monotypes. The need for a larger press is back in full force. Right now a much larger press is in the design department so she can finally scale up the printmaking operation. I decided early on that since I am probably never going to build another press this one should have all the embellishments and look like a piece of art in itself. It will become the center piece of her printmaking studio and a great example a home built press. During the design process I found I needed a gear reduction that had a large ratio in a rather flat package for the press. Typically these big presses have a reduction from the hand wheel to the roll of around fifteen to twenty five to one ratio. This is hard to do cleanly with chains and sprockets or with less than four or more gears.
American French Tool press. You can see these are massively built machines. Gigantic hand wheels are a signature feature of high end etching presses.
Many different designs were scrapped before it settled on something I liked. The following is a description of a unique type of speed reducer sometimes called a wabble drive.
As the design work proceeds on the new large press I wanted to prove out the gear reducer as designed on the computer. This press will take advantage of accurate plasma and waterjet cutting to make many of the profiles used throughout the machine. One set of profiles in particular are in the gear reducer. The hope is that the reducer is insensitive to the tooth shape and will operate with laser or waterjet cut teeth without and finish machining. Also because it is just a little unique and interesting I decided to built a full scale model for testing.
One of the main reasons we went in this direction is because of how compact this gear reducer is. It has a ratio of eighteen to one in a very flat package. I have never seen one on any piece of equipment which was another motivation for trying it out with a proof of principle. Anybody can put a bunch of chains and sprockets on to make a gearing reduction, but they lack the higher mechanical art that I am striving for in the large press.
This is a short video I shot of the working model. Its fun to watch the inner gear wabble around. I can see how this type of drive got its nickname.