Crowdsourcing A Build Decision

(John Ellenberger) #1

I’m in the last stages of a Sparkfun S3 => XL conversion. Its the hardest part because the XL has a pre-assembled wiring harness but the Sparkfun is all terminal strip based. I basically have two choices:

  1. Rip off all the terminals and just solder / shrink wrap everything
  2. Wait for the molex connectors I ordered from Digi-key and use them for the motor connections (the controller needs bare wires so not much point in doing anything with connectors).

Soldering would be more solid in a hostile environment (vibration, dust, etc.). Connectors are good for flexibility although not sure how often I would actually be disconnecting things

Comments folks?.


(Phil Thien) #2

Any chance you can post pics of what you have, and what you’re trying to get to?

(John Ellenberger) #3

Here’s a typical example on the X bar. Two molex males on the harness. Bare wires coming from the motors.

(Phil Thien) #4

I wouldn’t hesitate to solder that. In fact, a poor connection to a motor would be the Achilles heel of a stepper driver, so you could easily make the argument that soldering would be superior to adding yet another quick-break connector.

You don’t have to go nuts, I see a lot of people start lineman splices and I wouldn’t for wire of that size. I’d simply strip some insulation off, hold each side with my handy-dandy alligator clip holders, and tag it with some solder, it won’t come apart. In fact, that is how those existing male Molex connectors are attached to the wires.

Don’t forget to put the shrink-wrap over the wire before you solder. :slight_smile:

(mikep) #5

You do want to use the smallest solder connection you can though, and do it somewhere where the wire won’t be flexing. It will work harden and break if it’s somewhere it can vibrate a lot or bend repeatedly.

(Phil Gorsuch) #6

Second MikeP. Solder is excellent for electrical connections, but horrible for causing breaks in flexing copper cables due to work hardening - right where the wire hits the solder blob. So choose your locations carefully. Molex connectors when done right (crimped, not soldered if you have the wildly expensive crimp tool) are near indestructible and have the advantage (if said advantage is needed) of being plugged and unplugged at will. If you are not disconnecting solder’ll do it.

(Dan) #7

Re do the molex connectors and just solder at the connector. Don’t have any breaks or joins in the wires. Get new lengths of wire if you have to. Will make trouble shooting much easier just need to test continuity of the wires etc. For these kinds of things I prefer to do it once the hard way but do it right.

(John Ellenberger) #8

Thanks for the suggestions. Think I’ll molex the motors and solder anything else.

Most of us that do electronic stuff already invested in the crimper. Hoping it works on these because Carbide uses much heavier connectors than you typically use on electronic projects.

Although I have the expensive US-made version you can get them a lot cheaper if you’re willing to play the Chinese lottery: