Keyboard Shortcuts
Likes
Search
DIY Toaster Reflow oven
|
Jim,
I originally used a Silicon Horizon reflow oven controller board which cost around $75. I tested it and then put it up on a shelf until I got around to track down all the remaining parts to do the actual build. I bought via Amazon (its generally a crap-shoot regarding product quality in my opinion), a Black & Decker InfraWave 1200 Watt with crystal heating elements (exhibits shorter thermal inertia) instead of the iron heating elements. I hacked out all the guts and then lined the insides of the oven, between the inner and outer walls of it with high fibre-glass insulation sheeting, which I custom fit. Else ya can't touch the oven while it is operating. My unit is cool to the touch, even during 36 hour component baking periods. When I got the controller down, it worked three times and failed. I contacted the company and it had gone out of business. The schematics & source code had been promised to be on the CD shipped with the controller, but alas was not. So I reversed engineered the hardware and fixed it and in the mean time I acquired all of the source code from other users. To make a long story short, I eventually replaced that controller with the following, excellent controller: Depending on options it starts at $100 bucks, for the controller and the display screen. It works very well and I've used it for many projects over the past 7 years or so. What ever you do, be sure to acquire the oven with an internal fan. The B&D Infrawave does not have one internal, so I had to mount a small blower on the outside. Also the 'gold' thermal reflection tape really makes a difference in the internal thermal cavity stability. Best Regards tron nee -- SETV - Autonomous Instrumentation Platforms for the Detection & Measurement of Suspected ExtraTerrestrial Objects |
|
You do not want to use a relay (EMI), but an SSR with crossover detection, also called zero voltage switch. I? use my own PWM method by enabling X periods over a one thousand period timeframe. 1000 periods at 60 hertz is less than 20 seconds, so I can finely tune the temperature ramp in real time.
If your heater was much faster, you could reduce the timeframe to 100 periods but that cause other concerns. Just my few cents worth. Jean-Paul? N1JPL? |
|
toggle quoted message
Show quoted text
On Jun 5, 2020, at 3:56 PM, Steven Dick <sbdick@...> wrote:
|
|
There was a note from Adafruit just a few months ago about a Reflow Oven project based on their Micro-Python board (can't remember the name of it) along with source code (again Micro-Python).? The Adafruit board is overpriced, in my opinion) but wouldn't be too hard to replicate with a Blue-Pill or Black-Pill from Ali or BangGood.? Coupled with a cheap toaster oven this would be a very inexpensive way to go!
|
|
A good thing to keep in mind is that, where a contactor/relay rated at 30A will run just fine at 15A with no special effort, a 40A SSR will require a large heat sink and possibly forced air cooling, or at least mount it for best natural airflow.
Plus the issue of counterfeit and creatively rated specs. I've noticed that many of the heat sinks for SSRs have rather thin aluminum extrusion, here is one from Aliexpress: This one from brewpi has a thicker extrusion: Personally, I prefer something like this with the fins right out of the plate, as a shorter path means lower thermal resistance: ? Mount it for vertical airflow with large, well placed holes in the case, should get rid of heat very well. -- Steven Greenfield AE7HD |
|
Here's the manual for my Inkbird ITC106VH? (covers other models too)?
They have models for energizing external relay coils @ 12-24 and 120-240v if you don't like SSRs.? Much better than building your own IMHO....unless you want the experience and will probably spend more. There's really nothing fiddly about it if you're comparing to doing it all yourself. It works from -50 -> +1,300 deg C, 0.5 seconds control loop, 0.1 deg C control and will work as-is if you want to do your own timing manually. I built a small stand for mine and wired in series with a short AC extension cord. An easy project. A few years ago I bought a stuffed PCB from SparkFun that did this PID control plus reflow timing for US$85 but it's no longer available. Good luck? ? -mike |
开云体育The ones intended for 3D printer hot-ends should be ok as they run at 200-250C. ? 贬辞飞别惫别谤… ? As you say, read the specs.? The 3D printer ones have Teflon insulation which is nice, but that usually only covers the first couple of inches, the rest might well be standard PVC coated wire.? Ok for a 3D printer, not so much for an oven where the sensor needs to go in the middle of the plate. ? Tony ? ? ? From: [email protected] [mailto:[email protected]] On Behalf Of Steven Greenfield AE7HD via groups.io
Sent: Wednesday, 3 June 2020 11:45 PM To: [email protected] Subject: Re: [homebrewpcbs] DIY Toaster Reflow oven ? I don't know if 3950 is a generic term, or what, but Adafruit lists what they call an "3950 NTC" thermistor that is a 10k, max 105C with epoxy coating and vinyl wire. So read the specs of what you are ordering. I've been bit by that before on type K thermocouples, where some I bought had a sleeve that turned out to be plain heatshrink. So it burned to black carbon when I Kapton taped it to the side of a soldering iron... |
|
I don't know if 3950 is a generic term, or what, but Adafruit lists what they call an "3950 NTC" thermistor that is a 10k, max 105C with epoxy coating and vinyl wire. So read the specs of what you are ordering. I've been bit by that before on type K thermocouples, where some I bought had a sleeve that turned out to be plain heatshrink. So it burned to black carbon when I Kapton taped it to the side of a soldering iron...
Sure, no reason not to use something simpler to interface for the temperature. It doesn't really need a 1% resistor, just one that is temperature stable. So don't get them out of your old junkbox of grampa's carbon composition resistors. -- Steven Greenfield AE7HD |
|
This is the Pid controller you want. High quality and function .?
toggle quoted message
Show quoted text
https://www.amazon.com/TEMPERATURE-CONTROLLER-RAMP-SOAK-OUTPUT/dp/B01DC3KNS0/ref=mp_s_a_1_4?dchild=1&keywords=syl-2352p&qid=1591184860&sr=8-4
|
开云体育The picture didn’t come thru, but the usual aluminium-backed boards that most 3D printers use are only meant to be run at 100C-ish.? I think maximum is about 150C for that stuff. ? The silicone heaters go up to 350C, more than enough for SMD soldering.? For the price you might as well go and buy a cheap board heater. ? No real advantage in 3D printing for using a silicon mat over a PCB one except the mains rated ones tend to be high wattage so they heat up faster. ? Tony ? ? ? From: [email protected] [mailto:[email protected]] On Behalf Of Rob via groups.io
Sent: Wednesday, 3 June 2020 5:10 PM To: [email protected] Subject: Re: [homebrewpcbs] DIY Toaster Reflow oven ? Has anyone played with 3D printer heat tables for SMD ? ? The PCB are aluminium backed, so that sucks out any heat if you try to use a soldering iron, or even a hot air gun at times. ? |
开云体育Has anyone played with 3D printer heat tables for SMD ?
The PCB are aluminium backed, so that sucks out
any heat if you try to use a soldering iron, or even a hot air
gun at times. |
开云体育Yeah, they’ll work.? I was thinking of 10K thermistors for some reason. ? Don’t forget your lookup table. ? Tony ? ? ? From: [email protected] [mailto:[email protected]] On Behalf Of Rob via groups.io
Sent: Wednesday, 3 June 2020 12:35 PM To: [email protected] Subject: Re: [homebrewpcbs] DIY Toaster Reflow oven ? hmmm... wow...???? I did not know that.... 200 C limit ?!?!? I had huge success measuring 350 F? with mine....? laser printer toner temps..... and I thought the SMD cooking solder target was 210 C?? which is 410 F which is no where near 300 C?? 572 F?? written on the NTC3950 specifications. ? I think this definitely warrants some more research. =========================================================================================================== I found this on AMAZON: The temperature of the new NTC3950 thermistor can be up to 300 degree celsius. Easy to instal on your 3D printer or other DIY project with the ends of the wires are pre-stripped. Length: 1m/39.37 Inches. Accuracy: +/- 1%. ? ? On 06/02/2020 10:15 PM, Tony Smith wrote:
? |
开云体育hmmm... wow...???? I did not know that.... 200 C
limit ?!?!? I had huge success measuring 350 F? with
mine....? laser printer toner temps..... and I thought the SMD cooking solder target was 210 C?? which is 410 F which is no where near 300 C?? 572 F?? written on the NTC3950 specifications.
I think this definitely warrants some more
research. =========================================================================================================== I found this on AMAZON: The temperature of the new NTC3950 thermistor can be up to 300 degree celsius. Easy to instal on your 3D printer or other DIY
project with the ends of the wires are pre-stripped. Length:
1m/39.37 Inches. Accuracy: +/- 1%.
On 06/02/2020 10:15 PM, Tony Smith
wrote:
|
开云体育It’s occurred to me you don’t need the PID library, you could fake it easily enough. ? Say the profile first requires heating to 100C in 60 seconds, and the oven does that in 30.? PWM the SSR at about 50% duty cycle and you’d probably achieve that.? Then do the same for the remainder of the stages. ? Close enough for hobby & government work I’d say. ? Tony ? ? ? ? From: [email protected] [mailto:[email protected]] On Behalf Of Steven Greenfield AE7HD via groups.io
Sent: Wednesday, 3 June 2020 9:56 AM To: [email protected] Subject: Re: [homebrewpcbs] DIY Toaster Reflow oven ? Connecting to an existing temperature controller seems fiddly. |
开云体育Reading that arduino.cc thread where they talk about using a hotplate to heat up the board and then a hot air gun to finish the parts off make me realise that’s exactly how I replace LEDs on boards. ? The PCB are aluminium backed, so that sucks out any heat if you try to use a soldering iron, or even a hot air gun at times. ? You’ve been able to get these board heaters for a while: , but lately these ones have come out: that self-regulate to whatever they’re supposed to be.? That’s what I use. ? Tony ? ? ? From: [email protected] [mailto:[email protected]] On Behalf Of Steven Greenfield AE7HD via groups.io
Sent: Wednesday, 3 June 2020 2:37 AM To: [email protected] Subject: Re: [homebrewpcbs] DIY Toaster Reflow oven ? There are a number of DIY reflow projects on YouTube. The simplest being merely placing the PCB on a hotplate and watching it, the next step up using the hotplate at the soak temperature (drying the volatiles and activating the flux), then a hot air reflow gun to melt the solder. |
开云体育Thermistors aren’t rated to 200C. ? Tony ? ? From: [email protected] [mailto:[email protected]] On Behalf Of Rob via groups.io
Sent: Wednesday, 3 June 2020 12:07 PM To: [email protected] Subject: Re: [homebrewpcbs] DIY Toaster Reflow oven ? Just curious. What is wrong with using a thermister and a 100K resistor to read the temperature as an analog number and displaying it on the ARDUINO serial monitor? That number will be something like 400 to 1,000 and At the same time taking the temperature with a real digital thermometer and once you know what the target temperature equates to on the thermister then you never need the digital thermometer again. The rest is simply either solid state or relays ...all readily available cheap and documented stuff for the $3.50 ARDUINO UNO. Thats the spirit of ===>> home brew pcbs <<====??? ? I went down that path using a PIC16F628 6 years ago using BTA24 as my solid state relay. I sort of kicked myself when I learned ARDUINO a long time later. If I had used an ARDUINO then I coul dhave left the LCD out of the project. BUT the fruit of this labor IS the BTA24 carrier board because it can easily be attached to any arduino: ? ? On 06/02/2020 07:56 PM, Steven Greenfield AE7HD via groups.io wrote:
? |
开云体育Just curious. What is wrong with using a thermister and a 100K resistor to read the temperature as an analog number and displaying it on the ARDUINO serial monitor? That number will be something like 400 to 1,000 and At the same time taking the temperature with a real digital thermometer and once you know what the target temperature equates to on the thermister then you never need the digital thermometer again. The rest is simply either solid state or relays
...all readily available cheap and documented stuff for the
$3.50 ARDUINO UNO. Thats the spirit of ===>> home brew pcbs <<====???
I went down that path using a PIC16F628 6 years ago using BTA24 as my solid state relay. I sort of kicked myself when I learned ARDUINO a long time later. If I had used an ARDUINO then I coul dhave left the LCD out of the project. BUT the fruit of this labor IS the BTA24 carrier board because it can easily be attached to any arduino:
On 06/02/2020 07:56 PM, Steven
Greenfield AE7HD via groups.io wrote:
Connecting to an existing temperature controller seems fiddly. |
开云体育Watch out with ssr they can stick on , put some type of high limit safety device in the heater circuit in case it does. Saw this happen with a pizza oven and food come out on fire.?On Jun 2, 2020, at 7:56 PM, Steven Greenfield AE7HD via groups.io <alienrelics@...> wrote:
|
Steven Greenfield AE7HD