Hey Rob,
What size saw blade do you like to use in the jewelers saw?
Thanks,
Charles
I like to use the largest (coarsest) possible for the thickness of the material being cut. Using a coarser blade effects a faster cutting action.
For the overwhelming majority of metal used in this application, the thickness of the material will be above .100".
So the largest (size 8) blade will still work well. I don't have my chart handy, but I think that is the equivalent of 28 TPI.
On those special occasions where a really tight and intricate cut is needed, I'll use a finer blade, but it is solely to get the reduced blade dimensions.
I do have a selection of smaller blades that are used for the very thin-gauge copper, brass, etc. But those thicknesses are not applicable to the material discussed in this thread.
Back to the discussion of the grit/rod saws, they make them for jewelers saws, too. I found this out while trying to solve a peculiar problem.
A while back I made my son a fillet knife out of 1/16" 440C. He favors a large handle, and wanted me to use some of the lignum vitae.
After a preliminary fit, he said that the entire knife felt very unbalanced to him. For a fillet knife, it felt great to me. I realize this can be subjective to each individual, but considering the type of wood, I guess I could understand.
We decided to skelotonize the tang and do some minor hollowing on the inside of the wood, too. (Yes, this reduced surface contact, but three mechanical fasteners (Corbys) made up for it. That wood isn't exactly famous for holding glue, even epoxy, anyways!)
My problem was that the blade was already hardened, and I had my doubts that the saw blades would hold up. That's when I found out about the rod saw in a size for the jewelers saw.
They were expensive, nearly $10 each!
But, they were diamond-impregnated piano wire.
It worked great. The saw design has enough "give" so that it flexes before the wire itself stretches. Since the blade doesn't stretch out, this maintains constant tension on the blade and allows the control. And of course the fact that it was diamond grit meant I didn't have to worry about the steel already being hard.
The hardest part about all of it was trying to drill a starter hole for the saw. So we eventually ended up starting the saw off the existing center hole (for the fastener). The narrow kerf still allowed use of the hole for the Corby, too.
Probably one of my more "backyard-engineered" projects, but it forced me to think outside the box, and I learned a few things in the process.
Probably the most valuable lesson learned is that my son wants me to make him another one, and it's high time he make one himself.
Why? Because that knife is somewhere in Reelfoot Lake!