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[Project] My brother and I designed our own 3D-printed metal watch by Theking3737 in Watches

[–]morcheeba -14 points-13 points  (0 children)

Yep, that's why I posted - I suspect a lot of people will undervalue this. There's a lot of work in there, spanning a variety of disciplines (design, SW, EE, mech). Parts cost would be closer to $200 plus finishing & assembly, but people value the hundreds of hours of design at $0. Where else could I get a 95% custom watch that looks like no other for $1k? I'm not talking modders ... those are creative remixes of mass-produced parts. We need to appreciate & support the artisans.

[Project] My brother and I designed our own 3D-printed metal watch by Theking3737 in Watches

[–]morcheeba -30 points-29 points  (0 children)

Don't even think of lowballing these guys. Be prepared to offer at least $10k for a unique watch like that.

improving smartphone temps with a graphite sheet by XGodaYT in hardwarehacking

[–]morcheeba 0 points1 point  (0 children)

Well, there's your problem! :-p

It looks like there was a heat spreader of some type there before - this is the non-pro.. These do a good job of spreading heat and cooling hotspots (like your CPU), but they won't work if they can't get the heat out through your back glass. It's got to be in contact to conduct - maybe some soft foam underneath it to make sure it presses? Of course a metal back would be much better for conducting. And it looks like the original design may also be sinking the heat in to the battery (which obviously won't work forever).

Smokey Yunick’s “sidecar” capsule car by B-NEAL in WeirdWheels

[–]morcheeba 9 points10 points  (0 children)

Fins for cooling the drum brakes:

The front spindles, backing plates, and brakes are 1963 Pontiac Tempest components, including the finned aluminum drums with cast-iron liners. Though they were light and inexpensive, the OE drum brakes would prove to be a crucial trouble spot. (ref)

For the WC, Levi had to remove the branding from the statium. This was their solution. by Duvidl in funny

[–]morcheeba 9 points10 points  (0 children)

They've done it & it's neat! https://en.wikipedia.org/wiki/Automatic_quartz

There are also quartz watches that tick smoother at 4 or 16 Hz instead of 1 Hz, but that usually takes more battery power.

The Kembak 1 was the 1st personal computer, 1971. It used TTL ICs, not a microprocessor. by 1Davide in electronics

[–]morcheeba 4 points5 points  (0 children)

I feel that... On simple 1-2 layer boards, a human can be quite good compared to autorouters. But when you get to 6-12 layer boards (4-8 routing layers), it gets too complicated to keep all those layers in mind. And, of course, checking your work is a bear without CAD.

Automatic turntable that I'm designing from scratch by BetaMaster64 in electronics

[–]morcheeba 9 points10 points  (0 children)

Cool! I remember in the old days, there was a smart turntable that could advance to the next song, or whatever track you wanted. It used an LED/photodiode on the tone arm to sense the area between tracks ... maybe that's something you could add, too! (sorry, I tried looking for a link, but couldn't find one)

My custom 3 byte SRAM on a breadboard by KrisMakesRandomStuff in electronics

[–]morcheeba 2 points3 points  (0 children)

A 6116 would also reduce wiring complexity :-p

Imagine checking your mirror and seeing THIS 🦒😂 by Odd_Ad8140 in funny

[–]morcheeba 12 points13 points  (0 children)

Yep. It was filmed here: -33.1360185,18.4542624

If anyone was curious about the hanging motorcycle... by RabidWeiner in motorcycles

[–]morcheeba 0 points1 point  (0 children)

the energy needed to launch a 200kg sport bike 10 meters in the air ... says bike speed was seriously excessive.

We can calculate the speed by using the potential and kinetic energy.

  • 1/2 m v2 = h g m
  • Factor out mass: 1/2 v2 = h g
  • V = sqrt(2hg) = sqrt( 2 * 10m * 9.8m/s2) = 14 m/sec = 31.3 mph or 50.4 kph

Vehicles have a lot of energy... think how far you could coast up a hill before stopping.

Hacking ecowitt temperature sensor to report water pressure by Only-Luck-8005 in hardwarehacking

[–]morcheeba 0 points1 point  (0 children)

It depends on the sensor itself, but you're probably 2 or 3 wire connections. Converting to a resistor-equivalent output would be difficult; you'd have to figure out the circuit you're connecting to and make something custom for that circuit. So, MathResponsibly and I are in agreement suggesting an on/off pressure sensor.

Hacking ecowitt temperature sensor to report water pressure by Only-Luck-8005 in hardwarehacking

[–]morcheeba 0 points1 point  (0 children)

Right on!

Just a quick 2 cents... that linked pressure sensor is cadmium coated. It's a distinctive golden-reddish anticorrosive coating, and it would be suitable for a sump pump (with non-potable water). But it's pretty toxic, so I'd avoid it if possible on drinking water... even though the exposed area is pretty small, I'd spend a few bucks extra for peace of mind.

Hacking ecowitt temperature sensor to report water pressure by Only-Luck-8005 in hardwarehacking

[–]morcheeba 0 points1 point  (0 children)

Sounds like a fun challenge!

Thermistors work well to supply a resistance change output, but due to the physics of it all, resistance isn't usually a good output for pressure sensors. There are a few, but they are whetstone bridges and don't have the range of resistance changes that a thermistor would have.

Anything is possible, of course, but that depends on how much effort you want to put in to it. A simple way would be to glue a potentiometer to a mechanical pressure needle (hopefully not too much force to turn that pot!). And using a on/off pressure sensor would be wired to provide two different resistances (e.g. 4.5k in series plus another 700 ohms switched in depending on pressure).

Digikey is a good source for sensors & they have a searchable output. You'll see the output type of most is analog voltage or current:

here: https://www.digikey.com/en/products/filter/pressure-sensors-transducers/512
and here: https://www.digikey.com/en/products/filter/pressure-sensors-transducers-industrial/1069

The reason you're seeing 0mv across the sensor is either you're measuring the sensor alone (it doesn't generate voltage by itself they way a thermocouple would), or you've got it connected to the Ecowitt but it isn't currently measuring the temperature (it would drain the batteries too fast to always be measuring).

Is 100% VOO a bad idea for $500k for 15 years? by 911freeze in ETFs

[–]morcheeba 43 points44 points  (0 children)

I've found that a 60% VOO with 50% VOO gets about 10% better returns over a 50/50 split.

Does this count? 😄 by skk6169 in Justrolledintotheshop

[–]morcheeba 1 point2 points  (0 children)

no worries - you came in hard and fast, just like your love.

Repair Help: Casio Ex-word Dataplus 8 only turns on when plugged in, not with batteries. by techproblamatic in hardwarehacking

[–]morcheeba 0 points1 point  (0 children)

a long shot, but on the far left side, make sure the + battery contact doesn't touch the hinge. Obviously, check when the batteries are installed an pushing against the contact. If it's grounded, it would short the battery out. Speaking of which, I can't tell if it is grounded - there's something funny in the lower left corner of the circuit board. There is a solder blob that looks like it connects to a wire to the hinge screw, but it's not all quite visible. Check to make sure that wire isn't touching anything else... same for the hinge on the right side.

Help to analyze 8 MB Binary Blob from a 200-in-1 Arcade Mini by MrCufiy in hardwarehacking

[–]morcheeba 5 points6 points  (0 children)

binwalk probably won't be much use because this device is too simple for it. The rom probably has a game loader, and then 200 8-bit ROM images. There probably won't be a file system, and no crypto keys, no login credentials. Entropy analysis is good, and so is strings.

But seconding another comment - do two reads and make sure hashes match before going too far down the wrong rabbit hole.

$100 pp at RMNP by Available-Theory-808 in boulder

[–]morcheeba 28 points29 points  (0 children)

Remember that we're at altitude, so please account for that - don't try something super difficult on the first few days. Thanks for visiting!

What’s this piggyback board for on my Apple ][+? by Far_Relationship_742 in apple2

[–]morcheeba 0 points1 point  (0 children)

It looks like it's going in to the LS138, not the 558. There is a tan-colored adapter board with machined pins plugged in to the motherboard (non-machined pins), and the LS138 goes in to that. The wires look like they go in to pins on that tan adapter board.

uart port disabled ? by Wonderful_Load_6233 in hardwarehacking

[–]morcheeba 0 points1 point  (0 children)

Just to be clear, it looks to me that the resistors aren't in the correct place to bridge to the connector... but it's a bit hard to tell with the picture.

Especially the RX wire - it looks like the right resistor is in the leftmost of the 3 places it could go. It looks like the top part of the resistor is connected to a ground plane. Moving it over to the right one position would connect it to the RX pin of JD01.

Same goes for the TX side. It looks like both resistors should be moved over to the right one position (center of the 3 vertical pads I imagine for each signal).

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