#1. No have not tried the Granberg clamp on set up. I have not tried anything yet . I’m thinking you are recommending it . Would you say it is the better of the clamp on styles ?
I really like this style of sharpening guide, but read the other comments in the thread. And watch the videos referenced in that thread (the directions are not clear). I would try the Tecomec MS1 right now, but many similar styles are available.
#2. . . .So as you are running the file along the cutter at 30 degrees is the file kept flat
Yes. The value of the 10° down angle is a subject of debate. But that file holder needs to be kept flat. The clamp on file guides (#1 above) do allow the down angle, if desired.
This illustration, from a chart for Oregon chains, shows: the file diameter; '
A' - the top plate (e.g. 30°) angle; '
B' - the down angle (0° or 10°); (ignore 'C'); '
D' - the depth gauge setting.
#3 I have seen the wider stand alone raker gauges and the narrower ones . Not sure what are the best .
The Carlton '
File-O-Plates' are no longer available, as far as I understand; they were the originals.
Husqvara also makes stand alone, progressive depth gauge tools, if you don't use the roller guides.
The STIHL tools have to be imported from Europe.
More info in that thread, above, and:
https://www.arboristsite.com/commun...epth-gauge-filing-guides.334238/#post-6957347
Philbert