If you sell PCBs on Tindie, you’ve perhaps designed a board to be hand built, then eventually set it up as a PCBA for assembly elsewhere when the volume and maturity justifies it. I went through this process myself with one of my products. Admittedly, there was a part where I was applying solder paste for assembly which could have been done in a neater and less wasteful manner.
One solution is to use a solder stencil, which in my experience comes with its own set of challenges – including the need to actually design and make. The second solution is to use a dispensing setup that can help you more accurately dispense globs of solder paste than with a manual syringe. Such a device comes with its own set of challenges, often including the need for compressed air. The e.Dispenser from Dan M does things a little differently by precisely displacing solder paste with a servo-driven linear actuator.
I got my hands on one of these units to try out and I’ve been pretty impressed, but read on to see my thoughts on how the device works!
e.Dispenser Initial Impressions
The system sells for a list price of $149.00 USD, including enough accessories (sans actual solder paste) to get you going. There are also a number of additional options available, including a foot-pedal and on-dispenser device trigger.
The device is made in, and ships from, Mexico. As an American buyer, my first hesitation was that there might be some import duties and/or hassle, however, I’m happy to report that in my case getting it was no trouble whatsoever. It simply showed up at my house in Florida via UPS, 11 days after placing the order. The item was very well packaged in custom-cut foam, which could double as storage apparatus if you’re careful when opening it up.
The device itself was well-made, with a laser-cut housing, and an LCD character display that will be familiar to anyone who has browsed an Arduino projects site for even a few minutes. The reversible USB-C power input was a nice feature, and there’s a 3.5mm jack for accessory connection. Finally, the driving stepper motor is keyed in such a way that it can’t be reversed when plugging it into the controller.
Dispensing Solder Paste
The unit is easy enough to plug in and turn on, and features a menu system driven by two encoders. The left encoder selects the menu option, while the right actually modifies it. When you press the trigger button, settings are saved to the profile you’re working with. When either is pushed in (at any time) the left pushes the piston forward, while the right pulls it back.
To insert solder paste, a coupler is included that lets you push it out of your old tube into the new tube quite elegantly. From there, the machine’s piston can push it out blob-by-blob. This is where things got a little hairy, due to:
- I had no idea of the scale needed to push out a component’s worth of paste
- My roughly year-old paste, stored in a hot garage wasn’t doing me any favors.
Quite a bit of excess initially dripped out after dispensing, and didn’t get the right amount on my pads to begin with. I contacted Dan M. about my predicament.
Long story short: I was dispensing way too much paste, and, according to Dan, depending on the type of paste you’re using, tiny air bubbles can cause a sort of internal spring effect. He gave me a few suggestions on things to try, and after a bit of tinkering, it worked much better. Also, it might seem obvious to many readers, but pressing down on the board before triggering the paste seems to work better than triggering it mid-air and attempting to dip paste onto the pads.
Dan’s support was prompt and excellent, offering me input and settings to try. That being said, I should have perused the documentation on his website more carefully, especially the page about dot dispensing to get a better sense of scale. I eventually made several prototype boards using the dispenser, which turned out much better than my syringe-only attempts.
After a bit of adjustment, oozing improved significantly
In my testing, I still get some paste extrusion after finishing a job using the dot dispensing mode. If/when I continue to tweak things (and/or buy new solder paste) I suspect this will improve. This adjustability is an excellent feature of this device, and up to 5 setups can be saved to allow you to work with different paste setups and/or scenarios.
External Trigger
As mentioned earlier, there’s a 3.5mm jack into which you can plug a foot pedal, or a trigger that slips over the dispenser tube. Both worked as designed, and I primarily tested the pedal. It’s also easy enough to start the device via the button on the main controller, though using the foot pedal felt natural and helpful once I started using it.
Vacuum Pickup
In addition to outputting solder paste, this device is also capable of picking up components and small ICs using vacuum. As there’s no air compressor involved, the way it does this is by pushing the piston into position, then pulling back to create a vacuum when triggered. I tested this with a few addressable LEDs, and even the Ooberlights circuit board seen above, and it works well.
Testing out e.Dispenser's vacuum functionality @tindie https://t.co/STo3oiK2CQ pic.twitter.com/2eK4GT5NRp
— Jeremy Cook 🤖 (@JeremySCook) October 15, 2021
Human(?) Ergonomics
The fact that it doesn’t need an air compressor is probably the #1 feature that will draw people to this device. The tradeoff here is that the driving stepper motor is on top of the dispensing syringe, which means that the center of mass is well offset from its geometric center. This wasn’t a problem for the limited assembly work that I’ve done with it so far, and I am thrilled to have this as a part of my workbench for prototyping. At the same time, this would likely be problematic if put into constant use over a full production shift.
A fascinating possibility for this device is that it seems to be just begging for people to use it in an automated manner per its external trigger capability. Dan has a guide to setting it up on a 3D printer here, but who knows what other people will (and have) come up with? Notably, the device can dispense other types of paste, opening up possibilities further.
The Verdict
This dispenser is well built and well supported, and it fills the niche between “what am I doing with this squeezy syringe thing” and full offshore production. There’s also the exciting possibility of repurposing a 3D-printer or other robotics assembly to work with this device. If you fall in the category of avid SMD prototyper, then in my humble opinion, it’s absolutely worthy of consideration!
Disclosure
Dan M provided the product at a discounted rate to me for this review. I’ve tried to be fair, open and honest in my appraisal of it, but if you’d like a second opinion (or forty-second opinions), you can check out the device’s customer reviews.
