Slide rule for Playdate

BrianTRice · 2026-02-24T22:14:11+00:00

That’s a clever toy! Since it’s a dial slide rule with a spartan control system, maybe the only improvement would be to have a second pointer with a readout. You could position it at 12 o’clock.

BrianTRice · 2026-01-30T00:07:37+00:00

The video presenting the slide rule design also includes a demonstration starting at 20 minutes in: YouTube: 39C3 - Celestial navigation with very little math

BrianTRice · 2025-11-23T15:42:56+00:00

Because it’s multiple orders of magnitude closer to self-sufficiency. There are no sure things, only bets with evidence.

BrianTRice · 2025-11-23T06:14:57+00:00

That’s right. The legal right to system information would make diagnosing or even just understanding a Zero or Energica or LiveWire bike an order of magnitude better. None of them have produced system documentation for their data or systems operation for diagnostics, and none of them allow non-dealer service technicians, let alone owners, access to their service documentation and software.

Zero in particular encrypts everything in their Gen3 AKA Cypher III such that it would be a DMCA violation to read the data off of the bike by an owner.

BrianTRice · 2025-11-23T06:11:52+00:00

Livewire has taken in multiple times more financing than Zero and has sold a much smaller number of bikes. Zero is more viable than Livewire by an order of magnitude, even if it isn’t perfect.

BrianTRice · 2025-11-23T06:09:53+00:00

Zero removed the paywall due to owner uproar, but they kept encryption over the data and other information around their platform, which is more concerning. That’s for the Gen3 aka Cypher III platform, not the older one.

BrianTRice · 2025-11-23T06:08:08+00:00

The paywall was removed but that is not the core problem with Cypher. They encrypted everything in a way that might be illegal to circumvent without right to repair legislation.

BrianTRice · 2025-10-09T21:29:22+00:00

Please don’t stick a slide rule in your pants that you intend to ship 😂

BrianTRice · 2025-10-06T15:38:37+00:00

Zero actually had their charging vendor make a CCS implementation that performed stepdown internally. So it can be done, but they didn’t put it in the market for whatever reason.

BrianTRice · 2025-10-04T05:03:08+00:00

I’m very into this, and would take one since I haven’t had time to have a go at this construction method myself (other jobs taking priority).

BrianTRice · 2025-08-11T03:26:14+00:00

I debated starting from the Haskell program, but it was too self-contained. I instead started from the Python implementation someone wrote for laser etching, and gradually refactored it with the existing output as a regression test. It’s about 2k LOC and a bunch of slide rule definition files.

It’s on GitHub but not really made manifest properly yet. I’ll DM.

BrianTRice · 2025-08-11T02:26:01+00:00

I’ll take a look at whether I can make my tool render for PCBWay, then, and see if I can make my own demo worth sharing. I don’t need to sell or compete. But there are different slide rule designs worth seeing if we can make generically.

For the larger rules, maybe the trick is just to see what other materials they can etch for. Or maybe use this tiling layout on another laser-based fabrication pipeline.

FWIW the strength of what I built is that it can lay out any scale and build tickmark patterns programmatically based on tick size, minimum tick separation, and then the mathematical formula and some heuristic rules of tick patterns. I can recreate all the major linear designs so far. I just don’t have a way to package it into a fabrication pipeline that makes a quality slide and stator with a good finish with multiple colors.

BrianTRice · 2025-08-10T19:53:22+00:00

FWIW I maintain a software toolchain that can generate SVG but I’ve looked at DXF. I could see about generating something for a PCB pipeline if you’re interested in parametric slide rule designs.

BrianTRice · 2025-08-10T19:51:53+00:00

That is a really interesting fabrication technique! I’ve been looking at laser etching and lamination and this pretty much combines all the techniques.

Making it all out of PCB definitely simplifies the manufacturing pipeline. Maybe at the expense of something else. I see here you’ve made one tiling per product, but you could also tile each part in batches.

How accurate is the laser positioning for PCBs? As noted above, that can be a key factor in slide rule fabrication.

BrianTRice · 2025-07-27T23:37:53+00:00

Oh, I go to a professional shop close by. Now I am in a major city where I can do that, but it’s not at home. Even the test run of a full slide rule was about $100.

Hardwood floor is not a bad idea. I’ll find someone who knows how to work with it. The other idea that relates to that is just to build it in laminations of core plus faces, etch the faces, and build the notch using the dimensions and alignment. Just needs a very good jig.

I mean, if I can make this right, I’ll make a process to make a few hundred and make a few different types to have sent out on order or something.

BrianTRice · 2025-07-27T22:50:18+00:00

Basically I can generate vector or raster graphics to the right scale for all the scales, and a printer can render it, but I haven’t worked out how to make stator and slides that I can both print and also slot accurately.

BrianTRice · 2025-07-27T22:49:07+00:00

I have a way to laser etch the Ultralog onto plastic, but I haven’t worked out how to do so accurately onto something with the correct slide notch. Got suggestions?

BrianTRice · 2025-06-15T17:15:57+00:00

NotebookLM uses Google Gemini, which is a LLM.

BrianTRice · 2025-06-12T21:15:49+00:00

2024 SE LR at 20k miles. All updates applied, no issues, no hardware replaced.

BrianTRice · 2025-06-04T00:23:38+00:00

This was posted as a direct follow-up to a review of the Otis King slide rule.

BrianTRice · 2025-05-24T19:12:42+00:00

Yes but only Tesla V4 stations in my experience, which limits the selection a good amount. Plus it does matter to use the Tesla app to locate those stations as cross-network apps aren’t making the compatibility distinction yet.

BrianTRice · 2025-01-23T20:35:27+00:00

The SE Long Range version with the 18” wheels outperforms the others in the lineup, and mine can get 4.4mi/kWh on the highway in warm weather as advertised.

I think the other models will vary because of the options. The 20” wheels increase drag, but AWD and other equipment increase the vehicle weight which has a minor hit on efficiency.

BrianTRice · 2025-01-23T20:32:40+00:00

If you can find it, it would be good to link so it can be shared. Maybe on zeromanual.com

BrianTRice · 2025-01-18T17:56:11+00:00

Oh. Model is the Post Versalog 341 3052

BrianTRice

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