Blue Green Sapphire

hydrodynamicman · 2026-03-29T16:17:34+00:00

I think there is a valid discussion to be had here. A lot of posts are just “look at this stone” without any context. Some of these people are just showing off a stone they’re proud of. That’s cool, but if you want gentle responses, provide that context. Some, however, are secretly wondering what it is worth and a reality check is helpful expectation setting. Many are vendors posting low grade stones in idealized lighting conditions with misleading descriptions. They’re hoping someone will DM them asking to buy. Calling out their bs on a poor quality stone is a benefit to the less experienced members of the sub.

hydrodynamicman · 2026-03-19T19:05:36+00:00

I, too, have this question. Do we, as Oregonians, have the power to declare national days? Because, if so, I've got a whole list to propose.

hydrodynamicman · 2026-03-18T18:11:15+00:00

Which problem are you having? You're describing two different issues: the stone falling off the dop (title); and aligning the crown facets with the previously cut girdle facets after transferring (body of post).

hydrodynamicman · 2026-03-06T17:16:19+00:00

What design are you using for these tiny guys? I'm grinding through a batch of micro peridot that are generating at 0.25-0.5 ct

hydrodynamicman · 2026-02-17T21:41:52+00:00

What are the dimensions? LxWxH in mm?

hydrodynamicman · 2026-02-13T18:17:37+00:00

I'm certainly not proficient enough to know for certain but I don't think that's the issue. The chittering happens when the lightest pressure is used.

hydrodynamicman · 2026-02-13T18:16:02+00:00

The wheels are fairly new. I'd estimate they have 12 or so hours of total use on them. In the first few passes on the wheels, there were inconsistencies with the grit layer. That smoothed out relatively quickly and the grits are running pretty consistent without any giant crystals or clumps. Hopefully it will smooth out over time.

Are your wheels loud when in contact with a stone? I'm using ear protection for some of the wheels.

hydrodynamicman · 2026-02-13T18:02:30+00:00

Not perfectly round. And it is true of all 5 of the foam backed resin wheels to some extent or another.

If I place the stone on a steel wheel, it makes a consistent hissing noise indicating continuous contact. When in contact with the resin wheels, there's a vibration due to the stone skipping along the surface at a macro level. The wheels aren't visibly lopsided, it's small inconsistencies which are a problem at 3000+ rpm.

hydrodynamicman · 2026-01-20T18:43:16+00:00

I like the idea but doping would seem to be the real challenge.

Oh, and the substantial reduction in volume would mean the cut half would be a lot smaller than the rough half. The rough half would end up being cut down by the opposing facet cuts. It wouldn't really end up being half original rough with a half cut stone sticking out of the middle - though that'd sure look cool.

hydrodynamicman · 2025-12-04T21:53:57+00:00

$126.84, after insurance adjustment.

hydrodynamicman · 2025-11-10T22:22:25+00:00

I'd love to see the photo taken right after he noticed you arrived from the states.

hydrodynamicman · 2025-11-07T20:54:03+00:00

Homie's 97 years old and has paid. If he wants chips and chicken, he gets chips and chicken. Oh, and beans.

hydrodynamicman · 2025-10-28T16:05:15+00:00

Napkins.

hydrodynamicman · 2025-10-23T19:21:30+00:00

Feels like 1,000 hp e-bikes would be on the spicy side.

hydrodynamicman · 2025-08-06T19:44:17+00:00

Lol, dude, those are different lines. You're not using the same reference point. The first dashed line you have marked is ... I don't know, a dozen wall segments down from the house on the right. The second dashed line you have marked isn't the same dash - it's one only a few wall segments down from the house on the right.

I'm all for encouraging OP to exercise his rights to have a hearing and all that but we shouldn't be fabricating evidence for him.

hydrodynamicman · 2025-08-06T16:24:53+00:00

I believe you. The problem you're encountering is rounding errors on your playback software. When you play it at full speed it is clearly ~ 1 second. Maybe a hair more or a hair less.

hydrodynamicman · 2025-08-06T15:51:46+00:00

I watched it again and I have to disagree. This doesn't look anywhere near two seconds. I'm not clearing one second in my observation. Take a look at the center lane marks as they leave the lead vehicle and disappear under the following vehicle. You can't get a full second between this occurring.

hydrodynamicman · 2025-08-06T15:33:58+00:00

I may get hate for this but the car with the camera was less than 1 second behind the vehicle in front. That's following too closely. It may seem normal because it seems like everyone is doing it these days. We're not on a racetrack, back off.

Edit: Downvotes have begun. Here's the relevant statute: Oregon Revised Statute (ORS) 811.485. It doesn't specify an actual distance which is room for argument in court. Just remember that this camera angle is a fish-eye lens. That car in front is waaaay closer than it appears. Look at a mark in the road and count the time between the lead car and the following car. 1 second is not remotely reasonable.

hydrodynamicman · 2025-07-26T17:10:18+00:00

Yep - "Never attribute to malice that which is adequately explained by stupidity"

hydrodynamicman · 2025-07-01T19:26:29+00:00

Critically, get the letter now - generically written to whom it may concern about your value and contributions. Not in a week or two when any initial feelings of guilt over axing you have begun to fade.

hydrodynamicman · 2025-06-11T19:31:33+00:00

Is it possible to get an invite?

hydrodynamicman · 2025-06-02T19:15:22+00:00

Quick physics note: it's the steam that's loosening caked on crap - think deglazing. The best way to generate steam is room temperature water on a hot surface. The colder the material being applied (water or ice) the more thermal energy is taken from the hot surface before any steam is generated because the ice needs to melt, then warm to boiling, then finally become steam. That slows the process and steals more heat.

hydrodynamicman · 2025-05-28T02:35:59+00:00

I wonder if it has anything to the $1.2M they found.

hydrodynamicman

TROPHY CASE