Imex up in smoke?

[simonp]

I think the Imex just went up in smoke .
I was trying another profiled roast, but this time I had the unit in a cardboard box to collect the chaff, and to increase the ambient air going in to the machine, with the aim of reaching the desired final bean temp.

I was roasting a slightly samller batch than befroe, 100g, and all was going well, got to first in the desired time, and 1st was progressing weel, I had high hopes for a good roast, when suddenly everthing stopped, and large quantities of smoke started eminating from the machine, enough that I took it outside fearing a fire. The smoke sure didn't smell like beans.

The Imex is outside cooling I before I dare look at it, but I suspect something rather teminal

[Steve]

thats bad news simon, it was all going so well.

[simonp]

Hmm. found the problem. The temperature of the air in the box must have been higher than I thought as one of the motor temperature safety fuses has gone open circuit. This caused the motor to stop, but the heater to stay on, which is NOT good! The heater element overheated and set fire to the rubber grommet on the wires into the heating element chamber, hence the smoke. The heater element seem intact, although a little distended now.
I think I can get a new thermal fuse (apart from the usual difficulty of ordering small values of components), btu I need to find some small crimps as you cannot solder these in.
So, looks like the Imex is out of action for a while, so I need to wire the popper back up, and am back to roasting outside, that's if I can roast in the colder ambient temps now.

Moral of the story: DON'T run your Imex sat in a box to keep the intake air temp up!

[moccafaux]

Seems to be a very faulty construction. If anyxthing goes wrong, the heater should stop doing his job immediatley, not the ventilator etc.