Thread: Machinists Level. Build Log.

Hi Guys,

In my previous post I was left with cutting in half the bit of brass that I had machined to make the supports for the ends of the brass tube containing the vial.



The original intent was to just hacksaw it in half between the holes. Having realised that I had not made any allowance for the thickness of the hacksaw blade, about two millimeters, and not having another piece of brass rod to make another one, I opted to use the Dremal tool and a thin 25mm diameter, 0.4 mm thick saw blade to cut through it.

It was a few moments later when I started to feel the burn. I hadn't anticipated the amount of heat that would be produced by the thin blade and the quite high minimum speed of the Dremal tool. Anyway it then got clamped in the bench vice to finish cutting it.



These are the two pieces that I ended up with. You can clearly see where I stopped and restarted cutting. I now wanted to put a nice radius on the square end and take off any sharp edges. I had started to grind a lathe tool to do this and then had an idea.



This is what I wanted. They came out quite nicely.

Now I've used carbide router bits before in the mill to do things like large holes and counter sinking. The thought struck me that I have a suitable 12 mm radius cutter with a 6 mm shaft and I also have a 6 mm boring bar and holder for the lathe. So I pressed the router cutter into service. It also has a far better form than I could hope to grind by hand, which is what I had started to do initially.



So here are a couple of photographs of the router cutter mounted in the lathe tool post. Since I was cutting brass I set the cutter edge so that it had zero rake. I gave the end a bit of a rub with some emery cloth to get the worst of the scratches out.



A last picture for now of the tube supports sat on the base.

Thanks for looking.