08-30-2013, 12:46 AM
Hiya Larry,
I do like the holder it seems you've thought your way through the project carefully, FYI the angle of the HSS section is actually quite important in that this angle defines the front and side clearance of the tool and as a result the strength and therefore longevity of the cutting edge,
When I was originally taught about tool grinding the front and side clearance angles were set at 7-10 degrees, but that was in heavy industry, the 16 degrees will reduce some as the approach angle is somewhere around 40 degrees from what I can tell but even at 16 degrees it will last well given the lower stress of hobby use.
One thing I really like is how the bit is fully supported in a square hole, so many of these types of holders use a groove with a clamp of some kind and that always looks weak to me, considering that slipping of the tool is not always obvious to the operator, it tends to make me think that finish and indexing wouldn't be reliable on the other designs I've seen.
Regards
Rick
I do like the holder it seems you've thought your way through the project carefully, FYI the angle of the HSS section is actually quite important in that this angle defines the front and side clearance of the tool and as a result the strength and therefore longevity of the cutting edge,
When I was originally taught about tool grinding the front and side clearance angles were set at 7-10 degrees, but that was in heavy industry, the 16 degrees will reduce some as the approach angle is somewhere around 40 degrees from what I can tell but even at 16 degrees it will last well given the lower stress of hobby use.
One thing I really like is how the bit is fully supported in a square hole, so many of these types of holders use a groove with a clamp of some kind and that always looks weak to me, considering that slipping of the tool is not always obvious to the operator, it tends to make me think that finish and indexing wouldn't be reliable on the other designs I've seen.
Regards
Rick
Whatever it is, do it today, Tomorrow may not be an option and regret outlasts fatigue.