Some thoughts

I have some experience now, some thoughts too.

This is schematic view of single keycap mount I made:



Photo:



Mount's sucking area's flatness is important.

My first try was failed by this reason, I suppose. If flatness is not enough, air leaks and makes a mess. Float glass (common window glass) is overkill, but you shouldn't expect the bottom of a paper cup works well.

Alignment mark

I haven't make any alignment marks yet. But it is required in my experience. One is on sublimation film, another is on keycap mount.

How can I make alignment mark on sublimation film? Since my printer is low-end office/home 4-color model, I have to print the mark by dye-sub ink. The mark can't avoid heat and sublimation. Alignment mark on mount will be corrupted by dye-sub ink. Alignment mark on mount should be tolerant to dye-sub ink.

Therefore, alignment mark on mount shouldn't be plastic or porous. It should be heat proof, too. Scribe line on metal plate is a good choice in my opinion. I'll try later.

Color calibration and RIP

You can see dither dots in pictures like this:



Dye-sub printing by low-end office/home printer is in non-oem world. In official world, printer manufacturer provides color calibration and RIP with detailed description in exchange for much money. But in non-oem world, in exchange for saving money, I have to survey a lot of things.

Actually I'm not well informed about printing. I even don't have the knowledge about how much time required to do these things.

Blank margin

My keycap mount was made by plaster casting. The mask contacts tightly with keycap. But it makes a problem. To avoid dye-sub ink corrupts the mask (if mask is corrupted, ink re-sublimates and corrupts keycaps), I have to make blank margin at the edge of keycaps. It is ugly in printing pictures. I'll take some measures next time.

Temperature varies between center and rim of keycap mount

I made and tested keycap mount for mass production:



I heated it by common heat gun, measuring the temperature by pyrometer. I aimed much to gain standardized temperature, but I found a tendency: the center of the mount becomes high, the rim becomes low.

I don't know the reason yet. Air holes effect? Marginal area is too narrow? Mask material absorbs heat? I feel this is the most embarrassing problem so far...