Whats inside Weller WMRT Tweezers

[nikifena]

Hi there. I've got a weller RTW1 irons, but I have no the iron holder handle. I think to print similar handle with a 3D printer, so I will thankful if someone can send me several pictures how the handle looks inside.

I've found the male connector for the irons here: http://uk.farnell.com/binder/09-9792-30-05/socket-5way-panel/dp/1122809?st=Circular%20Connector,%20719%20Series


Niki

[eeviking]

You mean you only have the tips and want to diy the hand piece ?

What station do you want to connect it to?

All the WX hand pieces contain a small pcb with at least a accelerometer and eeprom to store temperature setting etc. Not something that is easy to reverse engineer.

But there is diy designs for stations that use the WXMP tips. I guess you could just make a 2ch version of that to run a WXMT tip. You just need to figure out the pinout.

[nikifena]

Yes, I have got the tips only.
I found this project on the net: http://kair.us/projects/weller/
and I have made my PCB design of the board
These tips have only a temperature sensor for cold junction compensation. So there is almost nothing.
I'm asking just for few pictures inside the tip holder.

Thanks

[eeviking]

Here you go 

Just ask me if you need more.

edit: This is a WXMT

[Mr. Scram]

Wow, a cut off cable tie as strain relief?

[eeviking]

Wow, a cut off cable tie as strain relief?

Hand made in Germany I think. If it works as a quick hack at home it must be good enough for production of 230$ handle right?

[eeviking]

As I got a question about it, I will just clarify that the pictures I posted are of a WXMT for WX stations.
Here is a thread on a German forum with pics and schematic of the WMRT if anyone want to build a DIY one:
https://www.mikrocontroller.net/topic/436075

[nikifena]

Thanks!
I'm still haven't made the tweezer complete yet, but if there is progress, I will inform you here.

[Spyke]

Anyone have any luck converting one of the WMRT 12V handles to 24V? I noticed Weller discontinued the 24V models and they're all 12V now, however the tips that plug in are identical so they must have simply wired both heating elements in parallel for 12V. I will dig deeper into it, so annoying to be sent a 12V unit that isn't compatible with the WD1/WD2 soldering stations, only the almost identical looking *multifunction(tm) WD1M/WD2M models or WM/WX base stations. AGH. They must have also moved the pin where the thermalcouple is, so the heater power stays off also.

EDIT: I'm looking over the Unisolder documentation first. I see independant heater1 and heater2 for the 1 jack, so this is how they make the 12/24V units auto switchable.

EDIT2: Bah, need a k-type thermocouple amplifier. I was initially confused by the old availability of 24V handles that mention WD1/WD2 compatibility. It seems it was a misprint and although the 24V handles exist, the tips still use k-type thermos.

[Mr. Scram]

Anyone have any luck converting one of the WMRT 12V handles to 24V? I noticed Weller discontinued the 24V models and they're all 12V now, however the tips that plug in are identical so they must have simply wired both heating elements in parallel for 12V. I will dig deeper into it, so annoying to be sent a 12V unit that isn't compatible with the WD1/WD2 soldering stations, only the almost identical looking *multifunction(tm) WD1M/WD2M models or WM/WX base stations. AGH. They must have also moved the pin where the thermalcouple is, so the heater power stays off also.

EDIT: I'm looking over the Unisolder documentation first. I see independant heater1 and heater2 for the 1 jack, so this is how they make the 12/24V units auto switchable.

That may explain why I have a handle with two sets of tips, of which one doesn't seem to respond to the station. I couldn't detect a difference between the tips after opening both up, but I may have overlooked switched pins. It's a WD2M station.

[Spyke]

Weller has gone absolutely mad on the marketing, so the WXMT/WMRT are identical, as is the WXRP/WMRP, did the change in soldering station *really* need new part numbers? Oh they updated the stand too... intentional just to confuse everyone perhaps.

[blacksheeplogic]

Weller has gone absolutely mad on the marketing, so the WXMT/WMRT are identical, as is the WXRP/WMRP, did the change in soldering station *really* need new part numbers? Oh they updated the stand too... intentional just to confuse everyone perhaps.

Your definition of identical is quite different to mine obviously.

For anyone reading the above comment by Spyke, disregard it, you cannot interchange the hand pieces (i.e. use a WR hand piece on a WX).

[Mr. Scram]

Your definition of identical is quite different to mine obviously.

For anyone reading the above comment by Spyke, disregard it, you cannot interchange the hand pieces (i.e. use a WR hand piece on a WX).

I agree with Spyke that Weller has gone off the deep end in that regard, though. There appear to be a whole host of very similar variations and it's often surprisingly hard to find out what you need exactly or what is compatible. Standardisation isn't really Weller's game.

[coppercone2]

Wow, a cut off cable tie as strain relief?

is this bad? i am serious, I have done this before.

[Mr. Scram]

is this bad? i am serious, I have done this before.

I guess it works, but it seems there should be a better way of distributing the stresses than using a cable tie with a big lump on one side. Though I'm willing to admit that Weller may have done its homework and found a more expensive option isn't much better.

[Spyke]

Physically identical doesn't mean electrically identical, oh they added a "motion sensor" instead of a reed switch, kept the same heaters and tips, identical enough, but not enough to force new equipment purchasing. Its a load of nonsense. They broke backwards compat because they could, not because they needed to. Oh they also added some flashy blue lights in some of their handles, not like that was ever important for soldering. Makes you wonder why they even released a physically identical looking base station WDxM only to just replace the entire works with the WX line shortly thereafter.

[Spyke]

Weller has gone absolutely mad on the marketing, so the WXMT/WMRT are identical, as is the WXRP/WMRP, did the change in soldering station *really* need new part numbers? Oh they updated the stand too... intentional just to confuse everyone perhaps.

Your definition of identical is quite different to mine obviously.

For anyone reading the above comment by Spyke, disregard it, you cannot interchange the hand pieces (i.e. use a WR hand piece on a WX).

Defender of Weller's shady business practices of cloning products and creating ever minute changes to force people to buy their new stations. Okay, I'm wrong, not identical, going to defend that it isn't shady?

[blacksheeplogic]

Your definition of identical is quite different to mine obviously.
For anyone reading the above comment by Spyke, disregard it, you cannot interchange the hand pieces (i.e. use a WR hand piece on a WX).

Defender of Weller's shady business practices of cloning products and creating ever minute changes to force people to buy their new stations. Okay, I'm wrong, not identical, going to defend that it isn't shady?

The purpose of my post was to clear up any confusion that you could purchase WR hand pieces and use them on a WX station as they cannot be interchanged It's not obvious just looking at the pics but the connector is quite different (incompatible) and they are also use a different ID (software lock).

I'm not entering any debate on right, wrong, shady or otherwise.

[Spyke]

Your definition of identical is quite different to mine obviously.
For anyone reading the above comment by Spyke, disregard it, you cannot interchange the hand pieces (i.e. use a WR hand piece on a WX).

Defender of Weller's shady business practices of cloning products and creating ever minute changes to force people to buy their new stations. Okay, I'm wrong, not identical, going to defend that it isn't shady?

The purpose of my post was to clear up any confusion that you could purchase WR hand pieces and use them on a WX station as they cannot be interchanged It's not obvious just looking at the pics but the connector is quite different (incompatible) and they are also use a different ID (software lock).

I'm not entering any debate on right, wrong, shady or otherwise.

Thanks, I was just frustrated how many different incompatible product lines, such short lived product lines also.
So it looks like the WT line (yet another new station), was the modern backwards compat I was looking for, supports all the old handles and all the k-type WM ones, basically just a modern looking WD1M/WD2M station, okay so they're not all bad.

[Spyke]

So Weller ended up winning in this case as I now have the WXMT, WXMP and WX1. Thankful to the great people at tequipment for the handling of the WD2M/kit WMRT returns. Hopefully this setup won't be ditched anytime soon for new handle support.

[ksilabs]

BTW, does anybody know what is the difference between WMRT and WMRT-MS? Everybody and their grandma (including Weller) explicitly tell the RTW and RTW-MS tips are NOT compatible and only work with their specific handles. Same applies to WRMP and their RT/RT-MS tips...

On the other end of spectrum does anybody know how to disassemble WTP90 handle? I do already know what's inside but would like to put MAX31826 everywhere as ID/Parameters EEPROM AND cold junction sensor if needed (sensor will be unused in irons with Pt100/Pt20 resistance sensors.) Also want to put simple spring motion detector everywhere (e.g. WP80, WMP, PES-51 etc) to make them motion activated. Not all that critical as there are 3D-printed handles out there but would like to keep original one.

Right now reverse-engineering WR3M (will publish full schematics when done) but hacking it to work with PES-51, WTP90 (and many others) is not a viable task because all those irons are different and it is almost impossible to tell e.g. WP80 from WMP -- many of older irons only have heater on pins 1/2 and thermistor on 3/4 (PES-51 has K-type thermocouple without cold junction compensation) so they only differ in heater resistance if power is different which is not a viable source to ID the iron. BTW, WR3M has pins 1 and 3 connected together on its control board thus wasting a precious connector pin.

For now idea is to re-do the WR3M control and display boards and use 8-pin DIN connectors for tool connection. There are limited number of Weller irons so it is not rocket science to make replacement boards with MAX31826 and motion sensor for ALL known ones with unified 8-pin connector pinout. That would allow to use it with almost any 12/24V single/dual heater wires while providing automatic tool identification, maybe small set of tool-specific values loaded from the tool itself, motion activation without any magnets and much more.

All this is going to be open source so it could work with tools from other manufacturers as long as those are 12/24V and modified accordingly and use the same plug/pinout.

Not going to reverse-engineer their software in PIC18F6722 as it is too much work with questionable benefit. Will make a new board and write software from scratch. Not sure which microcontroller to use but leaning towards my beloved TI DSP, probably TMS320F28035 that I still have a full tray in stock.

The next step might probably be making something akin WR3M from scratch with 5 or 6 channels so one station would cover everything.

[Spyke]

The MS is just milspec, physically the connectors are identical but if I were to guess they wired the pins for the heaters differently in the handles themselves to be different to the non-MS heaters to minimize leakage current to meet milspec. I happen to have MS versions of WXMT and WXMP and from what I can tell the physical properties of the plugs are the same. You'll notice the heaters have more shielding around them on the milspec heaters/tips for the micropencil and tweezers.

[Spyke]

Also the physical design of the WX and WM series of the tweezers and micropencil are identical, Weller didn't even bother putting the blue LED in them when they added the accelerometer and eeprom, like they were short on design time to redesign these handles slightly. No reason why they couldn't modernize those handles to be like the rest of the WX lineup, even if the tips remained the same. They could have added the fancy strain relief also.

[floobydust]

Note people are having reliability problems with the Weller tweezers.
The housing aluminium EMI coating flakes off, and the conductive flakes short the PC board.

[ksilabs]

I've purchased some RT-MS and RTW-MS tips so I would be able to find out the difference between MS and non-MS versions, no problems. Also got a couple of WTP90 heater cartridges really cheap from Amazon as well as second WTP90 iron so have more than enough to experiment with.

The changed  plan now is to throw out Weller WMRP/WMRT/WTP90 handles completely and only use their tips. Going to go full-digital route putting something like ADuC7061 microcontroller inside handles that would take care of all temperature measurements, button(s) handling, motion detection and would speak digital-ese with the station. Station itself would provide and control 12/24V AC power and user interface as well as compressed air / vacuum for the tools that need it. It would also serve as a proxy for iron microcontroller firmware updates and configuration (tool type/model, calibration, whatever) when connected to a PC and will be probably able to perform all that on its own using e.g. external USB Stick.

I would also make retrofit boards for popular irons (e.g. DXV80,HAP1/200,WP80 etc) so they would be able to speak digital-ese too. Will try to fit a status LED and a button in the handles too. The button would allow to turn the iron on/off without doing anything on the station.

The station itself would probably have a beefy toroidal transformer and a whole bunch of triacs (4 per channel to make it possible to feed either 12 or 24V to 2 heaters.) Will probably have something like 5 or 6 channels as mere 3 channels in that expensive WR3M is not enough so one has to purchase at least TWO of those (or a handicapped version thereof for a second station.)

I'm also thinking about putting a tiny OLED display next to each channel connector so every tool could show something useful and tool-specific in addition to the system-wide bigger display.

Everything is going to be open source so others would be able to join and adapt their own tools to that thing, not necessarily being from Weller at all.

Seems to be an interesting and fun project. I might even go crowdfunding and start building those in quantity if there was interest.

But that all is just in a conceptual stage right now so it might change significantly and I might even never take on that as I do have two WR3M stations on hand (as well as 2 WR3000s for using as part donors for first prototypes) and whole bunch of irons (WP80, WMP, WMRT, WMRP, DVX80, HAP200, PES51, WTA50, WTP90 in multiples) so I might switch to some other project but for now it is the most interesting of several ones I'm working on.

It wouldn't've even materialized if WR3M had supported that nice WTP90 iron

As of now I'm something like 80% done reverse-engineering WR3M main board. Will post a full schematic when done for everybody's benefit.
I do also have its PIC18F8722 binary firmware (available from Weller as firmware update) but don't know if I would even try to make sense from junk disassembled source -- it would be probably way easier and faster to re-do everything from scratch using more suitable microcontroller.

[floobydust]

Maybe look at: Weller WMRP and WMRT compatible soldering station  http://kair.us/projects/weller Offers source code and hardware using PIC16F1788.

[ksilabs]

OK, I do know what's different between RT and RT-MS cartridges.

RT-MS has a separate tip ground on that cylindrical part going into the handle. 3-contact jack pin closes to the tip is NOT connected to the tip as it is in plain RT cartridges. However this difference is superficial -- RT-MS has a PLASTIC washer covering that cylindrical part opening  towards the handle that is not conductive so those two contacts are not connected. Plain RT has a METALLIC conductive washer instead that simply shorts those 2 contacts. I didn't try it but would bet that removing that washer will make RT-MS from RT.

There is also some mechanical difference -- RT-MS has additional thin metal tube with nicely engraved "RT-xMS" and "Weller" over that bare tube piece between the handle and beginning of the heater. I'm almost 100% sure it only serves decorative purpose, nothing else.

Difference in the handle (if it exists at all) is that zero ohm resistor to pin 5 is removed and pin 5 is connected directly to the tip. That would've allowed that fancy 3.5mm "Ground select" jack on WR3M to actually do something (provided nothing else is connected, just WMRP-MS.)  If anything non-MS is connected that jack is purely decorative as that "anything" shorts pin 5 of all 3 connectors to station ground and "grounding jack" makes no sense at all.


I did also a quick teardown of WXDV120 desoldering iron to find out what is that their "totally digital" about. That was total shock as there is actually nothing "digital" in there except PCA9553DP/01 4 LED Blinker with I2C control, 3 LEDs, couple of resistors in voltage divider arrangement (it is probably that "digital ID"), small motion sensor (spring or ball type, much worse that common SW-18010P with a spring) and that's all it has for "fully digital". There is no memory of any kind in the handle. Unless they have something built into their homebrew overmolded connector (I seriously doubt they have -- I've bought a replacement WXP200 cable from Amazon for $8 specifically for teardown purposes and it is original Weller part in their packing having just straight 6 wires, nothing else -- all that "full digital", "stored calibration" and so on is even bigger lie than Volkswagen diesel emission data...

I do also have several plain DXV80 irons and they are almost identical to that "fully digital" one, also having 6 wires and a simpler board without LEDs, PCA9553 I2C LED Blinker and motion sensor.

Also have brand new WXP200 iron and there is nothing "digital" there too except the same parts that are inside WXDV120 iron. BTW, I do also suspect they made 120W desoldering iron off of 80W DXV80 by merely replacing "80" with "120"

There are chances I might be wrong and overlooked something but they are slim. I'm 60 y/o professional Electronics Engineer doing this for living my entire life.

Just to be sure I've purchased a WX2 station to actually hook up a scope (and LA if there IS something digital) to find out what's going on between an iron and the station.

However it looks almost certain that their WX series only standardized irons pinouts so they could throw away that extensive probing/switching circuitry present in WR3M and added blinking LEDs where it was possible (not in WTP90/WMRP/WMRT) and motion sensor switch.

[Spyke]

There is definitely an eeprom located in the WXMT tweezers.

[ksilabs]

There is definitely an eeprom located in the WXMT tweezers.

Maybe. The only place it could be hidden in WXDV120 is under the switch. I did NOT fully disassemble it to remove the board and make exact schematic, will probably do tonight.

WRT that eeprom in WXMT -- did you check the board? What is the eeprom p/n?

I don't have WXMT here, only couple of WMRT handles so can't check. I have WXMP-MS coming my way so will be able to check that one.

Right now from WX line I only have WXP200 and WXDP120 on hand, WX2 station is not even shipped yet.

BTW, the motion sensor is MVS0608.02 from Comus International, available from major vendors and cheaper from www.testco-inc.com -- I've just purchased 25 for retrofitting other legacy  irons.

[ksilabs]

There is definitely an eeprom located in the WXMT tweezers.

Maybe. The only place it could be hidden in WXDV120 is under the switch. I did NOT fully disassemble it to remove the board and make exact schematic, will probably do tonight.

WRT that eeprom in WXMT -- did you check the board? What is the eeprom p/n?

I don't have WXMT here, only couple of WMRT handles so can't check. I have WXMP-MS coming my way so will be able to check that one.

Right now from WX line I only have WXP200 and WXDP120 on hand, WX2 station is not even shipped yet.

BTW, the motion sensor is MVS0608.02 from Comus International, available from major vendors and cheaper from www.testco-inc.com -- I've just purchased 25 for retrofitting other legacy  irons.

OK, I was too quick to draw

I've removed the board from my WXDV120 for close-up inspection and indeed all the fancy stuff was on the back side, not visible with board in place.

I've underestimated Weller guys -- it is 4-layer board packed with quite a lot of stuff.

First of all there is a 4-channel Analog Devices AD7995YRJZ-1 ADC with I2C interface in SOT23-8 package. Then there is TS507 opamp from ST Micro in SOT23-5 and yes, Microchip 24AA04 4Kbit I2C EEPROM in SOT23-5 package as well as some resistors and capacitors.

Everything is perfectly readable by regular tools, nowhere to put any secret codes or read protect so the entire line should be easily reverse-engineerable.

It's getting more and more interesting by the day, having tons of fun

Will try to make a schematic in a day or two...

[ksilabs]

There is definitely an eeprom located in the WXMT tweezers.

Maybe. The only place it could be hidden in WXDV120 is under the switch. I did NOT fully disassemble it to remove the board and make exact schematic, will probably do tonight.

WRT that eeprom in WXMT -- did you check the board? What is the eeprom p/n?

I don't have WXMT here, only couple of WMRT handles so can't check. I have WXMP-MS coming my way so will be able to check that one.

Right now from WX line I only have WXP200 and WXDP120 on hand, WX2 station is not even shipped yet.

BTW, the motion sensor is MVS0608.02 from Comus International, available from major vendors and cheaper from www.testco-inc.com -- I've just purchased 25 for retrofitting other legacy  irons.

OK, I was too quick to draw

I've removed the board from my WXDV120 for close-up inspection and indeed all the fancy stuff was on the back side, not visible with board in place.

I've underestimated Weller guys -- it is 4-layer board packed with quite a lot of stuff.

First of all there is a 4-channel Analog Devices AD7995YRJZ-1 ADC with I2C interface in SOT23-8 package. Then there is TS507 opamp from ST Micro in SOT23-5 and yes, Microchip 24AA04 4Kbit I2C EEPROM in SOT23-5 package as well as some resistors and capacitors.

Everything is perfectly readable by regular tools, nowhere to put any secret codes or read protect so the entire line should be easily reverse-engineerable.

It's getting more and more interesting by the day, having tons of fun

Will try to make a schematic in a day or two...

BTW, it IS 120W -- heater is ~4 Ohm that makes it ~6A @ 24V when cold that translates to ~144W. Temperature sensor is Pt100. 6 wires to the station -- 2 separate wires for the heater, 1 common ground with tip connected to it so no "raised' or "floating" ESD protection is possible as it is hardwired to system common ground in the iron, 1 wire for power (probably 5V, don't know yet) and 2 wires for I2C SCL/SDA.

On the cable connector it looks like they dedicated separate pins for 12V and 24V power (looks like 1 pin for a single 24V and 2 pins for separate 12V powers for tweezers, only one of which is used on WXMP that has only one heater.)

Would be very interesting to find out what their female receptacle on WX station is. I was not able to locate anything like that so far -- there are many 12-pin connectors of similar size but I could NOT be able to find anything with the same contacts arrangement.

If somebody knows what connector they used (cable male plug might be their own as it looks like contacts are potted in epoxy instead of placed in some standard shell but female receptacle definitely looks like something standard) it would be highly appreciated.

The current plan is to put some intermediate standard cheap connectors in the station and make modular adapters for "new" WX-style and old 7-pin custom DIN ones so the station could work with any mix of irons by using proper modules. That would allow to use irons as-is, without any modifications with their existing cables. Adapters for legacy irons might have "conversion" circuitry that would make them look like "new" WX ones to the station no matter what they are.

That would also make possible to make adapters for irons from other manufacturers, with different connectors and make them look native for the station. As the entire control part is going to be developed from scratch it wouldn't be bound to those Weller codes/IDs only so it will be possible to add anything as needed. All source code is going to be GPLed without any secrets so anybody could add whatever features/tools he wants.

So if anybody knows what those WX female receptacles are please share the knowledge...

[Spyke]

Nice work at reverse engineering. I would imagine that plug is purely a custom job. Its good news that Weller have not employed some pesky DRM scheme even though they could have, as from what I understand the temperature info also gets set digitally down the wire, by use of that ADC being very close to the TC as part of the tool handle. Must be a very tight control loop.

[Spyke]

The cool thing you could fab one out of PCB with the proper rounded pins in the correct spot, would be great to test with incase you need a special run of jacks.

[Howardlong]

Note people are having reliability problems with the Weller tweezers.
The housing aluminium EMI coating flakes off, and the conductive flakes short the PC board.

Which model?

I've been using the same pair of WMRT tweezers for well over a decade with no signs of anything flaking off.

[ksilabs]

The cool thing you could fab one out of PCB with the proper rounded pins in the correct spot, would be great to test with incase you need a special run of jacks.

Sure, but I care less for plugs -- all WXxyz irons already come with their cables so it is only relevant for possible retrofitting legacy irons with WXxyz internals thus converting them to digital. Even that is not an issue as you can use whatever connector you want and make an adapter for its plug.

What I do care about is getting the matching female receptacles for ORIGINAL Weller WXxyz plugs for WX adapters so irons could be used as-is, without any modifications. The problem is those connectors have quite unusual contacts arrangement so I could not find anything like that so far.

In the meantime I'm going to make a WXDV120 board schematic today or tomorrow and, probably, do a board layout and order some boards for retrofitting legacy DXV80 irons.

I do already have (either on hand or in transit to me) WXMP-MS, WXMT-MS, WXP120, WXP200, WXHAP200 irons so I would be able to make retrofit boards for their legacy counterparts. I do also have legacy WP80, WMP, HAP200, lot of DXV80s, couple of WTA50s, several WTP90s so would be able to make something similar for those. WTP90 is my current favorite -- I like that iron. It is very light and capable of delicate jobs with its default XNTA tip but has enough juice for much heavier jobs with THM tips (BTW those are discontinued by Weller so go get yours while they are still available.) I do also have a couple of spare heating elements for WTP90 so I can keep them with some particular tips and change them as easily as RT tips.

Initial plan for the station is to make it 6-channel with built-in Air/Vacuum and Vacuum Pickup pumps, Air/Vacuum would have 2 connections for 2 tools each with built-in valve switching it between corresponding tools. Vacuum pickup would get a pedal and built-in vacuum release valve. It would be able to power any tool, legacy and WX, Weller or not with a proper adapter. Thinking of something looking like WR3M but with additional 3 tools connectors on the right so control panel would be in the center with 3-tool panels on both sides.

[Howardlong]

Some pics inside WMRT

I believe the SMD part marked 110 may be a temperature sensor KTY82-110, probably a safety feature.

The long thin white thing is a reed relay to detect whether the tweezer is in the stand or not.

The casing is plastic. The apparent case marks are evidence of the operator's fingers mating with super glue at some time in its history!

The internal metallic block doesn't usually have L R written on it, that was so I put it back together the right way.

[ksilabs]

Some pics inside WMRT

I believe the SMD part marked 110 may be a temperature sensor KTY82-110, probably a safety feature.

WMRT is not interesting, nothing to write home about... WXMT would've been more interesting but I will do it myself once the shipment arrived.

KTY82-110 is not a safety feature -- it is used to measure thermocouples (there are two in RTW, one per side) cold junction temperature to calculate the actual hot junction (tip) temperature.

[Howardlong]

Some pics inside WMRT

I believe the SMD part marked 110 may be a temperature sensor KTY82-110, probably a safety feature.

WMRT is not interesting, nothing to write home about... WXMT would've been more interesting but I will do it myself once the shipment arrived.

KTY82-110 is not a safety feature -- it is used to measure thermocouples (there are two in RTW, one per side) cold junction temperature to calculate the actual hot junction (tip) temperature.

Glad I bothered then. Sorry to disappoint you.

In case it had escaped your notice, the title of the thread is "What's inside Weller WMRT Tweezers". Mine was the first post to directly address this within the thread.

Have a great day.

[ksilabs]

Some pics inside WMRT

I believe the SMD part marked 110 may be a temperature sensor KTY82-110, probably a safety feature.

WMRT is not interesting, nothing to write home about... WXMT would've been more interesting but I will do it myself once the shipment arrived.

KTY82-110 is not a safety feature -- it is used to measure thermocouples (there are two in RTW, one per side) cold junction temperature to calculate the actual hot junction (tip) temperature.

Glad I bothered then. Sorry to disappoint you.

In case it had escaped your notice, the title of the thread is "What's inside Weller WMRT Tweezers". Mine was the first post to directly address this within the thread.

Have a great day.

Sorry if it offended you -- I didn't mean it...

[Spyke]

Since this topic has woken back up its perked my interest again. Here is the internals to the WXMT tweezers. Definitely more interesting than the RT, probably no room for the LED blinker chip.

[ksilabs]

Since this topic has woken back up its perked my interest again. Here is the internals to the WXMT tweezers. Definitely more interesting than the RT, probably no room for the LED blinker chip.

Looks pretty similar to my WXDV120 board. Almost same components and schematics.

Spent entire evening yesterday after my day job making Altium symbols and footprints for those components, hopefully will get to actual schematics tonight. Doing it the proper way as I want not just draw a crude schematics but also clone those boards and order a couple of panels along with stencils.

[Hydron]

There has been a fair bit of work on the weller WX series irons over on mikrocontroller.net: https://www.mikrocontroller.net/topic/367344
Everything other than my contribution is in German but google translate does a reasonable job on it. Nobody has had any luck with finding an off-the-shelf connector but I managed to 3d-print one which works well enough for my WXMT tweezers.
I have also had the tweezers working with a controller I lashed up on a breadboard but it is very rough (and needs some tweaking to the temperature calculation) so I haven't posted about it.

[ksilabs]

There has been a fair bit of work on the weller WX series irons over on mikrocontroller.net: https://www.mikrocontroller.net/topic/367344
Everything other than my contribution is in German but google translate does a reasonable job on it. Nobody has had any luck with finding an off-the-shelf connector but I managed to 3d-print one which works well enough for my WXMT tweezers.
I have also had the tweezers working with a controller I lashed up on a breadboard but it is very rough (and needs some tweaking to the temperature calculation) so I haven't posted about it.

OK, we'll see what I will find by reverse-engineering that WX2 station that is on its way to me now...

It might well be a totally custom connector made to Weller's order or even manufactured in-house One solution would be to replace it with readily available connectors from e.g. CNLINCO that are really high quality and have proper power rating like e.g. this one:

https://www.ebay.com/itm/153159218792

but it's unlikely people would cut their original Weller connectors and replace it with a generic one or replace the entire cable...

[ksilabs]

BTW, just got my WXMT-MS set delivered and can tell now what's the difference between MS and non-MS versions of both legacy and WX versions is.

The MS versions of WMRT/WMRP/WXMP/WXMT has a totally separate tip grounding all the way to the cable plug. WXMT-MS has a pogo pin in addition to that 5-pin Binder connector that contacts the metal body and has white wire soldered directly to that pogo pin so actual connection to the cartridge is 6 wires, not 5.

The non-MS version has its tip grounding wire connected to a common pin inside the cartridge so there is no separate tip grounding there -- connection to the cartridge is 5 wires.

And I was wrong thinking that common ground is connected to the tip. It is connected to one of the heater's terminals. Reworking (beautyfing) the WXDV120 schematic now, will post later tonight along with the board photos (just got a ring light so can make macro pictures now).

[ksilabs]

Here is the full WXDV120 Schematic...

[ksilabs]

Here is the full WXDV120 Schematic...

This is the final revised WXDV120 schematic and board layout. Each heater terminal connection takes an entire internal layer and Heater2 is NOT used as a ground plane -- it is just connected to the signal ground at one point at cable terminal. All signal nets are routed on top and bottom layers. It is 1.6mm 4-layer board with components on both sides.

[ksilabs]

Original board photos...

[langwadt]

Note people are having reliability problems with the Weller tweezers.
The housing aluminium EMI coating flakes off, and the conductive flakes short the PC board.

ours just killed a few boards, the tips got loose in the holder and pushed in shorting to power

[Hydron]

BTW, just got my WXMT-MS set delivered and can tell now what's the difference between MS and non-MS versions of both legacy and WX versions is.

The MS versions of WMRT/WMRP/WXMP/WXMT has a totally separate tip grounding all the way to the cable plug. WXMT-MS has a pogo pin in addition to that 5-pin Binder connector that contacts the metal body and has white wire soldered directly to that pogo pin so actual connection to the cartridge is 6 wires, not 5.

The non-MS version has its tip grounding wire connected to a common pin inside the cartridge so there is no separate tip grounding there -- connection to the cartridge is 5 wires.

A quick question about the RWT MS tips - from your description it sounds like the difference is mostly in the handle with the pogo pin - is there anything to prevent a MS tip being used in a non-MS iron? I assume the 5 pin connector/pinout etc is the same? Or would a modification to the tip PCB or wiring be needed (not a deal breaker if I can get a MS tip for a significant discount)?

[ksilabs]

BTW, just got my WXMT-MS set delivered and can tell now what's the difference between MS and non-MS versions of both legacy and WX versions is.

The MS versions of WMRT/WMRP/WXMP/WXMT has a totally separate tip grounding all the way to the cable plug. WXMT-MS has a pogo pin in addition to that 5-pin Binder connector that contacts the metal body and has white wire soldered directly to that pogo pin so actual connection to the cartridge is 6 wires, not 5.

The non-MS version has its tip grounding wire connected to a common pin inside the cartridge so there is no separate tip grounding there -- connection to the cartridge is 5 wires.

A quick question about the RWT MS tips - from your description it sounds like the difference is mostly in the handle with the pogo pin - is there anything to prevent a MS tip being used in a non-MS iron? I assume the 5 pin connector/pinout etc is the same? Or would a modification to the tip PCB or wiring be needed (not a deal breaker if I can get a MS tip for a significant discount)?

Everything else in MS/non-MS tips is almost identical. The only difference is where that grounding wire is connected. You can use MS insert in non-MS handle but it will get the tip floating i.e. not grounded. You will either have to install that pogo pin and connect the grounding wire in the handle to that pin or connect grounding wire to the proper pin in the cartridge itself to have it grounded.

[Hydron]

Thanks for the info, knowing that I've looked at the photos I took when I opened my WXMT and I think I see the hole the pogo pin mounts in. Should be easy to add one in parallel to the normal earth connection so that the handpiece is compatible with either type of RTW cartridge. Will post pics if/when I mod it.

Now I need to make some decisions as to which cartridges to buy - has anyone got experience using the Non-Wettable options (e.g. RTW6NW), or the wide ones?
I'm assuming the former help stop the part sticking to the iron once placed/removed, and the latter are obviously for lifting SOICs/TSSOPs, but as usual Weller has very little info available and I have no experience as to how well they actually work at those jobs.

Edit: a reflection in the photo had me fooled - no hole there for pogo pin

[sariniitb]

Hi,

I have a WMRT soldering tool as part of  my W3M three channel unit. Worked fine for 5+ years. Recently it's been malfunctioning with a couple of symptoms:

• When the WMRT connector is plugged in, the temperature display shows 600C and gets stuck at 600C. The tips don't get hot though. Diagnosis: the KTY82 sensor in the handle is probably kaput (thanks for all the detailed info an pictures above!). I opened the handle, reflowed all the solder joints on the little PCB. Now the controls on the unit operate and set the temperature correctly in the 100 - 300C range (see #3 below)
  
• The left tip doesn't heat up - only the right tip does. The open circuit resistance on the connector is also different. [1-7] right heater is ~ 2 ohm, [1-2] is 1k. Diagnosis: a loose wire joint inside the tip connecting the high current wire to the heated tip metal? after all, if the solder joints on the pcb needed to be reflowed, maybe the wire connections inside the tip to be rechecked? Started to disassemble the tip and couldn't get further than the attached picture. Some flimsy wires can be seen routed around inside the tiny black cover : the tips themselves simply sit in the grooves)
  Any suggestions if I should try to disassemble the tip further?? Not sure it's possible to open it up in a put-back-together working manner!
  
• Tried reassembling anyway after wiggling the tips around in there slots, in case its a loose slip on connection inside. Now a couple of other problems present themselves: (a) the reed switch seems to act like the 'NOT' of what its expected to do. When the tip is in the holder, the control unit activates it, and when it is lifted up, it gets deactivated - annoying, but workable (with a magnet stuck on the handle)
  (b) intermittently, the control unit goes back to the 'stuck at 600C mode. Probably the KTY82 is indeed broken and will have to be replaced, or the one sided tip heating causes some control fault?
  

Our country is locked down, so lots of time to fix broken things in the lab with whatever parts I have on hand (lots of 'em, but no KTY82]. Any ideas on what to do about the non-working left side tip? and/or the temperature control?

Best regards -
Pradeep Sarin

[sariniitb]

I did go ahead and disassemble the RTW1 tweezer tips. Rather simple : the black cover with 'L' 'R' white markings is just a flimsy plastic/paper card bent and slipped around the mounting nut of the connector on the RTW1.
Popping it off, reveals another flimsy little PCB  (pic 1 below). The wires going to the heater tips are soldered on! Very un-German engineering. The actual tips are simply hanging above the PCB with the stiff wire carrying the heater current.

Probably the wires were touching or there was some gunk in the left heater wire (pic 2). Cleaned the whole thing with IPA, reflowed all the solder joints. Now as per the wiring diagram (pic 3) on the front-end connector X1,  I have equal resistance 3 ohm of the L/R heater wires (1,3) and (5,3).

Put it back together end-to-end (RTW1 -> mates to handle -> handle -> cable to Control Unit
At the 'station connector' in the wiring diagram pin 1-2 STILL shows 1kOhm. Very puzzling - it's supposed to be a straight wire through from X1 to the station connector. Unless I am missing some funny ground connection...

Plugged the WMRT into the control unit, and as expected from above diagnosis, despite the fondest hopes, the left tip STILL does not heat up (right tip goes to 300C fine.

[ksilabs]

I did go ahead and disassemble the RTW1 tweezer tips. Rather simple : the black cover with 'L' 'R' white markings is just a flimsy plastic/paper card bent and slipped around the mounting nut of the connector on the RTW1.
Popping it off, reveals another flimsy little PCB  (pic 1 below). The wires going to the heater tips are soldered on! Very un-German engineering. The actual tips are simply hanging above the PCB with the stiff wire carrying the heater current.

Probably the wires were touching or there was some gunk in the left heater wire (pic 2). Cleaned the whole thing with IPA, reflowed all the solder joints. Now as per the wiring diagram (pic 3) on the front-end connector X1,  I have equal resistance 3 ohm of the L/R heater wires (1,3) and (5,3).

Put it back together end-to-end (RTW1 -> mates to handle -> handle -> cable to Control Unit
At the 'station connector' in the wiring diagram pin 1-2 STILL shows 1kOhm. Very puzzling - it's supposed to be a straight wire through from X1 to the station connector. Unless I am missing some funny ground connection...

Plugged the WMRT into the control unit, and as expected from above diagnosis, despite the fondest hopes, the left tip STILL does not heat up (right tip goes to 300C fine.

Sorry for disappointing you but that heater is almost certainly dead so you will need another tip. Nothing to repair there, it is like a burned light bulb.

[sariniitb]

Not burnt out.

I was able to get it working by jumpering across pins 1 and 5 of the end connector X1 to which the two heating elements are soldered. Pic RTW1_1 above.
 Of course this means the two heating elements are running in parallel from the same current source, and pin 5 carrying current to the temperature sensor is carrying the wrong current, so the temperature sensing is a bit off.

But the bottom line is that now both left and right tweezer tips heat up - havn't been able to measure the temperature accurately : but its good enough to lift off a few components from a dense pcb I needed to disassemble.
Eventually will purchase a new tip.

I still don't understand the circuit control completely - why the reed switch is doing the NOT of what its supposed to do. Wants to keep the tips ON when it's in the holder with the magnet, and OFF when lifted. So for now, I popped off the magnet in the holder, and stick it on the WMRT when in use (it sticks by magnetic pull of the reed switch).

Just posting the final info here, in case someone finds it useful.

[mvcz]

I had similar issue with WR3M and WMRT tweezers:

The left tip doesn't heat up - only the right tip does.

In my case, the resistance of heating elements was OK. I tracked the issue back into the WR3M unit where blown fuses were found. See simplified circuit diagram of the power stage (the component names are fictional because there is no marking on the silk screen). Each of three channels have two independent sub-channels (left and right). The left sub-channels are primary and have 12V/24V capability. The right sub-channels are secondary and the 12V/24V capability is available on channel 1 only (high power channel for hot air gun HAP200 https://www.hackerspace-ffm.de/wiki/index.php?title=L%C3%B6terich&mobileaction=toggle_view_desktop#HAP200). The WR3M somehow detects correct voltage (based on resistance of the heating element???). The interesting thing is that there are no fuses in series with the 24V triacs. It looks like that the main reason is to protect in situation when both 12V and 24V triacs are turned on simultaneously. Anyway, the fuses F1, F2, F3 and F5 were blown for some reason (it is a shared equipment in a lab). Therefore, the WSP80 was running in each channel since it is 24V and the WMRT did not worked in CH1 and just right tip was working in CH2 and CH3. Replacing those fuses fixed the problem. The fuses are in SMD 2410 package directly soldered on PCB and there is no access when PCB is mounted in the chassis.

It is an old topic but it can be helpful for someone with the same problem ...

[costas]

WMRT schematic !

[psvabenik]

Hi,
has anyone experience with different versions of the WMRT (and WMRP) soldering irons? I am about to buy one to be paired with WT2M station. Unfortunately I find different types of irons, some are 12V, some are 24V. I am confused from Wellers datasheets, which statest WT2M outputs 24V.
Is all the irons both 12V and 24V compatible? Maybe it is just bad marketing, where the WMRT has two separate heaters, each working on 12V (so they sometimes call it "24V"). Or is is completely different iron for different market?
I do not have one available, at least I could measure the resistance of the heater (so I can calculate 2x40W power).
I was also looking into the connector pinout, but could not find pinout for WT2M. Anyway some seems to have both options available, 12V and 24V on same pins. Can someone take me out of the confusion? Thanks a lot.

[mahi]

psvabenik: The Weller WMRT and WMRP are both 12V tools. There has been a lot of confusion about the "24V" marked WMRT tweezers, but general consensus is that this is a mistake/misprint on the early hand pieces. None of the WMRT or WMRP will work on 24V-only stations like the WT1, WD1, WR2, WSD80,... The Weller WT2M on the other hand supports both 12V and 24V tools.

Weller makes a total mess of releasing seemingly similar or related stations, but that do not support all tools. Always consult a compatibility matrix before buying Weller equipment: WT station compatibility matrix.

[psvabenik]

Thanks. Yes, I have seen the compatibility matrix, but it did not make things any more clear.
I also sent two questions directly to Weller, but no response.

However local distributor was able to reach back to me and offered me instead of WMRT tweezers (not being produced anymore) replacement WTMT. Seems very similar, but with different internal connector and with different set of tips RTWMS group. These seems to work also with WXMTS tweezers, which are for WX stations. At least some unification is being done.

[eliocor]

to your knowledge, is the "obsolete" WD2M base compatible with the WMRT/WMRP irons/tips?

[PlainName]

I am using WMRT tweezers with a WD2M base.

[alibenpeng]

I realize this thread is dead, so I started a new one:

https://www.eevblog.com/forum/reviews/weller-wx-compatible-diy-soldering-station-project/