OPEND CNC Mark 1A first venture into the world of DIY CNC.
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Part 3 Rail Grip Design
The rail grip is designed to have one surface fixed and the other spring loaded so as to take up any play that there might be. This design's key criteria is to keep the tension from the spring loaded bearing as close as possible to the fixed bearing so as to minimize overall frame stresses.
An offset bearing and mounting bolt ensures a large mechanical advantage of the lever. A leverage ratio of over 30 times is easily obtained.
By pulling the two levers together with a spring, the bearings can move closer or further from the rail.
Here the Y module can be seen with 2 of the Z axis guide rail bearing sections visible. One of the three Y bearing sections can be seen.
The above image is of the same Y module without the casing and with the rails visible. The highlighted bearings are the spring loaded ones.The horizontal unit only has one spring action bearing to reduce overall Y module size.
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