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TC4 for reflowing boards
tony359
Hi all

I am opening a new thread from the TC4 discussion.
I was searching the Internet for an USB thermocouple datalogger to create a profile for reflowing/reballing XboX boards.

You may know that the main issue with XboX (at least the first ones) was poor/improper soldering of the GPU chip. Reflowing or reballing them usually does the trick.

I was trying to fix some XboX, first using a heat gun, then with a proper SMD station, but I realized that it is not so easy. Yes, you can make the XboX working, but if the procedure is not followed precisely it won't last.
As for coffee, there is a precise temperature profile to be followed for reflowing a board.
A lot of people are just doing it wrong (including myself!), using a heat gun or the SMD station without taking real temperatures from the chips. Many other just take the temperature from the side of the chips, not very useful IMHO.

The actual procedure says that you have to sacrifice a board, drill a hole under the chips you want to reflow and put a thermocouple inside. That is the place where you need to keep an eye on temperature! You want the solder to melt, what happens outside the chip is important but secondary.

Now, I have a termocouple, but I was thinking that for the best result a datalogger would be better. And I found this website and your brilliant project!!

bvwelch from the other thread gave me some tips. I think 1s of update rate could be fine, the process must last for a few minutes (maximum 6 if I am not mistaken) so it should be fine.
What do you mean with "The 4-channel adc that we use is a bit slow-- something like 250mS to sample but most of us run 2 channels with an overall update rate of 1 second"? You mean that the more thermocouples used, the slower the update rate? Anyway I guess that 2 thermocouples could be fine.

I am looking forward to work with Arduino. And maybe I can try developing something, who knows. I am not a programmer but if I like it I could start doing something.

Is it possible at the time being to overlay a curve on the temperature graph?

Thanks to everybody for the project and the help!

Ciao
Tony
 
JimG
Hi, Tony -

Welcome aboard.

I think you would be able to do what you want using a TC4/Arduino combination, along with the Bourbon application, without any modification.

One of the capabilities of the Bourbon application is to plot a guide profile that is read from a CSV text file.

Although the Catuai application hasn't been brought fully up to date with recent enhancements to Bourbon, Catuai offers the additional ability to manually control the duty cycle of an electric heater (when combined with a SSR).

Jim
 
tony359
Wow, if the profile can be plot it's perfect! What does RoR means? The degrees/seconds shown on the display? That is an important parameter as well, since I can't heat/cool the chips too fast but I need to do it at a recommended rate.

It seems a perfect application then. I'll keep you updated on my developments!

Thanks
Tony
 
greencardigan
Hi Tony

Good to see the tc4 being used for something other than roasting.

RoR stands for Rate of Rise. The display shows this in degrees/minute.

Brad
 
tony359
That perfect, I just need to convert the degrees/seconds figure I have. I can't see how the XboX world missed this project, I'll make sure they all know smile

I see that TC4 boards are not available at the time being, any prediction on the availability?

Thanks!
 
JimG

Quote

tony359 wrote:
I see that TC4 boards are not available at the time being, any prediction on the availability?


They should be here early this week.

Jim
 
tony359
Great, I am looking forward to it!

Edit for adding a question: the green spiky graph I see on some screenshots, is the logged RoR? If so, why is it not smooth?
Edited by tony359 on 05/09/2011 1:22 PM
 
tony359
Question for Jim

Would it be possible to buy the bare boards and all the loose components to be soldered on my own? I have no problem soldering and I have an SMD station, but I do not have a proper source of electronic components here.

Alternatively, could someone advise for a good online electronic store in the UK?

Thanks
Tony

Edit: and BTW, what type of Thermocouples shall I buy?
Edited by tony359 on 05/13/2011 4:25 AM
 
bvwelch
Hi Tony,

Why not buy the board will all SMT parts soldered, then you can find the other parts - resistors, etc easily.

For mail-order, a buddy of mine likes farnell: http://uk.farnell...

Another possibility might be digikey UK: http://www.digike...

Any K-type thermocouple should work.
Edited by bvwelch on 05/13/2011 7:11 AM
 
tony359
hi Jim

I think I'll go for the complete board. Farnell - as far as I know - ships only to businesses. Digikey ships to anybody, but with ?12 of shipment below ?50 it's useless. I don't want to save ?5 on a finished board!

Thanks for the TC, I'll order Arduino and buy the TCs at the same time.
 
JimG
I think that's a better plan. That way I can set up the EEPROM for you, too, with some calibration constants. I haven't figured out an easy way to do that except on finished boards.

Jim
 
tony359
Yes, I would have liked to do the soldering but without a store willing to ship the component ad a decent price it't not worth the time.

I have placed the order, both for TC4, Arduino and TCs. Now the fun begins smile

Thanks
Tony
 
tony359
I'm picking up this old thread of mine to ask a question.

I'm finally trying to reflow a board with the help of the TC4 - I am using Artisan to keep track of the graph. I have made a template graph using the designer which I will try to follow.

My question is: obviously Artisan is designed with coffee roasting in mind - so it comes with nomenclature and features which do not apply to me.

Besides doing what I did, do you have any recommendations on what to do for my task - even a different software if that helps?

Thanks!
tony359 attached the following image:
artisan.png
 
tony359
I have a more specific question on the subject: on my first attempt, at around 120 degrees the graph sort of "reset" to the starting point. I'd imagine it has something to do with the coffee roasting process which does not happen when reflowing a board!

Can anybody help me setting up Artisan so that that does not happen please?

Thanks a lot!
 
MaKoMo

Quote

tony359 wrote:

I have a more specific question on the subject: on my first attempt, at around 120 degrees the graph sort of "reset" to the starting point. I'd imagine it has something to do with the coffee roasting process which does not happen when reflowing a board!

Can anybody help me setting up Artisan so that that does not happen please?

Thanks a lot!


Roasttime starts at 00:00 after the CHARGE event has been set. By default Artisan is configured to detect a drop in bean temperature and register CHARGE automatically. You can deactivate autoCHARGE under menu Config >> Events.
 
renatoa
If that reset is labelled TP, then this is Turning Point, and its automatic detection can disabled from Config menu, Events dialog, Mark TP checkbox.
If not TP related, a screen copy could help to dignose.

And yes, Artisan defines itself as a "roaster-scope", an oscilloscope for roasting, so it is heavily related to the specific coffee roasting processes and events.

However, a custom profile can be done without relating your temperature change points to roasting specific events. Just clear all the events in Designer, and manually add your points that define your profile.
Charge and Drop are start and finish events that can't be removed, though...
 
tony359
thanks guys. I disabled the "auto charge" and it worked ok!

"oscilloscope for roasting" - amazing! smile
 
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