DIY reflow oven display opinion

TC · 2014-02-02 14:41

Hello all,

I have been tinkering with making a reflow oven for a few months now. I am starting with the display, and I have a demo of the reflow cycle. But I would like others input and ideas about it. Please take a look at this video and tell me your honest opinions, or changes you think I should make.

The values for time, and temp are just for looks and placement. They will be getting changed later.

Thanks
TC
[video=youtube_share;1dtkeVUmeNU]

Don M · 2014-02-02 14:51

Looks good. I have a reflow I built using a controller I bought from a guy in Florida. I see he's out of business now. It is a Microchip PIC based small board that uses a thermocouple and drives a SSR to control heating in a Black and Decker Infrawave oven. It interfaces via USB to a program that runs on a PC. It works well but I wish that it was "self contained" not needing a PC to operate. I just use one of those miniature ASUS netbooks to run it.

It works really well. I just used it again last week to build 7 boards. I think it would be neat to see a Propeller based add-on solution for this market.

TC · 2014-02-02 14:58

Don M wrote: »

Looks good. I have a reflow I built using a controller I bought from a guy in Florida. I see he's out of business now. It is a Microchip PIC based small board that uses a thermocouple and drives a SSR to control heating in a Black and Decker Infrawave oven. It interfaces via USB to a program that runs on a PC. It works well but I wish that it was "self contained" not needing a PC to operate. I just use one of those miniature ASUS netbooks to run it.

It works really well. I just used it again last week to build 7 boards. I think it would be neat to see a Propeller based add-on solution for this market.

Thank You

Well isnt that ironic, I am making this one using a propeller. I am going to have 2 thermocouples, one for above the board, and one for below the board. 2 SSR's again one for the top, and one for the bottom. 2 PID's controling 2 PWM's. 5 buttons. the noritake display. options to change and create reflow profiles. a profile for heat shrink. I am using a $15 wal-mart toaster oven.

*EDIT*
I might add a servo to push the door open a little for the cool down cycle. But first I have to see how hot the area gets so I dont melt the servo.

Prophead100 · 2014-02-03 18:32

Nice project. Are you using a PID routine ? I would love to see more on the code and hardware if it is open source. ( Interested in building one my self)

The display is pretty good although maybe a little busy. You didn't mention which Noritake display you have, text only or graphics/text. They are great displays! I really like the graphic ones. Perhaps you could look at showing the reflow temp graph (lines) where you are in the cycle (dot) and a simplifed temperature readout (text). (A text display may be able to do it with the custom characters approach.)

You also could periodically alternate the graph with a detailed text readout momentarily if more detail is needed. That way you get a nice over and then can focus in on details if needed. Remember, the beauty of a VFD is that you can change display at different times or use sequences. For example, you can change the brightness and display something in large font (e.g. Starting Reflow) at the beginning or end of a cycle then use dimmer smaller detailed text during the cycles. That way you can tell what is happening even when you're not loooking closely.

Most PID type controllers I used in the kept it simple so that you could see "actual', "target or deviation" and a power on/off light. In your case it would be something like:

Cycle ##.## Time Remaining ###
Top ### C +/- ## Error On/Off
Bottom ### C +/- ## Error On/Off

JonnyMac · 2014-02-03 18:50

Unrelated: Can I ask about the part # and supplier of that display?

Too_Many_Tools · 2014-02-03 18:54

FWIW...a quick and dirty temperature sensor/display for an oven is a barbecue thermometer...or multiples of such.

The wireless remote ones work great if you need remote detection.

TC · 2014-02-04 04:56

Prophead100 wrote: »

Nice project. Are you using a PID routine ? I would love to see more on the code and hardware if it is open source. ( Interested in building one my self)

For the hardware, I am using Maxim's MAX31855. It is a simple thermocouple chip that only uses 3 I/O's, and only outputs 3 values, a 14-bit thermocouple value, a 12-bit cold end(internal)value, and a 3-bit ERROR value OPEN, SHORT to GND, SHORT to VCC.
For the software I am using this. there might be a better way to skin a cat, but this way works.

PUB PID | e, P, I, D


  cur_error := set_pos - cur_pos
  P := K * cur_error
  
  I := I + K * cur_error * dt
  
  e := cur_error - pre_error
  D := K * e / dt
  
  pre_error := cur_error

  output := P + I + D

I am going to combine the PID object, and a PWM driver into one object that will run in it's own Cog

The display is pretty good although maybe a little busy.

I do agree with you, it looks a little busy. But I wanted the important info on it.

Most PID type controllers I used in the kept it simple so that you could see "actual', "target or deviation" and a power on/off light. In your case it would be something like:

Cycle ##.## Time Remaining ###
Top ### C +/- ## Error On/Off
Bottom ### C +/- ## Error On/Off

I like that setup. I will give it a shot and post the video.

JonnyMac wrote: »

Unrelated: Can I ask about the part # and supplier of that display?

It is a Noritake CU-Y series of display. The part number is: CU24063-Y100. It is there RS232 series model. I got it for free, they sometimes send out free evaluation kits. It came with a wire so I could hook it to my breadboard, and a blue filter(wrong size, but I not complaining).

The display is a 24x6 character display that is the same size as a 20x4. It has brightness adjustment for the whole screen, and each character. an insane font table. font magnification.

I have seen them being sold on DigiKey, but Noritake has an online shop that has better prices low quantites.

Too_Many_Tools wrote: »

FWIW...a quick and dirty temperature sensor/display for an oven is a barbecue thermometer...or multiples of such.

The wireless remote ones work great if you need remote detection.

That is not a bad idea, But a few months ago, someone ordered the wrong thermocouple probes at work (wrong ends), and they were just going throw them away, so I grabbed a few.

Igor_Rast · 2014-02-04 13:59

Looks great , Id say keep up the good work ,

ive worked on a reflow oven before, struggled a bit with that pwm indeed then ran outa time

got a tread going , hopefully ill be able to pick it up soon and make it work
im using a maxi 6675 for the temp and a z240d10-17 as a relay .
plus a 4 *20 lcd

ill be folowing you closely

good luck

TC · 2014-02-04 14:28

Igor_Rast wrote: »

Looks great , Id say keep up the good work ,

ive worked on a reflow oven before, struggled a bit with that pwm indeed then ran outa time
got a tread going , hopefully ill be able to pick it up soon and make it work
im using a maxi 6675 for the temp and a z240d10-17 as a relay .
plus a 4 *20 lcd

ill be folowing you closely

good luck

Thank you for the very kind words, I am trying my my bast. I have also struggled with the PWM and the PID. But not any more. Right now I have the thermocouple hooked up to a resistor, and the output of my PWM is powering that resistor. Still have to get the PID where I like it with little overshoot, but it is holing it at around +/- .50C

I have been thinking posting in "Projects" my progress.

Igor_Rast · 2014-02-04 14:36

Like id said ,ill be keeping a close eye, and if i can and know ill gladly help

would love to see some schematics on that once you got that working,
to be honest , i have no clue what that PID looks llike or whatever it is ( i did a quick wiki on it do ) . so ill be intrested
my ssr software was not so fine , beter said Smile , so im still on the lookout for a better driver (schematic for that )

in my old thread you can see a few pic of it

Cheers

TC · 2014-02-04 15:05

Igor_Rast wrote: »

Like id said ,ill be keeping a close eye, and if i can and know ill gladly help

That would be great, thank you.

would love to see some schematics on that once you got that working,
to be honest , i have no clue what that PID looks llike or whatever it is ( i did a quick wiki on it do ) . so ill be intrested
my ssr software was not so fine , beter said Smile , so im still on the lookout for a better driver (schematic for that )

I don't know much about a PID, I'm learning as I go. I did hours of searches, YouTube videos. and asking questions.

in my old thread you can see a few pic of it

Cheers

It does not look that bad. I like that you moved the heaters to the top. Im going to keep mine like it is so I can heat both sides of the board. I also took foil tape(it is used for home air conditioner ducting) and laid 3 layers all over the inside. And I also filled all the seams with JB weld(says it is reated up to 500F or 260C).

Igor_Rast · 2014-02-04 15:42

Your welcome

TC wrote: »

I also took foil tape(it is used for home air conditioner ducting) and laid 3 layers all over the inside. And I also filled all the seams with JB weld(says it is reated up to 500F or 260C).

id love to see some inspiration pictures your oven en JB weldings

if you can, mine is full of holes still.

doesn't the tin foil tape start smelling when you put ON the oven , or is it managable ( small exhaust fan) orso.

TC · 2014-02-04 15:51

Igor_Rast wrote: »

Your welcome

id love to see some inspiration pictures your oven en JB weldings if you can, mine is full of holes still.
doesn't the tin foil tape start smelling when you put ON the oven , or is it managable ( small exhaust fan) orso.

I will post some pictures tonight when I have the chance. For the foil tape, I have no idea yet. Since it is blocking some of the heat, the temp sensor that came with the oven does not shut off, I don't want to fry it from testing, unless I I know what temp it is at.

Igor_Rast · 2014-02-04 16:02

Bye all means take your time

(Blue)Smoke, is the last anyone would be waiting to see :cool:

Cluso99 · 2014-02-04 16:08

I intended to make a reflow oven, but I ended up with a Torch T200C+. It works fine apart from the poor PC software, but of course is expensive compared to DIY.

My oven has 40 settings of Temp + Time (ie 150C 10s)
It displays the current internal temp, the set temp, and a bar graph of the %heat (ie the pwm of the heated elements).

What I would like to see is the current internal temp (you have 2 and this would be better), the set temp and time left at this setting, plus the overall time elapsed or remaining.

There are two fan units in my unit. One just circulates the air, and the other is an exhaust fan that comes on when it is trying to cool the temp.

I hope this helps you.

BTW make sure your temp sensors can go to at least 300C. The bimetal wire and joint can only go to ~200C. There are some nice metal tube thermocouple sensors that have threaded ends so can be bolted into your oven as a permanent fixture. You can get them in various lengths. You could also buy the cheap temperature meters and use their internals.

TC · 2014-02-04 16:52

Igor_Rast wrote: »

Bye all means take your time

(Blue)Smoke, is the last anyone would be waiting to see :cool:

SOOOOO very true

TC · 2014-02-04 17:05

Cluso99 wrote: »

I intended to make a reflow oven, but I ended up with a Torch T200C+. It works fine apart from the poor PC software, but of course is expensive compared to DIY.

My oven has 40 settings of Temp + Time (ie 150C 10s)
It displays the current internal temp, the set temp, and a bar graph of the %heat (ie the pwm of the heated elements).

What I would like to see is the current internal temp (you have 2 and this would be better), the set temp and time left at this setting, plus the overall time elapsed or remaining.

I figured they would have information like that.

There are two fan units in my unit. One just circulates the air, and the other is an exhaust fan that comes on when it is trying to cool the temp.

I might add an exhaust fan at a later date.

BTW make sure your temp sensors can go to at least 300C. The bimetal wire and joint can only go to ~200C. There are some nice metal tube thermocouple sensors that have threaded ends so can be bolted into your oven as a permanent fixture. You can get them in various lengths. You could also buy the cheap temperature meters and use their internals.

The probes I have are Omega GKQIN-18(*)-12l, they have a max temperature rating of 980°C (1796°F). I have pipe connectors that use a compression fitting on them to hold the probe, it is water tight.

xanatos · 2014-02-04 20:21

Thanks for the Noritake info (along with everything else). I like the looks of those for my reflow oven... ordered two!

TC · 2014-02-05 03:29

xanatos wrote: »

Thanks for the Noritake info (along with everything else). I like the looks of those for my reflow oven... ordered two!

You are very welcome. And thank you.

I have always liked the look of VFD (vacuum florescent display), and how easy Noritake makes it to control. Hope you like them.

xanatos · 2014-02-10 13:28

My Noritake displays arrived today - along with the cool filter demo assortment. Downloaded the demo stuff and the datasheet for the display and it's working at 9600 baud, but still trying to get the character control codes correct. I've gotten good "default" text to display so far anyway

I also received my MAX31855 chips & K-type thermocouples. Got everything now... looks like a project is about to be born!

Dave

TC · 2014-02-10 14:50

xanatos wrote: »

My Noritake displays arrived today - along with the cool filter demo assortment. Downloaded the demo stuff and the datasheet for the display and it's working at 9600 baud, but still trying to get the character control codes correct. I've gotten good "default" text to display so far anyway

I also received my MAX31855 chips & K-type thermocouples. Got everything now... looks like a project is about to be born!

Dave

That is great! I'm still working on mine. I'm in no real hurry, I want to make sure everything is the way I want it. Keep us updated

xanatos · 2014-02-13 13:19

I've got most everything running on the stamp now, and I made a quick "little-of-everything" file of BS2 code for driving the Noritake with a stamp - if anyone's interested in taking a look at that code, you can see it in this post on the Basic Stamp forum.

Have fun!

Dave

TC · 2014-02-13 16:52

xanatos wrote: »

I've got most everything running on the stamp now, and I made a quick "little-of-everything" file of BS2 code for driving the Noritake with a stamp - if anyone's interested in taking a look at that code, you can see it in this post on the Basic Stamp forum.

Have fun!

Dave

Nice job Dave, Looks good. I dont know what it is, but I like VFD better than LCD(monochrome).

xanatos · 2014-02-13 17:10

TC wrote: »

Nice job Dave, Looks good. I dont know what it is, but I like VFD better than LCD(monochrome).

LCD vs. VFD is more of an application-by-application decision. I don't think a VFD would be a valid replacement for the LCDs in my DieselDocks, but I believe it's definitely a better choice for things like my Reflow Oven. The considerations here include end-user experience and skill with utilizing technology, and average distance of user to product.

Choice is better than no choice!

And having choices to tailor the end-user's experience is important.

I like them both!

Now I want to start messing with serial graphic displays!

DIY reflow oven display opinion

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