The shape that you are looking for is not uncommon in packaging. 30min at Staples or the grocery store might be a little easier than building a vaccuum pump and burning your fingers on hot styrene.

Christian

[Design-HSB]

Hello Dallas,

I have also been built and used vacuum forming molds.
The Stirnwandjalosie is made ​​because it has many details.



If I understand correctly you want to rebuild the exhaust possessions.
All surfaces are ruled surfaces simple and no free-form surfaces.
Thus, it is safe easiest and most stable part of the plates to put together.
To help you so you can create the block of wood and form the plates of it.
In deep drawing, otherwise you have to be very careful not traveling the plate on the sharp edge.

[greenie]

Malachi, if your only ever going to make that ONE item, then making a vacuum box is a bit over the top.

Using a cigarette lighter on a bit of polystyrene, is surely a disaster waiting to happen.

You can get polystyrene to do your bidding, with a simple shape, by using a fan forced oven, to soften the styrene quite easily and in a fully controllable way too.

The shape you want, the exhaust hood, does lend itself to this type of heat forming, you will have to make the 'buck' a bit deeper and higher, so you can trim of the unwanted edges and get the straight edges you require.

Be extra carefull with the finish on the 'buck', as what imperfections that are on the surface of it,  these will come through with the soft styrene replicating these imperfections.

Put the 'buck' in the oven at about 200 Celsius and let it heat up for about 10 mins, then, open the oven and place a square/rectangle of polystyrene over the top of the heated buck.

Close the oven door and watch as the styrene starts to droop with the heat, this will happen in about 5 to 7 mins, when it has dribbled down over the 'buck and you reckon it's right, out of the oven and let it cool, jobs done, eh.

Your only using 'gravity' to pull the heat softened styrene down over the 'buck', --- it will work, ---- you might have to try it a few times to get it correct, BUT IT CAN BE DONE.

I used this method many years ago to make ends that 'bowed out' for a storage tank, I even swiped the dogs metal food bowl to do this, that worked like a charm, as the heat was coming from the inside of the metal dish, as well as from the fan forced air in the oven.

Just remember, that there is more than -------------- " one way to skin a cat ".

Thinking outside the box at times, has it's many rewards.



regards  greenie

[Mobilgas]

I seen this on E-bay last year there was a guy that would sell you a Old...Mattel Vac-U-Form machine that's been Upgraded-converted.  Punch in Mattel Vac u form machine on E-bay and it will come up.....and he tell's you all he does to the machine in upgrades 

[pwranta193]

In the vein of "not answering your actual question" - this has wine bottle/lead foil written all over it.  Find your buck, and cut panels to approximate and emboss/rub/shape to fit.  Not like you haven't done something similar 

Or are you looking for an excuse for more work bench cluttering gadgetry?  That's always my secondary goal.

[Malachi Constant]

Or are you looking for an excuse for more work bench cluttering gadgetry?  That's always my secondary goal.

No additional cluttering is required here!  Spend 10 minutes yesterday looking for a little tube of Dremel cut-off wheels that were right behind another object in the clutter.  Doh!

Thanks again for all the very helpful replies -- you guys have a lot of resourcefulness.  Have an idea in mind and hope to make a preliminary test of that later this morning ... and if that doesn't work, there are at least a dozen back-up plans in this thread ... AND ... one member kindly send a PM offering to vacuum-form the item on his gadget if I make a buck, so that's yet another great back-up plan.

Stay-tuned!  (It won't happen super quick, but it'll happen eventually ... and there may or may not even be progress today!)    -- Dallas

[Malachi Constant]

Progress report!

First, thanks again to everyone for all the great ideas you've offered ... no doubt, many of them will find use in a variety of projects.

Now, here's what ended up happening ... while reading Gordon's description of using male and female forms to press plastic shapes ... and thinking about the inside and outside of this particular shape (shown above) ... it occurred to me that I could simply build the thing if I had some hollow quarter round ... which I could make by cutting hollow tubing into quarters!  

Those of you with the appropriate tools and soldering gear could make the same shape from thin-wall brass tubing ... I ended up using PVC (or ABS or whatever it is) because it was the only thing I had on hand with the right diameter ... and it will get some skirting (again as shown above) that will give the appearance of a thin profile at the bottom edge.

So, first step, cut a length of tubing long enough for the desired pieces ... cut some styrene squares that match the diameter and mark center lines on those for quartering ... then score the quarters and cut in half.  The squares were glued to the tubing:  (a) to provide center marks for sawing along the length and (b) to keep the tubing from rotating while being fed thru the saw (actually a cut-off wheel mounted in a Dremel drill press).

The only "trick"here ... and this is essential for this particular shape, is to cut the miters before cutting the tubing into quarters ...

Rather than building any fancy jigs to support the pieces while cutting into quarters ... a scrap of stripwood was used.  

Then the pieces were glued together, a bit of styrene added to fill the rectangular opening at center ... some preliminary sanding ... and there's the basic shape awaiting final sanding, putty & detailing.

[Gordon Ferguson]

That works !

Well done always nice to see another way of approaching a problem .......... And you could now use that as your "buck" if you wanted to practice your plastic moulding 

[chester]

Bingo!

[greenie]

Well there ya go, more than one way to skin a cat, eh.

regards  greenie

[finescalerr]

My heavens, that actually looks good! And look at all the trouble you caused before you thought of it .... -- Russ