PINS

[dfkrug]

I would rather the pin wear and replace that. Bushings are a PAIN.

This is the way I am now going. Softer pins may extend the life of the
bushings. This is esp important if the bushings are welded in, rather than
being inserts.

When I built my CADDigger 10y ago, I used mechanical structural tubing
(1.00" ID with 1/2" walls) and chrome plated 63/64" rod I found at my local
steel surplus supplier. The critical joints used nylon bushngs.

Since moving on to Prairie Dog backhoes (Woods 7500 clone), I am now
working with 25 mm chome plated steel pins, drilled and grooved for
grease. The critical joints DO have replaceable bushing inserts, but I
prefer to replace the pins, which are easy and cheap. The factory pins
are only about $15 or so. One guy I sold a b/h to has broken 2 pins
at the grease groove, but I think he is running over 3000psi. This was the
bucket pivot at the end of the dipper stick. The newer Prairie Dogs
now use 1 1/8 pins in some places. I read somewhere that chome
plating can cause embrittlement of the substrate. That was info related
to the hot rod guys who love to chrome plate suspension components.
Not good for strength.

Now when I custom make pins, I buy 1" mild steel rod (A36?) at the
steel store. No grease grooves. Mechanical tubing is very hard to find,
however. Sometimes I use shedule 40 pipe with 1" ID and ream them.