I've moved this thread to the Questions on Scott Bonnar Cylinder Mowers forum so it can be continued - it is way out of scope for the Introductions forum. You might consider a different title for it.
Steve, I think that video is useful but it avoids some of the main issues.
He is doing the same job that Deejay does with his "Bedknife Buddy", a small file set in a plastic block. This tool sharpens the bedknife's cutting edge. That is an operation that needs to be carried out regularly, not rarely like resharpening the reel. The problem is to remove only a very small amount of metal, and keep the entire length of the bedknife edge not only perfectly straight, but also parallel to the axle of the reel. The video makes no mention of this entire subject: he just trusts his air tool to do all that for him. I rather doubt that it can, though it may come closer to doing it than the Bedknife Buddy can. Whatever the tool does not do inherently due to its design, the operator has to do through skill and care. Meanwhile I was not comfortable with his failure to deburr the top edge of the bedknife after he sharpened it.
Note that on the subject of paper cutting, the video says it is a test you routinely make whether you are using no contact or light contact. Because there is more than one opinion on this subject and Deejay is sensitive about it, I won't go into it further.
