After learning about all of the features and capabilities of the WXsmart system, this chapter will explore just how I felt about using it over the last two months under many typical usage scenarios. In full disclosure, I am not IPC certified (although one day I would like to do) but I do quite a bit of soldering as part of my work and hobby for repair and troubleshooting. Many times, I tackle soldering jobs which some of my colleagues would consider a challenge and have become comfortable with SMD soldering. Throughout my soldering career, I’ve used everything from simple no-brand mains soldering irons through to mid-range systems from Chinese vendors such as Atten and high-end soldering stations from established brands including Weller, Ersa, JBC, Metcal and Hakko. I can definitely say that my technique has evolved over time and the choice of a particular tool can come down to the work being done and a bit of personal preference depending on prior experience or technique. Thus, the past two months have also served as a good break-in period for me to learn how the WXsmart system behaves and handles.
Table of Contents
Setting Up
Getting started on a day’s soldering is very easy – power up the station and turn on the channels and watch them roar to life!
If soldering irons could race, the WXsmart’s WXMPS MS/WXUPS MS handpieces with their corresponding tips would probably win most of the time with heat-up times ranging from 3 to 10 seconds approximately. This is so fast that it has changed my philosophy about sleeping soldering irons – in the past, I would set long sleep times to avoid the potential for sleep occurring during a soldering job as the warm-up wait would be annoying and there was always the potential that a joint could be poorly made if the iron was not quite up to temperature. Now, with such speedy irons and a ring-light indicator of temperature being within process windows, I set aggressive sleep times as short as two minutes. This is because the issues are mostly avoided – warm-up is fast, process window indications are obvious and sleep times are clearly shown on the LCD with motion sensing waking up the iron reliably. It’s also nice that they have a very flexible silicone cable and metal bodies for a premium feel.
For soldering, it is worthwhile to wake up the WCU and initiate a calibration especially for new tips. This procedure is simple and surprisingly fast, taking under 10 seconds most of the time. The system gives a clear indication of the calibration status, especially if it fails due to offsets being outside of adjustment range.
It is nice that Weller’s safety rests give a choice of brass wool or sponge cleaning. I’ve personally used a sponge most of the time, but have been transitioning to the use of brass wool, so having both is a nice touch.
Attaching handpieces to the station is a bit of a process, especially for air-based tools. The connector’s locking collar first needs to be lined up with its arrows to be able to insert the plug fully into the station, then rotated to lock. This can sometimes be tricky as the collar freely rotates and may not be in the correct position at first. For an air tool, the end of the silicone rubber hose needs to be pushed over the port on the WXair. This can also be a bit tight in the case of the vacuum port, requiring a bit of manipulation (sometimes with fingernails) to form a good air-tight seal which might degrade the end of the hose (requiring it to be trimmed occasionally). A nice connector wouldn’t go astray, I would think.
Through-Hole Soldering
The obvious place to begin is with through-hole technology, as this is perhaps the old baseline for hobbyists. I had proposed in my application to test this by constructing some commercially available Chinese electronic kits.
Police Flasher Kit
The first was a police flasher kit which was easily achieved using RTMS-series tips.
For this, I was split between the use of the conical and chisel-shaped tips. I have always been a conical tip user from the day I started to learn how to solder, even though many introductory guides frequently recommend a chisel tip. Having tried both on this board, I can understand some of the heat transfer benefits that the flat-tip of the chisel has, but I also experienced the annoyance of needing to rotate the iron as the tip is not rotationally symmetrical. With a conical, a similar level of heat transfer can be achieved through careful angling and wetting of the tip, so I am not completely sold on the chisel (but it is available for those who prefer it).
This kit was built with Sn100c solder with bright and shiny joints, even though it is lead free. The Weller Erem 622N side-cutters were excellently sharp, cutting through the leads with ease (and sometimes, through the joints too when I’m not being careful). I even managed to stuff up the orientation of the LED in the bottom right. Quickly desoldering it using braid and resoldering bought it back to life without damaging the LED.
For such a simple kit, it is no surprise that it works just fine. Through this experience, I observed that all of the RTMS and RTPS tips seem to have a bit of a “tilt” to them and are not exactly perfectly straight. While that doesn’t stop the tip from working, it does affect the handling slightly. Changing the tips is very easy as it is just a plug and unplug operation and having the rubber grips integrated with the tips is a nice touch, just in case they ever get sticky, as they can easily be replaced.
One downside of this is that the grip design has no flange that stops a finger from extending beyond the end of the grip. This is potentially an issue if someone were to hot-swap a tip, which is something Weller does not endorse in their manuals but will probably happen in the field. Some other manufacturers provide a silicone pad to insulate the user – in this case, as long as nobody slips, there is no issue. But if the user slips off the grip while pulling a hot tip off the iron, that could result in burns. Likewise, the tip stand will have the (potentially warm) iron tip facing upward where it could be inadvertently brushed by a user’s hand as they graze for their next tip, so perhaps just let it cool first!
7-Segment LED Clock Kit
The second challenge was a seven segment LED clock kit. Again, the RTMS tips handled this with aplomb with no complaints at all.
To add to the challenge this time, this board was soldered with all lead-free solders I had on-hand. This meant that some joints were made using SAC305, Sn100C, 99C and 95A alloys. This is particularly pertinent as lead-free solders behave differently, may require better temperature control/higher temperatures and have slightly different finishes with regards to good joints.
In the end, I was satisfied with the quality of the joints regardless of alloys used. The temperature maintenance of the RTMS tips was superb – I didn’t have to increase the temperature above the 320/350°C that had been set, nor did I ever feel like I was waiting for the iron to recover its temperature. Even with the challenging 95A alloy, which was the one I had first obtained over a decade ago and caused me to turn my back on lead-free, the soldering experience was quite acceptable even though the solder did feel a bit “thicker” as it didn’t flow quite as well. I think this is conclusive proof that my early difficulties with lead-free were a mixture of alloy and poor soldering iron temperatures. With the WXsmart, working with lead-free is very much like working with the ordinary 60/40 on my other station.
Surface-Mount Soldering
Of course, through-hole technology is now considered rather ancient and surface mount technology is mainstream. As a result, I decided to also construct a few SMD practice kits to see how well it handled. Keep in mind that these were my first SMD attempts with the station, so some of the results are down to the operator-in-training (especially providing too much solder).
SMD Practice Kit 1
The first SMD practice kit comprises an array of 0805, 0603, 1206, SOT-23 components with a single SOP14 integrated circuit. This straightforward kit was assembled using a mixture of RTMS and RTPS conical tips.
One thing to notice is that the tip to grip distance of the RTPS and RTMS tips are quite short, at around 30mm and 45mm respectively. The RTUS tips aren’t much longer at 50mm, which is all positive when it comes to controllability of the tip. The RTPS tips are finer with a smaller wetted area which minimises the chance for solder bridging and is suitable for working on individual IC pins for example.
The kit was constructed using a mixture of techniques. I first tinned one pad, then used the tweezers to hold the component as the solder was reflowed and then soldered the other pad. Once everything was completed, I covered the board in flux and gave it a blast with the WXHAP 200 hot air pencil to “straighten up” the components (hopefully without blowing them off). I was not entirely successful, in part due to providing too much solder on some pads allowing the components to “flap” in the hot-air breeze. I did discover that controlling the hot air speed is a bit tricky with the one-button control on the unit and the fact that the temperature and airflow speed screens took a few swipes to get between.
Nevertheless, the solid LED gives me an indication that my soldering was successful … although if you expected more, then prepare to be disappointed as the transistors and the IC have nothing to do with the circuit whatsoever!
SMD Practice Kit 2
One kit is nice, but two is better! This one is a bit more lively and is one I have also previously completed using another station but with leaded solder.
Constructing this one was quite similar, however, I had to replace R49 with a smaller resistor (680k rather than the original 2M) or else the 555 just refused to oscillate. I suspect there maybe some leakage due to flux or perhaps ESD which is causing this problem.
Nevertheless, when constructing this kit, I was pleasantly surprised by the temperature regulation of the hot air pencil. I am so used to burning LEDs when trying to use a hot air gun on them – the plastic encapsulation would just char and bubble. But using the WXHAP 200 and the same “gentle” 320°C setting, I didn’t see the same issue and being quick with my hands and tweezers meant that I could realign the LEDs with care using hot air without a single casualty!
On a positive note, the rubberised coating on the tweezers is not only ESD safe, it also keeps the fingers away from the heat! Thus, it would appear my previous failures to do LEDs with hot air may be down to poor temperature regulation. Once again, the WXsmart is showing me how it’s done! It’s also a nice touch to have everything integrated into the one station, as some of the best soldering stations out there don’t have any air capabilities.
SMD Pico-Soldering: Challenge Accepted!
I wasn’t entirely happy with the kits above since I’ve done them before (with lead-based solder) and I knew I would most likely succeed. A true challenge is to attempt something I haven’t done before! I had seen some SMD Challenge PCBs out there that challenge hobbyists to construct a circuit with smaller components – 0201 and 01005 specifically.
While the kits exist, they seem to be often out of stock and the costs of buying such a kit and getting it shipped to me is exorbitant. I actually worked out it would be cheaper for me to design one of my own and buy a lot of extra parts and still be ahead!
What I’m presenting is a little out of order, as I actually attempted this first because it was the first to arrive due to the wonders of international logistics. Who would have thought – a PCB I hastily designed (complete with an error) and a cart full of parts would arrive before pre-packaged kits!
Is it any surprise that I was able to complete this too, and all without a magnifier on the bench. I did use the Andonstar digital microscope to check the result and did lose about half of the 01005 parts because I took my eye off them for a bit and couldn’t find them again!
The tips of the Weller Erem E5CSA could not be faulted though. They were, even after being dirtied by flux and residue, closing in perfect alignment and carried the 01005 parts without flinging them across the room.
There is the obligatory bodge wire on the back as well.
The board is basically the same I concept to the previous … just with different sizes of components and footprints (including the KiCad hand-soldering footprints which I didn’t find any better).
It’s important to note that I didn’t just do this one – I did it three times, trying four different alloys.
Close-ups of the NE555 and CD4017-equivalent ICs.
Progressively increasing resistor sizes – 01005, 0201, 0402, 0603, 0805, 1206.
Progressively increasing LED sizes – 0402, 0603, 0805, 1206.
I think it’s clear that there should be no doubt about the WXsmart’s SMD pico-soldering credentials, when even in my (uncertified) hands, I am able to construct circuits including 01005 parts - although for comfort, I still prefer to stick to 0402 or larger.
Heavy-Duty/Mixed Soldering
Let’s change speeds and focus on heavy-duty soldering applications where the WXUPS MS is needed.
RF Injection/Isolation Transformer
This board is of my own make and is designed to allow for a Coilcraft RF/isolation transformer to be connected to a BNC input and output with configurable protections. In this case, I’ve replaced DC-blocking capacitors with jumper resistors.
While most of the board is SMD which can be done with the WXMPS MS, the connector shells are big heat sinks and are best done with the WXUPS MS.
Using the WXUPS MS with the RTUS 016 C MS tip made this challenge a walk in the park. The larger contact area, thermal mass and responsiveness of the iron meant very little dwell time was necessary for the joint to reach the required temperature before applying solder.
Kycon KPPX-4P Adapter
For a troubleshooting exercise, I needed to build an adapter that would accept a KPPX-4P plug and connect it to a DC electronic load, passing about 6A of current. This necessitated thick wires and soldering directly to a plug which I salvaged from a PCB using the WXDV 120 vacuum desoldering tool.
The speed of the WXUPS MS meant that the wires and pins could be heated up effectively and the connections made without melting the connector or insulation. This was also done with lead-free alloys, for the additional challenge.
10.16mm Heavy Duty Terminal Blocks
The final exhibit was to solder down some 10.16mm terminal blocks to a MOSFET test PCB I had developed for the former Aim-TTi QPX750SP 50A Power Supply RoadTest. This was a two-layer 2oz copper board intended to carry over 50A.
This was no challenge for the WXUPS MS, although a bit of dwell was necessary to let the heat travel through the board as it’s a massive heatsink! The lead-free joints were well formed. I even tinned some 6mm2 wire with ordinary PVC insulation and managed to do it without completely destroying the insulation.
Overall, I can say that the WXUPS MS is quite competent at heavy duty soldering tasks and the active tip technology means that the irons are very responsive to load. I’ve never seen the screen show any significant deviation in tip temperature so it would seem the feedback loop is quite tight.
Vacuum Desoldering
Enough of assembling things – what about disassembly? This is where the WXDV 120 vertical desoldering tool and the WXHAP 200 hot air pencil can be used.
While the WXHAP 200 has previously been used to straighten SMD components, it can also be used to heat them up to be plucked right off the board. This is no issue for smaller SMD components, but because of the size of the nozzle and the power rating of the pencil, it probably won’t be suited for large chips with many pins. The body of the tool does feel a bit light and hollow as it’s made of plastic, but it does the job.
The WXDV 120, however, was the big surprise to me.
I raided my junk box for things to pull apart and the WXDV 120 practically managed to desolder everything that was through-hole. Being a vertical tool, I was expecting to see clogs as solder might get stuck in the tube being sucked against gravity, but I was pleasantly surprised to see no major clogs formed with the vacuumed solder resting at the back of the filter. This was desoldering old parts with mixed solder alloys, some of which is very crusty – it just did the job and cleaning was made especially easy with the brass pipe cleaner. I didn’t have to resort to anything more drastic than that.
The tips for the WXDV 120 come in bullet and “flat” tip shapes. I’ve often used the bullet sort, but it would seem the flat tips do a better job of heat transfer and of clearing plated through-holes (even though that’s never going to be 100% when there’s a component leg in the way). The downside is the greater chance of marring the surface of the pad, but with more practice, I suppose I could use it even more effectively.
The key downside is the WXDV 120 gets hot when in use. This is somewhat unavoidable, as there is a hot tip through which the solder and air is getting sucked through, thus the heat goes up into the filter located on the rear of the handle. It would seem the WXDP 120 horizontal version avoids this, with the filter outside the handpiece. It also feels a bit hollow as it is also made of plastic.
Conclusion
In my two months of using the Weller WXsmart, I’d have to say that it is a very competent soldering, rework and desoldering station without any major faults.
The WXMPS MS handpiece is very versatile, working magic with through-hole and surface-mount components alike. I was able to construct a number of electronic kits including my own SMD challenge which had components as small as 01005 with no problems. The WXUPS MS handpiece is adept at high-power soldering applications, soldering large terminal blocks to 2oz copper PCBs, tinning 6mm2 wire, soldering BNC connector shells and plastic Kycon KPPX-4C connectors with no trouble at all. Both handpieces feel premium with their metallic bodies, flexible burn-proof silicone wire and feature very fast heat-up. It’s so fast that it’s usually ready by the time I’ve picked it up and positioned it on the workpiece. Rarely am I ever waiting for the iron – I don’t think about waiting for it to heat up and I don’t think about waiting for it to recover temperature between joints. I can just get on with the job of soldering – and that’s a great feeling. The LED light ring is also an excellent addition, as it gives me instant feedback as to whether the iron is ready. Calibration with the WCU is fast and straightforward, adding additional reassurance of correct soldering temperature. The tips all have short tip-to-grip distances of 30mm, 45mm and 50mm for RTPS, RTMS and RTUS tips respectively which provide better control.
The WXHAP 200 hot air pencil did a good job of reworking components, straightening SMD parts including LEDs without cooking them and allowing for other parts to be plucked off boards. While it’s not as “big” as a mains powered hot air gun, it has a precision that the other usually lacks. The WXDV 120 was a surprisingly competent performer, desoldering through-hole components with little fuss and without clogging up. It is easy to clean and the nozzles are available with a rounded and flat profile, the latter improving heat transfer and sealing to pull just a bit more solder out of those annoying plated-through holes.
The main downsides include the potential safety issue if someone does not follow the manual, changes a tip when hot and manages to slip. Similarly, a hot tip in the tip stand could be easily grazed when selecting another tip. The tips themselves all seem to have a slight tilt, so they aren’t exactly straight when rolling them around on a desk which can make for a bit of awkwardness in handling. The main power connections also take a bit of care to align arrows before plugging in and then rotating the locking collar which may sometimes necessitate two hands. The hot air tools do feel a bit light and hollow due to their plastic construction and their air hoses can be a bit finnicky to attach and detach. Not being able to have both attached at the same time is a bit of a potential disadvantage as it necessitates frequent switching depending on use case. Controlling the hot air tool temperature and speed necessitates moving back to the home screen, to the benchtop control screen and then the WXair control screen which is a few more steps than would be expected. The vertical desoldering iron can, due to its design, get rather warm in use.
While the list of gripes may seem a bit long, they are mostly minor and they shouldn’t overshadow the fact that the WXsmart does exactly what a good tool should do – get out of your way and let you focus on the work. I’ve never enjoyed soldering quite as much as I have when using the WXsmart and it’s also completely erased my biases against lead-free solder by showing me what proper temperature regulation can achieve.
However, in full disclosure, my use of the WXsmart was not without mishap as one tip managed to overheat and fail on initial start-up and another displayed some intermittent behaviour during the review which may have been caused by a handpiece contact issue. The items have been returned to Weller for analysis in exchange for replacements and to Weller’s credit, their support has been very accommodating.
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This blog is part of the Weller WXsmart Connected Hand Soldering Platform RoadTest Review.
