To start vacuum forming, must to prepare tool of vacuum forming. This tool sell at the shop of plastic model, but it's expensive. So, I make by my hand in economy. :D I got little wood box and crevice tool of vacuum-cleaner in 100 yen shop. (this store is like an one dollar shop or 99 cent shop in USA) And I bought a punching sheet and sponge tape in other store. The cost of materials is under 1000 yen (about $10). :)
Next, I assemble a vacuum forming tool.
1. Cut short crevice tool, make a hole in the box for crevice tool. insert a crevice tool in the box, and fix by glue.
2. Put a punching sheet on the box by glue, and moreover gummed tape. And put sponge tape.
Box size is 11cm X 11cm. The inside diameter is 9cm X 9cm. But this inside area is a little wide to miniature. So, I made frame that made in paper and sponge tape to make little area.
Prepare two plywoods (11cm X 11cm), make hole 6cm X 6cm each, sandwich a sheet of plastic 7cm X 7cm (0.3mm thick) between plywoods, and fasten with a clip. This photo is plastic sheet after heat and vacuum. I have tried and practiced some various mold. I practiced in the mold of kouglof in this photo.
I guess that this hole is still a little wide. I will make new frame that inside area 5cm X 5cm.
Well... I have made a lot of trash now. XO I understand:
simple form（circle or square plate etc.）could vacuum forming well.
detail and very little or thin line etc. could not or difficult.
But I guess I could do it. I need more time to succeed....