Hawk's Babble-Log

Here is Sherline’s Step Block Hold-Down Set in action… or, rather, inaction. The whole idea of a hold-down set is to keep your part fixed in place to the mill table so that you can work on it. In this picture, I’ve got a 70mm x 70mm x 147mm block of aluminum fixed to the table with the step block hold-down set and two blocks of wood. I needed the wood because the block of aluminum is much taller than the two included step blocks, and I didn’t have two more step blocks to stack. In fact, with the current threaded studs (3.5 inch), this is the maxiumum height that I can hold down. I could go taller, but I’d have to get some longer threaded studs and some bigger blocks.

Here’s a better look. I’m not using an endmill for this, just a regular drill bit that I found in an accessories kit for my Dremel. It’s the smallest drill bit I’ve got. You can see the bits of aluminum which have been carved out of the block. Also, in the lower-right, under the X table, is an additional step-block included in the set. This one is uncoated aluminum and is intended for me to cut to specific size. I think that’s pretty cool.

Not too long after I started, I rotated the whole mill so that I could get a better look at what I was doing. “But Hawk, _what_ are you doing?” you may ask. Let me take a moment here to clarify something: I don’t know what the hell I’m doing. But it’s fun!

Actually, I’m trying to cut a smaller block out of this large block. After quite a bit of grinding, I did put a good notch in the side of the thing. But this tiny drill bit is not designed to do what I’m trying to do; it’s the wrong tool for the job. It’s not even an endmill. It took about an hour to do the first notch, and about a half an hour to do each hole.

Here you can see that I’ve made four additional perfect holes. A note about the handwheels on this mill: they’re _excellent_! I can easily adjust my part in either X or Y direction to 1/100th of a millimeter. And this is only if I stick with the markings on the handwheels. I could turn a handwheel between the markings, and get half of a hundredth of a millimeter travel.

Notice how the additional holes are exactly spaced? I advanced the X handwheel exactly two millimeters for every additional hole. Same thing applies to the Z axis, which moves the drill bit up and down. I was able to make good progress using this tiny drill bit, by advancing down one millimeter, then pulling out to remove the excess shavings, advancing one millimeter, puling out, and so on. When I reached 12 or 13mm depth, I had to pull out every half millimeter. It was easy to tell how deep I was going just by turning the handwheel and counting revolutions: one revolution = one millimeter. I went to 14 millimeters depth.

I’ll make better progress once I get a circular saw blade. Then I’ll turn the headstock 90 degrees, change the orientation of the block, and be able to cut straight down the whole block. That’ll be fun!