Bacteria's project - making a vacuum forming table

[bacteria]

I don't have suitable tools to make the mold out of wood, only have normal saws, electric hand saw, electric sanders, files. No sense in paying lots of cash out for better tools for the job when I don't have any other need for them.

I noticed on my first mold that the areas I got smooth came out perfectly on the plastic, however of course any imperfections on the mold also come through, hence making special care this time!

Clay is expensive, hence the piece of MDF. To make one half of the mold with just clay would need four blocks of clay, £12 total; using my MDF piece brings this down to just under one and a half or thereabouts (about £4.50). The red tools in the pic are designed for clay shaping, and by using a small amount of water, I can get the surface of the clay virtually smooth before I even start to sand it.

My first effort came out of the mold ok as the mold sides are sloping, so just needed a tiny flex to remove the plastic from the mold on the top. I knew if the slopes are vertical or worse that the plastic will not release from the mold - anyway, I want this casing to be very sloping and curved on the sides (one of the reasons for the vacuum casing in the first place) What is "draft" BTW?

Got my design completely symmetrical - my method was easier than using graph paper - fold a piece of paper in half, cut a shape with scissors, open out - to identical and mirrored halves. Old school trick I remembered from yonks ago.

I don't have much space on the vacuum table for holes as, to keep costs down on the plastic itself, got sheets a bit bigger than the mold rather than a lot bigger. This might give me more rejects or may not, however a far cheaper option (plasticard is not cheap). I will probably however put tape over the existing holes and drill smaller ones in their place, and more of them.

[bacteria]

Had more problems. The clay didn't want to stick to the MDF and so I got lots of cracking on the clay. Useless.



The only choice (using clay) is to just make the whole thing with clay and be done with it. Wasted a couple of packs of clay so far as it is, so may as well just "go for it".

Started again, cut out a piece of mounting board as the bed for the clay.



Spent most of an hour, got the whole mold completed. If I get any minor cracks or imperfect surfaces, I can fill them in with clay; once fine, I can sand the mold to be completely smooth, in preparation for the vacuum process.

This took about two and a third packs of clay to make.



Off to sleep now, came of a Night shift a couple of hours ago, need sleep...

Hope the clay mold works out ok; if it does, and with careful sanding, I will end up with a very sleek system. Here's hoping anyway! The casing will be able to take a variety of popular systems: PSone, N64, SNES / NES (via Retro Duo), plug'n'plays (Namco, Radica, etc). Any console board no larger than a PSone's.

My intentions are to make these systems above in my new casing, then offer for sale empty cases so others here can make their own systems in a similar fashion.

This has become my primary project at the moment!

[collinE]

I don't want to be a debbie downer, buuutt...

I'm 90% sure your clay will crack. big time. I don't know anything about the white clay, but if it's anything like regular gray clay, then it's gonna shrink a ton, outside to inside, and the uneven shrinking will cause it to crack. I tried making a big fat block of clay for my mold, but it ended in tragedy.

I really hope this works, as you've spent a lot and tried a couple of times, but I'm nervous. The best case scenario that I see is that it'll shrink without too much cracking, and you can cover it with more clay, which would bond better to the dry block.

[hailrazer]

What about the Styrofoam type blocks at the craft stores. They are rated to withstand 500 degrees or higher.

And they are only $8 for a big block.

http://www.joann.com/joann/catalog.jsp? ... =xprd78641

Can't you just use that and carve it like you need it ?

[Turbo Tax 1.0]

wood makes the best molds in my opinion
the one downside is some of the tools needed to make a nice wood mold. do you know anyone who would be willing to help you out?

It's nice to have a carpenter friend

you may want to try making a plaster mold. those worked alright for me but it was more difficult to get a symmetrical peice

[hailrazer]

Oooh another idea I had.

How about expanding spray foam ?

Spray it into a wood box that's like 8"x12"x5" and after it hardens , remove it and carve it in the needed shape.

That stuff get's hard as heck and is supposed to be very heat resistant.

Oh and for a good simple vacuum former guide watch this :

http://www.youtube.com/watch?v=e5CGfoxnKaQ

[collinE]

For all the money spent on clay a better long term investment would be a power jigsaw, workbench, some wood and a few different grades of sandpaper.

ah yes, I agree. Most all of us have tried taking the cheap way out to discover that cheap usually means failed attempts and wasted time, but that's all easy to say in hindsight. Who can say "no" to spending a few bucks on a mold instead of spending hundreds on all the right tools? (also harder to convince a wife to spend that much on tools )

What about the Styrofoam type blocks at the craft stores. They are rated to withstand 500 degrees or higher.

And they are only $8 for a big block.

http://www.joann.com/joann/catalog.jsp? ... =xprd78641

Can't you just use that and carve it like you need it ?

in a word... no. I went out on a search for something to use as a mold that was easy to shape with a dremel, file or sandpaper. Here's what I discovered.

white packing styrofoam: makes a proper shape if sliced with a sharp knife, but crumbles into balls if torn or cut with a serrated blade. Melts at too low of a temperature and is kinda squishy.
craft styrofoam (the kind that was linked to) good stiff foam. melts at high temperature and is fairly easy to shape. Unfortunately, its extremely porous. It's more like having the foam from a bubble bath harden. so if you wanted to make a unique case with a ripply effect, it would be good. but it would be bad for a smooth, flat case.
green flowerpot styrofoam This stuff is really fine in texture and you can carve it with your fingers. if you want to round an edge or sand it, just use your finger tips like sand paper. but it dents ridiculously easy and always leaves you feeling like you just handled fiberglass insulation.

again, that's why I've chosen plaster.

[bacteria]

Thanks for the thoughts, guys, nice to hear about alternatives.

My previous two casings failed because I tried to save a few quid (or bucks as you would say), by using MDF or something else to fill the middle. The MDF one failed because the clay didn't want to stick to it when drying, so the clay mis-shaped on those edges and cracked badly. That is why I have made my current casing entirely out of clay; it is on a layer of mounting board, primarily so I could get the sizing right and also manouver the clay easier.

What I need is a very smooth final surface, otherwise any bumps will show on the final casing - I want the surface to be completely smooth. This means a very hard surface, otherwise it will quickly deform and the mold will be useless.

I don't have professional woodcrafting tools, or the skills to make symetrical and curved edges and sides, nor can justify the cost of such tools. Bear in mind I only want to make two molds here!

This is why I really want the clay idea to work - very easy to shape, easy to work with, dries very hard, no skills needed (anyone can do it).

Will update you later with how the mold fared....

[bacteria]

Looked at clay after 24 hours since formed - no cracks (yet), base raised on sides by about 3mm as top side was able to dry better than underside, so I turned mold over and pressed it down with an MDF block. Flat again, one small hairline crack from this, will resolve when mold drier.

Another 24 hours and I may well have some cracks; however I think if I turn the mold over every 12 hours or so I can reduce any bowing. The clay is still not dried out after all. Going to take a bit of a risk, put the clay into my airing cupboard for a while to speed up the drying time. Will have to monitor it though, so it doesn't dry out too fast (or cracks will show).

Gave me a chance to hold system for the first time though, as the clay is hard enough to lift up and hold without deforming. I must say, the shape, as a console case, feels really comfortable to use.

I placed an old PSone screen on top (slightly off-centre, sorry!), and then used PhotoFiltre to overlay my idea for what goes where:



Layout:

All formats:
Light grey - speaker grill area. Speakers are larger than the area shown, this is just for the grill holes.
Green - shoulder buttons (systems which need them).

PSone:
Light and dark blue - joysticks
Yellow - d-pad
Orange - 4 action buttons

N64:
Light blue - d-pad
Yellow - joystick
Orange and to the south of the dark blue area- A, B, and 4 C buttons

SNES / NES Retro Duo:
Yellow - d-pad
Orange - 4 action buttons

Plug'n'play: (re-house existing project if I feel like it)
Yellow - d-pad
Orange - 4 action buttons

When this mold is dried and complete I will make the backing case section. This will be again, one-for-all; the backing will be flat, although the sides will slope as per the PSone case front (with CD remover section), so as to allow for a flat area for a cart slot holder for the SNES and N64, and also to accommodate the PSone CD eject area. It is unlikely that any bondo will be needed to make the N64 or SNES systems, however bondo will be needed to secure the PSone CD tray opening section to a heavily cut backing to the case.

Comments welcome!


UPDATE: Case has been drying now for 36 hours; about 6 of which were in the airing cupboard (out of there now). NO CRACKING! Clay works!

Tomorrow I will get busy with sanding!

[bacteria]

Clay didn't crack. Finished sanding.





Made new holes in table:



Kitchen setup:



Far better result! I just need to sand a bit more here and there on the mold and try again. Close to final result now!

I stated the vacuum cleaner before putting the plastic on, works fine. Holes in table are smaller now and better placed.



Pressing the plastic top lightly, the mold dropped out of the plastic shell. Excellent!

Updated my website with step-by-step guide.

Will post in News when next mold done (after slight sanding to mold to get it "just right").

[marshallh]

I don't have suitable tools to make the mold out of wood, only have normal saws, electric hand saw, electric sanders, files.

You just listed all the tools you need to make a simple wood mold

Whatever works, I guess. But in my opinion there is no equal to a wood mold. It's durable, heat resistant, and never cracks or breaks. And most of all, the surfaces are perfectly flat and consistent.

[Turbo Tax 1.0]

its easy to put some nice designs on wood molds too

I am really happy with my latest, not even using bondo on it

[collinE]

awesome. That's great that it all worked out for you. I wish I could find some of that clay here in the US as I'm amazed that it didn't shrink or crack.

and I agree that wood is, by far, the best for mold making. *sigh*

[bacteria]

marshallh - I had a go with pine but it was really hard work trying to shape it. If the sides were straight with rounded corners only, then yes, I could do that, however my shape is very curved and complex to carve from wood unless I had a workbench attached heavy duty jigsaw with a very small blade. I don't have this. My woodmaking skills are probably not up to the mark to produce a mold I would be happy with.

Clay on the other hand is really easy and quick to work, with simple shaping tools and electric sander and hand sanding tools. Clay is also very easy to sand finely. I could also put on a thin layer of varnish to preserve the mold when it is "perfect".

I had thought about making a top on the case with sloping sides, like on your L64, however decided against this as I prefer flat buttons (not angled) which means flat button and joystick areas. Given this, the top on my case is flat as there is little room that won't have buttons or joysticks on.

Heat is not an issue, the fact that you can nearly touch the plastic when straight out of the oven indicates that. The clay isn't going into the oven after all, so is absolutely fine. The plastic came free from the clay mold very easily too.

The clay is robust, it is designed for model making.

Turbo Tax 1.0 - (as above). We all have different skills and strengths. I am good at thinking out of the box, using logic and experience and gut instinct. Woodmaking is not one of my skills, apart from making furniture out of MDF). Although it seemed clay wasn't good for making a mold, it is excellent; I tried to penny-pinch and wasted time and money; when making the mold completely out of clay I got a prefect result.

My design won't need any bondo for the case front, however the back will as I will need to hack the front of a PSone case (with the CD opening device) to put into the back of the casing.

collinE - Thanks, pleased you like it!

It doesn't matter what the mold is made up from, it is the result it gives that is relevant and important. I'm not making china pottery after all, just a hard mold to shape plastic sheets over. You got a splendid result from your plaster after all (although you had some issues).

Looked on e-bay just now, for "modelling clay", the one I use is air drying, some dry when baked in the oven I notice and there is also a polymer version (different brands).

Interestingly, the only one on e-bay for the UK is expensive, double the price I pay and only 250g, mine are 500g. I must have used about 1.3kg of clay for this mold (ignoring wastage). I have a "The Range" store near where I live, which stocks the stuff. I will have to pop in again as I need another couple of packs of clay for the case backing (which I will make after doing the internals for the PSOne console portable, as I will know then exactly the dimensions needed for the backing).

[Triton]

We all have different skills and strengths. I am good at thinking out of the box, using logic and experience and gut instinct.

and with the tools you had avaiable you couldnt figure out how to round off corners on a block of wood? that gentle of a curve should be easy to cut with a handheld jig saw or even a coping saw. or just cut the corner off at an angle and sand it out? im glad the clay worked for you but it was probably more work than the alternative in the long run/

when i was workin on vacuum forming i made my mold out of expanding foam and plaster plus some bondo. if i were to remake my mold i would go with that pink insulating foam and bondo instead, much easier to work with and more rigid