Finally got around to finishing off the reflow controller kit that I bought months ago from Sparkfun. It initially had a sluggish response, but once I covered the glass door with aluminium foil the performance improved significantly. Although I still have the original profile in Program 1, I added a Lead-free profile to Program 2. I used the Pickit2 with the stand alone programming software to modify the EEPROM to store the new profile before programming the PIC.
Nice work. I finished my controller, but haven't fully modified the oven yet. And after I finished soldering the LCD to the board, I realized that I should have not attached it directly to the board, but use a cable to allow the LCD and possibly switches to be mounted in a nice case, since the Vregulator and relay poke up higher than the LCD. Oh, well!
I've been using mine off and on for about 7-8 months now - it works really well and follows the standard profile almost perfectly (only the cool down is slower). I used a Black&Decker oven (<$30 shipped from Walmart) with top/bottom elements to get an even heat distribution. I did about 2/3 of my ACL strobes with the oven.
I'm using the same combo as well. It seems to work well enough, but I wish the Sparkfun controller had a fan output to control the cool down. Right now I have to watch it and when it gets to the cool down period I prop the door open about 1/2 inch. I did a run of 25 of my DMX dongle boards with it and they came out great.
I was looking at the Sparkfun temperature controller kit (for toaster oven), but was thinking that the LCD and buttons would be better on a separate PCB. How many people here are interested in making a temperature controller?
I'm now interested in making my own reflow oven. I'm super sick of hand soldering thousands of smd components especially 0805 resistors and caps.
I've had the kit from sparkfun for 2 years, and although i have pro-grade ir ovens and a 5 zone conveyer oven for production, my $60 oven still is in use in my workshop at home. My major mod was to modify the oven so i got both the grill and bake elements coming on together, so i could get the temp up fast enough. Ha'dn thought of covering it with tinfoil.. I also have the problem with the cooling.. I pretty much just stand and wait for it, and then just prop the door open just enough.. ( the cooling is important, and it can't be too slow, or too fast )... I'd get as many problems in the oven as i would on the pro gear.. Most of the problems though are related to solder paste.. The smallest parts i use regularly are 0402, and i get a few tombstones, but nothing that can't be fixed. If you're going to the hassle of all this, then you'll almost cetainly also want to consider some kind of vacumn pickup tool, this does'nt need to be eloborate eitehr, and i'm sure that the diy- spirit would invent something pretty quick. If i was going to redesign the spark fun system, i woudl (a) replace the relay with a Triac, with a zero cross opto-coupler. (b) get rid of the buttons, lcd in favor of a web based controller, using a pic24 or similar, making storing profiles trival, and making it more useful for other tasks ( drying components for example needs 3 hours at 55deg C, prior to relfow if they have been exposed to moisture.. It would also be useful for other task, like curing the paste used for through holes etc.. Theres actually lots of thigns that it coudl be useful for.. The other thing i might consider is having a second output for controlling a fan, so i could assist with the cooling side of things..
After this subject came up again in chat last night, I search and found this 2400W oven: http://www.breville.com.au/cooking/ovens/the-compact-smart-oventm.html It's a bit fancy (electronic controls) and certainly more expensive ($199 RRP) than the 1600W units, but the extra power may make it quite worthwhile. There's also a physically larger version for $299 RRP. http://www.breville.com.au/cooking/ovens/the-smart-oventm.html
