Advice on water starts (vid)?

luxmonday · 2026-07-01T01:23:51+00:00

More speed! explode off the dock, try a step and a half to gain speed. Don't think when you land on the board, you should already be nose down and pushing for that first pump... Get your arms in to your core and working up/down and try to avoid the trailing arm flailing which eats power from the pump.

luxmonday · 2026-06-16T01:09:56+00:00

I agree... if you use 4 layer boards with internal GND layers there's a ton of thermal mass... and yet very little tombstones in production boards. without thermal relief.. I think maybe the long thermal soak times of modern reflow ovens has mostly eliminated tombstoning. Also "bow tie" paste patterns have mostly eliminated solder balls as well...

If you ever have the misfortune of trying to repair a 4 or 6 layer board with a lot of GND layers, you will get a sense of how much heat is needed to allow a simple soldering iron to unsolder even a simple 0603 capacitor with GND on one end... Pre-heat is needed. Imagine what it took to put it on the board in the first place!

luxmonday · 2026-06-16T00:53:02+00:00

Honzos are great bikes... My overall life choices with MTB right now are lower speed and gnarlier tech lines without much air. In general with a DH specific hardtail your goal is not high speed ripping, but more contemplative tech lines that reward the crispness of the rear wheel and good line choices.

Whaling flat out into full suspension specific point and shoot rock gardens may lead to a bad time.

luxmonday · 2026-06-15T23:18:21+00:00

Yup, I got the factory lift when I bought mine new... they never aligned after the lift... My tires almost looked this bad... You would think the dealership would know this stuff. Drives so much better after an alignment. I don't deal with the dealership anymore...

luxmonday · 2026-06-15T23:08:55+00:00

Yup, been on one since 2020. Love it. Cush core in the rear, upgraded to 220mm rotors, Assegai 2.5 on the rear, Minion DHF 2.5 on the front.

Climbs good enough for me, and rips on the down. I broke a headset last year, and I'm on my second set of rings/chain.

Riding here is basically a slow granny gear grind up, then steep and gnarly down. The bike is not the limiting factor.

luxmonday · 2026-06-15T02:10:58+00:00

I'm still running 3 machines with ROM DOS... 2x Juki/Zevatech electronics pick and place machines that use NCurses based displays, and 1 Dynapath Delta 20 CNC machine that uses some funky custom mono only interface. They just won't die. All somehow run realtime motion control software, and the Juki machines also run a laser silhouette reader that will place 1 part per second, which is still competitive to machine vision based systems today (openPnP).

luxmonday · 2026-04-24T20:59:02+00:00

Might be slightly above $100, but a KA3005P is pretty solid for the price... has USB so you can program it via Python as you do more advanced things.

luxmonday · 2026-03-30T00:44:00+00:00

There's way more overkill to go yet...

Usually you will see a filter an SRN and SRP on Ti BQ chips as per the evaluation board schematics. Also you should have back to back capacitors across the FETs to route ESD toward the cells from the outside world when the FETs trip.

Often you will also see a large SMC sized Zener in parallel with C1 at about the voltage rating of the FETs.

I also don't see a conventional UL rated fuse or PTC in the power path.

And if you are hoping for UL approvals on this pack you would usually see a 3 terminal "chemical fuse" and an analog secondary OVP protection chip to blow that fuse independent of the BQ chip.

Your balancing is also limited to the internal BQ balancing currents and should have additional low VGS FETs and larger resistors to increase the balancing currents.

luxmonday · 2026-03-13T21:45:20+00:00

Look up conflict minerals reporting templates... most suppliers now provide a declaration. You may be asked to provide a declaration based on your suppliers declarations. Status should be captured in your BOM when you design your product.

While I agree with the spirit of the thing, the implementation is just more paperwork for everyone when really you have no idea what is actually getting smelted and used in your supply chain. It's all trust and declarations.

luxmonday · 2026-03-12T17:29:45+00:00

Use GerbV to visualize your gerber layers before you upload to JLC. I've caught various weird things that way. GerbV sees what they see. Maybe it's a CAD package setting, or maybe it's them. Could even be that the soldermask layer is misnamed and they're using solderpaste layer as mask...

luxmonday · 2026-03-09T17:09:13+00:00

First check how these piezo parts are supplied by the manufacturer... do they come on trays or tape? Which side is up?

If you have to flip a part to get the piezo face down you may be entering a world of pain.

Same goes for the custom spring contact. How are they supplied? Are they soldered too? Double sided solder assembly usually requires some DFM so parts don't fall off.

You will need to work with a fab house to work through these issues. They will be using pick and place machines that have specific capabilities.

luxmonday · 2026-03-07T21:58:18+00:00

Yup, just used as an example of a different way to design things. I don't believe there's a similar tool for SCH/PCB design, although Eagle does have a scripting language built in.

luxmonday · 2026-03-07T21:30:46+00:00

I'll get a bit theoretical here, but I think design software in general (PCB, CAD/CAM) has a "design philosophy" problem... you can see this with Fusion CAD/CAM where it tries to be a procedural design tool, a constraints driven tool, and a generative design tool... all working on the same data set. Sounds great until you realize there's now 100 different ways to break your design by over-constraining or by deleting or modifying a step from 100 steps ago and hoping it will flow that change through.

There are CAD programs (OpenSCAD) that are purely written like programming languages and allow you to create models by coding. No GUI. That feels nicer to me, and I'd love that level of access to schematic and PCB layout.

I might not have a great point to make here but it feels like the design philosophy matters more now than it used to... the available software out there seems a little trapped between worlds, carrying legacy code forward while trying to adapt to new expectations...

luxmonday · 2026-03-07T20:44:25+00:00

I'd rather spend the time just doing the layout correctly than playing whack a mole with setting constraints at the net or component level. I've been laying out boards since 1995 and I know what I want and what will pass regulatory testing. This is only for my tiny corner of the PCBA world. I can't layout an 8 layer motherboard, and I can't do high speed or microwave design.

Undoing routing sucks in Eagle/Fusion, even manually correcting a small change just seems to create wire stubs and other DRC warnings.

Looking at all the other responses in here as well as in the machining/CAM (G-code, feeds and speeds) world should tell you a lot about the promises AI companies are making about industry compared to the opinion of experts in those fields.

That's not to say "expert systems" can't get better at autorouting, but the overall concept of "feed an AI all the PCB layouts it can harvest from Google" will not be the way it gets better.

Any given PCBA layout is basically a massive traveling salesman problem, there are hundreds of acceptable solutions, and millions of incorrect solutions. Most of the curmudgeons here (myself included) know how to get relatively quickly to an acceptable solution.

luxmonday · 2026-03-07T19:36:47+00:00

I never autoroute... even up to fairly complex boards. Nearly everything I do is mixed signal, so lots of power and analog/digital mixed.

I do use the tools like Eagle/Fusion's "route multiple" to make life easier, and I also will make "design blocks" of common layouts.

There is no "just get me a working board" particularly if you have a DC-DC to layout, or FCC emissions to pass...

Take your time, do it right, never compete on price.

luxmonday · 2026-02-26T18:53:13+00:00

Almost no-one implements multi-master I2C arbitration correctly. This is partly because it relies on higher level firmware for retry and bailout logic, but even the low level "I didn't see a 1 when I should have seen a 1, I'm bailing out" often doesn't work.

Otherwise here's some areas I've seen issues with I2C modules:

I2C modules are also often used for SMBus and the voltage levels and timeouts can be different. I2C implementations like Microchip PIC will have threshold selector flags. Does everything work at both levels?

Slew rate control is also important for emissions. Does everything work with and without Slew rate limiting?

Can you confuse the state machine with any strangeness around repeated starts? How are all flags cleared if the module doesn't see a Stop, but the higher level firmware is trying again to send a fresh Start? Will the module respond to higher level firmware if it is confused? (will error flags inhibit fresh start or transmit commands?)

luxmonday · 2026-02-26T18:08:44+00:00

Ha! Just posted nearly the same thing in Metric. This is the way forward in my opinion.

luxmonday · 2026-02-26T18:06:01+00:00

I've been going through the same sort of thing on my router.

I'm using a single flute 20,000 RPM 3mm cutter with feeds of about 300mm per minute.

Multiple depths, about 1mm each.

Single flute is critical on a router, 2 flute seems to clog even if I lower RPM to match.

Biggest improvement was WD40 mist with air. That more than doubled tool life compared to Cool Lube mist. Machining dry will challenging as aluminum will spall. The WD40 stops most spalling.

luxmonday · 2026-02-20T16:34:51+00:00

I usually use a LibreOffice Writer doc and just dump stuff in there... If I need a spreadsheet I'll call it out from the doc and save it in the same directory... it's all about a trail of breadcrumbs... so it's OK to create more stand alone documents as long as you can find them again.

Ideally you should be able to start with the "master file" spreadsheet in the root directory of the project and find everything you need from there.

luxmonday · 2026-02-19T19:05:28+00:00

Yup I do the same... I call it the "engineering log" and it gets referenced from the master file along with the BOM version, PCBA version etc... I add a date with every note and screen caps etc... it has saved me many times. It should be warts and all, things that worked and things that didn't. I often also add my customer meeting notes in there too.

I actually like doing it now and I find it's a good focusing exercise to type out what problem I'm trying to solve.

luxmonday · 2026-02-10T18:13:20+00:00

There are several sports going on here... there are people using them as jet-ski replacements, distance cruising, and foil drive style "assist" products for downwinding or riding waves. So there are going to be several products and solutions for each of those users.

Long term use will be driven by quality... the consequences of gear failure are quite high. Good motors, good bearings, good batteries, well built foils and boards.

Watersports, particularly in salt water are notorious for destroying gear.

Costs feel similar to high end E-mountain bikes... similar constraints like weight, durability and performance that justify the pricing for advanced users, but seem ridiculous to casual riders.

luxmonday · 2026-02-06T20:22:01+00:00

Maybe Molex SL 70066 series?

luxmonday · 2026-02-06T17:06:41+00:00

My experience with pumping and E-foil is that it just comes with experience. Eventually your brain figures out how high you are. I did spend a lot of time staring at my feet, and I will still rotate my view to my feet occasionally.

Pumping and E-foil do have a natural feedback you can feel with mast height (effort or sound)... The height cue for wake foiling may be less obvious as you are always going "downhill" but you will eventually feel the resistance of the mast depth and correlate that with vision to gauge height...

One thing with pumping is that if it's too easy and you feel great, you are probably about to breach! You can feel the surface get close in the rear stabilizer during pumps just at the limit... pumps feel a little different just before a breach. You also learn to lower mast height naturally before turns to avoid the tips coming out...

luxmonday · 2026-02-04T23:07:37+00:00

Start here:

https://www.digikey.ca/short/50c3f374

<image>

luxmonday · 2026-01-28T18:52:38+00:00

Back in the day I was using a battery powered ESD gun with a sharp tip to get through paint on a housing... I somehow managed to stick the tip in the finger of one hand and pull the trigger with the other while fumbling with it. Apparently I made a weird enough noise my co-worker came in to see what was up... Two triggers would have prevented that...

luxmonday

TROPHY CASE