MTBob
Well-Known Member
This is a follow-on posting to my earlier post where I questioned whether a Viel Grinder could / would make satisfactory serration grinds before I bought one. Well, after some brief testing, I think the verdict is in - it works!
With literally no modifications, this grinder will place serrations on the edge of a steel blade with repeatability - in depth, lateral position and relief angle, all of which can be adjusted.
So, here's the setup:
Using the square block blade fixture that came with the grinder, I simply bolted a chunk of 1/8" thick low carbon steel under the bolt washers. Amazingly, no mods necessary at this point.
The lead screw at the bottom is either 2mm or 13 pitch which gives about .077" lateral travel per one revolution. This screw moves the blade that amount and, by experimenting, I found the sweet spot for the grinding increment - in the case with this specific wheel - to be 2.5 turns of the handle.
While this machine also features the use of a template to cut unique forms (for wood molding cutters), I didn't use it in this trial. I may machine a template and see if that method works better than using the lead screw to adjust the serration spacing.
But, there's still more to figure out:
- the grinding wheel is apparently 36 grit and leaves a rough cut and wears away fast
- profiling the edge of this wheel with a diamond dresser works, but the profile only lasted for a couple of cuts as the wheel wears away.
- so, I need to find a CBN or equivalent 7" thin blade that will work in this grinder and will not deteriorate with use.
Also, I'm not sure yet whether the serrations should be ground before or after heat treating.
With literally no modifications, this grinder will place serrations on the edge of a steel blade with repeatability - in depth, lateral position and relief angle, all of which can be adjusted.
So, here's the setup:
Using the square block blade fixture that came with the grinder, I simply bolted a chunk of 1/8" thick low carbon steel under the bolt washers. Amazingly, no mods necessary at this point.
The lead screw at the bottom is either 2mm or 13 pitch which gives about .077" lateral travel per one revolution. This screw moves the blade that amount and, by experimenting, I found the sweet spot for the grinding increment - in the case with this specific wheel - to be 2.5 turns of the handle.
While this machine also features the use of a template to cut unique forms (for wood molding cutters), I didn't use it in this trial. I may machine a template and see if that method works better than using the lead screw to adjust the serration spacing.
But, there's still more to figure out:
- the grinding wheel is apparently 36 grit and leaves a rough cut and wears away fast
- profiling the edge of this wheel with a diamond dresser works, but the profile only lasted for a couple of cuts as the wheel wears away.
- so, I need to find a CBN or equivalent 7" thin blade that will work in this grinder and will not deteriorate with use.
Also, I'm not sure yet whether the serrations should be ground before or after heat treating.
