Change gear question

[grit]

My lathe came with a pile of change gears. Most are metal. Two are some sort of composite material. This material is the color of carboard, lightweight, very strong, and has a weave pattern on the surface. My first impression is these two gears are patterns. Then, I had second thoughts.

Anybody know if these are gears?

 

[apakesha]

What is the diameter of the gears and how many teeth? They are probably gears for the cross slide/ carriage. They are probably the weak link. If for some reason the carriage is left on power feed and the cutting tool crashes into the chuck you will destroy a gear or break a tooth on the gear. Instead of breaking multiple gears and twisting and breaking shafts, you are given a couple of spares that are made of brass or plastic composite that will be sacrificed and leave the rest of the gears in the carriage intact. I'm pretty sure that this is what they are.
Mike

 

[shortgrass]

What is the diameter of the gears and how many teeth? They are probably gears for the cross slide/ carriage. They are probably the weak link. If for some reason the carriage is left on power feed and the cutting tool crashes into the chuck you will destroy a gear or break a tooth on the gear. Instead of breaking multiple gears and twisting and breaking shafts, you are given a couple of spares that are made of brass or plastic composite that will be sacrificed and leave the rest of the gears in the carriage intact. I'm pretty sure that this is what they are.
Mike

I wonder what those 'shear pins' are for that connect the feed rod & threading rod to the transmission?