Open source Weller RT compatible soldering station with Tweezers :)

[riccardo.pittini]

I developed a soldering station compatible for Weller RT tips.
It was developed for personal use as I simply found that Weller RT1 tips are great fr SMD work but the station + handle price is not low!

It is compatible with Weller:
- RT micro
- Recently discovered that works also with RT Ultra and RT Pico
- I'm finalizing the tweezers (they work as well )

Here is a link to the station and the firmware + design files.

Some specs from my Tinde website:
https://www.tindie.com/products/pittinihub/soldering-station-rt1/

GitLab project:
https://gitlab.com/pittinihub/solderingrt1

It would be great to have some comments
Thanks

[riccardo.pittini]

Just wanted to add another teaser

Some comments on the tweezers:
- You can run one set of tweezers from a single channel (placing effectively the TCs in parallel, not ideal but for simplicity it works well enough). In this case you have to consider that large differences in thermal mass between L+R heaters will cause a temperature difference on the tips .
- You can use the two channels to drive independently the L+R heaters in the tweezers

[flywire]

Regular package includes: ... 3d printed case

Poor design. Could have used a $1 Electronic Project Box.

[homebrew]

Hm, since you asked for comments, here are some thoughts for improvements ...

1) Add input protection / add protection at all! No fuse(s) and no reverse polarity protection in current schematic. No overcurrent protection. If that thing is really meant to run from batteries (or LiPo) A LOT has to be done ...

LACKING EVEN MOST BASIC PROTECTION IS IMMEDIATELY A BIG THUMBS DOWN !!! 

2) "Beef up" Input barrel jack. The current model specified in the schematic is rated to 2.5A only:
https://lcsc.com/product-detail/AC-DC-Power-Plugs-Receptacles_XKB-Connectivity-DC-005-5A-2-0-SMT_C319134.html

3) Select proper output connectors. These are just headphone jacks. Their current rating seems to be just 500mA:
https://lcsc.com/product-detail/Audio-Video-Connectors_Korean-Hroparts-Elec-PJ-313D-6A_C95463.html

4) Limit/monitor the output. A short in the output (or anywhere for that matter) and this thing will go up in flames if the power supply has no sufficient protection!

5) In your firmware I cannot see code for UVLO. The voltage is sensed but I didn't see code handling an undervolt condition anywhere. Maybe I've overlooked that. This is highly important as under a certain threshold, your MOSFETS will not turn on completely anymore, dissipate all the heat and burn. I wouldn't suggest handling this in software at all! If it is important for safety I would recommend doing this in hardware.

6) Publish the board layouts. I mean - why not? If somebody would "steal" your design, the lacking board design files will not stop anybody at any level of experience ...


Honestly, this currently doesn't feel very safe at all!

Not even talking about a CE ...

[riccardo.pittini]

Thanks for the comment . I just give some thoughts about the design.

- Correct you can use a "Electronic Project Box" I just found them to not to be the size i liked, plus more difficult to make nice cuts for LCD buttons etc. I find good quality 3d prints better than standard "electronic boxes"
- Ja.. the project started in a different way.. just needed something to work for my home table...  then it added things piled up as functionality (as well as for the code). Design needs beefing up and there is very few space left in the code (current rom usage is about 92% and 50% ram .. more or less)
- UVLO it is in the code, just handled in another section ( in lcd_print.ino)... don't ask why... -_- but it was the quickest way i found to update the state machine (considering corner cases)
- you are right (i'll upload them), I don't know I held a bit back, anyhow it is never meant to be a commercial product or not nearly close to that. It is a DYI project for myself, nothing more. I simply wanted to share feed and get reasonable comments and ideas of what could be interesting adding (e.g. I added recently standby detection in software).

[homebrew]

Very cool, that you really care about your design.

For me it is the big plus of doing open hardware and hobby project - you are not forced to design something down to a price. It can be completely uneconomical, manufacturability is normally not a thing, either.

However, perfection is the thing that keeps me going. If I decide it is worth my time to really engage into something I want to max it out.

I've seen that you already uploaded the Gerber files 

[riccardo.pittini]

I worked on some mass production units so I took it as personal exercise to simplify it as much as possible and cost it down.
So if someone want to build it it can do it very cheaply (without counting personal "working hours" of course).

What I struggle with real "open projects" is that there are too many voices in the air and too few hands doing the real job/implementation. Overall I am glad with the level of design I brought this project to.

[HB9EVI]

what tweezer are these? this is something what I'm still missing on my bench; are they Weller RT-series too?

[riccardo.pittini]

I designed the case and figured out connector and connections for the Weller tweezers (RTW 1 and similar).

[algorithm]

Is this for sale for the people like me who dont know how to get a board made?
Recently my cheap yihua hakko knockoff died so Im trying to find a good replacement. Might be interested in buying one if possible.

Great work btw. Keep it up. 

[benoitpixel]

Hi, Riccardo,

Quote from: riccardo.pittini
" I designed the case and figured out connector and connections for the Weller tweezers (RTW 1 and similar) "

On the attached photo, I am looking for the 5-pin female connector that can be seen in the 3D black case.
Do you have a reference for this connector and where did you buy it?
Thanks for your help.

[croma641]

Binder 09-9792-20-05

http://kair.us/projects/weller/diy_wmrt_handle/index.html

[benoitpixel]

Thank you croma641

[riccardo.pittini]

I know many people will say "no no no".. you can still connect the thermocouples in parallel and the resistive elements in parallel.
In this way you can drive both left-right elements with a single channel, main drawback is that you loose precision in the temperature control (e.g. when you have different thermal mass between left and right side of the tweezers). It is not an optimal solution, but sufficient for amateur /not pro use.