The dealers that use automatic chain sharpener machines... do they even touch a raker?
First address the stereotypes: grinder vs hand filing. I can ruin a chain either way! It's the results you are after, not the method. Biggest problem is if they do not care, or want to take the time on set ups, etc. Depth gauges can be done on both manual and automatic grinders. Local shops around here charge $75 - $85 / hour for service, so at $7.50 / chain, the most they can spend on one is 6 minutes (takes me 10-15 minutes for a good job on an average chain). I can buy a new chain on sale for $8 to $15, so estimate what dealer costs might be, and if they would rather sell you a new loop or sharpen.
So, wondering... are there people in your area that sharpen chains by hand for hire?
What would you be willing to pay? Again, compared to the cost of a new chain? Might find some retired guy who pays himself very little, but hard to find a business that can afford to do the full-service sharpening at what people expect to pay.
You might want to look into some of the mail order sharpening services if you cannot find someone in your area (trying to find the link for a guy who bought 3 Franzen grinders and charges postage one way).
If someone gets hurt from a chain that is too aggressive your opening yourself up to lawsuit because you altered the chain . . . . I know a Stihl dealer who got sued because they took a link out of a stretched chain and it broke and the guy got hurt from it. I don't know all the details but the lawyer had a field day with that one.
Anybody can sue you for anything. If you are in the chainsaw business, you need good liability insurance. Refer to the $75 - $85 shop rates mentioned above.
The Stihl owners manuals tell you to file the rakers so I'm wondering too.
+1
You guys that file your own chains, how long do they last in hardwood? Mine sharp chains don't seem to last as long as think they should!
'Sharper' chains cut faster but dull faster. It's a trade off. Best is to find the angles that work for you, for your saws, your wood, your cutting, and either sharpen those yourself, or find someone who will sharpen to your specifications, rather than to 'default' angles.
Philbert