Today I made a start on my composite oven, which I will use to cure pre-preg parts as big as an entirefront end of a mini. I would have liked to make it big enough to fit a roofpanel but it would be too big to fit in the space I have.
The main housing is made entirely of celotex / kingspan and is designed so that it can be dismantled and flatpacked when it's not going to be used for a while.
I started out with 6 sheetsof 50 x 1200 x 2400 celotex these were cut down in to 2 sections of 1700 x 1200 used for the front and back, 2 sections 1000 x 1200 for the ends and 2 sections at 1700 x 1000 for the base and top. The lid is designed to simply sit on the top and the other edges are all morticed so that they interlock with a snug fit and the whole assembly is pretty much self supporting, although I will use something to secure the sections in place. Here are some images of it so far:
I ended up with a spare sheet and some decent size offcuts which I may use to make a smaller oven for use with smaller parts, this way I save on electricity costs be heating a smaller area. I will make it using the same methods.
Tomorrow I plan to tidy up the edges and add some re-enforcement with aluminium foil tape, which will hopefully minimise the wear & tare from dismantling and assembly. I may also make a start on mounting the element and fan motor, but this will require some fabricated steel and I'm not sure if I have any suitable material knocking about. I will also have a go at getting the vacuum fittings installed.
The electrics will have to wait as I still need to get an enclosure for the control circuits, some wire, terminals and switches. I would also like a little advice on how to connect a safety shut off to prevent things getting too hot if something goes wrong with the control system. I have looked at a range of thermal cut out switches but have not managed to find one that can handle the current to run the element, so I can't simply wire it in series with the main power feed. Does anyone have any advice here? I have considered using a relay, but need to explore my options here.
Looking at the size of it I might have to re think my plan of a removable lid for access, at 1150 mm deep it would be difficult to get smaller parts in and out, so I may look in to a door on the front panel, however this would involve some kind of frame to support the door, this would add a fair bit of weight and complexity therefore making it more difficult to dismantle / reassemble.