It’s been a long time since I was able to work on this project. Nearly cut-off finger, then tree illnesses in quick succession, and then a huge workload that took several months to get rid of. But this week I finally could dedicate each evening a bit of time, and today I finished grinding the primary bevels.
I cannot actually say how much time did my new magnetic jig/fixture/chuck/norris actually saved because I only used it for the beginning of this step – establishing the bevels with 40 grit belt. After that, I went free-hand again, because I need to alternate the grinding angle slightly with each belt change – so for 60 grit I ground with the point slightly up, 80 grit point down and so on. That is the only reliable way to make sure to have ground away all scratches from the coarser grit before going to the finer one, and additionally, it does help to make the grind more even and true.
I still wasted a lot of time due to my abysmal skill with the belt grinder, unfortunately, and I am not completely happy with the result skill-wise, especially the ricassos. I think I can still substantially reduce the time and improve quality by exercise.
Nevertheless, this time around it took me 6 hours for 12 blades, so 30 minutes per blade. And since it took me 75 minutes last time, that is a very significant time saving of 45 minutes or 60%.
Not all of that time saving is due to the fixture though. About five minutes per blade were saved by working in a batch and thus not changing the belt up on the machine until all blades were finished on the same level. And about fifteen minutes were saved by me not going above 120 grit. So the chuck saved me perhaps ten minutes, which is still substantial and I am not complaining. I will make a better and permanent one from aluminium and brass, definitively.
So now to coat the blades in protective coating or foil (I will split them in order to be able to evaluate if there is a difference) and into the heat treatment with them. That step is going to be really interesting – if I do not get it to 11 minutes per blade or lower, it will be more cost-effective for me to send the blades for hardening. Which is something I do not want to do because that means sending away some of the fun, plus it would make all my time plans dependant on someone else’s capacities.