It's sad to hear the poor performance of embossers. In terms of lifetime, I only have about 150 or so pages created with my prototype molds, but I haven't been able to detect a degradation in the embossing quality. I think at that number of copies created and a set of molds only costing $1.50, it makes me feel it's gotten some value out of it. I think someone can buy the equipment I'm using for around $800 in total. Obviously there's a bit of a tradeoff and at some point the number of molds would exceed the cost of an embosser, but I argue this approach is pretty quick for a manual one (for now).
The pain of the approach is the printing times for sure. One bit of confusion I can clear up is that, while yes, the single 3D printer I use can only print 4 unique sets of page molds a day, using the molds is fast! My time to beat is 15 seconds to manually position a sheet of paper between the mold bodies and roll it though a cheap roller press. 4 pages a minute is pretty quick for an embosser, but this is still just manual. Now imagine it automated :) Expecting a human to do 15 seconds/press for a full work day makes me sad, but that'd be a lot of birthday cards.
I really appreciate the link to the BrailleRap project. It's cool to see innovation in the space, and I subscribe to the RepRap philosophy. I'm currently prototyping designs to automate the pressing process, but until that component is automated, this approach lies somewhere between manual and automated embossing in terms of utility. That being said, still much more accessible and cost-effective.
