Friday, 21 August 2020

Straight razor from table saw blade

So a while back I replaced the table saw blade in the workshop and got the idea in my head to try and make a straight razor out of it.

I sketched out a quick design and then cut it from some scraps of redwood (the same stuff I used in the ring box project - not sure if that's the correct species, but it's wood, and it's a red-ish colour, so close enough.) on the bandsaw. Fortunately I had two scraps the same thickness, so I needn't worry about the thickness of each of the scales (sides) being identical.

The blade itself was sketched out in marker on the old table saw blade and cut out with an angle grinder. Once the rough shape was done, a mix of bench grinder and rotary grinding tools were used to refine the shape.

The gap between the 2 scales of the handle was padded out using some brass sheet, cut to match the shape of the scales, whilst including cut out space both for the blade to fold in to, and to allow the tang to rotate into when the blade is opened.

This, and the scales were both epoxied together, and then two holes were drilled and brass pins added, for additional strength and their own aesthetic quality.

The third brass pin provides the hinge that the blade will pivot from to make the opening and closing mechanism.

Before the blade and handle were put together, it was easier to finish each part separately.

In the case of the handle, this meant sanding to round off the edges and make it more comfortable to hold, and a wipe out with danish oil.

In the case of the blade this meant a lot of grinding, sharpening and honing to get it to a sharp enough edge to cut hairs. With hindsight although it probably isn't the best steel to use for a blade, it is sharp enough to shave with - it just requires frequent honing.

But, at the end of the day it works, I'm pleased with how it's turned out, and I learnt a bit more about blade making and the dark arts of sharpening and honing along the way. I also now totally get why some people fall into this particular niche rather than just more general metalworking... I'm actually quite tempted to go find some better steel and make another already.

Saturday, 8 August 2020

Tattoo Machine for Leatherwork

This is the fifth of my 'Lockdown Projects' - Projects made during the Coronavirus lockdown, which I limited to one week, and only using materials I had to hand.
Before I start this write up I just want to emphasize this tattoo gun is not intended for use on anything other than leather. Using it for anything else risks a number of heath issues.
With that out of the way, I’ve been intrigued by the idea of using tattooing as a way of patterning it. A quick search shows that it’s not an uncommon practice – particularly it would seem, for leather boots.
The theory goes that given that leather is essentially just skin, it would tattoo in the similar way to a person.
After seeing a home-made tattoo gun in an episode of Orange is the New Black years ago, I’ve had the idea in the back of my head to build one and try it.
During lockdown, it seemed like a thematic fit to finally hack one together.
The body of the machine is from a mechanical pencil. 
The main needle mechanism is a sewing needle, with an empty metal pen refill, and a hook made of a bent paperclip. These bits are epoxied together for sturdiness.
The motor was taken from a handheld fan. A button provided the connection between the needle mechanism and the motor.
The bracket was a small bit of metal from the junk bin - that was probably once part of a printer or something similar I’d previously dismantled.
The motor and bracket were fixed together with cable ties and a final cable tie tensions the mechanism so that there’s less rattle and wobble in the needle.
Initially I used 2xAA batteries for a power supply, but after a bit of testing, it needed more power, so I replaced that with a USB connector.
Obviously I didn’t have any tattoo ink to hand, so I just used leather dye to test.