I had to load some more components on my trusty Pick and Place machine and decided to document the process for all the Internet to see.
If you are not made from money, chances are you have encountered this problem. Sometimes it is too expensive to order a whole reel of parts. So what to do with a cut tape of 100 or so components?
Most distributors offer a “reel” service – that is they would make your cut-tape onto a reel – this would save you all this trouble. I personally found this solution to drastically increase your price per component though. For example, a cut tape of 100 capacitors, would cost you $1-$3, the tape reel service is $7, which is more than twice the price for the components.
On some machines, you can cut a small strip, just long enough for the job and use the “IC tray” mode. But what if we can do better?
First, you need a reel where to put the components. You can 3D print one – I made a model here. It is two pieces (left and right) you can print separately. It is standard 178mm reel. I have printed both 8mm and 12mm wide versions, by adjusting the hub width. Initially, I tried 130mm diameter reel because it is suitable for smaller 3D printers, but it was a pain to work with on the machine. It was too small to stay on its own, and I had to put it on the the reel shaft. This, in turn, was a major issue every time you have to replace a component you have to remove all reels. So please use 178mm it would save you lots of pain.
Anyhow the reel is easy to put together, just print the left and right part, align them together and press. There is a little hole on the hub to feed the cut tape make sure the left and right part line together. It should look something like this:
You can see the cut tape of 0402 capacitors I’m going to use underneath. Make sure when you put the tape on the reel, you wind it in the correct direction – the tape sprocket holes should be on the correct side.
For example, this, turns out, was the wrong way for my machine:
Anyhow here is it wound up the right way.
This is all and good, but to properly install the reel in the pick and place machine you would need about one foot of plastic tape from the reel. The normal reels have about 30-40cm of empty space so that you can thread the tape through the mechanism. With the cut tape this means losing quite a bit of components.
Not to worry I have just the trick for you. For 8mm wide cut tape use this wonderful 3M product I found on Amazon – 0.188″ tape. The one I use looks like this:
For 12mm wide cut tape use 1/4″ 3M tape, for example, this one.
You would need to cut two pieces of sticky tape one about a foot – enough to get from your pick and place pickup to the tape collection wheel and wind on the wheel about once. The second piece about one to one and a half inch.
First you snake the longer piece of tape on the pick and place machine – follow the normal path for tape collection and make sure the tape is not twisted. I stick it a little on the collection wheel as well as on the pick and place pickup wheel.
It helps if you put the tape on the next position, where you insert the cut tape.
Now, peel off the plastic tape from the component tape for about an inch. You would lose 10-15 components – it is a worthy sacrifice. Why an inch? As you can see in the picture, I have to guide the tape about that distance to make sure it is not stuck anywhere. If your machine uses different setup adjust the length as needed. You cannot go smaller than 1/3 (one stapler size) inch though you’ll see why in a few paragraphs.
Insert the cut tape in the machine as if it was a regular tape, then tape the short piece of 3M tape over the peeled plastic tape. I use this to increase the plastic tape strength, because my machine pulls like there is no tomorrow.
Now turn the tape over and stick the long piece of tape on the opposite side.
Just like this:
Finally put a stapler on the small segment. The sticky tape alone would not hold to the pull force of the machine. The stapler would ensure the “mechanism” stays together.
Make sure you lock all 3 pieces with the stapler – the two tricky tape pieces as well as the plastic tape between them. I found that micro staples work for me. For example this Amazon item.
Here is how it should look like:
Finally, place the other end of the 3M tape over the collection wheel and pick up the slack:
The demand for my CD-changer emulator is picking up, so I’m making several boards at the same time. Placing of the components on the board by hand and re-flow with hot air.
These 6 board take about 4 hours in this stage plus another 4 hours or so to solder the optical connector and other connectors. My hands feel tired after a while. I’ve heard that good scotch helps with this condition.
If you can’t recognize what this is, here is an explanation.
When creating PCBs, one can order a stencil – usually from a thin sheet of stainless steel. On this stencil, there are cut small holes (with a laser cutter) where one is supposed to apply solder paste on the PCB.
So the operation is: you align the stencil on top of the PCB; then squirt some solder paste on top of the stencil; then use a flat “applicator” to smudge the solder paste over the stencil holes. In the end, you lift the stencil up, and you end up with the solder paste applied in a thin layer over the solder pads on the PCB.
To aid in this whole process is this contraption – a stencil printer. You align the stencil on the device and put come L shaped holders on the bottom to hold the PCB in place. The bolts on the bottom are to help to align the stencil and the PCB. When the alignment is achieved you put the PCB in the holder on the bottom; lower the stencil; apply solder paste; lift the stencil; remove the PCB. The whole solder paste application takes about 1 minute.
I should have gotten it sooner. My only regret is not getting a larger size printer, as you can see the stencil frame is a bit larger than the printer base – it still works though.
I’m very pleased with the new box design. It allows me to play with multiple color plastic, so just in time I created a “4th of July” (red, white and blue) device edition.
I had to re-design the new box. Before I was trying to make it from 2 parts – top and bottom. This process had issues because the bottom part would not 3D Print correctly – it would keep curling up due to stress in the ABS material.
So finally I made the box bottom from several pieces. The bottom has 4 curved corners and 4 side panels, which slide down – you can see one of the side “panels” in this picture.
Also, you can see the size of the old device version compared to the new version.
I was not satisfied with the previous Pi Zero board, because it was larger than the Pi, so here is a new version which has the same size as the Pi Zero.
Here is the new board mounted on top of a Pi Zero:
The spacers are a bit too short – you can see the bolt hitting the HDMI connector.
Here is the final version in a new box:
I got this great 3D printer – the Rigidbot – from Kickstarter. The project was only a year late, but they delivered excellent kit. As with many 3D printers it has become a labor of love.
I printed so many connectors and parts for the CD-changer emulator project. It never broke down on me.
I changed the connector to the bed heater because the original was prone to melting down. There are a few excellent upgrades for the printer offered by Peter Stoneham. I have his single extruder mount; ingenious belt tensioners; metal bearing holders. I also printed a few excellent mods by Walter Hsiao. He wrote an excellent article summarizing his updates.
The hotend is E3D V6 with an auto-leveling probe. I still use the original controller board with Marlin 1.1.8 and the original power supply. This GitHub repository has all the latest updates and modifications for Peter’s extruder, 16T pulleys & auto leveling probe.
The Raspberry Pi foundation did something weird, and all Raspberry Pi model A+ disappeared from the market. I could not order anything.
A month later they announced a new board – the Raspberry Pi Zero. It was great except it was also made from unobtanium. I managed to get a grand total of one from an eBay scalper.
Anyhow, I had to design a new version of the CD-changer emulator which worked with the Raspberry Pi Zero because it looked like the days of the A+ model were numbered.
So this is the first board I did, which was just a bit bigger than the Zero itself. On the image, you can see the board in a new box for it. The Pi Zero is MIA.
Also, my SMD soldering skills have improved slightly.
Ready to be dispatched to it’s new owner unit #27.