Vacuum forming coil housings.

[dfbowers]

Nice job!
I have alignment tabs on the edges of my former so it goes into the right place everytime.
Along with temperature, I measure the amount of sag in the plastic while heating for consistency.

Inside your tabs.. no need for a wrinkle. It may be too hot if that occurs. Use a piece of wood to stretch and coax the plastic to the center of the tabs. It took me a long time to get it right but I hardly ever have a dud or a wrinkle anymore.
don.

[cristiano.sar]

Here are some more videos about my vacuum forming process:
Latest formed shell done today: https://www.youtube.com/shorts/U3bLslijPjY
Explanation of the process (in Portuguese):

[MartinB]

Finally it almost worked!
I added some screws to the frame, to keep the sheet in place while heating.
Also bought an infrared thermometer to ensure a good temperature.
Used 2mm polystyrene because here is difficult to get other thicknesses like (1.5 or 1.6mm).
Formed at about 150 degrees celsius at the center of the plastic.
My only problem is that it seems that I slightly moved the form to one side (not perfectly centered) so one of the sides not formed perfectly but I will fix this next time.
Here is a video and some pictures of the work:

https://youtube.com/shorts/GFSJxs51uoY

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From error to success (left to right):
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Thanks!

Well done. Try adding two small wooden pegs to the bottom of your former. These should line up with two holes in your vacuum table and will prevent the former from moving.

[cristiano.sar]

Finally it almost worked!
I added some screws to the frame, to keep the sheet in place while heating.
Also bought an infrared thermometer to ensure a good temperature.
Used 2mm polystyrene because here is difficult to get other thicknesses like (1.5 or 1.6mm).
Formed at about 150 degrees celsius at the center of the plastic.
My only problem is that it seems that I slightly moved the form to one side (not perfectly centered) so one of the sides not formed perfectly but I will fix this next time.
Here is a video and some pictures of the work:

https://youtube.com/shorts/GFSJxs51uoY









From error to success (left to right):


Thanks!

[MartinB]

https://sites.google.com/site/dbcoil...-vacuum-tables

Thanks Don,
Great piece of work

[dfbowers]

Sounds interesting. Can you share some details?

https://sites.google.com/site/dbcoil...-vacuum-tables

[MartinB]

I now use a two stage vacuum system. For years I got away with just using a shop vacuum.. You can make up for the lack of high vacuum by getting the plastic hotter but there is a very fine line between too hot and too cold. You can do it but will waste some plastic until you get the correct time an temperature.

Sounds interesting. Can you share some details?

[dfbowers]

Try this link..
https://sites.google.com/site/dbcoil...-vacuum-tables

Don..

[cristiano.sar]

Thanks all for the tips, I will try with a thinner plastic (1mm), also I will pay more attention to the temperature and reduce the ears thickness and open some holes near them.

[David_1]

I now use a two stage vacuum system. For years I got away with just using a shop vacuum..

can you explain a little more please.. I am just starting with a shop vac ??

[dfbowers]

I now use a two stage vacuum system. For years I got away with just using a shop vacuum.. You can make up for the lack of high vacuum by getting the plastic hotter but there is a very fine line between too hot and too cold. You can do it but will waste some plastic until you get the correct time an temperature.

[MartinB]

This was my first vacuum form try, but I failed.

I think this polystyrene (2mm thick) plastic is too brittle.
I need to find an ABS sheet but it is difficult here in Brazil.

You will have several fails before you get it right. Keep on trying. Looks like your plastic cooled before it had fully formed. You probably need more holes in your vacuum bed. Make sure these follow the inner and outer perimeters of your former, especially on the tight inside curves. Also, drill a few small holes through your former between the lugs. If you don't want to re-drill your vacuum bed, lay over a piece of ply or MDF with holes drilled to suit your former. The oven method never worked for me because the plastic cooled to quickly, so I built a simple forming machine with integral heater.

[Op04]

This was my first vacuum form try, but I failed.

I think this polystyrene (2mm thick) plastic is too brittle.
I need to find an ABS sheet but it is difficult here in Brazil.

The ear part is too thick, make it thinner. Good luck!

[David_1]

cool ive built the vacuum base, but the plastic I have is wrong.... going to watch you vid now

[cristiano.sar]

This was my first vacuum form try, but I failed.

I think this polystyrene (2mm thick) plastic is too brittle.
I need to find an ABS sheet but it is difficult here in Brazil.