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Milling with the Hobbymat

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Chipswitheverything:
I would agree with people's above comments about lack of sharpness of the cutter at the extreme business end : the tip sharpness is lost pretty quickly in use. And I would think that sloshing with cutting oil, probably of a straight variety on EN8 , but soluble would help too, would be absolutely necessary for a better finish.
Milling is a very vibration prone sort of job, and a very light machine with the cutter extended some distance from the spindle nose will have its limitations in combating it. Mostly, when I can,  I use simple home-made cutter holders that tuck a smaller diameter end mill, 8 or 10 mill or equivalent, up into the taper of the spindle for the best rigidity.
  If the side flute cutting edges are in sharp condition, then turning the head and arranging the workpiece to use them could be beneficial, - though admittedly, hardly worth it for a one off job that, as you say, can be cleaned up. Dave

vtsteam:
Keeping HSS end mills sharp needn't be expensive or require a complex cutter grinder. (Though they are wonderful if you have one) I made a sharpening jig for a small damaged 5" disk sander that does a great job on the ends of the flutes. Grinding the side flutes is another matter, but most of the time, for me, it's just the ends that need a touch-up.

crueby:
Vtsteam - interesting jig!  Do you tilt the table slightly to give the cutting edge a relief angle?

vtsteam:
Yes, Chris. also that slide you see has an angle built into it as well, it's not 90 degrees to the disk. So it's a compound angle

I don't remember the angles I used, it's been a few years, and it retains it's setup, so I haven't changed it, but I can look it up.

If interested I can do a write up on making it in the tools section.

I also can use it to similarly set the compound grinding angles on a lathe tool for things like say, making an acme threading tool (which I have done).

Another point in its favor -- we're told not to grind on the side of a grinding wheel for safety reasons, but the front leaves a concave grind. But a disk sander has no such problem. And the grit can be easily renewed with a new disk.

internal_fire:
How well can you sharpen to the same depth on each tooth? I do not see any sort of axial stop in your photos.

I have tried similar things and always end up with one tooth doing all the work.

I have a wheel that is specifically designed for side cutting. I don't work it hard of course. The heavier cutting is done on the periphery.

Gene

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