Far Side of the Moon

The Tinkerer — Tue, 09 Jul 2013 22:23:45 +0000

“What do you want? You, you want the moon?! Just say the word and I’ll throw a lasso around it and pull it down. I’ll give you the moon, Mary. Well then, you could swallow it, and it’d all dissolve, see? And the moon beams’d shoot out of your fingers and your toes and the ends of your hair. Am I talking too much?” – Jimmy Stuart – It’s a Wonderful Life

I’ve been married to my wonderful wife for 5 years. The traditional gift for the 5 year anniversary is wood. No pressure for a woodworker… Well, she made it easy on me, she asked for the moon.

I started by consulting NASA’s website. I was in search of topographical data I could translate into toolpaths for the ShopBot. I was in luck when I found the GLD 100 map. I chose the far side of the moon since we otherwise don’t get to see it and I’ve been known to indulge in Pink Floyd.

From there my friend Ben Hribar helped me out with some photoshop work. We produced a grayscale image where lower elevations were black and the highest elevations were white. Once that was done, it was on to modeling.

The software I use with the ShopBot has a tool that allows you to import a grayscale image, set a few parameters like material thickness, the range from lowest cut to highest cut, and a few others. Once the image was processed, I was left with a 3D model ready to carve.

I created a roughing toolpath to remove the bulk of the material with a 1/2″ square endmill.

Then I created a finishing toolpath to give a nice finish with a 1/2″ ballnose mill. See my post on router bits for more explanation of these.

The moon is carved from a single piece of 3/4″ baltic birch plywood. I love the way the alternating layers of dark and light veneers accentuate the topography.

I cut a second ring to mount on the back of the moon. It’s purpose is to provide a lip to hang the moon from, hold 4 – 3/8″ dowels to bring the moon away from the wall, and to accept a strip of LED lights.

I chose analog LEDs for the price and simplicity of setting them up. The set I bought came with 16′ of LED tape, a power supply, a controller, and a remote control.

An intro to 5-axis CNC machining – part 1

The Tinkerer — Mon, 25 Feb 2013 20:22:14 +0000

I had the opportunity to tag along on a road trip with some members of the ShopBot team. They were headed to a shop in Wisconsin to help a customer with two ShopBot machines, a monster 16×5 3-axis machine and a brand new 5-axis machine. I have to admit I was there for the 5-axis. I had not seen their machine in action and I was excited to see it run.

3-axis: A machine that can move a tool (commonly a spinning cutter bit) along a horizontal plane (X-axis and Y-axis) such as a piece of plywood, as well as move vertically (Z-axis) to adjust the depth of cut and carve things such as a topographical map. The adage goes that a 3-axis machine can cut valleys and carve “mountains” but is not capable of creating “caves”. You could cut parts for plywood furniture or create 3D carved signs.

5-axis: A five axis machine starts with the same 3-axis movement as above. It adds two rotational axis by adding a “shoulder” and “wrist” or by allowing the actual workpiece to move in 2 axis. A 5-axis machine can carve a complete 3-dimensional object from a block of material. You could use a 5-axis machine to carve a bust of Beethoven for your piano.

One of the most important aspects to any cnc machining work is figuring out how to hold your material in place while the machine makes it’s cuts. A CNC Maching service can assist with a range of projects. Material holding even more critical with 5 axis machining especially when you consider you may be cutting away the bottom of your block of material. Material stiffness is also a concern since any flex in your material will degrade your cut quality. You can find out about Sliger Machineworks and learn all about this type of machining. Used for removing jammed or stripped nuts without damaging the bolt, a nut splitter is an essential tool in the kit of an onsite engineer.

In addition, one of the most essential things you can do to preserve your expensive equipment is to lubricate it properly. You will be rewarded with longer living and better performing equipment if you choose the right lubricant like Altemp and apply it properly. If you need an additional cnc machining equipment, purchasing used cnc machinery equipment is worth considering.

Many people employ jigs, screws, or adhesive to secure their material.

There are 2 flavors of 5-axis machining. “3+2” and full 5-axis.

During “3+2” machining, 2 of the axis are locked while the other 3 move to do the machining.

During 5-axis machining, all 5 axis are in motion while the cutting bit is in contact with the material.

This video shows an object being carved using both methods.

shopbot – Tinker and Futz

Far Side of the Moon

An intro to 5-axis CNC machining – part 1