On Nov 3, 2017 9:19 AM, "Josh Malone" <[email protected]> wrote:
> Would a hot-air station work to soften the plastic first? > Probably. You can order pin headers in several different materials, and some have more heat tolerance than others. So, if you go on digikey and specify the material in the filter, you can give yourself one that's intentionally easy to soften. Then again, I don't know that won't cause the plastic to stick to the metal like paint and get in the way of soldering later either. The current DigiKey cart at http://tandy.wiki/Model_200_RAM has a particular model of pins that has a reasonably high quality insulator, that was somewhat difficult to pull the pins out of. Still essentially do-able for a one-off, where you are just making your own one or a few boards for your own machines. No way would it be practical for producing 75 of them! But I had some other pins from ebay that were cheap, typical example: http://ebay.com/itm/142204120781 You find those just by searching "machined round pins" These cheap ones pulled out of the plastic much easier. They also break pretty easy too so you have to be careful. If you bend a pin, you can't bend it back. It just breaks off. I just grabbed the plastic with my fingers catching the edge of the plastic, with the no-shoulder pin pointing into my palm, and the side with the metal shoulder away from my palm. No pliars on the plastic side, just fingers, to avoid squeezing the plastic, which would just make it harder to get the pin out. And used the tip of needle nose pliars to grab the big metal shoulder firmly, twist back and forth a few times while pulling. Usually popped right out after a couple twists without too much violence. It was actually not too bad assembling once the pins are extracted, as long as you have a vise like in my pictures, that can hold the board out flat and elevated. You just drop the pins in the holes, solder (from the top), and nip off the tops. I used flux to ensure the solder flows down into the hole well from soldering from the top like that. The pins fit in the holes well enough that you don't have to do anything special to ensure they all point the straight down. I assume this is no accident and it's what Steve intentionally designed as the most practical solution available given the vertical height limitation. Except, Steve, I think there is an option available that would be easier to build, but would require moving everything around on the board. If the components were all on the underside of the board, then we could just use some low profile pin headers without having to extract or cut anything. I will have to poke around a little later to get some exact dimensions, but just looking visually at my finished and installed unit, I think I can tell that there is a way with merely some physical rearrangement. Maybe the pin headers wouldn't even have to be special low profile ones. Actually, no need to guess... I can make a physical mock-up using my extra boards and components. Just solder the pins in the wrong way and tack the components to the wrong face with glue or double sided tape. I will do that. -- bkw
