Tag's position doesn't make sense.

[bofh69]

Spools are on almost all printers/MMUs either standing on their outer edges (like in Bambu Lab's MMU), or they are hanging from their middle hole. In both cases the specification's position of the tag won't tell where a tag will actually end up when used in a printer/MMU.

The position should either be relative the spool's outer edge, or it should be relative the edge of the hole, almost never is the center of the hole the right point to base the position on.

My spools hang from the center hole so I would recommend that 😜, but I don't know what's most common these days.

[Grogyan]

In most cases, a smartphone app to transfer the data to your preferred slicer would be necessary

[bofh69]

@Grogyan for such a workflow the location of the tag doesn't matter. It's when the reader is mounted on the printer or MMU where it matters.

I've got a reader connected to my printer. It will generate entries in Spoolman for new OpenTag3D and OpenPrintTags. It's later tells the printer which spool and filament is loaded. I autogenerate slicer filament config from the content in Spoolman, and the gcode verifies that the right filament is loaded before printing. All would be more or less automatic if spools came with tags in the right spot...

[queengooborg]

I'll have to admit I'm a bit confused by this. The positioning of the tags roughly match the placement that Bambu Lab uses on their spools?

An excerpt from the spec:

• The center should be 56.0mm away from the center of the spool
• The tag should never be more than 4.0mm away from the external surface of the spool

[bofh69]

An excerpt from the spec:

* The center should be 56.0mm away from the center of the spool

Yes, and that is the problem. The diameter of the inner hole is not specified (and shouldn't be), so where the tag actually ends up when you use the spool isn't specified as you never use the center of the spool for anything.

Either you hang the spool from the center hole or the spool stands on its edges. Then the tag's position will be relative the center hole's inner edge or the spool's outer edge, never it's center. Different spools have different large holes and different diameters, so the current specification doesn't make it end up in a known position.

The specification should either base it's position relative the outer edge or the inner edge. The first is good for MMUs like bambulabs where the spool is standing, the second on systems like mine where the spool is hanging from the center hole.