RobCox
Member
- Messages
- 391
- Location
- Cambridge, UK
Back in 2019 I was given this collection of endmills by a neighbour of ours:
They range in size from 16mm down to 3mm, some imperial, some metric, but they're all decent quality, Clarkson, SKF, Dormer. Some were useable as is, some a bit dull, some "modified". They were a "round tuit" project. After 4 1/2 years, I finally got around to it.
I wanted to sharpen all the edges, not just the ends, so in stages I made up various fixtures to enable me to do this on my Union Tool and Cutter Grinder. The collection of fixtures looks like this disassembled. First, a multi axis fixture for the spindle head, something I made shortly after acquiring the machine as it didn't come with one:
Second, the spindle head which came with the machine. I removed the original spindle as it has a not very useful MT4 bore:
Third, the spindle used to hold the mills. Home made, with an ER32 collet chuck end and 12 holes around the collar for indexing. This has to be a smooth sliding fit in the above bore to successfully grind flutes. This was drilled and turned from bar stock but the collar was heat shrunk on:
The whole lot gets assembled with various other components to make this assembly for sharpening the flutes:
The indexing finger is 6mm HSS ground for clearance. Everything is adjustable with 1/4-20 brass tipped grub screws (so the shafts dont get marred up).
To use it, the procedure I came up with is as follows. Set the endmill spindle parallel to the table and set the top axis horizontal as well.
With everything horizontal, set up a height gauge on exact spindle centre height:
Using a height gauge to set to the height of one of the tips of the end of the flute to be exactly on centre height:
Then adjust the indexing finger so it is near the flute edge but just back from the tip:
They range in size from 16mm down to 3mm, some imperial, some metric, but they're all decent quality, Clarkson, SKF, Dormer. Some were useable as is, some a bit dull, some "modified". They were a "round tuit" project. After 4 1/2 years, I finally got around to it.
I wanted to sharpen all the edges, not just the ends, so in stages I made up various fixtures to enable me to do this on my Union Tool and Cutter Grinder. The collection of fixtures looks like this disassembled. First, a multi axis fixture for the spindle head, something I made shortly after acquiring the machine as it didn't come with one:
Second, the spindle head which came with the machine. I removed the original spindle as it has a not very useful MT4 bore:
Third, the spindle used to hold the mills. Home made, with an ER32 collet chuck end and 12 holes around the collar for indexing. This has to be a smooth sliding fit in the above bore to successfully grind flutes. This was drilled and turned from bar stock but the collar was heat shrunk on:
The whole lot gets assembled with various other components to make this assembly for sharpening the flutes:
The indexing finger is 6mm HSS ground for clearance. Everything is adjustable with 1/4-20 brass tipped grub screws (so the shafts dont get marred up).
To use it, the procedure I came up with is as follows. Set the endmill spindle parallel to the table and set the top axis horizontal as well.
With everything horizontal, set up a height gauge on exact spindle centre height:
Using a height gauge to set to the height of one of the tips of the end of the flute to be exactly on centre height:
Then adjust the indexing finger so it is near the flute edge but just back from the tip: