Smonson's poorly-thought-out toaster oven reflow experiments

[DrF]

What about getting one of those controller kits?
They were quite the fashion a few years ago, I suspect they have come down loads now with the masses of cheap micro controllers all over the place.

To control the oven? I'm expecting it to be a lot quicker and cheaper to scratch-build it. Plus, I don't know what kind of display I need to mount on the front yet. It depends on what will fit into the space.

Just a idea, I don't know how tight the tolerance for over temperature or under the parts could take, from when I looked into this before there was ramp up times, time profiles for different stuff/size of boards etc. lots of pretty graphs so im guessing its a bit more complex than turn the timer on for 10 mins and hope?

[Smonson]

Yup - it would take a few days to get the software up and running, but that's all part of the fun!

[Smonson]

I've got this all together now, hardware-wise.

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There is a fly in the ointment however. After some initial testing it seems that the heat from the heating elements takes about 120 seconds to be fully picked up by the thermocouple. I assume that this is because the large thermal mass of the big metal probe that it's encased in. Probably made for taking temperatures anally or something.

It's a bit useless for negative feedback on the heating element with a delay like that since the entire soldering operation is only supposed to take 240s - I might need to look for a different one that can heat up quicker before I can use this thing without setting all my boards on fire.

[Smonson]

OK, I got a "low mass" thermocouple and the response time is very good now. I've put everything together and covered the whole inside with heat-reflecting tape. I did a quick "manual" test with some random blobs of solder on old PCBs and it seems to work pretty well!

Now I just have to make the software a bit more automatic, and, I guess, make up a little bracket for the screen and buttons (low priority).

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[Icky]

Nice work @Smonson. Thats quite a hack going on there.

[Smonson]

Nice work @Smonson. Thats quite a hack going on there.

Thanks Icky

[alannguyen]

Yep. Me again with another hare-brained scheme.

I impulse-bought one of these $29 ovens at K-Mart and decided that the almost impassable mountain of junk in my garage could be bigger.

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It is packed with features:

• Low flammability sheet metal construction
• Dial goes all the way to 230C
• Satisfyingly loud DING! noise

Perfect for soldering!

Fascinating project you have going on here @Smonson.

[Smonson]

Now, after years of not having a functional 3D printer, with bezels!

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I feel this is a significant usability improvement. Hope they don't melt!

[Icky]

I am intrigued as to what the device is to the left of the toaster @Smonson

[Smonson]

That WAS a '90s tape carousel robot, but it's been stripped and is now a very heavy, solid steel cupboard under the 3D printer.