There was a nice exchange on social media about connecting to test points. (Photo stolen from that thread).
It seems 1.2mm is a pretty standard test point size. Anything smaller seems to cost a bit more (more expensive/breakable pogos, delicate test rigging). I made this pin 1mm in diameter because smaller just seems a bit insubstantial.
The bread board pins are nickel plated copper. The other option is gold, which is more solderable but $$$$. I’m wondering if we can get then raw and dip them in lead free solder or something.
It’ll undergo some changes after I talk to the pogo pin boss on Monday, and I’m open to any suggestions.
I snipped off the long side of the probe cables custom milled pin and filed the surface. Soldered it onto one of the test points on a pico. It didn’t solder as well as a copper or gold plated pin but after a few tries it stayed. Looks pretty cute to me.
Here are some more photos of the new pins. They are super cute! They stand really well once placed on a solder pad but they are also quite tiny, so you’d have to use tweezers to place them gently on test points.
I like these A LOT! I was skeptical, but it really is nice. I’m hesitant to make a bunch though. They’re pretty pricey. We did a sample batch of 100 - 80 tin plated, 20 gold plated. The milling was around $60 (400 RMB), the gold plating for 20 tiny pins was 200RMB ($30).
We sent some to the twitter user who ask for a way to connect to test points. I’m eager to hear what he thinks. We have some extra so I guess I’ll put them in the shop, but there’s only ~70 left (10 gold, 60 tin).
We were warned about the tin plating turning sour over time. I lean towards gold, but the batches would need to be pretty large to make the cost reasonable. I get the feeling this is just a me and one other guy project, and that’s fine
We also found something similar from a pogo pin maker, but not exactly built for this purpose.
What I’m wondering is if the connection to a test point on a PCB is stable enough with these test point pins.
You most probably don’t want to have to hold the pins in your hand because you want your hands on your keyboard to be able to debug and work with your DUT. In my experience you need some mechanical force between PCB and test point to get a reliable connection.
I think the ideas behind these are promising, but I consider the prices of all these quite hefty.
Maybe these ideas can inspire you and your good connections into the Chinese manufacturing network allow to create something with a similar usability, but at better pricing.
Acupuncture needles are available for very cheap and bending the front part with pliers is easy. The PCB base is simple. The only thing that would have to be custom build would be the needle holders.
Maybe using a magnetic but insulated base and holders with magnets on the bottom would make this more easy to use.
A friend has a magnetic gooseneck thing in their office.One of the mid-range ones, I guess. It’s really cool, and it seems to always be in use when I drop by.
This is probably a better line of pursuit than a solderable milled pin, but I enjoyed getting to use the milled pin folks for a second project.
But it still requires the holder set to be bought from Aliexpress and I’m guessing that this set is still a bit overpriced. So I went searching on Aliexpress for the main obstacle, the holder arms. I found these:
I ordered one each and will check if they are suitable.
I did some digging on taobao and 1688 a while ago. There’s a huge range of quality and options, bit most of it is not at all cheap even on the Chinese market.
We’re going to send some off to the twitter user who inspired them for testing.
