stud_rescale does not work as expected

[gordonb3]

That is: it only changes the size of the studs. What it fails to do is change the opening of the posts (which should match the stud diameter), as well as their spacing.

I tried to edit some of the parameters, but I guess I'm not completely following the code. I added stud_rescale as a factor to stud_diameter, but that did absolutely nothing until I changed the value of stud_rescale in the main code. For some obscure reason I still had to also define stud_rescale in the block() call to observe any change. Interestingly this did not just enlarge the opening of the posts, but also decreased their overall diameter, thereby making the loose fit when stacking blocks even worse.

[gordonb3]

Sorry about the triple commits mentioned. The first two are actually bogus, I made some pointless changes along the way as I was zooming in to the correct locations to fix the posts diameters. I amended those pointless bits.

Verified on Creality K1C, with parts 3031 and (custom designed) 87580 printed and connected to their originals.

[cfinke]

stud_rescale is intended to address the mismatch of stud size to post size, probably because of shrinkage of plastic or slight inaccuracy of printers when printing the studs. If the posts are rescaled too, the mismatch will never be corrected. Ideally, after printing a brick with a stud_rescale value, the printed studs should measure exactly at their nominal dimensions (and so should the posts). If both are undersized, try rescaling the entire brick.

It was kind of a hack, and maybe should have been addressed by just having recommended scale values for the entire brick when printing in a given material on a given printer.

[gordonb3]

The brick was correctly sized from the start. The problem as I initially found was that the studs were too small and an original LEGO piece would not clamp on to it. It was at a later point that I noticed that with the studs increased in size, you can no longer fit them inside the posts, which is really the reason why I initially made the studs too big as that allowed the printed bricks to stack correctly, but that failed with part 87580 (2x2 with a central hollow stud). Note: on my model, the original LEGO part does not fit the printed post either with current master.

[cfinke]

Ok. I'm going to do some investigation and test prints and see what I can find out.

[gordonb3]

part 87580:

    union() {
        place(0,0,1/3)block(
            type="tile",
            width=2,
            length=2,
            height=1/3,
            reinforcement=false,
            stud_type="solid",
        );

        difference() {
            place(0,0,1/3)block(
                type="brick",
                width=1,
                length=1,
                height=1/3,
                reinforcement=false,
                stud_type="open",
            );
            block(
                type="tile",
                width=2,
                length=2,
                height=2/3,
                reinforcement=false,
                stud_type="solid",
                block_bottom_type="closed"
            );
        }
    }

Reason for editing: incorrect part number