Get on with it ! Kids, don't try this at home

I've gotten sidetracked from the vacuform construction process. One late night I though it would be fun to see what the heat distribution of my vacuform oven would look like, if I used 9 halogen linear tubes as the heat source distributed evenly over 1 m^2.

I went on to build a software simulator to generate some nice pictures of what it would look like. The first simulator was stochastic and the pictures were not really nice (see an older post). Version 2 of the simulator uses real physics to calculate the temperature change in each spot of the vacuform oven.

This picture is the result of that simulator:

The color indicates how hot a certain spot is. This is what the gradient looks like:

An AVI file is available here (900KB):

And an animated GIF here (2.3MB):

Here are all the files and the code (9.5MB):

At this point I should probably say that I'm not a physicist or an engineer. So basically, I have no idea what I'm calculating when I do these simulations. They just seem to make sense as far as I know.

In any case, this is where I got sidetracked. After spending hours (and hours) on the simulator, I still don't have any reasonable results because I have no idea if my simulator even matches the real world.

So, let's just get on with it. Instead of using software to simulate the oven, I just built a smaller version of the oven.

These are the professional blueprints
Apologies for not using the more standard cocktail napkin for this, but I had none handy.

By the time I got to the basement, the plans had already been revised (just to show how rocksolid my ideas are)

All the wood was cut to length (and recut to length after another design revision)

And some holes were drilled with my newly bought drillstand. This drillstand is actually quite handy. When putting together the vacuform frame, all the holes I drilled were out of alignment. This thing makes sure that all holes are straight.

Of course, it didn't take long to break the stand. What do you expect for 25 euro ? :) I'm taking it back to the shop to be replaced. The stand was still good enough to drill holes though.

The mini-frame I built for this experiment is actually better constructed than it's bigger brother. Using pre-drilled holes, I was able to put the frame together very fast

And here is everything together:

Allright, now we are getting to the "Don't try this at home, kids" part. So, Don't try this at home kids:

To mount the linear halogen tube into the oven, I made my own version of a lamp socket using a couple screws and bolts and some high-gauge electrical wire. At this moment, the oven will use only 500W (1 lamp), but when using 9 of them, it will suck 4500W. The wiring I use here is 4mm^2.


When plugged in, the oven lights up nicely

But after only 10 seconds, the wood started to burn

I expected this to happen (really) and bought some heat isolation that is placed behind heaters to reflect the heat. I will put it in there later and try again. Stay tuned