T962A First Mods & First Reflow Test

[@Ferreira019760]

As a suggestion, why not just reposition the thermocouples to have them at the same level as the board? You can isolate the tip with capton tape and tape it to the board or a jig where the board sits in. I wouldn't advise placing it on the metal tray as the temperature inertia could throw off the controller. This type of procedure is used in autoclaves for curing composite fibres in the aeronautical industry, so it works. You may have to tweak it a bit to get it just right. From what I'm understanding, the thermocouples are placed too close to the heating element. If that is the case, no wonder you are getting that difference in temperature. The area where the thermocouples get hotter than the rest of the oven, so the thermostat kicks in and cuts off the resistance. Also make sure that the junction isn't touching anything grounded. I seriously doubt that oven will have the thermocouples opto-isolated, and if that's the case the readings will be all over the place. If your method doesn't work, try this, it could work, and let us know the result. Best of luck.

[@tstoegi]

I haven’t changed the firmware on my T962A. Using the recommend profile that’s listed in the manual does the job pretty well. Solderpaste XG-50 (Sn63/Pb37) and Profile #2.

[@UnexpectedMaker]

I also know of people running stock T962 without issues.. it really depends on the paste and how badly calibrated the unit is... seems I got a pretty bad one ;)

[@julianpetit4180]

I do see Fraps as screen recording software :)

[@corban111]

Is there room to put an internal circulation fan? That would be one solution to getting even temperature distribution.

[@UnexpectedMaker]

Not really, firstly you can't stick any old fan in there as none of them are rated for such high temperatures... most are not rated about 80/100deg C, so you'll just destroy it.. and a fan that can do high temp either needs to be in 2 parts, like a convection fan with the motor mounted externally and a metal only shaft and blade inside... I've not found any small enough, or an industrial axial or blower fan... which cost more than the reflow oven ;)

[@corban111]

Yeah, I was thinking of a fan forced fan from an oven off the top of my head which is only about $60 from an appliance spares shop. I know it will probably be too big, but maybe there are smaller versions / modifications to the impeller that can be made. Just a passing thought which may prompt some better ideas ...

[@jmicari]

Hey mate. We need to catch up soon. Was looking at one of these myself. Will wait till you iron out the bugs ;) btw reflow master is still going strong.

[@3DPrinterDoctor]

Should you be put the PCB in a cradle? Will give you a bit more height and the tray won't act as a heatsink.

[@UnexpectedMaker]

A cradle would be tough as I reflow all sorts of different sizes boards and sometimes a few at a time... but lifting off the tray and raising the PCB's is on my agenda for sure.

[@Synthchaser]

It looks like you installed the firmware where you can calibrate an offset and gain for the built in thermocouples, but you didn't configure any values for them. Unless I missed something, that would explain the huge margin of error.

[@UnexpectedMaker]

Sure, and I have tweaked the settings since :)

[@TheDefpom]

There were calibration settings in the firmware that you showed to set the thermocouples up, have you tried adjusting those, it may be all that is required. I doubt that there will be that large a difference in temperature over that small distance, maybe only a few degrees, calibrate the thermocouples, it is normal for the TC not to be perfectly accurate, they are never perfect.

[@UnexpectedMaker]

Yes, adjusting the offsets did nothing measurable... I should have the new temp sensor this week, and once installed I expect much better results due to correct cold junction compensation. It should close the gap quite a bit, but of course that only works with the new firmware too. I know that the TC's are never perfect... and of course my DMM is far from a perfectly calibrated test, but the discrepancy is huge.. way to big right now for reliable use :(

[@leorusnac]

I thought you were installing your reflow master at first :D

[@UnexpectedMaker]

No, current Reflow Master is not capable of driving a T962a :(

[@TheDefpom]

Were its temperature readings accurate before you reflashed it?

[@UnexpectedMaker]

I good question and I don't know as I never planned on using the stock firmware, so I never ran it before the upgrade.

[@andymouse]

Hi Seon, did you anticipate some problems with this device? because you seem remarkably calm, if I had bought something new and it was that far out of whack and basically not working I would be going mad and would be straight on to the manufactures with thoughts of getting my money back, certainly not ordering parts to fix it...……….so I just kinda wondered what your thoughts are?....did I miss something in this tale?

[@UnexpectedMaker]

I did a lot of research and had been following other peoples journey with their T962/A's before I purchased, so I knew what I was potentially getting myself into. I think I started looking into it way before I. got my toaster and built my Reflow Master... I think Jon Oxer's video on his T962C was my first introduction to them. ... It really isn't a great reflow unit, but a toaster oven can't do what I need either, so my choice is a T962A with heavy modding, or a USD$3000+ small commercial unit :(

[@andymouse]

@@UnexpectedMaker Wow.. thanks that explains everything!.....I knew Aussies were laid back, but I thought ya had lost ya grip on reality there bud.

[@UnexpectedMaker]

Oh, I wasn't overly happy mate... but I didn't want to make a rant video about it and right now I am more focused on a solution rather than complaining ;)

[@scottwillis5434]

If you want a high quality unit tuned up and working perfectly on arrival, not sure you should be shopping in China. Things from there cost less for a number of reasons. Keeping in mind that Japanese *used* to mean low quality. Then they did what it took to change that.

[@SimjetAU]

Didnt the new firmware have TC compensation offsets...couldnt you just add the required temperature offset there

[@UnexpectedMaker]

It needs a combo of both. The offset delta varies as the temperature rises, so just using a software offset will still leave one end of the temp range incorrect.

[@shaische]

Did you have to power on the machine to flash it? When I try to flash it, I powered it on and it started heating and the fan was working. I immediately unplugged power mid-flashing as I was concerned and now whenever I power it on, it keeps heating. Is this normal? If it is, anyway to circumvent it?

[@thai19995]

Hey mate, what kind of Kapton tape did you use? Is one with 155C enough for this kind of operation? Thank you :)

[@Olfox2]

Hi Maker :) i tried to flash my oven too, but i have error with the software, what version of the software magic flashing are you using please ? the UI as change, but all feature are looks to still be there. I'm using 12.80 with the same FTDI232RL board than you . Thanks a lot !

[@coldfinger459sub0]

Wonder if there’s anyway the mod to put a convection high temperature fan to do low volume air circulation inside to even up all the temperatures

[@UnexpectedMaker]

The T962A has a fan that rotates the entire reflow process - to circulate the air, but it doesn't do a great job.. too much movement also cools down the air too much, not enough movement does nothing, and every reflow profile requires a different amount of movement.

[@paulrautenbach]

Is there no forced air circulation in the reflow compartment of the oven?

[@UnexpectedMaker]

There. is from the back fan cooling, that is what the "MIN FAN SPEED" setting was, but though it pushes air around, it's cold air, so more movement reducing temperature. it's more a hack than a feature.

[@edgarvilmanyi3948]

Hi, where did you get the hex file to flash? , i download a group of file from Github but no hex on it...

[@UnexpectedMaker]

It's on the Unified Engineering github, check under releases?

[@edgarvilmanyi3948]

@@UnexpectedMaker Thanks

[@christelting1359]

Rather than put the PCB in immediately you should have just did the TC and run a PC temp monitoring program.

[@Snaked514]

Hello , I have this tool but it working in 110v. I need to convert 110v to 220v. I from Argentina. How do I make it work in 220v. Thank you, regards

[@UnexpectedMaker]

You'll need to buy a step down transformer to get your 220V down to 100V. Should be able to get one from an electronics shop.

[@spsarolkar]

Does it support ROHS pcbs

[@nheng6913]

As UM has shown here, the unmodified unit will not reach lead free reflow temperatures. You also need good uniformity of temperature. If you have serious money into your boards, you may want to consider having them reflowed commercially.

[@jmanbrosef689]

Can you try and make some pizza in there?

[@UnexpectedMaker]

If I can't get it reliable enough for reflow, I promise I'll make a video of my trying to cook a pizza in it...!

[@jmanbrosef689]

@@UnexpectedMaker reflow boards and make pizza in there at the same time = efficiency

[@andrewkieran8942]

@@@jmanbrosef689 I like my pizza how I like my gasoline -- unleaded.

[@scottwillis5434]

On the off chance that you were serious: DON'T. There's going to be some nasty-tasting toxic stuff in these.