My Solution for the Thermoforming Machine

Thermocouple and controller like a Watlow? You may get them used cheaply.

'... I can't spend alot on this project....'

Probably the best place to get what you need, on the cheap, will be garage sales, or items put at the roadside for pick up.

People throw out a lot of items with heaters and temperature controls. The obvious ones are on baking ovens and toaster ovens.

People also throw out a lot of hair driers. The temperature a hair drier is set to is lower than you need, but you can probably get the bimetallic switch to work around the temperature you need with some trial and error modifications....plastic deformation of the switch.

A small metal circulation fan will be very helpful to insure fairly uniform temp. I'd just look for a small motor with a long shaft, so that it can be away from the heat....but then again you need this to be airtight right? Hmm, that needs some consideration.

The air tight part of the process is the actual formation of the project piece. The heater part of this gadget can have some air circulation as long as it allows the plastic to heat up to the 300 to 375 degrees it needs to be able to sag before it is vacuumed over the mold piece.

That certainly makes it much less complicated.

One inexpensive way to do it would be with a thermostat from an oven, and a diffuser on a cheap heat gun (since it already has the fan). A cheap heat gun alone might work acceptably with some trial and error modifying the airflow.

Very clever on suggesting hairdryers, toasters and other non used items for your thermoforming heater machine. I have did recently hear too that advancements inthermoforming can increase profit margins which is always great- see here for details http://www.ceramicx.com/thermoforming/