Good times dear fellow makers. In this instructable I want to share another, as we think, useful project, my son and me, did in order to simplify and speed up our printed circuit board (PCB) assembly. For our hobby/small business we do some and sometimes a lot device prototypes. Those PCB prototypes have few to many SMD components and while one may think that toothpicks and forceps are just fine for this type of work, we and especially I, find it very inconvenient. The reasons are:
- fine finger tremor. This is not specific to me, but to all of us. It's very noticeable when you try to pick and place really small components. The coordinate table takes care of this problem.
- eye strain: I use many types of head magnifiers and they really help, but your eyes get sore after a while anyway. This project uses USB microscope.
- neck aches: you need to keep your eyes at specific level in order to focus your magnifiers. Very noticeable if you do this for a while. USB microscope takes care of it as you won't have to bend over your PCB anymore.
- inconvenient process overall as you need to pick, rotate, drop, pick up again your SMD in order to orient it right on your PCB. Instead doing gymnastics over your PCB, you pick SMD with vacuum pump by pushing foot pedal, rotate with two fingers, look to your monitor, align SMD component, lower it to PCB and let the foot pedal go - component placed.
So in all those ideas in mind we searched for alternative and cheap ways to solve all the above inconveniences. We found this project online:
the project looked very useful and we just wanted to repeat it, but after thinking and rethinking, we came up with somewhat different version of that machine. We tested it, found it very useful and decided to share it with other wonderful makers on instructables website.
SHORT DEVICE DESCRIPTION:
The pick and place machine, described in this project, consists of:
a coordinate table made of square plywood; four linear bearings mounted on four lead rods; terminated by eight terminators at the rod ends.
few cast acrylic parts, cut on laser cuter, designed to mount X onto Y bearings. Those parts hold the machine head together as well and provided the area for convenient arm placement.
the head made of, as described above, the plastic parts attached to two linear bearings; stainless steel tubing; two needle bearings; notebook spring; two washers; rubber grommets; tuberculin syringe; needle; USB microscope; metal hose clamps.
black box: provides 110VAC input and output plugs; converts 110VAC to 12VDC; converts 12VDC to 5VDC; status LED; 3.5mm connector for foot pedal.
Step 1: Parts
Pick and Place machine itself:
1. X x Y x Z plywood.
2. 4pcs 10mm OD x 500mm Linear Shaft ~$30 on aliexpress.com
3. 4pcs x SC10LUU 10mm Linear Axis Ball Bearing Block ~$21 on aliexpress.com
4. 10pcs SK10 10mm Linear Rail Shaft End Support ~$10 on aliexpress.com
5. M5 or in other words 5mm metric bolts and nuts. Length depends on thickness of your acrylic. I had them in our local hardware store.
6. Aoyue 932 Vacuum Pickup Station. ~$44 on amazon.com. May just reverse aquarium pump. Look for it on instructable website.
7. USB endoscope 2MP 9mm lens. I've bought it on ebay from seller: epathdeals2012
8. Seamless stainless steel tubing 3/8" OD x .049" wall from US seller.
9. 2pcs Koyo BH-68 Needle Roller Bearing 3/8" ID, 5/8" OD, 1/2" Width ~$10 from amazon.com
10. eye bolts for vacuum hose and cable management from local homedepot.
Black box (if this seems to be complicated, let me know and I'll find some simpler solution):
1. PC Power Socket and PC Power Plug ~$10 for ten of them on amazon.com.
2. Tattoo Foot Pedal Switch ~$3 from ebay. I've bought from seller: babastoreong
3. I disassembled one of small 110VAC to 12VDC power adapters and took the actual PCB from there and placed it in the black box.
4. I used 7805 voltage regulator and a couple of capacitors to get stabilized 5VDC output used for signaling the relay module
5. I used arduino relay module for switching vacuum pump on and off via foot pedal
Step 2: Assembly
1. cut plywood to the size
2. cut four X x Y pieces. Used to raise shaft terminators above plywood.
3. put linear bearings on shafts and terminate the ends using terminator screws.
4. bolt X axis bearings to Y axis bearings by using acrylic parts and 5M bolts and nuts
5. slide Y axis bearings to 0 degree; mark positions for wood blocks, drill holes and screw the blocks to plywood.
6. bring Y axis bearings to max degree; mark positions for wood blocks, drill holes and screw the blocks to plywood.
7. bolt X axis bearings to acrylic parts; take X bearings and glue all the plastic parts together with acrylic solvent and let them dry overnight.
8. pull metal hose clamps through the designated holes on head's front and mount needle bearings.
9. put USB microscope through eye bolts first, as it will be impossible to do afterwards. Pull zip ties and mount USB microscope in place.
10. mount head.
11. cut stainless steel tube to desired size - think twice, then rethink and only then cut. Cut tuberculin syringe in half and use epoxy to glue it to the tube. My syringe was a really good fit for the tube, very tight. Put epoxy on the syringe part with the needle attachment all the way in so only the needle attachment is sticking out. Glue another half of syringe tube to the top end and make sure it's sticking out for vacuum hose attachment later.
12. put stainless steel tubing through upper needle bearing; put rubber grommet/washer/spring/washer; then move the tube through lower needle bearing and put another rubber grommet on it to keep in place.
13. As an extra part I used thin sheet metal for placement of cut reel pieces with SMD components. The reason is: when I use one project I cut the reel pieces appx ten components each; use thin double tape to hold them to the sheet metal; when done with this project, you pick the metal sheet and put it away; then grab new sheet, put it on those magnets, tape another set of components and you are ready to go. For this I used harbor freight neodymium magnets. I drilled really tight fit holes and glued the magnets into the holes.
14. use provided USB microscope software. I found it kind of hard to use the whole system as microscope is aligned from the side and when you pick and place components, the components land not to where you expect them to be. I solved this by placing a little arrow, cut from anything you want, I used a piece of sticky note paper, on monitor somewhere in a middle. Then you place your pcb, place component on PCB, lower vacuum needle to the component and hold it there, grab the microscope software window by the upper bar and while holding your right mouse button - align the middle of component to the arrow. Now you are going to be very precise.
Step 3: Enjoy
From now on enjoy, not struggle by populating your PCB. We actually speed up and upgraded all steps of our PCB assembly and this pick and place is only one of them. We came up with excellent idea to cut and use our own stencils; the pick and place SMD components; and we bought an IR oven and modified it as well. So our hobby lab became a little fab. If anyone is interested in any of the steps, we may write another instructable or two. Glad if we could help anyone. The instructable is not finished yet and I'll take some pictures and attached them as well as I'll rewrite some steps to make them clearer. I'll modify and add .DXF or even PDF files to the instructable for those mentioned acrylic parts as well.