I have been tweaking and practicing on my new Ferdco Pro 2000 for the last several days without so much as a missed stitch.  Last night I thought I would try 4 layers of 11/12 oz veg tanned (5/8" thick stack), to see how the machine would handle that.  Good Idea, bad execution, as I used some older leather that was given to me and although not cracking by any means, it might have been a little too dry, and tough for this test.  At about 2 inches into the test piece, there was a loud thunk and th