I want an expanding crimp-on mechanism - Page 1
Forum section: electronics / projects

author: Lasherž
author_rank: Contributor
timestamp: July 19, 2023, 03:35:42 am
content: Hello,I'm wondering if anyone is aware of any preexisting crimp-on mechanisms similar to an alligator clip except that instead of clamping down it expands outwards instead? I might be able to just modify an alligator clip but I'd much rather get something purpose-built.The use case is that I'm conducting multiple multi-channel car amplifier board repairs weekly on the side and I would like to very quickly connect loosely (but not falling out) to channels without involving the set screws on the amps every single time I test a channel and with enough pressure to get electrical contact at low voltage. The idea would be that the mechanism expands in the hole and holds the wire there long enough to get a few multimeter readings and then move on to the next one with a quick squeeze and release.Some amps an alligator clip will work, but I'd say most don't such as this RF P1000x1BD I'm working on currently.Thank you!Edit: After some pondering the best I can come up with is modifying the press paddles on an alligator clip so they fit into smaller spots and then crimping a wire with it facing the wrong way and expanding the teeth directly to remove... Surely there's a better way lol.

author: donlisms
author_rank: Frequent Contributor
timestamp: July 19, 2023, 06:47:47 am
content: I don't do car amplifier repairs, but I do make a lot of connections... I'm sure folks here would have more suggestions if you could post a picture of a typical use case!

author: gnuarm
author_rank: Super Contributor
timestamp: July 19, 2023, 07:17:05 am
content: Quote from: donlisms on July 19, 2023, 06:47:47 amYeah, I'm not picturing this at all. Are you talking about binding posts with a screw knob to attach a bare wire, and also has a hole for banana plugs? If so, you can either use banana plugs, or you can crimp ends on the wires to insert where you normally would insert the wire. Much easier to use than wire and no wild strands sticking out. I never liked using those binding posts with wires.

author: ArdWar
author_rank: Frequent Contributor
timestamp: July 19, 2023, 07:41:53 am
content: Can 2mm banana jack do the trick? The extra springy version usually can cover from about 12AWG to 8AWG hole.

author: jpanhalt
author_rank: Super Contributor
timestamp: July 19, 2023, 08:32:34 am
content: There are compression spring contacts (attachment), which are often caller pogo pins. You can solder connecting wires to the cylindrical body.

author: Lasherž
author_rank: Contributor
timestamp: July 20, 2023, 02:47:28 am
content: Quote from: donlisms on July 19, 2023, 06:47:47 amQuote from: gnuarm on July 19, 2023, 07:17:05 amThis is a bit of a best case scenario here, but distribution blocks use the same method of a hole with a set screw coming in from the side. The only difference between the wire mounting locations on amplifiers is that they often don't have contact surface anywhere except for the bottom, where the set screw pressure is highest. Amplifiers don't always have such a wide open design, but it's always either a set screw or a track bolt that a plate rides up and down and it's a similar clamp down happening. If they were all the same size then I could certainly use banana plugs.Quote from: ArdWar on July 19, 2023, 07:41:53 amThat's a great idea with expanding fins held in by pressure. In fact I would bet that those would work great on the P1000x5bd that I mentioned and if I set the set screws correctly then I could plug and remove banana plugs from the remaining gap very well. I didn't know they had ones that had so much variation, that sounds like easily the top option.Quote from: jpanhalt on July 19, 2023, 08:32:34 amThat's more or less what I was looking for except that it would need to open sideways and preferably with at least 3 expanding points to stabilize it. Those seem to only open in one direction which would be difficult to keep in the wire hole.

author: tooki
author_rank: Super Contributor
timestamp: July 20, 2023, 03:26:17 am
content: Check out the Stäubli test and measurement catalog, they have a number of such doodads, maybe one will do the trick:https://www.staubli.com/content/dam/spot/TM-Main-11014124-en.pdfIn particular, take a look at pages 98-114.