You’d be surprised at how much the thickness of the tape measure can ruin the accuracy of your measurement.
For example a three inch cylinder (76.2mm) has a circumference of 239.39 millimeters. Wrapping a tape measure around it that’s one millimeter thick results in a circumference (77.2mm * pi = 242.53) that’s 3.14mm different, or nearly 1/8th inch (3.175mm) different.
I said surprising, not interesting.
The Machine Shop has a steel Pi Tape measure. (Pi as in 3.14). It is a circular tape measure that is very accurate. It is rolled up in a metal container about the size of a can of shoe polish. The last I saw it, it was in the tollbox by the HAAS in one of those drawers. It will measure up to a 7 inch diameter if I remember correctly. The can is in a clear plastic bag with instructions as how to use it. You read the measurement the same way you read a machinist’s micrometer.
I suggest that the measurements be in mm. That is what the values are in RDWorks for diameter of objects.
Whoever cuts it is welcome to use whatever units they want. While the diameter entered in RDWorks needs to be correct, it’s not used for the measurements I’m asking for.
I got a question from a potential member as to whether it was working on the dms facebook page. @michaelb do we know yet?
Still haven’t had time to do that testing, so no, not working yet.
Okay new month!!! Who wants to help test the rotary with my rolling pin!!!
It should be working (only on blitzen) but if you can come by tomorrow you can do it after maintenance day!
Will there be assistance??? I have my notes from class, but have not yet used the rotary on my own.
I don’t know how long I’ll be able to stay after but there will be plenty of knowledgeable laser peoples around to help!
Perhaps you could write up a Wiki entry on the current methods for using the Rotary and post a link to it here? Saving “institutional knowledge” in the Wiki is good, even if it later becomes obsolete.
See here, Help with project etching duck calls
Basically, it doesn’t work*. Anyone willing to put the time and test material into figuring it out is welcome to, but all the methods I can find are simply hacks to work around the root problem that we can’t seem to solve, so I’d rather not perpetuate (and spend the time to support) those hacks.