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- Feb 24, 2014
- Messages
- 240
Tony from QLD sent us his Spyderco CPM S30V for dent repair and re-profiling.
The plan is to sharpen it at 13 dps (degrees per side) - the lowest edge angle we recommend for vanadium-rich CPM steels.
We repair dents by grinding at a high angle, at 30 dps, on our CBN square-edge wheel #160. The red line on the photo is where I grind at 30 dps.
Takes about 1 minute. This is how the edge looks after this step.
We then set the grinding angle at the target of 13 dps, and grind the bevel on the same #160 CBN wheel.
Note that I do not grind the heel of the blade at this step. Because this blade has no choil, transition to the bevel will not look nice if done on the square-edge wheel.
We then continue on our round-edge CBN wheels #400, followed by #1000.
The round profile of the corner of these wheels grinds a beautiful transition to the bevel:
Next, we hone on paper wheels, our usual sequence for "supersteels" of 10 micron diamonds - 5 micron diamonds - 2.5 micron diamonds - 0.5 micron diamonds - 0.25 micron diamonds.
The edge is then finished on the Tormek leather wheel with 0.1 micron diamonds, the honing angle is controlled with our Frontal Vertical Base.
Grinding and honing angles are controlled with our computer software for Tormek and paper wheels.
The following chart shows BESS sharpness scores as we progress the honing. Where the tester reading is over 100 BESS, we thin away the burr; and where it comes under 100 BESS we hone the edge apex.
Final sharpness score is 45 BESS, in HHT test the knife splits a head hair.
When I say "our own CBN wheels" I mean that we now make our CBN wheels by my design and specifications.
We've been grinding on CBN wheels on Tormek for the last 3 years, and I've summarized what we've learnt on our website
http://knifegrinders.com.au/11CBN.htm
The plan is to sharpen it at 13 dps (degrees per side) - the lowest edge angle we recommend for vanadium-rich CPM steels.
We repair dents by grinding at a high angle, at 30 dps, on our CBN square-edge wheel #160. The red line on the photo is where I grind at 30 dps.
Takes about 1 minute. This is how the edge looks after this step.
We then set the grinding angle at the target of 13 dps, and grind the bevel on the same #160 CBN wheel.
Note that I do not grind the heel of the blade at this step. Because this blade has no choil, transition to the bevel will not look nice if done on the square-edge wheel.
We then continue on our round-edge CBN wheels #400, followed by #1000.
The round profile of the corner of these wheels grinds a beautiful transition to the bevel:
Next, we hone on paper wheels, our usual sequence for "supersteels" of 10 micron diamonds - 5 micron diamonds - 2.5 micron diamonds - 0.5 micron diamonds - 0.25 micron diamonds.
The edge is then finished on the Tormek leather wheel with 0.1 micron diamonds, the honing angle is controlled with our Frontal Vertical Base.
Grinding and honing angles are controlled with our computer software for Tormek and paper wheels.
The following chart shows BESS sharpness scores as we progress the honing. Where the tester reading is over 100 BESS, we thin away the burr; and where it comes under 100 BESS we hone the edge apex.
Final sharpness score is 45 BESS, in HHT test the knife splits a head hair.
When I say "our own CBN wheels" I mean that we now make our CBN wheels by my design and specifications.
We've been grinding on CBN wheels on Tormek for the last 3 years, and I've summarized what we've learnt on our website
http://knifegrinders.com.au/11CBN.htm
Last edited:
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