Originally Posted by
Recycled Flyer
Getting back to the lower shelf cracking off on the contra piston, is there a stress riser of an included angle of 90 degrees machined in the silicon tube groove?
Maybe it's better to put a radius in it.
I did think about a radius both before it cracked and definintly after it cracked. I just did not know how to radius the silicone band. I did do an experiment after the crack and was able to get a radius in the silicone band by putting the silicone ring over a round rod and using my hobby knife tip to cut the 45 chamfer edge on the silicone ring while it was turning in my lathe. I however did not put the chamfer in my newest contra because the grove was so shallow that I didn't think it would need it. I will see how it holds up with a little more use.