[ckelly78z]

I bought a Harbor Freight chain sharpener to deal with my 5 chains, for my 20" Stihl MS310. I got really tired of $6-$7 per sharpening per chain from the local small engine mechanic.

This units works kind of like a chop say that grinds the angle you want when you pull it down. It has a brake to hold the chain in place, and multiple adjustments for depth, and angle.

The SE mechanic was grinding the chains too far (probably in an effort to warrant me buying new chains) so I started doing them myself. I find it almost theraputic to sit on my shop stool, and watch each link get sharpened for next to nothing $$. I suppose at some time, I will need to replace the thin grinding wheel, but I haven't ran out of adjustment yet.

Too much angle will get you an absolute chip throwing beast, but will dull quickly, and risk being chipped easily.
Too little angle will get you a chain that stays relatively sharp for a longer period, but may take more effort to make long cuts.