I spent a large part of my day yesterday sharpening and cambering plane blades for my family of Stanley planes. I use a mix of premium, wood, & restored planes. I typically use my restored planes more for rougher work reserving the premium planes for fine work. One reason for this strategy is my three Lee Valley BU planes have blades that can be a challenge to camber. I am aware that this can be done, and have read Derek Cohen's methods for doing this on his Blog. Still it makes more sense to me to set the premium planes up with smaller cambers for finer work. Obviously the thinner, often softer metal in older planes can be easier to grind camber into.
I probably should add that I have a grinder and CNC wheels. I realize that some may find these devises unnecessary but I am a tremendous fan. The speed and precision with which I was making cambered edges yesterday is something I have struggled with for years. Just being able to get immediate feed back, due to the faster cutting wheels, has dramatically improved my ability to make better/sharper tool edges.
I spent a while on Derek's site yesterday rereading various articles he has written on sharpening, especially since he started using CNC wheels. Like Derek I am largely a hand sharpener who likes to get done with the sharpening and back to cutting the wood. I was interested to read how Derek had evolved in his thinking about how much camber to put in a blade. From what I read I believe Derek himself is still working out precise cambers for specific planes and the blades they use.
The question that seems to rise is matching the camber to the width of a particular blade. Too much camber and the plane either does not take a full width shaving or the amount of wood, the shaving, the plane tries to take is more than can comfortably be managed. The issue for me is my desire to have planes that can remove larger amounts of wood. I was tuning up Stanley #5 1/4, 4 1/2, 5 1/2 & 6 planes yesterday experimenting with whether the thinner blade on the 5 1/4 made taking a larger shaving easier than attempting something similar with a #6 with 2 3/8" blade or a # 5 1/2 with a 2 1/4" blade. My base for testing being a Stanely #5 with a hand ground/sharpened blade that has been my go to for stock removal.
Thus far my results have not been conclusive. My 5 1/4 has major camber at this point, so I am not getting a full width shaving, even with the 1 3/4" blade. The 5 1/2 has much less camber and takes a full width shaving, but so far not too thick. I am having a problem with Stanley's fairly small mouths. Blades with large amounts of camber tend to clog the mouth due to lack of room for a large shaving to pass. I am thinking about opening up the mouth of one of my Stanley's, once I figure out which one might be best at taking larger shavings.