rcnewcomb
07-26-2009, 03:39 PM
As you probably guessed the Kasota limestone won.
I had a slab of 2" kasota limestone and I needed to plane it down by 0.5" to remove an earlier carving that didn't turn out as well as I wanted.
I was using a 0.75" HSS bit at 0.5ips at 13000RPM at 0.05" depth per pass with a 40% stepover. It was about 60% complete when the Y motor faulted. Note the scorch marks and the rounding on the tips of the cutter.
Lesson learned: High speed steel is no match for limestone. Go with carbide or diamond.
The Y motor finally ran out of steam to try and drag that dull bit around any further and tripped the fault.
A larger image is available here: ->Link (http://www.222artisans.com/images/HSS075bit01.jpg)
5033
I had a slab of 2" kasota limestone and I needed to plane it down by 0.5" to remove an earlier carving that didn't turn out as well as I wanted.
I was using a 0.75" HSS bit at 0.5ips at 13000RPM at 0.05" depth per pass with a 40% stepover. It was about 60% complete when the Y motor faulted. Note the scorch marks and the rounding on the tips of the cutter.
Lesson learned: High speed steel is no match for limestone. Go with carbide or diamond.
The Y motor finally ran out of steam to try and drag that dull bit around any further and tripped the fault.
A larger image is available here: ->Link (http://www.222artisans.com/images/HSS075bit01.jpg)
5033