ashwinearl
Knifemaker / Craftsman / Service Provider
- Joined
- Nov 9, 2006
- Messages
- 562
Hi All,
I've been researching and practicing different approaches to flat grinding and am curious about the hybrid approach of starting with a hollow grind first then switch to flat platen. I'd also seen the Nick Wheeler approach of creating multiple shallow hollows parallel with each other. I gave this a shot briefly but found it hard to do.
This thread briefly mentions roughing on a wheel first (https://www.bladeforums.com/threads/bevel-jigs.1499447/#post-17225644). It mentions speed and saving belts as advantages.
Those of you that do this method, can you explain your basic process.
I typically scribe my desired pre-heat treat each thickness and then grind 45degree ish bevels to the scribe lines using a worn belt. For a flat grind, I typically start at the transition of that first bevel and the flat blade and walk the grind towards the spine. So there is some meat left at the edge from the first initial bevel
Once I reach final depth I work on getting moving the flat grind back towards the edge and get rid of what was left from the initial bevel.
I have a 10" wheel to work with. Using online hollow grind calculators and depending on my steel thickness (1/8 to 5/32), it says I can grind to a height of 0.7 to 0.8" I like to flat grind higher than this typically.
Do I perform a traditional hollow grind to this max height, following the basic approach of my flat grinding, where I start the hollow grind just underneath where that initial 45degree bevel ends?
This would leaves two points of contact near the edge (but not to it yet) and that last height I left off with the hollow grind to index the flat grind off of.
I tried this once and it worked ok, I was surprised how fast it went. My problems are that success is dependent on performing the initial hollow ground decently enough to have a straight line at the top of the grind. Also plunge lines are hard for me regardless of wheel or flat platen.
I've been researching and practicing different approaches to flat grinding and am curious about the hybrid approach of starting with a hollow grind first then switch to flat platen. I'd also seen the Nick Wheeler approach of creating multiple shallow hollows parallel with each other. I gave this a shot briefly but found it hard to do.
This thread briefly mentions roughing on a wheel first (https://www.bladeforums.com/threads/bevel-jigs.1499447/#post-17225644). It mentions speed and saving belts as advantages.
Those of you that do this method, can you explain your basic process.
I typically scribe my desired pre-heat treat each thickness and then grind 45degree ish bevels to the scribe lines using a worn belt. For a flat grind, I typically start at the transition of that first bevel and the flat blade and walk the grind towards the spine. So there is some meat left at the edge from the first initial bevel
Once I reach final depth I work on getting moving the flat grind back towards the edge and get rid of what was left from the initial bevel.
I have a 10" wheel to work with. Using online hollow grind calculators and depending on my steel thickness (1/8 to 5/32), it says I can grind to a height of 0.7 to 0.8" I like to flat grind higher than this typically.
Do I perform a traditional hollow grind to this max height, following the basic approach of my flat grinding, where I start the hollow grind just underneath where that initial 45degree bevel ends?
This would leaves two points of contact near the edge (but not to it yet) and that last height I left off with the hollow grind to index the flat grind off of.
I tried this once and it worked ok, I was surprised how fast it went. My problems are that success is dependent on performing the initial hollow ground decently enough to have a straight line at the top of the grind. Also plunge lines are hard for me regardless of wheel or flat platen.
anybody know max . belt speed on this grinder ?
