T962A reflow oven - how to set own profile? - Page 1
Forum section: electronics / general

author: Yellofriend
author_rank: Regular Contributor
timestamp: June 13, 2017, 08:22:55 am
content: Unfortunately I have a T962A reflow oven. The documentation is rather poor and I can't work out how to set my own profile.I solder only lead-free, with the lead free profile the PCBs go dark brown. Even with the 'coolest' solder profile #2 (225°C 10 Sec) my PCBs solder, but get quite dark. Strangely, when I measure the temperatures they are even below what the display shows.I know the machine can solder with your own profile, but how you set it? The Chinglish manual doesn't go very deep into it.The profile I need is for Koki S3X58 406-3 (which is a rather standard lead free paste, but does not requite cooling)

author: SMdude
author_rank: Frequent Contributor
timestamp: June 13, 2017, 08:41:42 am
content: They are a good oven, but there are some modifications you should probably do to make it work properly. (I still need to do mine)I bought one and for the price the build is quite reasonable. And they are very consistent with their manufacturing!https://github.com/UnifiedEngineering/T-962-improvementsGood luck!

author: Yellofriend
author_rank: Regular Contributor
timestamp: June 13, 2017, 08:47:25 am
content: @SMdudeThat seems a good way, will look into that.For my urgent needs actually I now see how to do it. Temp can be set for ever 10 Sec. However the real temp seems to be way off.Mods aside, I might try vapor phase in the near future though.----------Update: It helped me a lot when I did an Excel and print it out. Easier to type it in again.That chart is for my oven, which seems way too hot, therefore the rather low lead free temps.

author: theatrus
author_rank: Frequent Contributor
timestamp: June 15, 2017, 03:40:25 pm
content: The built in controller UI is... not usable. I highly suggest even just reprogramming with the Unified Engineering firmware. At which point, add some more profiles to the source code as you run your oven, since even those stock profiles aren't useful for the larger A oven.I've found adding more dwell at levels (closer to most manufacturer suggestions) prevents overheating from the large IR emitters. This took a batch of boards with thermocouples taped to them to fine tune, but now I have something that works really well with Kester NXG1 lead-free pastes.

author: ar__systems
author_rank: Frequent Contributor
timestamp: June 16, 2017, 10:24:31 am
content: this oven and IR heating in general is unusable. I tried to run a small batch of boards on it and it was a disaster. They pump heat with IR heater but measure temperature of air. Depending on the properties of the PCB it can get way hotter than measured temperature.The first thing I noticed when switched to reflow oven is that my PCBs don't look tanned anymore.

author: Yellofriend
author_rank: Regular Contributor
timestamp: June 16, 2017, 10:36:29 am
content: Quote from: ar__systems on June 16, 2017, 10:24:31 amIt's quite an advanced skill to tan a PCB - without actually soldering it.I will look into the controller software in the short term, and in the medium term for another oven.This said, I wonder, wouldn't it be possible to replace the quartz heater tubes with conventional heater tubes? Shouldn't that make things better?

author: ar__systems
author_rank: Frequent Contributor
timestamp: June 16, 2017, 10:48:45 am
content: you will also need a fan to circulate the air inside.

author: theatrus
author_rank: Frequent Contributor
timestamp: June 16, 2017, 07:07:22 pm
content: Quote from: ar__systems on June 16, 2017, 10:24:31 amStock, yeah its unusable for lead free processing. It can work for prototypes with about $5 of parts investment - any proper commercial prototype oven is a much bigger deal, and often 240V.Replacing the firmware withhttps://github.com/UnifiedEngineering/T-962-improvements, adding a cold junction temperature probe, and then writing some custom profiles for your boards makes boards no longer charred black messes

author: Yellofriend
author_rank: Regular Contributor
timestamp: June 18, 2017, 06:53:53 am
content: I need to get the USB-TTL 3.3V thing for the firmware.But in the meantime this attached image made me think...How about if I cover the quartz heater tubes with some type of thin steel sheets with holes - similar what you see at the top and bottom. I believe the tanning comes from the direct line heat. If that get's reduced that might help a little.Might have to stretch the profile then a little as the heat build up might take longer.

author: penguinman
author_rank: Newbie
timestamp: July 02, 2021, 12:11:30 am
content: I am so happy you now see how to do it.For everybody else who is wondering how to do it, I will provide the answer:Firstly, you don't have to muck about with the firmware like some are suggesting. Ignore them.I do recommend replacing the tape with 'Kapton' tape , and any physical improvements to make it safer and better insulated.Now , to set a custom profile:Select a profile with a *, eg Profile 8.Press the 'S' button breifly to enter edit mode.Use the F1 and F2 buttons to move the bottom curser left and right, to a particular Time on the X axis.Use the F3 and F4 buttons to set the temperature.Make sure you create a reasonable profile that can be achieved with the heating / cooling system . Remember there is thermal inertia / lag.When you are happy with the profile, save it by pressing the 'S' button again.This will save the profile.I found, I needed a profile with a fair 'soak' time, and then a fairly sharp rise to 270 degrees, to reflow leadfree solder consistently.I get no 'brown' boards or discoloration at all.Each board is checked, inspected after it leaves the oven.Preheat the oven with an empty cycle before first use.