Homemade manual pick and place - Page 1
Forum section: electronics / general

author: jefflieu
author_rank: Contributor
timestamp: July 17, 2017, 12:52:09 pm
content: Hello,Inspired by this guyhttp://vpapanik.blogspot.com.au/2012/11/low-budget-manual-pick-place.html] http://vpapanik.blogspot.com.au/2012/11/low-budget-manual-pick-place.html, I've made similar manual pick and place device with some improvements.The bill of materials are posted herehttps://blog.jayvee-store.com/2017/06/26/manual-pick-and-place-machine/I'm from Australia, so all the parts to construct the frame are from Bunnings warehouse.It works quite well and very helpful if your hands are not so steady.

author: jmelson
author_rank: Super Contributor
timestamp: July 17, 2017, 08:57:11 pm
content: On small boards, you can usually rest the heel of your hand on something to steady it. Or, maybe your forearm. I agree, on larger boards, you don't have a place to rest your arm without touching the board, so that is a problem. I'd invest in good tweezers and a stereo zoom microscope first, WAY more useful. I do have a full-auto P&P machine, but did a LOT of manual P&P before I got it, and still make prototypes by hand, as well as a lot of rework. I've always found ways to just use my hands and good curved-nose tweezers to do it.Jon

author: jefflieu
author_rank: Contributor
timestamp: July 17, 2017, 10:29:23 pm
content: Yeah? I decided to do this after many times of touching the solder paste of the unplaced area with my little finger.What's the stereo zoom microscope you use?Thanks

author: Gary.M
author_rank: Regular Contributor
timestamp: July 18, 2017, 02:56:24 am
content: You seem to be struggling with the fine placement accuracy to put the part down with the result that the placement is very slow.

author: jefflieu
author_rank: Contributor
timestamp: July 18, 2017, 12:22:08 pm
content: Yeah, I think I'll get better in terms of speed.I don't have any problem locating the part. I do get some difficulty releasing the part.For some reason, sometimes it takes a while to release the small part (not sure of static or the pipe is too tight, the pressure not released). I'm still working on that. With proper solder paste, it'll make small part stick to the board better and not get moved at releasing.You've done it before? Any trick?Quote from: Gary.M on July 18, 2017, 02:56:24 am

author: jmelson
author_rank: Super Contributor
timestamp: July 18, 2017, 08:58:19 pm
content: Quote from: jefflieu on July 17, 2017, 10:29:23 pmI got an old Olympus stereo microscope through an eBay contact at least 10 years ago. I had to make my own stand for it.There is a Chinese microscope that we got at work, it also works well. The big deal is to get a long working distance, at least 4", 6" is even better.This gives you room to have the board, your hands, and a soldering iron under there. I made my own ring lights that are behind the objective lenses, so you don't lose any of the working distance.Jon

author: SVFeingold
author_rank: Frequent Contributor
timestamp: July 18, 2017, 09:25:03 pm
content: I've got an old Olympus as well, if you can get one they're great scopes. The ring light works pretty well but often times I'd prefer a separate light that I can position. The reason for this is that the ring light creates a lot of glare and it can be difficult to tell what you're looking at. I.e. is that shiny bulge between the pads a solder bridge or just flux?

author: sleemanj
author_rank: Super Contributor
timestamp: July 18, 2017, 10:11:51 pm
content: Quote from: jefflieu on July 18, 2017, 12:22:08 pmAre you just stopping the pump to release vac? Maybe use a NC solenoid valve on a tee to open the suction line to atmosphere would be better.

author: jefflieu
author_rank: Contributor
timestamp: July 19, 2017, 12:24:29 pm
content: Quote from: SVFeingold on July 18, 2017, 09:25:03 pmYeah, I have the ring of LED on my USB scope as well, but it's too shiny and gives glare bounced off the PC board. Natural sunlight is the best.Quote from: sleemanj on July 18, 2017, 10:11:51 pmYeah I just stop the pump to release. Do you know of any small solenoid valve that I can get from ebay? The tube is only 5mm inner diameter.

author: sleemanj
author_rank: Super Contributor
timestamp: July 20, 2017, 12:35:07 am
content: Quote from: jefflieu on July 19, 2017, 12:24:29 pmDon't know about eBay but a search of aliexpress shows a couple...https://www.aliexpress.com/wholesale?ltype=wholesale&d=y&origin=y&blanktest=0&SearchText=air+solenoid+valve+5mm&tc=af&isViewCP=y&catId=0

author: DTJ
author_rank: Super Contributor
timestamp: July 20, 2017, 01:36:25 am
content: For vacuum release on my unit I used a couple of these solenoids:http://www.ebay.com.au/itm/1-8-2-Way-Normally-Closed-Pneumatic-Aluminum-Electric-Solenoid-Air-Valve-12V-DC-/172511868369I wired in a relay so when one was operated the other was released.They are plumbed with one in series between the vacuum source and the pick up needle.The second one is T'd off the side on the needle side of the first solenoid and vents to atmosphere.When the foot switch releases the in line solenoid closes (stopping vacuum) and the second solenoid opens releasing any residual vacuum in the line.I'm also using a compressor from an old bar fridge (courtesy of curbside pickup) as a vacuum source. It pulls a good vacuum and is very very quiet in operation.I use a short piece of PVC storm water pipe as a vacuum reservoir.

author: Mr.B
author_rank: Unknown
timestamp: July 20, 2017, 02:00:50 am
content: @DTJI really like that design.I have been thinking about building something for a while.No excuse now... Guess I know what I will be doing this weekend.

author: DTJ
author_rank: Super Contributor
timestamp: July 20, 2017, 02:18:24 am
content: Quote from: Mr.B on July 20, 2017, 02:00:50 amInitially I build an XY carriage style machine but for me I found there was too much inertia and stiction when moving.I copied / modified a commercial system (that I can't remember the name of).I need to add an arm / wrist rest as occasionally I'll end up dobbing my little finger on a board, smearing the paste.Make sure your base board is thick / rigid enough as the arm puts quite a bit of bending force on it at full extension.I used cheap 8mm ID bearings and some 25x25 aluminium bar I had lying around. The mount to the board is an old Ikea couch leg.Three's lots of good ideas to be found googling "manual pick and place machine"http://www.briandorey.com/docs/diy-pick-and-place-part1/02.jpghttp://www.briandorey.com/docs/diy-pick-and-place-part1/03.jpgWhat would be really cool is to build some mechanical reduction into the mechanism like this manipulator does:https://www.singerinstruments.com/wp-content/uploads/2015/03/overview-mk11.jpg

author: Mr.B
author_rank: Unknown
timestamp: July 20, 2017, 02:31:14 am
content: I have an articulated monitor arm that was purchased ages ago.I never used it in the end because it turned out to be too lightweight for the monitor.Hopefully I can reuse parts of that and add some bearings at the joints.Love the Singer mechanical reduction unit.

author: jefflieu
author_rank: Contributor
timestamp: July 20, 2017, 12:03:31 pm
content: Thanks guys!I'll checkout the valve.I also realize that in my setup, I rely on the arm/palm's muscle to move the nozzle X-Y, which is not ideal.So for precision I have to involve the left hand fingers as well.With DTJ design in the video (without wrist rest), I'm impressed that you show quite precise control with your arm.With a wrist rest, it's even better. you can manoeuvre using fingers which is meant for fine control, quicker and more precise.Thanks DTJ for sharing, that's pretty impressive pump.

author: DTJ
author_rank: Super Contributor
timestamp: July 20, 2017, 01:41:11 pm
content: Your set up is pretty neat too Jeff. I'd like to add a camera at some stage when funds permit.The video was shot on the first try out, it's a bit smoother to operate when you're sitting down and not holding a phone camera in your other hand.For your linear stages would having pre-loaded linear return springs under the X & Y carriages make it easier to operate smoothly?That way you when you relax the applied force it will move back slowly.Maybe use very long springs to get a uniform linear force.

author: ar__systems
author_rank: Frequent Contributor
timestamp: July 20, 2017, 06:40:17 pm
content: This is the contraption I use for manual placement and soldering.right hand rests on the carbon fiber board and left moves the pcb around as needed. This prevents me from touching the paste during manual placement, allows to keep my hand always in the same place, and also keep the microscope focused on the same work area.

author: DTJ
author_rank: Super Contributor
timestamp: July 21, 2017, 01:59:58 am
content: Using the bridge is a good simple solution. It also lets you still use your microscope that my system doesn't.

author: Gary.M
author_rank: Regular Contributor
timestamp: July 21, 2017, 02:14:35 am
content: I came across this yesterday, and have ordered parts to replicate it.https://blog.ohmnilabs.com/diy-vacuum-pickup-smt-pick-and-place

author: DTJ
author_rank: Super Contributor
timestamp: July 21, 2017, 07:28:54 am
content: The constant current mode on the power supply seems to work well.

author: mairo
author_rank: Unknown
timestamp: July 21, 2017, 10:10:30 am
content: This is not for DIY, but the layout looks simple with good access to a number of feeders.

author: DTJ
author_rank: Super Contributor
timestamp: July 21, 2017, 11:18:35 am
content: Quote from: mairo on July 21, 2017, 10:10:30 amIt could be DIY......Look at the manual feeders here:https://www.aliexpress.com/wholesale?catId=0&initiative_id=SB_20170721011506&SearchText=manual+pick+and+place

author: DTJ
author_rank: Super Contributor
timestamp: July 21, 2017, 12:59:49 pm
content: @Mr.BThis is the system I got my ideas from:http://www.farnell.com/datasheets/1526394.pdf

author: Mr.B
author_rank: Unknown
timestamp: July 23, 2017, 09:01:33 pm
content: Quote from: DTJ on July 21, 2017, 12:59:49 pmLooks fairly good.I like the idea of what looks like a sliding wrist rest.I ran out of time this weekend just gone.I will have a go at starting a project to build something similar to yours next weekend.

author: DTJ
author_rank: Super Contributor
timestamp: July 24, 2017, 01:41:57 am
content: Quote from: Mr.B on July 23, 2017, 09:01:33 pmThe main thing I noticed when making it was that it needs to be quite rigid so it doesn't sag.The holes for the bearings in the arm need to be a reasonably good fit. I used 8mm bolts in the joints for rigidity.

author: Mr.B
author_rank: Unknown
timestamp: July 24, 2017, 04:40:59 am
content: Quote from: DTJ on July 24, 2017, 01:41:57 amNoted.Thanks.

author: Kjelt
author_rank: Super Contributor
timestamp: July 24, 2017, 07:56:00 am
content: I always use 45 degree needles and hold the pincet under 45 degrees.That is to have a clear point of view because I place the parts looking under a stereo microscope.That is the main disadvantag I see from these placers you need a camera and can only see a part of the picture esp. with square ic packages.

author: DTJ
author_rank: Super Contributor
timestamp: July 24, 2017, 10:46:44 am
content: Quote from: Kjelt on July 24, 2017, 07:56:00 amThe camera for the placer is next on my shopping list.I've been trying to think of a way to use my placer underneath my microscope. Not sure its doable - maybe putting the PCB on a small rotary table.I use the the placer as I end up with too much hand shake using just tweezers under the microscope. I also get sick of having to bob my head between looking on the bench for parts (which I can't see without my glasses) and looking down the microscope.

author: Kjelt
author_rank: Super Contributor
timestamp: July 24, 2017, 01:13:55 pm
content: For most microscopes you can buy eyepieces for glasses you don't have to switch anymore.The only problem I have is the minimum 5x zoom, it is just too much for normal P&p IMO.3x would be ideal.If I would build a manual P&P I would choose that multiple pcbs can bevfitted since looking up where to place the parts costs time. Doing the same parts for multiple pcbs after eachother makes it faster.

author: jmelson
author_rank: Super Contributor
timestamp: July 25, 2017, 10:36:48 pm
content: Quote from: Kjelt on July 24, 2017, 01:13:55 pmRight, I take my glasses off when using the microscope. If you can get your eyeballs up close to the eyepieces, you get about 2X the field of view. With everything blown up, uncorrected astigmatism is not a concern. I'm massively nearsighted. When doing full assembly manually, I pull out the required number of parts next to the board, and then mount, say, all the 1K resistors at one time, then move on to the 10K or whatever. I do a lot more inspection/rework than assembling boards completely by hand, so that doesn't take adding parts, just checking for bad joints and solder bridges. Also, in some cases, I can line up a bunch of small boards, and put all the R1 on every board, then do R2 on every board. This saves me time by mounting all the similar parts, not having to check the BOM over again for each board.Jon

author: jefflieu
author_rank: Contributor
timestamp: July 28, 2017, 12:25:03 pm
content: Quote from: Kjelt on July 24, 2017, 01:13:55 pmYou tend to know your way around the pcb pretty well after the layoutOf course, doing 2/3 at a time would still be faster. At home, 2 3 boards at one time seems good as they would fit into the oven as well.

author: Kjelt
author_rank: Super Contributor
timestamp: July 28, 2017, 03:07:45 pm
content: Maybe I am just getting old, pcbs with upto 30 components are ok, but last month I did a pcb with 80 components and I had to search each part almost everytime. Hands are still steady thoughThere was this softwaretool discussed a year back or so which was no longer maintained unfortunately but would display each next part on a monitor. Might have to dig into that one.

author: DTJ
author_rank: Super Contributor
timestamp: July 29, 2017, 05:24:34 am
content: Quote from: Kjelt on July 28, 2017, 03:07:45 pmI looked at that software. It was neat but for me it was just a bit cumbersome.I print out an A4 overlay of the board and use coloured highlighter pens to mark all the same value passives.I also note how many of each there are and get that number of parts out, that way if there are any left over I know I've missedsometbjng.I find it works very well.