Brain Climbing Hold

I am exploring the use of 3d printing to make holds for a climbing wall I am building. While it would be possible to directly print holds this is not optimal for several reasons. In order to be strong enough most holds would need to be printed of a high strength material (ABS at minimum, but optimally nylon or PET) and they would need to be printed at 100% infill. But high strength materials are notoriously difficult to print in big blocks and high infills. Even if the print could be accomplished it would be extremely time consuming and very expensive. Climbing walls need a lot of holds so directly printing them one at a time just isn't the best solution.

Climbing hold producers cast their holds from resin, typically polyurethane. It would be possible to print a master from and make a mold from it. However, mold rubber is quite expensive and the mold making process is time consuming, and with a little 3d printed cleverness it can be avoided. It is easier to turn the master