CountryBoy19
Stainless
- Joined
- Aug 14, 2012
- Location
- Bedford, IN
I have a turn-of-the-century (nope, not this century, last one) clay target thrower (skeet/trap thrower) that is giving me fits.
It's cast-iron, made by the Western company. Parts are NLA and I've had to make a few due an unfortunate mishap before it came to me. I've attached a crude cross-section of the problem area drawn in paint.
It has an automatic "wobbler" on it which is a marvelous piece of engineering for the period it was made. The cam (pictured in blue) that determines the "random" positioning rotates on a tapered bronze bearing (pictured in yellow). This bearing is centered on a cast iron stub (pictured in green) that sticks up from the base and is pressed into the cone of the cam with springs (not shown).
The prior problem is that the bearing froze up in the rotating cam and tore up the linkage that moves the cam. A couple years ago I took it all apart and lubed it well and it worked great. I'm just now getting around to fixing the broken linkage so this can work like it should and having sat for about 18 months unused the fresh, new grease I applied to this conical bearing surface was solidly stuck. I thought maybe it was the cold and the consistency of grease I used (I chose something firm so the spring pressure wouldn't extrude it out of the bearing). However, upon tearing it apart I found something more sinister. The grease had suffered from what I now know as "hydrostatic extrusion". That is where grease under constant pressure will actually extrude out the oils leaving behind the binders making a sticky/hard mess.
I need a heavy grease that will not extrude out under pressure and one that will not suffer from hydrostatic extrusion (separation of the binder from constant pressure). Any thoughts/recommendations?
Last night I applied some good old white lithium grease to see if it works, but I'm not holding my breath. It seems a bit think to resistant being pressed out of the bearing.
It's cast-iron, made by the Western company. Parts are NLA and I've had to make a few due an unfortunate mishap before it came to me. I've attached a crude cross-section of the problem area drawn in paint.
It has an automatic "wobbler" on it which is a marvelous piece of engineering for the period it was made. The cam (pictured in blue) that determines the "random" positioning rotates on a tapered bronze bearing (pictured in yellow). This bearing is centered on a cast iron stub (pictured in green) that sticks up from the base and is pressed into the cone of the cam with springs (not shown).
The prior problem is that the bearing froze up in the rotating cam and tore up the linkage that moves the cam. A couple years ago I took it all apart and lubed it well and it worked great. I'm just now getting around to fixing the broken linkage so this can work like it should and having sat for about 18 months unused the fresh, new grease I applied to this conical bearing surface was solidly stuck. I thought maybe it was the cold and the consistency of grease I used (I chose something firm so the spring pressure wouldn't extrude it out of the bearing). However, upon tearing it apart I found something more sinister. The grease had suffered from what I now know as "hydrostatic extrusion". That is where grease under constant pressure will actually extrude out the oils leaving behind the binders making a sticky/hard mess.
I need a heavy grease that will not extrude out under pressure and one that will not suffer from hydrostatic extrusion (separation of the binder from constant pressure). Any thoughts/recommendations?
Last night I applied some good old white lithium grease to see if it works, but I'm not holding my breath. It seems a bit think to resistant being pressed out of the bearing.