Roadrunner electrical probes

prusaprinters

<p>This is better than putting an oscilloscope probe in your helping hands.</p> <h3>Print instructions</h3><h3>Roadrunner Probe Revision A</h3> <p>Released 2020-10-04</p> <p>Copyright (c) 2020 Josh Myer <a href="mailto:josh@joshisanerd.com">josh@joshisanerd.com</a><br/> Released under a Creative Commons CC-BY-SA license</p> <h3>What is this?</h3> <p>These are some basic electronic probe stands. They can be used to<br/> hold a small pogopin or needle onto a pad on a PCB, with a built-in<br/> channel to get a wire out the back. They are designed to accept a<br/> simple Dupont-style male at the head end of the wire, and I use them<br/> with male ends on the other side.</p> <p>This project is heavily inspired by Giuseppe Finizia's excellent PCB<br/> Workstation designs. If you work on a PCB which can be clamped in<br/> place and will be under examination/work for extended periods of time,<br/> his design is almost certainly superior to this one. There are<br/> several of them, my favorite is probably<br/> <a href="https://www.thingiverse.com/thing:3615910">https://www.thingiverse.com/thing:3615910</a>, but check out the rest of<br/> his thingiverse for some alternative designs.</p> <p>But, if you, like me, want to have a little arm of these guys that you<br/> can pull out for quick probes here and there during a reverse<br/> engineering session, these might work for you.</p> <h3>Supplies needed</h3> <p>You will need the following to finish this:</p> <p>To hold the body to the upright:</p> <ul> <li>M4 bolt (hex-head, which is important, 10mm or longer)</li> <li>M4 nut</li> </ul> <p>To hold the probe and wire to the head:</p> <ul> <li>A needle/pogopin/lightweight probe</li> <li>A wire (I use 30cm/1' dupont male-male cables)</li> <li>M3 screw (5mm or so, button head strongly preferred)</li> <li>M3 washer</li> <li>M3 nut</li> </ul> <p>To counterbalance the base:</p> <ul> <li>9 US Nickels (there are 3 counterweight slots in the base: 20mm<br/> diameter, 6mm deep)</li> <li>Tape to hold the counterweights in</li> </ul> <h3>Assembly</h3> <h3>Nut handle</h3> <p>To assemble the nut handle, push an M4 nut into the slot on the nut<br/> handle. It will go in a little bit, but you will need to exert<br/> significant force to actually cram it in there. I use a little C<br/> clamp for this job, but an arbor press would be ideal.</p> <h3>Base assembly</h3> <p>On the base, there is a slot on one side. This is the probe slot,<br/> which gives your sharp probes a safe place to live when not in use.</p> <p>On the upright arm, note that one side is flat: this is the side the<br/> probe arm will mount to.</p> <p>Clip the upright arm into the base, with the flat side facing the<br/> probe slot.</p> <p>Ideally, place 3 stacks of 3 nickels into the cylindrical recesses on<br/> the bottom of the unit, then use adhesive tape to hold the coins in.</p> <h3>Arm assembly</h3> <p>To assemble the arm, we will thread the wire, then attach it down.<br/> Starting from the head of the unit, place your wire such that it will<br/> make good contact with the M3 washer. Then, without leaving slack,<br/> insert the wire into the channel down the side of the arm.</p> <p>Once the wire is in place, use the M3 screw and washer to hold the<br/> wire down, with the M3 nut on the back. You can put a washer between<br/> the nut and the arm as well, if that makes you happy.</p> <p>We will attach the probe in the final step. Attaching it now leads to<br/> lots of poking.</p> <h3>Arm attachment</h3> <p>Once the wire is run down the arm, you can attach it to the upright by<br/> using the M4 bolt through the upright arm, threading that through the<br/> slot of the probe arm, and then using the M4 nut handle to screw it<br/> down. Note that the nut handle has a thin plastic layer between the<br/> nut and one side. This takes the place of a washer, so assemble it<br/> with that side facing the probe arm. If you've installed it the right<br/> way around, the whole nut will be visible after it's screwed down.</p> <h3>Probe attachment</h3> <p>Finally, loosen the M3 screw at the head end just enough to slip your<br/> needle/probe/pogopin up underneath, then gently cinch it back down.<br/> In particular, if you're using pogo pins, be careful not to crush<br/> their delicate tubes. This is part of why I use sewing pins for my<br/> probes.</p> <h3>Complete</h3> <p>And that's it, you now have a probe.</p>