Tuesday, March 31, 2015

HT1 HIDDEN TANG - GUARD FITTING


For this version of the HT1, I want to make a guard of 416 stainless steel. I have some 3/8" x 1-1/4" bar that I will cut just a bit longer than the depth of the blade.
Cutting on my Porta-Band.
Here I marked a centre line and will mark the tang right up at the ricasso.
Marked. Now I measured the thickness of the blade right at the ricasso. It's a hair over 0.13", so I will use a 0.125" (1/8") bit and drill a series of holes on the centre line.
Here the aim is to stay on the line no matter what.
Once the holes are in, I go to the "back" of the guard and enlarge them with a 1/4" bit. This is only done part of the way. Do not go all the way through to the front or you will be tossing this piece of stainless steel in the scrap bin.
Clearly marked the front. We're going to be focusing on this face much more the the back as it will be exposed. The back will be hidden and requires much less attention.
Here I am using an old 1/8" drill bit in the cordless drill. Running a slow RPMs, I am riding the flutes to remove the steel between the holes.
Once I can get round needle file in it's a matter of working this up and down to create the slot.
Test fitting the slot. I had to grind some of the tang. It is very important to know every part of the screw and tang must be smaller than the final position of the guard. Otherwise, the slot will have to be unnecessarily enlarged to pass over this spot and this will leave a gap then the guard is in place.
A square needle file helps to make the slot fit precisely. This is a trial and error process. Always filing small amounts and test fitting.
Once the guard will pass almost to position I stopped filing. The last bit of interference will hold the guard tight and close any very small gaps.
Now the roughly shape the guard on the band saw. This saves on belts a little and is cooler on the hands.
I hit the guard with the Scotch-Brite belt for a brushed look. The rest of the guard shaping will be done after the handle components are epoxied and set.

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