The end of our grant is fast approaching and we’ve got a few projects left to finish up. So today is going to be another double session of basically finishing the projects we were working on last week.
With the beeswax/tar goop that we painted on the canvas last week now dry, it was time for final assembly.
We affixed a couple of crossbeams under the bellows. They serve two purposes: 1) to allow air to flow into the valves from underneath and 2) to set the angle of the bellows for best airflow effect.
The best angle for the two bellows is to have the airstreams cross about three inches in front of the snouts with the soapstone barrier about an inch in front of that. We lined up some steel rods down the centerline of each bellows to determine where the airstreams would cross and then marked the crossbeams before affixing them. There’s no special measurements of where they should go other than the back one shouldn’t obstruct the valve holes and the front one should stick out the sides so that it can be clamped or bolted or staked into place when using to keep them from moving about.
The last step today was to attach the handles and test the results.
There is one final step left to do on the hinges which is to affix the leather hinges to the sides of the side, but we want to use them for a while and break in the leather before making a slice and tacking them down. And we also need to drill the hole in the soapstone and maybe build a portable table to hold it all for using at events or just outside on nice days.
Now back to the shears…
Shears are one of those projects that seem like it should be easy, but in practice turn out to be more difficult than imagined. We had started with about 18-inches of 9/16-inch 10851085 1085 steel is a hardenable steel round steel stock. First we flattened out the spring area in the middle and drew out the ends to thin them out. And that’s where we left them last week.
So this week we needed to create the blades on each end and fold it and then finish it.
It’s been a while since we’ve done blades so it was a nice refresher. Drawing them out, grinding them, heat treating, and tempering are things we are familiar with but with shears the blades need to be at 90º angles to the flat spring area and facing the same direction as each other. I can neither confirm nor deny that there were mistakes made in that process. It’s really hard to get two blades that are exact mirrors of each other.
The last step was to fold them and line up the blades. Keeping them equal lengths so that the tips were even required wrapping the spring area around a big steel rod (vertical worked best) and either push/pulling the ends or hammering a bit on the spring area.
Then the big test of whether or not they would actually cut anything.
Well, they did pass the test, but we learned so many things that we’d like to do differently that we may have to try another pair soon. Things we’d do different are: 1) longer blades and not so much concern about the length of the reins, 2) have the blades be flat on two dimensions (spine and one side) that that they don’t rub and interfere with use, and 3) set shoulders to define the spring and blades areas, and 4) draw out only the reins area and not the blades area (we needed a bit more mass to work with).
Good thing we brought donuts to the smithy today because we spent over 6 hours in the forge getting these two project finished up.