vacu-forming canopies

[razorblade]

I have been trying to do a little vacuforming and finally got a set up where i can pull canopies preety good but i have run into a problem when i pull a canopy over the kit canopy it turns out a little bit larger which i should have known it would does anyone know of a solutin to fix this i thought about trying to make a pattern but this would be hard to do and keep the raised details has anyone run into this before and if so how did you solve the problem thanks a million Razorblade

[Francis]

There are 2 solutions that I know of. First, is to make your master undersized to compensate for the plastic thickness. Second, you make a female mold. Personally I preffer the first option as it is easier but labor intensive. Have you tried triming it to make it fit? It sometimes works. Good Luck.

 

Francis

[LSP_Matt]

you got me thinking

 

could you do it like this?

 

1. Take an nice 'alginate' impression of your cockpit canopy by imbedding it... detail areas first

2. Pour up your impression with a fine grain stone to make your working model

3. Use a material of less thickness than your master canopy plastic and when vacuum forming, give it heaps to thin it even more.

 

I'm wondering if this might give you what you are after...keeping the surface detail and shape but by creating a copy of only marginally larger dimensions.

 

Anyway thats only my idea /0.02c worth

 

You've got an interesting problem

 

[Derek B]

Hi razorblade,

 

My experiences of moulding canopies tend to be somewhat variable. On the whole, using kit parts is a quick and easy way of reproducing the items you want, albeit sligtly oversized. If you keep the mouldings thin, and carefully seat and seal the canopy edges to the model, then in all honesty, most people will not even notice that is slightly enlarged. The downside is that raised canopy detail does not come out very cleanly with this method. I always sand off all of the canpoy detail (which also gets rid of the oversize problem as well. Besides, the kit detail is often incorrect anyway!). You then have two choices. Either leave the master pattern completely devoid of panel detail (which means you have to work out where they go later during the masking and painting phase), or re-scribe the lines on the sanded and reduced master pattern. This will give you a faint outline to work with (saves you guessing where to place the panel detail). The above also generally applies to hand plunged canopy forming as well, although you will be very lucky if you can reproduce the scribed lines with this method (although there are ways around this - but that is a little more advanced than what we are looking for here).

 

HTH

 

Derek