is 180mm x 280mm to small for a vacuum forming table

[blaze3927]

Well I'm thinking of building a vacuum forming table for home use (becaus I don't want to goto school in the holidays) and the biggest thing I'm ever gonna use it for is a n64 portable case, would a table 180mm x 280mm with a frame of 150mm x 250mm be big enough (for a n64P case)? (I've just bought a ton of styrene sheets that are 165mm x 265mm.
Also another Q
when using A vacuum form table how much styrene needs to be covered by the frame, as in when the styrene is getting clamped by the frame the overlap (styrene not in contact with the table clamped between the two pieces of the frame) keeps the styrene in place (is that correct?), so how much would need to overlap, would 5mm be enough
thanks

[Tibia]

I'm not sure that would be large enough for an N64 portable, but that all depends on the size of your portable. The N64 console is closer to 300 mm, so you might be a bit on the small side, again, depending on your build.

As for the clamp edge, the best tutorial I've seen was using screen frame, and that's closer to 15-20mm.

[bacteria]

You need more than about 5mm overlap unless you were able to clamp the plastic really really tight - the plastic will change shape when heated, if the plastic overlap sags, sheet ruined. Ideally, need more like 10mm overlap.

Your plastic sheet needs to be a fair bit bigger than the case mold; bear in mind that the more stretched the plastic, the weaker and thinner it gets. If for example, your case is 20cms wide and say 3cms tall, then you need approx: 3cm+20cm+3cm + 4-5cm on each side = 34cms to make a 20cm case. If you make it under 32cms, the plastic will be thin and weak - a 2mm thick sheet of plastic will end up under 1mm thick, to give you an idea. You with your 15cm x 25cm sheet will be good enough to make a case about 6cms x 16.5cms if 2.5cms thick, maximum. To put this into perspective, I am using minimal sized sheets, 32.5cms x 22cms and I can get a case 22cms x 13.3cms fine - c. 2.3cms thick is excellent, 3.3cms is ok but no thicker.

[DopestKidEva]

uh, why dont you make a big one? That way you can use it with any portable you make and you dont have to worry about size.

[blaze3927]

Thanks for the info
(google sketchup is epic!)
might consider building bigger table, but another question (on same subject) My portable is gonna be
205mm x 150mm, 35mm deep (but case will be in two parts so 17.5mm)
I couldnt really do the math for bacterias thing (not sure if I %100 got it)
so would my 1mm thick 265mm x 165mm cut it for my case?

[bacteria]

Best to use 2mm styrene not 1mm, you will find the thickness is less anyway after the vacuum process is completed as the plastic will stretch so be thinner.

Ok, logically, if you think about it, your case at 205mm:

17.5mm high
205mm wide
17.5mm high (other side)
gradient (case won't be completely 90 degrees after all; allow say 3mm each side (?)
so far = 246mm
you then need the frame to grip some of the plastic sheet or the process can't work, allow minimum of 10mm each side
=266mm
Bear in mind, you will also lose some plastic thickness as you need the plastic to melt a reasonable amount to cover the case, so you will probably end up with about 1.5mm on top and 1mm thick on sides by using 2mm thick Styrene (I use Plasticard, same stuff, called Syrene in the US)

In other words, yes, if your sheet is 265mm and 2mm thick you should be fine for a case 205mm wide and 17.5mm thick.

In regards to height, by the same maths, 165mm high would give 105mm on a case - so no, not enough that way - you need about 210mm high plastic for 150mm case height.

My sheets are classed as A4+ at 325mm x 220mm. My case is similar width to yours but 137mm high - the size of sheet I use is ideal- you really need a sheet that size too for your system - the size of sheet you suggest will not work, period - too small.

Hope this helps.

[blaze3927]

thanks heaps for the info
im gonna go get bigger sheets (for the n64p) and use the smaller stuff for my ps1p micro, for which the sheets will def be big enough :):)

[blaze3927]

one more question (probably more to come )

I'm using a wooden mould for my case, do you (bacteria or anyone else that knows about this stuff) think it would be wise to make the holes for the buttons, controls etc in the wooden mould? or just leave it and make them on the plastic after it's been vacuum formed?
thanks

[bacteria]

Make the mold flat and add the holes afterwards in the case. Making holes in the mold will only suck the plastic in them, you will still need to make the holes but will be harder and less likely to end up as nice.