Overview of Linkage

There are undoubtedly any number of ways to redo the linkage for stiffness and lack of slop. After two years in service (the hammer was considerably cleaned up for these pictures) the design shown here has proven its worth, and we feel we can recommend it

Upper clevis

A new control rod is fabricated from four pieces as shown on the picture on the right. Using this kind of structure allows the length to be adjusted rather precisely while being much stiffer than the original pieces.

Section of 1/2" all thread

Section of straight rod

Lower Heim joint

This is a view of the upper clevis. NyLock nuts were used where ever it was possible to reduct the possibilities that something would vibrate loose.

Here are two views of the bottom connection to the treadle. The nut and bolt through the Heim joint are tightened so that the center of the joint does not turn ... it is the outside shell of the Heim turning on the inner ball that allows the needed movement while minimizing play.

A Note of Caution

It is terribly tempting to refit the slot in which the saddle pin rides in the yolk. One should refrain from doing this altogether, because any upwards pressure on the pin can cause the babbit bearing in the saddle to wear out very much prematurely.

(By the way, the hammers that haven't been cleaned up for picture taking tend to look a lot more like the top of this picture than the rest of the pictures in this section. Hammers should be kept sloppy goey with lubricant and grease.)