Use this space to cheer the creator along, and talk to your fellow backers.
Have a question?
I really like the Kester line of products. I'm currently making everything with their
NXG33 (http://www.techni-tool.com/488SO910). I've also used their R276 (http://www.techni-tool.com/488SO540). These match up well with the two profiles I ship with RefloLeo as examples. I also purchase them from the same place I linked. It has to be shipped via overnight and comes in a box with an ice pack to keep it cold. So, shipping is kind of expensive. I've been working on that same tub of NXG33 for a while now. It sure goes a long way. I've made all of the RefloLeo orders and over two hundred other circuit boards from another project and still have most of the paste in the jar. It may last me a lifetime, assuming it doesn't go bad. Overall, I like the NXG33 blend much better as it flows nice and is easy to work with.
What soldering paste do you recommend - both leaded and lead free?
Hi John, thank you for clarifying the reset switch, guess its not needed. I will take a look at the code and see if I can add a reset in, but as it stands, it works well.
I see the case has been popular with the download numbers showing, so I hope u enjoy it!
Thanks for making a great case design. I'll have to print one of those out and give it a whirl. Looks nice.
Regarding the reset switch, that is there to help facilitate uploading new firmware. It pulls the reset line low on the micro controller to induce a reset. Sometimes this is necessary to get the bootloader to run on the micro controller. It wasn't intended to be used outside of that scope. If you need a way to stop the heating process in some way, perhaps you could program the down arrow to turn off the relay, display a message and to into an infinite loop. If I never need to stop mine, I simply turn off the power strip I have both the oven and RefloLeo connected to. It is my sort of emergency stop by just cutting all power.
I agree, screw holes would be nice to have and not hard to implement. Perhaps some longer screws around the LCD could be used to mount as well since those do fully penetrate through the cicuit board.
Just got my RefloLeo, and noticed a few annoyances as 'reset' doesn't seem to exit the current programme run if it is in a heating cycle, also there are no screw holes, and the reset switch needs to be a tactile button switch for future builds.
Anyway, the reason for this 'comment' is that i have desighned and built a case for the RefloLeo.
Please see it here: http://www.thingiverse.com/thing:160587
Finally freed mine from customs duty :)
Will test it as soon as possible :)
Just got it today!! Now I need to test it and get a toaster oven, some krylon tape and figure out where the heck I am going to get a good selection of surface mount part here in Ottawa, Canada. The adventure continues. BTW, REALLY NICE JOB JOHN!
Still waiting on mine :(
Got mine, works great, did a test run with a Black & Decker TO1332SBD, no hassles!
Got mine today! Nicely packed - arrived in perfect condition and I did a quick power up to check it - will get to interface it this weekend and test with my oven. Even have a board waiting for reflow! Very nice product John, thanks!
Glad to hear you received your RefloLeo. Indeed, you'll need to find a way to get that oven to heat up at least to 225 degrees to handle the lower melt lead based solder. On my oven, it has two knobs (temperature and time). One I set to "toast" and the other is set to "leave on". Both heat tubes light up fully nice and bright red/orange and RefloLeo is able to switch the power to control the temperature in the oven. Each oven is different and if you are unable to get it to reflow temperature in any way (225 and 255 degrees Celsius), that does make for a show stopper until you can try another oven or defeat that temperature feature in some way. It does sound like the oven is cutting out before max temperature. 450 degrees Fahrenheit is about 232 degrees Celsius.
Got mine hooked up... I'm worried my toaster oven isn't stout enough! I ran profile 0, and it can't seem to ever reach 213C. Right now it's hovering around the 180C mark.
The oven has "Warm, Toast, Bake, Convection Bake, and Broil" settings. Toast seems to run the elements hottest, but no setting actually causes the elements to glow red. I have the thermostat on the oven set to 450F (max) and the timer set to "always on". I can hear the thermostat clicking inside the toaster, and I think it's cycling on and off even with the temperature setting maxed.
Ooo, the first RefloLeo sighting in the field o.O. Glad you received it. As for those memory cards, I did nothing special to them. I just put them in a small USB adapter and plugged them into my Windows 7 computer and it saw them just fine. They seemed to be formatted just fine right out of the box with no changes needed. I dropped a couple text file profiles on the card for profiles 0 and 1 (0.txt for low temp solder and 1.txt and high temp solder). RefloLeo picked up on them just fine. If you happen to do some bad things to the card, the files can be downloaded again from the Github site, or you can make your own.
Link to files:
It appears to be a standard FAT filesystem. The "selftest" file that is on the download site activates the self test procedure that I use on all RefloLeo boards before shipping. It tests all major components to make sure everything is working in top shape about 5 seconds before it goes into a box. When running the self test, if you push the middle square button on the circuit board, it delete the selftest file from the card and upon next start-up, will be running normal profiles.
Good luck. Hope that helps.
Got my RefloLeo today and gave it a smoke-test (lamp & lightbulb). Seems fine in advance of actually having a toaster oven.
Only issue I'm having is being able to mount the SD card. Tried Mac and Android, no luck. I expect it's a simple case of the formatting on the card, but I'd like to resolve the compatibility issue. Any obvious recommendations? like perhaps "format the card on the target machine and trust RefloLeo to read it"? (hey, call me an optimist).
Indeed I am using RefloLeo for my production needs. I used it last night to bake a small batch of optical laser sensors to fill some outstanding orders. I have mine dialed in pretty well to just pop the ready-to-bake boards in the oven, flip the on the power strip to "ON", choose my profile and hit the go button. I then stand around for a few minutes waiting for the magic to happen. I never get tired of watching the solder paste turn into flowed solder and the little parts do a dance as they get situation on the pads. I'm planning to try and bake 3-4 RefloLeo at a time if I can get them all to fit in the oven at the same time. I've found that the sides do not get as hot and reflow as soon as the middle section of the oven, and that makes sense given where the heating elements are in my oven.
Thanks for the update John! Are you using a refloleo for your production?
Hey Paul. Glad to hear that you are ready to go. I'm just as eager to get going on my end as well. I have most of what I need to get started with the making of these. Right now, I'm awaiting the arrival of the circuit boards. I'm told they were shipped out on Thursday of last week. I was waiting to reply here to see if they turned up in today's deliveries, but it did not. I feel confident that package will be here any day now and hopefully tomorrow. Once that is here, production will begin immediately.
The only outstanding issue at this point is one of the parts that is backordered and backup suppliers are also out of it too. This is the screw terminals where the relays and thermocouple connect to the board. I have a few thoughts on alternatives and work-arounds if I don't wait out the backorder, which is due in mid September. I'll probably check with the supply house and if they are still looking at September, I'll make some alternate arrangements as I really want to start shipping these out as soon as they are done and tested instead of piling them up, waiting for one last part before they go out the door. I'll let everyone know when production and shipping begins, along with gathering up shipping address via a follow-up survey.
John, any updates? I bought my SSR yesterday (triac with snubber) so I am itching to use it. I also have a good idea on how to incorporate the PID as well :)
RefloLeo was made to be reprogrammable so that everyone can make theirs do what they want it to do. The firmware I made for it is fairly basic, but does a good job at baking circuit boards, which is what it was made to do. Certainly PID would be a nice upgrade in the code and there is a standard Arduino PID library that should be relatively easy to drop right in and go.
When it arrives, you'll be able to do reprogramming straight away using the Arduino programming language and upload that code through that interface since RefloLeo will come with the Arduino Leonardo bootloader installed. If you choose, you could also bypass Arduino all together and compile your own AVR binary and just upload that through the ICSP programming port.
Adding PID control to mine is on the to-do list, but I just have not worked on it yet, but a very achievable goal. You'll want to keep an eye on the switch frequency for that mechanical relay as it cannot take those fast on/off pulses that many PID controllers output like a solid state relay could. Eventually, PID with an external solid state relay would be a very nice setup to really dial in that temperature control.
Thanks for the update John! Question: is the refloleo easily programmable? I have been looking at PID algorithms to use with a solid state relay as we had discussed. Ideally, the PID code is a relatively easy drop-in for the control portion of your code. Maybe I should look at the code first... Doh!!!
Thanks for your ongoing commitment John.
Sure Paul. I've been busy every day on this project. I started right after the project closed by ordering the longest lead time items to get them in the pipeline, which are the Power Switchtails and the circuit boards. I'm now focused on testing what I'll call the "resale items", which are items that come with RefloLeo that I didn't make. Those include the USB power cord, USB power supply, SD memory card and thermocouple. I have tested and received the USB power cords and SD memory cards. The thermocouple test was successful last night and I've placed that order to fill the full quantity needed. I'm still awaiting the sample batch of USB power supplies to arrive to test their consistancy and suitability. If all checks out, I'll fill the rest of the order for those. Testing is both checking out the product to make sure it works as intended as well as the ability of the vendor to deliver in a timely manner on a small pre-order.
While I'm not doing those items listed above, I'm refining the software and even working on a next version with more features and optimizations. These sorts of updates can be tracked on the Github site where I upload those sofware and hardware revisions if you so choose to follow along. You all will be receiving version 1.2 and version 1.3 is a design in progress for sometime down the line. I'll be using the prototype to version 1.2 to make your rewards and it is still purring along great.
Looking forward, I'll be going through the individual component orders to double check availability and even swap in a few higher quality parts as needed to reflow the circuit boards when they arrive. All together, it appears everything is still on-track for an on-time delivery, if not sooner. I see nothing standing in the way holding up progress.
I should be getting the funds from the project tomorrow. My credit cards are already squeeling at me, but I'd much rather meet my committments than worry too much about the money at this point.
Ask questions if you have them. Have a great day.
John, anything new and exciting you could update us with?
Go- go- RefloLeo! Can't wait to give this a try - congrats on the successful campaign!
Great job John, congrats!
Thanks for the quick replies John! Just getting back into electronics after a long hiatus! I can't build it cheaper than I can get it from you! Keep up the good work :)
Thanks :) I'll stick with Severin as i could bake something to eat (with solder taste), too :P
For reference, I'm using this toaster oven currently and is the one featured in my movie:
"Black & Decker TRO964 Classic Countertop 1200-Watt Toaster Oven"
I see a few of them for sale out there on the Internet. I don't think it is a current production model. It seems to get poor reviews since it burns everything and has no safety. Seems like a perfect fit for reflow soldering!
And i still can't edit my posts :S
Thanks for the advice, will have an eye one 2034 and report when i've tested it :)
Maybe buy a better cam for your next presentation as i think you are a very cool electronics engineer :)
Saw the last project of yours and thought you could expand it to a LEGO Mincraft like open source electronics kit (maybe using the BrickPi) :)
Just an idea :)
Thanks again for the cool project, cheers :)
@Dominik Those look like fine ovens. I cannot tell from the dials if one of them is a "stay on" sort of setup that bypasses any sort of maximum temperature regulation. I would be a little cautious of the Severin TO 2035 as it appears to circulate the air. My only concern is if the air gets to moving a little too much and pushes your parts around on the board while the solder is in a liquid state. It probably won't due to the surface tension of solder and parts, but just one thing to keep in mind.
Parts and cost wise, I agree that it would be similar in cost if not more for just one of these built as a home project with the cost of the circuit board and parts being nearly double in cost in small amounts. The flip side is the cost to make lots of them at a time like this project. Seeing the current volume, it appears it will still be me, a workbench and a good set of tweezers :-). I bought some nice ceramic tipped tweezers this week in preparation.
I haven't bought one yet, but i think i'll have to test it myself... These are the ovens i am considering: Severin TO 2034 or Severin TO 2035.
If it has a thermostat i'll cut the wires :P
Thanks for the quick reply :)
Thought myself often about a project like this as i really wanted to go further into micro electronics and now i have an incentive to do that (was thinking about taking the source files and do it another time, probably never, then calculated the costs and resulted in that it would cost the same or more) :)
Thanks again for the cool project :)
Thanks for the questions. I am indeed using celsius as that seems to be how most things in the world are rated. It just makes it easier to compare things despite my local units of measure being of another unit.
I've reflowed both leaded and lead-free solder using this setup with peak temperatures of 225 and 255 degrees respectively. My oven doesn't seem to have any limits on its maximum temperature. This is an old oven I bought for $5 on Ebay a few years back. I knew I wanted to get into making my own electronics some day, so I bought the oven, but didn't use it for about 5 years until the bug finally bit me and I got started with it. At the time when I bought the oven, I didn't even consider a maximum temperature. Perhaps I was lucky in that it doesn't have a max temperature. I'm curious though, even though a max temperature is specified, does it actually prevent you from achieving this by some internal safety measure or you just can't set the thermostat to regulate at that temperature? On my oven, I have a "toast" setting that just leaves the oven on and the temperature just keeps climbing with nothing to stop it.
Hi, i wondered if it is Farenheit or Celsius on the display, but then i read the source code and assume it is celsius.
Could you confirm this, please?
Do you use leaded or unleaded solder paste as i looked for oven and found just one with 230°C max and it is told just leaded solder paste would work there
Thanks for the great job you've done there,
The Z height will be driven by the height of the LCD screen. I will be using quarter inch spacers between the RefloLeo circuit board and the bottom of the LCD. I suspect that the specs on the LCD are available on-line. The model I'm using is an HD44780 16x1 LCD. If price is less, I may substitute in a 16x2 model, but the overall dimensions should remain the same. It appears to be about 10mm tall from one sites I saw it for sale on (yes, a bit of mixed units of measure there...).
Regarding a housing, you'll need to be a little careful on the up, down and select portions of the circuit board. On the left side of the LCD, those are capacitive touch buttons that are actually copper right on the circuit board, under the soldering mask. So, you'll either need to extend those buttons with something that is conductive or leave them exposed so that you can still operate the controls on the screen. I didn't intend for this model to have a cover, but if you are creative enough to make one, that is great. Most of the guts of the operation are up under the LCD.
Hope that helps.
It would seem that this needs a electronic housing (bezel, bumper style). To design our own housings physical dim's would be useful. Eagle files don't have Z height. Guess this can wait until we have one in hand.
@Dexter Glad to hear this will be useful. I can say, it has made my life a lot easier when baking my PCBs. No more sitting by the oven with a stop watch flipping the switch on the power strip on and off to manually follow a suggested reflow profile.
Today, I added a profile logging feature to the main RefloLeo Arduino sketch (v1.2.1 on Github). It opens a log file each time you run RefloLeo so you can see the output of what the profile looked like when you are done each time. It even keeps logging down to 125 degrees so you can see how you did on the cool-down after peak temperature too. I did this primarily since I was working through the development of my own high-temperature profile for lead-free SAC305 solder paste (alloy Sn96.5Ag3.0Cu0.5). After about 5 trial runs on the oven, analyzing the log file and tweaking the profile each time, I had a profile that pretty closely followed the suggested profile for that solder paste with a peak temperature of 255 degrees. I topped the evening off with reflowing one of my optical laser sensor boards with the high-temperature lead-free solder using the new profile and it worked perfectly. Now I can feel good about shipping lead-free rewards to my friends in Europe!
Hey John, this is a really great idea! I can't wait to get ours and try it out, I'm constantly doing SMD prototyping and small runs, I hope this helps out and speeds that up. Thanks John!
Thanks for the questions. Generally speaking, you can reflow a board more than one time. It is not uncommon to reflow a board in an oven a second time if there are some connections not working quite right. In your case, you can add some components and bake the board again and the other components should be OK.
Each oven is going to behave differently regarding how much air it leaks, where the heating elements are, how powerful it is and a variety of other factors. Also, the correct reflow profile will need to be a combination if what is best for the soldering paste you are using and the parts being baked. So, knowing that, you will need to experiment a bit with your own oven and how it behaves to get the right reflow profile. It is fairly simple to make your own profile by changing the one stored on the SD memory card. Generally, the main factor to consider are how much overshoot the oven will have after it is switched off. For example, in my oven, when I cut the power at 130 degrees, the temperature continues to rises about another 25 degrees to around 155 degrees while the heating elements cool down. I'm sure your oven will vary some as well. In short, these are the main factors to consider:
Oven overshoot after power turned off
Recommended profile for the soldering paste
Maximum time / temperature of parts being baked
Hope that helps. Let me know if you have any more questions or concerns.
Two questions: I purchased a couple kits recently that already have a SMD microprocessor soldered to the board and require soldering other components. Will this be OK to do with RefloLeo? I already purchased a toaster oven and noticed that it's 1,300 watts. Will we be able to simply enter this parameter into the program and have everything work OK, or will it require more than that?
After researching the options, I will incorporate the inductive kickback protection for each of the two MOSFETs via TVS diodes between the source and drain. This will shunt the over-voltage spikes to ground and protect the MOSFET from damage while switching the mechanical relay coil. The currently selected MOSFET can already sustain a 2KV ESD discharge, but adding external over voltage support with a TVS diode will be another layer of protection. Thanks for the input on that. I really want this to be a great product that will be easy to use for everyone.
It sounds like something specific to how individual files are downloaded on Github. I normally drop the files in my local repository on my computer and sync it directly. I would suggest the zip file download for sure. I never had problems with using it that way.
As for protections from relay inductor kickback, you bring up a good point. Currently, there are no extra protections around the FET for that. There are a few methods that could be employed and I'll probably explore those since I'm working through the revisions from the prototype to the production version. Do you have a preference of what you would like to see there such as a varister, rectifier diode, zener diodes or others? This is what is great about open hardware projects that we can collaborate and make a best of bread product.
As you indicated, the Power Switchtail II that I will be sending with the full $99 kit does include protection circuits for just this sort of thing.
I tried running Eagle 6.1.0 and Eagle 6.4.0 under Mac OS X.
If I directly download the individual files from github => error message
and file sizes == brd ~ 381 KB / sch ~ 688 KB
If I download the ZIP file from github and then decompress => no problems
and file sizes == brd ~ 127 KB / sch ~ 201 KB
Perhaps there's a problem with the individual files uploaded to github?
Perhaps I'm not understanding how to use github properly?
What I wanted to look for was the presence of any protection circuitry around the FET.
It seems to me that the design really needs the specific type of relay you've specified
for isolation and avoiding inductive kicks from the relay coil. The people who have pledged
at the two lower pledge levels should be aware of this. Not complaining - just commenting.
Thanks for your interest in this project. The $99 complete kit will come with a Power Switchtail II as featured in the video. It is a mechanical relay that is enclosed in a housing to for the most amount of safety. It has a three prong 120VAC plug on one end and the complementary three prong receptacle on the other end. This allows the relay to be plugged in-line between the wall outlet and the toaster oven. I'll give a link to the Power Switchtail II website below so that you can read more about it:
I designed this using Eagle version 6.3.0. I downloaded the zip file from Github just a few moments ago to test and had no problems opening the Eagle files. I'm not sure what the issue might be on your end. Did you try to open the SCH or BRD file that gave an error? Perhaps we are using different versions? The INO file is an Arduino file, so if you had tried opening that with Eagle, I imagine you would have issues. I'd be happy to send you a copy of the design files via email if you think that would be helpful. Let me know what I can do to help.
What kind of relay are you proposing to use (conventional, solid-state, etc.)?
Which version of Eagle are you using?
I get an error message when I try to look at the files on github.
line 5, column 6: This is not an EAGLE file.