I was going to file this as a bug report, but after thinking about it a while I’m not sure it is a “bug” as much as something that might just need to be called out in the documentation. It led to me recutting my brace plates out of an abundance of caution.
I’m going to paste what was going in the bug report but the TL;DR is Is there a known rounding funkiness in the calculator where inches rounds to 1/8 in, but mm rounds to the next largest whole unit, leading to some slight weirdness at large numbers especially when flipping back and forth between mm and inches?
I don’t know what I don’t know, so I recut my braces using a manually converted and input mm measurement (v/s the slightly shorter autoconverted inch to mm measurement). Not the end of the world since I have a whole sheet of the 1/4 MDF i cut them from and have enough material to screw it up 5 or 6 more times! But I am curious.
Using the LR4 calculator (link above) to calculate strut plate length in mm gives a slightly smaller measurement for strut plate v/s rail length, while in inches it gives the same length for both. Example: a 49x97 inch table gives both strut and brace length of 55.625 inches. Changing units to mm gives a length of 1407mm (rail) and 1409mm (strut plate) - a slightly (2mm) smaller rail v/s strut plate.
Additionally, when inputting 49x97 in inches and then swapping units to mm (for example, because my sheet goods are in inches, but the .svg generator is in mm) it autoconverts to 1240mm x 2460mm when the actual measurements are 1244.6mm x 2463.8. When swapping BACK to inches after checking the mm readout, it will read 48.875x96.875, which different that what I input originally. This all might just be a byproduct of rounding to the closest 1/8 of an inch but whole millimeter, now that I’m looking at it… But I was not expecting it to change my inputs (changed from 49 to 48.875 and from 97 to 96.875). It converts back and forth as expected for smaller values - 24x48 inches seems to be fine (although should it round to 1219mm and not 1220mm for the 48in measurement? 48x25.4=1219.2).
I didn’t catch this the first time running thru it.
