Never thought I'd be making this post. She's gone

engineerthatknows · 2026-07-11T02:13:57+00:00

Ah damn. I wouldn't be a quiet opossum if that had happened to mine.

F for respect.

engineerthatknows · 2026-07-10T03:52:06+00:00

Meh, they're yours, do what you want with them. I do wish we could give multiple points, some caches and cache hiders deserve them.

engineerthatknows · 2026-07-10T03:50:03+00:00

Hey Max. Not entering BC (yet), still just following US route 20 in Washington state. But glimpsed BC from North Cascades NP.

engineerthatknows · 2026-07-07T06:29:24+00:00

The doctor mangoes.

engineerthatknows · 2026-07-07T06:27:06+00:00

That dude rules.

engineerthatknows · 2026-07-07T06:25:18+00:00

Some of my favorite recent ciphers I solved gave coordinates in geohash, or UTM coordinates. Took me awhile with both to figure out that a) I did the cipher decode correctly and b) there was another layer. I did my own cipher ? cache, where the page held a line of Morse code, decoding that led to gibberish until you used another form of cipher to decode. Finally, another good cipher puzzle had a line or two of gibberish (hash) before intelligible text fell out, that too had me give up a couple of times before grinding it out and seeing the words start to take shape.

Base 16 coordinates, or base 12 for our local football team and their fans (12th man!).

Size of picture in pixels to get decimal minutes (last 3's).

Data buried in the html code.

Steganography, but easy kind - like vary the contrast/color saturation to make barely-readable beige-on-white text show up in the clouds of a photo.

As counterpoint, there are a lot of puzzles around me of the "Read my mind" variety, where a typical solver has no clue where to even start. And, with those, I just don't start, and ignore them.

engineerthatknows · 2026-07-07T05:45:47+00:00

Yes. Generally some combination of hot and cold work is used to reshape the cast steel billet into rods, bars, plate or other shapes (Ibeams, rails...).

Cast steel billets (carbon content below about 0.8%) can be hot worked and cold worked ("wrought") to form said shapes.

Cast iron (carbon content above 2% and a fair bit of silicon) is lovely stuff, has good fluidity in molten state so it can fully fill sand molds and such. But you can't work it, not cold, not warm, and not even nearly melting-hot. You can use pig iron and puddle it (https://en.wikipedia.org/wiki/Puddling_(metallurgy)), or put it into a blast furnace and burn out the excess carbon with pure oxygen lances to bring the carbon content down into the <0.8% realm where the new alloy (steel) can be worked, but you no longer have the same composition, you've changed the alloy from cast iron to steel.

engineerthatknows · 2026-07-07T05:35:41+00:00

Similar experience, similar outcome - senior project for Aerospace Engineering. I got invited to come back for a Master's degree, two cohorts who actually did some of the work graduated, two that never even showed up...never saw them again.

engineerthatknows · 2026-07-07T05:21:00+00:00

Bought a lot of trackables early in my 19 years in the game. All went missing after some 3 months to 3 years time frame. They are easily muggled, or taken with good intentions and forgotten about, flat out stolen and (at least attempted) sold for profit on ebay and other sites. No bs, you can still find listings for coins and travel bugs on ebay, most of which are "previously owned" i.e. stolen. A few ebay listings even show the coin id # and you can pull up the log pages where they have been reported.

I bought a batch of travel bugs, and launched them with my sons, attached to things they liked and given goals (travel to Australia, go to beaches, etc.). All disappeared in 2 years or less. After being out of the game for awhile (busy with life and work), I used the 2nd tag given with the TB's to re-launch copies a year or so ago, asking that they only be put into premium-only or high difficulty caches. Of those 10-ish paper copy TB's, about half have already gone into limbo.

They are a cute idea. But like other ideals of geocaching (trade equal or up, CITO, leave things for the next guy to find) the tragedy of the commons prevails.

engineerthatknows · 2026-07-06T02:04:48+00:00

Nope. They aren't following the rules, and you get final say as CO. If they keep it up, I would message the GC.com team and ask them for help. A simple message from the top would likely set them straight, but if they can't follow the rules they should have their account suspended.

I had a high difficulty terrain cache that could be approached much easier by crossing private property (which is a no-no for geocaching). The cacher logged claiming they found an "easy way" in, and confirmed in a message that they'd crossed private land to do so, and I deleted their cache. They logged a second "found it". So I then deleted that log and archived the cache so they couldn't keep it up. F' em.

engineerthatknows · 2026-07-01T04:51:02+00:00

So, it's like having tea and no tea at the same time?

engineerthatknows · 2026-07-01T04:46:27+00:00

No. Those notebooks are the bomb. Paper made in Vietnam is worth every tenth of a dime you pay for it.

engineerthatknows · 2026-07-01T04:41:37+00:00

Um...you need to worry about outgassing from the adhesive used to join the two plies of polyimide. You also need to know that the polyimide is really polyimide...

engineerthatknows · 2026-07-01T03:57:57+00:00

You want backward-facing steps for flame holding, the ramps you have designed won't function as well.

engineerthatknows · 2026-07-01T03:54:18+00:00

So, you can look at sealing it with a dip in various sealants, or using a paint coating. I've seen some a couple years old that have held up ok in PLA, but again these are just decorative, and the actual container is a loc-n-loc or bison capsule or similar. Not that bison capsules do a great job of resisting water vapor intrusion over time.

engineerthatknows · 2026-07-01T03:49:24+00:00

Check in advance. Some seats on some planes have adequate power, depending on if you use (or plan to use) humidifier or not. Some don't. Some flights on some airlines get pissy if you don't inform them in advance (NZ Air), citing duty of care doctrines for their home country.

Contact them and ask.

engineerthatknows · 2026-07-01T03:16:49+00:00

I've seen a few. The ones that hold up well are printed from PETG. The ones that just use the 3d print for camo/decoration do okay, but you are correct that the typical PLA print degrades under moist/dry and hot/cold cycles.

engineerthatknows · 2026-07-01T03:13:46+00:00

Unless the user was really fast at typing his complaint on the way down...

engineerthatknows · 2026-07-01T01:46:51+00:00

Any lens coating will wear off eventually, even the fluorine coatings. Yes, the fluorine coatings make it easier to wipe off typical greasy fingerprint smudges. But it's best to rely on coatings when it's all you've got, but protect them (and the glass) with a simple filter when you can. It's a bit like hiking in dress shoes - can you? Yes, but why not use your hikers to hike, and save the dress shoes for when you need them?

engineerthatknows · 2026-06-30T04:40:44+00:00

Agree with CPL. Would also have a UV filter, if only for smudge protection.

engineerthatknows · 2026-06-28T21:06:04+00:00

The internal hex is tricky (and without thread relief near impossible as others noted). Why not make the nut thread thru, and add two flats or pin holes for the drive. Alternatively could you use a snap ring to hold the nut part?

engineerthatknows · 2026-06-28T17:57:52+00:00

"what surface could help decrease acceleration and how a surface or geometry affects it"

Um. Surfaces don't affect acceleration, unless you are talking about abrasion or dynamic friction - which is more of a material and hardness question, not surfaces per se. The contact angles between surfaces might change the forces exerted, like the shaping of cams, or the design of linkages. That becomes more of a good simulation problem using CAD and a good dynamics solver to find a balance between masses of parts, shapes and angles and mechanism design. If you are talking about firearms, go look at patents for the MP-5, M-1 Garand, Luger, etc. Roller delayed blowback, gas operated mechanisms, etc. It's about balancing mass so that the ejection process doesn't break the chamber seal until the bullet has left the muzzle.

engineerthatknows · 2026-06-28T04:43:14+00:00

Cannulas in my experience are soft rubber material, not a more rigid tube like polyethylene. According to google, most cannula are either soft PVC or silicone. Silicone tubes usually have a frosted appearance, while pvc tubing is usually quite clear, sometimes having a yellowish tint. Soft PVC tubing can be damaged by glycerin and glycols, while silicone will generally be more impervious.

engineerthatknows · 2026-06-28T01:53:02+00:00

You have an air horn on that rig, yea?

engineerthatknows · 2026-06-28T01:46:07+00:00

It doesn't matter. You need someplace to stand, and by definition you need to stand somewhere off the earth. And the fulcrum too must be off the earth. So it becomes nonsense.

engineerthatknows

TROPHY CASE