I was talking with my team (ie, my kids) the other day about this CNC robot and the kinds of things you can use it for and one of my girls brought up the question of what we would name the robot. After a little while, we decided on 'Santa Clause'.

I'm realizing now maybe I set the expectations just a tad high.

This past weekend I got to work on the Z-Axis. I still have a little ways to go on it, but here is what I have now:

This shows the front of the z-axis – where the trim router will go.

This shows the back of the z-axis – the part that will mount onto the gantry built previously.

Some mistakes I made you should watch out for:

• There are two 1/4” wholes on the side panels that need to be 5” from each other, not 5” from the top!
• The 5/16” bolts that you need should be threaded ALL THE WAY to the head. As you can see in the pictures here, I didn't get the correct type and will be fixing this shortly.
• If you don't have a 7/8” bit, go get one - I thought I'd wing it, so I took a bearing, put it in place, tapped on it with a mallet to get its impression in the wood, then I removed it, took a sharp chisel and widened the 1/2” hole that was already there. Then I put the bear back and used my ½ ton arbor press to put the bearing into the wood. Worked, but if I were doing it again – I'd just go buy another drill bit!

Here's a picture that shows the bearing recessed into the wood on the top of the Z-axis:

Some tips:

• I used a milling machine to drill all the holes. A drill press would work great too. The one hole I drilled with a hand drill was off 1/8” and so I'm going to redrill it.
• Use a grinder to grind down the bolt heads. If you don't have one, get one. Keep a small bucket of water nearby as the metal can get pretty hot and you will want to dip the rails in once in a while to cool it. Even a grinder head on a rotary tool, such as a Dremel, will work better than using files.
• When you are ready to drill the side panels, clamp them together and do them at the same time. That makes sure the holes all line up and saves you some cutting time.
• I recommend NOT gluing the sides and top – at least not until you have put everything together and are happy with it.
• The instructions call for a 3/4”(diameter) x 1/8” (deep) recess for one of the 5/16” bolts, but not the other two. I liked the way the bolt head fit in the recess so I'm planning to drill recesses for the other two.

I still have several things to do to wrap up this part – I'll post a photo when I'm finished. School is out now, so I'm hoping to be able to get a few things done in the evenings now.

Until next time, you better watch out and you better be good because Santa Clause is coming.

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