Weeny solder bot (LinuxCNC on A4 paper size)
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- Опубліковано 30 вер 2024
- Could this be the world's smallest LinuxCNC build? Let me know if there's a smaller one out there.
Video about weenyPRU: • Palm-top LinuxCNC (wee...
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I love a good Rube Goldberg machine as much as the next guy, but wouldn't dip soldering these boards be the simplest solution?
Being the "simplest solution" is not all there is to it. Depends what you're interested in and enjoy spending your time on. I have no interest whatsoever in designing, building, owning or using a solder bath and I'm getting tired of seeing dozens of comments assuming I didn't know about them just because I never mentioned it in the video. It's also unlikely I could have put one together for the $81 I spent on this. I like designing and building LinuxCNC machines and this was a fun challenge to make something really small, and validate the PRU I spent a couple months designing and programming. Feel free to approach your own projects however you see fit.
@@iforce2d I hope your day gets better.
Grow up
@@JohnJones-oy3md
@@brycecrichfield1934 What do you mean by that?
@@JohnJones-oy3md
Purely from a soldering perspective i would: Add in a tip cleaning method, move the solder feed so it somes in at ~45 degrees so it pushing into the 90deg corner created by the pin and soldering iron. When the iron is moved onto the pin do a mini solder, just to wet the iron and pin, this will immensly help with getting the heat into the pin and pad and when timed right will wick down through the board, then do a final squirt to bring you up to the correct solder amount. drag vertically off each pin to help prevent the bridging.
Fully agreed. Some great tips here
I agree with everything here from my own experience soldering, but also would like to add that almost all those solder joints have too much solder imo. I could be wrong.
Vertical dragging is what I immediately thought, shouldn't be hard to implement by retracting the soldering iron + pushing the board against the tip. Also, using a thinner soldering wire could help controlling the amount of solder feeded into the pin...
@@Karshilistics You're 100% correct. He's using about 50% too much solder, which is causing the globby joints & the bridges as the excess builds up on the tip of the iron.
the other thing which is a bit more complex would be to have an insulated conductive ring at the end of the solder extruder then measure conductivity through the solder and you would be able to retract and determine a zero point for the solder after each joint, and actually control how much is extruded into each joint without the assumption.
Try adjusting the movement vertical before horizontal instead of both at once and that may stop that bridging.
To do that he would have to move the bottom board at the same time as he raises the soldering iron, but yes, same thought I had.
@@AlJay0032 It would add a bit more complexity to the motion, but doable albeit a bit steppy in motion.
Came here to say this 🙂
I'd bet more flux would help. Tends to keep things round and shiny. Maybe you can just get a solder reel that has more in it.
Or a wet sponge function after so many pins.
An engineer is somebody who will spend 5 years building a machine to avoid doing 5 minutes of manual labour.
Yet the machine has potential to survive me, you, 3 or 4 of your descendants generations and keep being unbeatable at whatever many million times it accurately repeated it's gracious routine, completing for the many billionth times what one designed and built while onlookers saw him spending dollars to save pennies.
i realize my exponential emphasis on random number.. it quickly jumps to billions, making sure the salad sells 'à la Musk' a french would surely be yelling to inspire a bit of ... oh damn, that was some extra strenght H20 i subjected myself to. Geeeszz, beezz and louise. Thel-ma what ya stunk!
These sorts of machines are useful for two purposes: 1) soldering prototypes with tiny components too small to reliably do by hand, 2) soldering LOTS of boards if you're running a home fab to sell some kind of electronics.
I've been watching your videos for 9 years and haven't ever commented, just wanted to say I'm constantly amazed by what you manage to accomplish. Do you work on all these things after your day job? Thanks for all the great videos over the years
I've been watching for quite a few years. But I've still been wondering the same thing, how do you manage work time and hobby time
@@BuzZ.agree. I built the cheep ass quadcopter long ago. My favorite UA-camr.
I'm guessing he is retired. Not sure though
@@rowannadon7668 I don't know if he is retired but for sure he is single!
This video/project was such a wonderful treat. Thank you for taking use along your journey!
you do know that when you export the gerber files on easyEDA, there is a drill hole file that you can use for knowing the hole positions. No need to select them one at a time like that.
Yes, I do know that. But I would still need to define the order somehow, and which ones I actually want to solder, and tag them as being ground/signal, and move them so that the first pin is at 0,0 position. DXF is more convenient for this. In QCad you can select elements by type and size, eg. circle of max radius 2, so you don't even need to manually select them in the DXF anyway.
@@iforce2d okay. Nice progress by the way, loving the videos. I always learn something new from you.
That "clicky thing" on the back of the extruder anchors PTFE tubing. A larger size PTFE tubing than what you are using that holds 1.75 ID tube for 3D printer filament. It might be a good idea to get a short piece of that tube to make solder wire a smooth transition into the extruder. It looks like you may be running the extruder in reverse because that is usually the exit path of a 3D printer extruder. Fantastic job though. Love what you have made here.
Have you considered syringe dispensing solder flux and low temp solder paste. Two syringe screw dispensers. You can get much better flow control, less material and better adhesion with flux. Just a thought.
You can turn a raspberry pi on and off safely by grounding one of the GPIO pins (requires adding a line dtoverlay=gpio-shutdown to /boot/config.txt). I think it is GPIO 3 on RPi 3 but not sure, you can google it. Note that if you disconnect the power after pi is shut down using this method, when you reconnect power pi will turn on.
Not sure if you though about it already, but adding a PTC heater module to bottom of the bed to pre-heat the board and the pins to about 120°C
I feel like that would make it quicker, with better joints and would produce nicer joints since it wouldn't burn all of the flux out of the solder (possibly also more reliable too)
Prob the easiest thing you can do to improve it dramatically
Maybe also shield the machine from drafts. The pins on the edges might be cooler so dont wet properly.
You may get better results if you add a routine to lightly tin the iron before it makes contact with the pins. I often see this in soldering robots. It helps to preheat the pin before the final solder is added, and will give you higher quality joints that are less likely to bridge.
I tried that but the solder just flows down under the rear of the iron and does nothing useful.
Perhaps add a conductivity check from the solder to the headed pin through the iron. I think G-code has a way to do a "trigger action" instead of the down/wait/up and have ground and normal actions.
A conductivity check could also check the resistivity and estimate the temperature. An ideal one would have extra pins which checked to ensure they were NOT touching anything else.
But very cool.
I LOVE the idea of a conductivity check. Once a connection is detected between the iron and the aluminum solder tube, you then start measuring how much solder is dispensed. Brilliant!
Wow super cool. If you used a pine64 soldering iron you could get the status from it
Really cool! Improvement... maybe add some sort of fluxing before soldering? Try a different soldering pen/point? Amazed how you made this!
A tricky task to automate, very impressive. Well done.
I may be a bit late to comment as others might have already suggested this but you will need to add flux for this type of soldering process.
I would suggest going with some water soluble flux + solder with water soluble flux inside(for example Kester) manually applied before soldering step then you will need an extra cleaning step which involves distilled watter and then drying with compressed air.
Flux can also be integrated on your robot, to dispense it automatically along the pads in straight lines.
And some form of hot air blown over the PCB will help preheat everything and will help with those GND pads.
I think he's using some flux-core solder -- board gets pretty shiny with what is likely flux.
@@MatthewWalker0that is not enough.
@@voltlogFlux core solder is enough in most applications. Many commercial solutions don’t use additional flux. Cost to benefit. Also, compressed air is an opportunity for ESD damage.
That is really impressive! Hey, for powering off with a graceful shutdown, could that not be done with a switch wired to a free pin on the pi, which just starts a script for a graceful shutdown? Hopefully that would keep the SSDs happy 😃
Hot off the press -- the Pi 5 now has a (gasp!) power button!
Two things that I think would help a lot. The first one's easy. Flux the board before you start soldering. That will help keep the solder where you want it and make much better solder balls. The second one would be a little more difficult but if you can figure out a way to clean the tip of the iron every few joints that would help reduce contaminants in the solder joints and make for cleaner soldering as well. Also if you could bring the soldering iron straight up as quickly as possible at the end of the soldering action then move it to the next location it would probably help reduce bridging as well.
Yep, yep, yep.
Flux could be added just before soldering with an atomising spray or foaming hand soap dispenser or a simple peristaltic pump into a small brush that visits the next joint just before soldering the current joint.
@@KallePihlajasaari or just brush it on before the process starts. It would literally take 5 seconds.
Exactly. When it comes to soldering, too much flux is never enough, and doubly so when it's a machine doing the soldering. And the contact must cease before all the flux burns up.
you shouldn't need extra flux when using flux core solder
@@Phil-tl6ln ehh. It depends. Flux core solder is good but added flux definitely makes things better. This is especially true in less than ideal circumstances like where the iron isn't perfectly aligned or when the tip isn't getting cleaned frequently enough.
The design of your 3-axis PCB-Soldering-Robot is just sinply beautiful.
Do you have some CAD-files you could share with me? I would love to build another instance of your nachine for me, myself and i (and really only this one and only one, as a gift to myself, because i love these technical advanced and very well build gadgets with a real and also very well working purpose for them existing in my everyday life.
This is definitely the perfect project for me, this time of the year. I'm fully prepared to create something really amazing from your CAD-files this winter...
Sooo clever. You're fast becoming one of my favorite UA-camrs! A decent quality flux applied by syringe first should make a big difference for not much effort if you haven't already tried that. Awesome project, thanks for sharing.
Curious question, why go through this trouble when you can dip solder? Great machine btw.
Yeah, you can get a solder pot large enough to solder this board for $50. It will take about 10s to dip each board.
Cool project still, and could be useful if you end up needing SMD parts on the bottom or something.
Cant wait for the solder benchy.
amazing project - i could only dream of such level of expertise! Little hint for "Linux stuff" perhaps: just wire another switch to a GPIO of the Pi, and enable "gpio-shutdown" in config.txt... and for starting linux-cnc, a basic systemd-service should do the trick...
Can you not export a drill file? Really interesting toy. I think I "need this". 🙂 Not all extruders drive both sides. Is your extruder upside down? The quick coupler usually holds the PTFE tube in place.
Love this project!! When manual soldering, I use another PCB for pins alignment. Since the boards are the same size, you can also use various clamping methods to keep alignment perfect. A bare PCB could also be used in the machine. I love using LinuxCNC. The code interpretation is excellent. I build a full pick and place using LinuxCNC with reusable subroutines in gcode which is so convenient: ua-cam.com/video/CVlad7l9HvI/v-deo.html The video was made 12 years ago, so the editing was kind of bad. The "o" codes are brilliant! I used them exactly that way you did.
I'm using the second PCB stacked method for my bed-of-nails (for test and flashing firmware), but it would not help for soldering on the female headers. A bigger problem is that it's almost impossible to keep 112 pins aligned well enough to place a board onto, when the holes are that large. The first holes jig I showed (the wooden one) had only slightly larger holes than the aluminium one and it was so frustrating I only ever used it once. The difference between using a 1.2mm drill and 1mm drill was quite significant.
2 thoughts: Could the soldering iron be mounted on a sprung caddy so it is compliant to the PCB? I saw some variability in how much the PCB gets pressed down. And not every hole is identical - some have square footprints, some round, maybe adjust the timings slightly for preheating?
Flux, different retraction speed and angle (even a slow helix away!) Looks great though - did you consider a solder bath?
Wow! I needed headers on my JLC boards too, but I just placed SMD ones and had it done as part of the build. They will hand-solder TH pins too of course but I wanted to use the economical PCB-A option :) Hi again from Nelson
a quick suggestion here, try using flux on the board before soldering, there are some fluxes that you can spray on or just put it with a brush, it will make a world of difference, trust me
It looks like the main issue is that the solder's surface tension pulls an unpredictable volume of solder in. You could abate this with finer solder wire perhaps, but I'd also try it at a higher temperature. I usually do through hole soldering at 370C personally.
How I would approach this is a PTFE tube that goes vertically down over the pin and solder pad, then a measured shot of powdered solder gets fed from a screw conveyor and falls down the tube onto the pad. As long as the acceleration of the machine isn't too fast, the powdered solder would stay put and then the entire thing could be popped into a toaster oven.
Why are you making it so difficult? Just flood solder the whole thing at once, or even wave form soldering is easier.....
From an agricultural-looking vice and rusty hacksaw, through "DIY CNC", a vast array of projects, balloons, carbon-fibre, anything that navigates itself, anything that flies, anything that navigates itself and flies, a mouth-watering selection of electronic and coding examples, "Another DIY CNC", to this elegant baby... is there no end to it?!
That's an evolution path that Charles Darwin would be proud of. More Please, Thankyou. 😜 👍
Why don't you add a button to turn it off, rather than sshing to it? No need for wifi. .. or use a sequence or combination of existing buttons/jogs/clicks to tell it to shut down.
why ssh to poweroff? why not just make a software power button, using like one spare gpio pin, and when it's triggered, you simply trigger the shutdown?
I've got a feeling that for many of these Cartesian movement platforms that don't require high stiffness, it's probably easier to just modify a cheap/broken existing 3d printer/laser cutter than it is to design and build something entirely new.
Plus, you could probably abuse the bed heater and hot-end heater circuitry for something too.
some ideas:
- make the vertical move after the joint go higher before moving sideways, to avoid pulling the solder blob onto the neighboring pad
- instead of just moving down onto the joint, you could also shove the iron into the joint horizontally by say, half a mm, to make sure the tip is pushed up against both the board and the pin to ensure the solder adheres to both. if you're concerned about guillotining the pins off, you could put some spring between the z actuator and the tool. have the spring preloaded against a rigid connection, so that under normal circumstances it's rigid, but once you're pushing against something the spring can give. that way you can add a small amount of overtravel to guarantee good contact, while limiting the excessive forces that would otherwise generate. since the "z" axis is diagonal, this might also help protect against y-axis overtravel as well.
- maybe break the solder dispensing into 2 phases, one small pre-extrusion to help wet out the surfaces and help with heat transfer, and then the main push to actually solder the joint. then you have the ratio of the 2 extrusions, and the 2 different dwell times, so more variables to manage!
- maybe start out by just brushing on some flux before loading the board? or have some sort of rotating tip cleaning tool to park the soldering head on periodically
- you could pass the solder through an extra pair of rollers with an optical encoder to detect when the extruder is slipping. then you could retract the solder, and wait an extra second or so, and then try again, maybe let out a beep and/or log the event so that you can adjust your settings accordingly. that way if the joint is still cold, it'll adjust automatically. you could set a limit to the number of retries so you don't scorch the board if the solder is stuck for unrelated reasons.
- add a power button, so you can shut it down without SSH, the raspberry pi has support for using a GPIO pin as a power-off button. also, you could try booting the system in read-only mode, to reduce the risk of SD card corruption. You'd need to do a bit of work to make sure that nothing's trying to write logs or temp files to disk, and mount a tmpfs to any directories with writes you can't get rid of. of course then it's a pain to add new gcode files, perhaps you could add a USB port and use a USB stick for gcode and any other files you want to be writable. then you either mount that read-only on the pi and edit on another machine, or accept the corruption risk, with the scope of damage limited to just the files on the flash drive, that are backed up and/or tracked in git on another machine anyways
- probably overkill: instead of passing in a flag to your g-code to choose between 2 hardcoded dwell times, you could have your planning tool could calculate the dwell times dynamically, you start with a base value that you set by hand for signal and ground pins, and then for the last N (maybe 5-10?) pins, divide the dwell time of that pin by the linear distance from the current pin and length of time from it, sum them up, multiply by some constant, and subtract that from your base value to approximate heat contribution from neighbors
27:07 personally i think it's the tip size that's causing the bridging problem since it's heating up other pins also some cooling would be nice also like a fan blowing it so it cools off the pins
well it's easy to change the user that any service runs as, lol
cronjobs are cool, but you don't actually need them, and using proper services can start up a bit faster
First thought is alternative, more user-friendly input methods for the commands. Could there be a way to let a person manually move around the iron, then the robot can mimic that movement, and the human can adjust it as it runs. That might be very applicable for soldering, and obviously has been adopted in various other robotic tasks. But soldering could be "trained" using a "measuring arm" easier than a lot of things...
But scanning the PCB design file and knowing what to do from that is amazing on its own, which is where you're heading?
Hi, do you have the design CAD and github? For the haters, I am an engineering student and I have a motor disability, which means I can't weld, this type of project saves me from facing many difficulties in my job, thanks genius 🙂
If you create an account on OnShape, you can then clone and edit the document here:
cad.onshape.com/documents/8772eadd554229639cccf922/w/724ba612e6207c47367c52a7/e/f15084f5b3072012a55be740
I'm not sure I can recommend this as a path to follow though. Would be easier to retrofit a 3d printer.
See this for some inspiration: ua-cam.com/video/hkpD51YkC58/v-deo.html
SOLUTION TO BRIDGING:
Because the Z axis is diagonal, the Z+ motion (iron up) includes a vicarious X- motion (iron left). Add a function that accepts the Z axis angle as an argument/context (because you may alter this angle at some point) and have it return a X+ value that will be perfectly vertical to the PCB's reference frame. Once you have this ability, you might modify your "iron lift" gesture to be a more intricate "iron dismount" gesture in the shape of a capital J rotated 180 degrees. To clarify, the way you would draw a J on paper in the X,Y plane. Here, we are dealing with the X,Z plane. And we are drawing the handle of a down-pointed umbrella. 🌂
Amazing work regardless, my brother! ☮❤🌈
Cool project! The strange nut on the extruder is for the bowden tube. You have kind of mounted the extruder backwards, not that it matters much, but it would probably hold the tube more securly than the rubber thingy. You could keep it as is and run an bowden tube to the spool instead of moving the spool.
I think it would not hold the PTFE tube because this one is smaller than the standard PTFE used for 1,75mm filament. But, yes, it seems the extruder is mounted backwards.
it's beautiful, looks to me like a wedge tip about half as wide as the one you are using would solve your bridging problem. I have one on my Hakko about that size, 0.6mm. I'm guessing it must exist for the ts100, if not you could turn a small slip on sock/tip adapter from some copper rod. Lovely stuff, you must be pretty pleased with it. Would it be possible to sense the temp drop from the TS to determine soldered vs non soldered pin given the larger thermal mass? I don't know if that data is on the TS usb line? Maybe sense current draw? That way you could do a smart second run. PS how do I get my hands on an iomixer board?
are you using leaded solder? i don't know if there are any rules you have to follow if you're selling these, but i always recommend going with the good stuff, eutectic leaded solder, if possible
If you change the order of the pins in such a way that it the solder is on the side with an un-soldered pin, it should reduce bridging.
And maybe lifting the iron up vertically instead of at an angle?
Nice project! Impressive! FYI, you can also setup a pushbutton to power off the raspberry pi, no SSH needed. If you also end up with different boards to solder, you could add an lcd to select which file to run. I have a couple of projects that could use the board that plugs into the pi and steppers. Definitely looking into it more.
It appears the iron is leaving the pin to quickly.
Try using a soldering tip with a slight valley ground into the tip. Like a V shape that the pin will sit in when being soldered. It will help keep the pin centered when the solder tip is pressing on it and solder is extruded
*edit: add a cylindrical sponge that is on a small motor, so before each board you can have the iron tip be cleaned on the rolling sponge, with a water dropper to keep the sponge wet
The soldering iron is a TS-100 right? IIRC, it's entirely open source, you should be able to modify it to give temperature feedback...
I was surprised to see the relay cuttings its power too. More work obviously but surely this is the perfect job for a tweaked soldering iron firmware controlled by LinuxCNC
This looks absolutely great. You are a real inspiration.
Impressive. You might try retracting the iron a little more before moving to the next pin, should turn a bridge into a spike, alternatively, you could repeat the job without using solder. Both will take longer of course but more retraction will be quicker than repeat.
Have you considered putting a camera on the z axis, a little bit of wizz-bang coding to identify a bridge and have the iron go back for a re-heat to break the bridge.
I'd think retracting it slower, like in two steps, once to just the very tip of the through hole, and then again about 100ms after that to the top, before moving. Also I do think using a little flux paste would help, like just brushing it over everything before starting the soldering. Rosin core seems to be causing buildup on the iron.
I dream to be as talented as you sir
Where in the world did you learn how to be as skilled and crafty with electronics and such as this?
I watch a lot of UA-cam.
Actually using real flux might help out too. Human soldering might work perfectly fine with just flux core, but actual liquid flux pre-applied to the board might help the robot.
As a PInecil V2 owner i'd like to mention i can utilize either bluetooth or usb-ttl/serial in order to get a live-reading of the iron's temperature and other things, so i think using a pinecil might be able to give the ability to read out and utilize your iron temperature :)
alternatively utilizing a pinecil breakout board you could modify iron os to output certain pins to high or low depending on its temperature :)
Also a common thermistor might do the trick. He mentioned he’s not actually familiar with 3d printing in general, but measuring tip temperature is a common parameter for initiating the job and for validating that temperature remains as expected throughout the script.
3d printer extruders with two driven rollers are a relatively new thing that Bondtech in Sweden popularized with the BMG extruder. Plenty of printers still use a single driven roller and a spring loaded idler wheel.
A newer Bondtech innovation is the LGX with two larger diameter (20mm ish) driven rollers to let more teeth engage the filament and travel in a shallower arc.
Two larger diameter, lighty textured or rubber covered aluminium or brass rollers might be optimal for solder dispensing.
Love the gimbal jog controller and the pass through X axis belt drive.
nice project :)
a button that runs a pi shutdown script might be easier than adding wifi, most of my pi projects have a hidden shutdown button somewhere for this reason
You could have the end effector apply solder paste and then heatgun each row of pins. Would be likely be much faster.
Soooo impressed with your skills, have watched you for years, you are the one that got me tinkering with arduino GPS and GSM modules!
But, it kinda depresses me that I’m not capable of achieving something like this! lol!
For a better solder joint and finish, try putting extra flux on the board and drag iron up the the pin to finish.
Also, firstly, try adding a tiny bit of solder to the tip before moving to the pin, it will give a greater heat transfer area between the iron, pad/pin and with the extra flux, the solder will be attracted to the pad/pin and should require less time for the iron to heat it up and make it more efficient.
Hope this helps with your masterpiece!
quite an amazing project my man. I would recommend if you are looking for better throughput to get a solder pot where you dip solder the boards and making fixturing for that.
Completely awesome!
You might want to try to add the solder a bit earlier and dwell a bit longer in exchange for that.
Will help with the heat transfer and you may even get less bridging.
Also regarding bridging: In 3D printing it often helps to move faster in order to prevent stringing - you might want to try moving the iron away from the pins with a quicker/jerkier movement in order to break the tension of the molten solder an (hopefully) get less bridging.
Also: Engineer a way to automatically clean the tip between runs! ^^
Problem is TIP, type of solder (radius) and timing
but Great WORK !!!!!!!!!!!!!!!!!!!!
Incredible as always ! .. have you thought about solder bath ? .. smd connectors ?
Are you using lead free solder? Either way, I suspect the joints will improve if you play with the soldering iron temp (perhaps 400C), dwell time (longer, so it flows further) and perhaps the solder quantity (slightly less?). Also, perhaps raise the iron rather than move laterally, to avoid solder tails. And is there a slightly smaller tip?
Excellent work! Looking forward to future updates.
Maybe try a "manual wave" / "bucket" tip, these tips have a small divot intended to hold solder for performing manual wave soldering.
Usually flux is used in conjunction with these tips, but the thought is the divot has surface tension helping to pull back excess solder, and also there is the remnant left in the bucket that would help to preheat the next joint....
Not sure if you can get those in the TS-100 range, certainly can with JBC.
I was expecting you to add a wet sponge to the build platform to occasionaly wipe oxide off the soldering iron tip. :)
Nice Project, thanks for showing this off:)
Also, the lack of expertise, especially that of UA-camrs is unrivaled!
EFFING WAVE SOLDERING ...
In addition to the tips pointed out already (moving vertically before laterally and adding tip cleaning,) you could add a button to execute the shutdown process. Press and hold for 5 seconds, and only have it work if a job isn't running, maybe?
terrible method.
You can use flow soldering instead of proposed method.
flow soldering can solder this pcba in only 5 seconds.
26:32 You're using way too much solder, so it's building up on the tip & giving you those bridges. (You could get away with that feed if you were using 0.5mm solder instead of 0.8.) I suggest you feed maybe 30% less solder per joint. Your post solder-feed dwell time needs to be a bit longer too, for better wicking into the PCB holes.
BTW, I learnt to solder more than 45 years ago, & I can solder a board like that faster than your machine, with zero errors. ;)
You're off to a good start, but there are *lots* of ways you could improve your process just with better parameters.
I would recommend some better soldering tip. I love my ts100 and I used it a lot but I know that the weller tips for example, from work, they work much better. They don't have to be cleaned as much and they transfer much better the heat
In the extruder section, the little clicky bit (the first thing the solder contacts on its way to the extruder) is for holding the bowden tube (basically, the equivalent of the little white piece that came in the package for your bowden tube.) It's presumably sized for a 1.75mm ID bowden (for 3d printing.) You could either leave it as-is, or if the teeth inside (which are there to grip the tube) interfere with the solder, you could either remove it or replace it with a smooth piece of aluminum (using a die to engage the threads that the bowden holder is screwed into.
Some suggestions:
(1) Use variant of PCB as fixture: If you are iterating a new PCB, milling and drilling a new aluminum pin-holder fixture each time is very tedious and wasteful. Instead, you could use the PCB itself as the pin holder.
With not much effort, while creating the actual PCB design, you can add outlines that the PCB fab can mill out to create windows where your already-mounted SMD components can fit (corresponding to the pockets you would have made in the aluminum fixture.).
(2) part of the rationale for the pin-holder fixture is so you can load up all the headers at once. You can't place them on the PCB itself because when you flip the board over they all fall out. Even if you did get the board flipped with headers in place, the headers tend to wiggle around in the hole clearance, and end up slightly non-uniformly aligned.
You can solve that problem by modifying your header footprints in the PCB software, so that some of the holes are slightly offset in different (but symmetrical) directions. This creates some friction that (a) registers the header uniformly and (b) stops it from falling out when you flip the board. You can then use a much simpler non-custom fixture that just pushes on the tips of the headers (assuming uniform height) and doesn't need to have holes for each pin specifically. That also avoids having the aluminum fixture acting as a heatsink on the pins.
I wonder whether you could actually use a cheap *unmodified* 3D printer? You can find them for $100 these days. The hot end of a printer that does PLA has to reach 200 degC - which is well within the range for melting solder. The extruder motor should be able to push (and pull) the solder without problems...and you have full 3-axis control using G-code. The printer bed is typically made of aluminium or steel. The only problem (I suspect) would be pushing on the pin with the brass printer nozzle and then aiming the solder correctly...but a cunningly redesigned nozzle could fix that. You could even use the bed heater to pre-heat the board slightly.
Quite cool contraption you have going on here. Some observations from real life soldering vs machine soldering is that in real life most of the thing happen so much faster. In real life it would not take more than 5 minutes to solder this whole board. more like 2-3 minutes. As I understand it takes 10 minutes? But this also affects the end result of you having bridges and bulky solder joints as all the flux inside the solderwire is used up way before solder iron stops soldering:
1) Solder iron should go up much faster so it would drop the solder and would not bridge
2) Solder should retract much faster. If you have grip problem use extruder with dual gears or use two extruders back-to-back.
2) It's way too much solder
3) You should add flux to make solder more liquid (you could just put it on before soldering or add additional nozzle, or make some contraction where solder will bas flux and is covered with it)
4) you don't need wifi to turn off rpi. just use one of the gpios and hook up switch. You can make it trigger shutdown command.
Happy tinkering.
The barrel fill is horrid 🤦♀
More dwell time , more heat & probably longer off joint time ( Iron recovery time ) .
Keep playing with the settings , it can do a lot better .
Back steeping down runs looks better than moving up the PCB .
Very nice build. As I see you use the extruder backwards. The clicky thing should hold the PTFE tube from moving, Pretty much what you’ve done another way.
Can get a similar “no motor in the way” by having a Core-XY system. Was almost trying to look where flux gets into the picture, but guess you are just using flux-core solder - might not be good enough, which is why all the bridging happens. And you might consider doing retraction for the solder as well, just like you do with the iron - pull it a bit backward, for those cases where maybe it didn't melt properly.
Regarding startup and shutdown:
Startup can be done via systemd, it's possible to say which user the task should run under.
Shutdown: in raspi-config tööl, it's possible to set up the main file system as read-only, so it's not possible to corrupt the SD card. And by remoting in, you can still upload a different job, it just gets lost when you remove power (as it will be stored on a ramdisk, not the main SD file system).
If you're gonna battery power it, you can't do much better than tool batteries (e.g., Milwaukee or Ryobi One+ or whatever tool brand you've got a bunch of). Thingiverse has the appropriate mounts for most brands, and you can send it off to be printed - or drop $130 on a cheap resin printer (you're gonna want it to be solid).
Extremely cool machine/video. Your 3d hotend is unusual as it doesn't have a thermister. If you added that ~back~ ;) you would know your tip is ready. PTFE trade name is Teflon and it's rated for quite a bit of heat in cookware.
Such a nice project. The solder tip looks a bit bulky. Also the angle of tip movement is too flat.
some soldering flux would help out greatly with those beads and bridging, you may even notice you will have to use less solder. why not just buy a $30 replacement iron for a solder station and use it, because they have a temp sensor in them, and its really easy to read, its resistance based.. also you can get soldering flux in a surrenge or pump that can be activated by a push button. but this process only assumes that you can mount the threw hole components so that they dont fall out when upside down. this is where a solder bath is usefull, because you just flow the bath under the board.
No need for wifi, just add a simple script that looks at a gpio (if one is free), and plop a button on it. Hit the button, the script could send 'stop what you're doing, and go home' commands to the software if possible (i havent played with linux cnc yet), otherwise then send the shutdown command to the OS.
Very cool solderbot build though! One question, why jog after homing? Is there an issue with designing the solder jig based on the home position? I might have missed the answer to that skipping around the video...
When I hand solder connectors like that I put the iron on the joint and dab a little solder on. Just enough to make a thermal connection between the iron, the pin and the pad. I then let it heat for about a second and apply the rest of the solder. That ensures I don't get a dry joint which can happen if the pad isn't hot enough, when the flux is still active. Seems like it would be easy to implement on your machine.
Nice machine and works really well. But I think you have the soldering methology wrong. The heat conduction into the parts to be soldered is poor when dry, as in no solder applied, once the solder is applied and starts to flow the heat conduction is massively increased. So, partlcularly for the ground pins which you rightly identified needed more heat, you need to dwell AFTER the solder is applied, this will incourage the solder to flow down the PTH and reduce the occurance of blobbing and bridging. Brushing on some liquid flux would help too.
Excellent work!
Have you tried a slower move upwards and then away from the soldered pin to avoid the horizontal solder spike?
Another thought is that you could try a move where you solder it as you do, lift, and then come back onto the same pin and reflow it before moving to the next pin.
Again, great job!
Glad to See Your palmtop LinuxCNC working. Very nice!
PTFE (aka Teflon) is used on non-stick cooking pans, so it can handle temperatures under 250C like a champ and I don't think the heat will reach the 350C on the soldering iron up there.
The bridging is due to moving away at an angle - you need the iron to lift completely vertical, up the pin to ensure a good "conical" solder. Also, slow down the retraction of the iron and keep the iron in contact with the pad for a few milliseconds more to allow the solder to flow.
You non-solder points are most likely due to a slightly uneven bed - I'd manually solder some of the pins in the corners to begin with and clamp down the board (using mount holes if you have them) or just some clamps / alligator clips might help
Your V2 upgrade should be leadscrews - belts loosen over time and your accuracy needs to be within 10's of microns ;)
I had a few comments, but I see that other folks have mentioned most of them. I noticed the unsoldered pin happened because the iron tip didn't make good contact with the pin, so the solder just pushed against it instead of melting. Tweaking the appropriate parameter might help. As far as motion systems with stationary motors, you might look into H-bot, which is easiest to build, or core-XY, which is considered superior but is more complex and probably unnecessary for a small setup like this. Your setup is like a modified H-bot, but with more parts and without the symmetry.
Pinecil soldering irons have an optional GPIO breakout board. You could use that to communicate with the CNC controller.
Regarding getting feedback for control stuff. I'm not 100% on it but I believe the Weller WX tips have the thermocouple built in, if that is the case they use a 3 pole TRS connector and you could make a cable or pcb with the connector that has the cables run to a controlled power supply and a sensor for the thermocouple. This would allow you to make the software side control the heat and maintain a specific temperature, allowing you to know when it's warmed up, adjust and also cool down if needed. The tips themselves aren't cheap but if it allows you the control via software it may be a worthwhile upgrade. I have a few tips myself and could test to see if I would be able to control them with a bench top power supply and if there is the thermocouple in it and readable if you'd be interested in trying this.
Love the project, but had you considered using solder paste and a hot air gun, treat it as though you were surface mount soldering ?
You can fix the belts with a couple of pins and folded back on itself. No need for screws.
At 43:46, the white plastic clicky thing is a locking mechanism to hold the bowden tube in place. Usually, the filament, or in your case, solder, would come out of that side, not in, as you have it.
Impressive design and engineering skills, but this problem was solved decades ago, it's called wave soldering and you don’t need and program it for each board design.. Maybe make a mini table-top wave solderer?
Seems like you have flux problems here, my dear friend. Before starting to solder, try brushing the board with flux, and then you can proceed with the soldering routine.
Cleaning your tip I think would help halfway through and might help with bridging... if you look closely when it goes to some of them it's running off on the pin behind whichever you're soldering...
If you switched out your soldering iron for a low powered diode laser (say 20 - 40 watts) you could do away with all the complexity of the need for controlling vertical movement. Just build a box with a see through top for safety and you're all set to go.
how you've never heard of a solder pot just boggles my mind, inventing solutions for problems that have already been fixed AGES ago
I work with a professional Ersa Ecoselect 4 machine
First a nozzle sprays flux on all solder joints, then the PCB gets preheated by IR heaters (like soldering ovens do) only then do we actually solder
To get reliable consistent solder joints