As awesome as it is to build things and as much as i am all for hobby projects..Not my experience. You might do without proper profile if you are doing mostly resistors and not too demanding components and are willing to do some manual rework. But even a simplest thing like a 317 with a PCB heatsink: Good luck soldering the regulator properly without tombstoning a close by 0603 or 0402 resistor unless you have a proper pre-heating phase. With slow enough heatup and long enough reflow phase you might, but then you kill your 100+ pin ICs. MatCat is doing it right.
ya really don't need to worry about reflow profiles for hobby toaster ovens.
A variac on the cable and a one-off temp sensor to figure out the ideal variac position is all you need.
Sorry, i dont want too come across as negative.
Not my experience. You might do without proper profile if you are doing mostly resistors and not too demanding components and are willing to do some manual rework. But even a simplest thing like a 317 with a PCB heatsink: Good luck soldering the regulator properly without tombstoning a close by 0603 or 0402 resistor unless you have a proper pre-heating phase. With slow enough heatup and long enough reflow phase you might, but then you kill your 100+ pin ICs. MatCat is doing it right.
Nice work :-+Yeah I planned to shorten that phase a little bit, plus when I did that run I had 6 boards in the oven in various locations to look for hot zones, really the only boards that lagged where the ones towards the front by the window, which makes sense. Overall I am pretty happy! Now it's time to put some polish in the firmware, and whip up a good companion PC software for it too.
One suggestion: you can see how the inductor reflows later than the smaller components when you ramp up the heat. At the same time you also make the notice that the reflow phase should maybe be a little shorter. I have tried to avoid over 20 sec in liquidus. One way to get that is to prolong the soak phase at ~150 C. I have set it at 2 minutes and in practice it is about 90 seconds due to the lag of actual temp vs setpoint. Anyway, that gives the larger components some time to warm up to the soak temperature and from there they reach liquidus a bit quicker making the relative delay shorter.
Today I did 100 boards so it was a good test of the system, I did tweak the reflow time so that liquid stage was about roughly 20 seconds, and that worked perfectly, though I think I will slightly lower the peak temperature by about 20F. I also aluminum-foiled the door (except small window). First reflow was 63 boards since that was all I could fit on the rack, only had 2 fails do to parts going cockeyed but that was mostly because of an uneven spot on the rack, and I was happy to see pretty much all of the boards reflowed at the same time, showing that there is little in hotspots, the oven is getting warmed up pretty evenly. I do have a video which I am currently editing of that.
I will post full schematics for my design shortly, I need to polish it up a little and fix the UART RX/TX issue. I will post the full Altium Designer project, as well as gerbers. I still have some work to do on the firmware to enable full PC functionality, plus PC code to go with, so once I have all that working I will also publish all the code.