This is one of those projects that took about a year to complete. I got started on it and had to set it mostly aside to knock out other needed projects for neighbors/friends and myself before finally getting back to it nearly a year later.
This is mostly a plasma project with some spindle work for the acrylics and UHMWPE, some welding, grinding, painting and powder-coating.
First off it started with a simple flat pattern wire-frame design in my legacy CAD system. People tell me it is kind of eclectic / busy, but I like it all the same… I wanted it to have enough depth / color / texture that it would look reasonably decent even when it was not lighted and that leads to a bit of that busy feel. Also, adding some depth / layering to it breaks up what could easily have just been a flat back-lit piece of steel and makes it unique.
At the beginning of this project I was hand editing the G-Code from my legacy CAD system to add the small handful of commands needed for ohmic-touch off’s, moving to arc-start length, initiating the arc, pausing for pierceing, moving to cut height, etc. By the end I had written a small python program to find the necessary places, and insert those automatically as well adjusting feed rates, currents, voltages and pierce delays for material thickness, consumables, etc.
With G-Code in hand it was off to the AVIDcnc on the plasma table side of the machine. This is 16Ga mild steel, so it cuts at incredible speed.
For anyone here not familiar with plasma cutting here is a video snippet of this piece getting cut out.
Video Snippet of the part above being cut.
In the video you can see that I had not installed the UHMWPE seperators between the plasma table and spindle side of the machine, so I was making quite the mess on the spoil board.
This next photo is a little bit out of order (it was taken much later in the project) but it shows the detail of that cut and a close up of how the lettering comes out from the plasma cutter. I mentioned above that I had to set the project aside for most of a year. When I came back to it most of these pieces were pretty badly rusted, so in this photo I had just finished laying them out on the welding table and hitting them with an orbital sander to remove the rust, when I noticed the cut quality and snapped this image.
Next up, I needed to cut the letters that would project forward from the face of the sign. The flying cap on the letter ‘M’ hangs out there quite a distance, so I wanted to use a little bit of a thicker material for this. I went with 10Ga mild steel to help with rigidity. When it is lighted one can’t really tell at all, but when it is not lighted the thicker material there really adds to the depth and the overall look/feel. This material is 10Ga(0.135in)
I was going to use 3/16 or even 1/4in material for this, but this material was donated(in trade) by a friend, so I went with it. It worked great. The material had an approx ~1in bow in the middle but that did not affect the cut in the least. The torch height controller on the AVIDcnc did its thing and went right up/over it.
The image below shows how the parts look, fresh off the plasma table, without any of the follow on cleanup steps.
The next parts to cut came from some perforated stainless material. These are one of the items that add some “texture” to the design when it is lit. It helps to break up some of the blue light and since it blocks ~3/4 of the blue light in that area it adds a shading effect. Of course, when the light is off the stainless just pops!
It doesn’t show in the photo below, but there is a heavy chunk of cast steel sitting on the material just off the right side of the photo to keep this smaller piece from moving around while being cut. The perforations in this material are 0.093in on 0.140 staggered centers. One just leaves the THC engaged and it cuts just fine. You can feel the vibration in the Z-axis, due to it, but it cuts just fine.
The next parts to be cut were the banding rings, to hold the faux neon and those pieces to get bent around / welded to form the edges of the sign as well as some of the pieces that layer in, in front of the main body.
And here some of the setup and fitting of the steel in preperation for welding. I used a number of pieces of pipe to hammer form the material over to get just the ‘right’ curve. This is one of the harder parts of the project. After these steps these parts recieve a pretty good number of ‘heavy’ tack welds.
Then back to the AVIDcnc plasma cutter again to cut some 3/16in mild steel plate to make some of the skeletonized parts that layer in out front of the sign.
And then one last part to get layered in… (Back to 16Ga material)
There was quite a pile of parts starting to stack up, so I snapped the photo below to see most of the pieces layered together. The pieces are not spaced correctly and aren’t quite aligned right in the photo, but it was at this point I could really get a feel that this desgin was going to work out!
And then it was time for more tac welding. Tac welding along the edges of thin gauge steel unsupported, out in air like this is always a trade-off getting things hot enough to really melt but not so hot that one blows through the metal. Having taken the time to pre-hammer form each piece so it is already the right shape seems to help and one can use far fewer tacs.
Next up it was back over to the AVIDcnc, but this time on the spindle side of the machine. Here I am cutting 1/8in acrylic and 1/16in UHMWPE. The acrylic is cut with the brown paper protective coating left in place to help keep it from getting scratched up. It is only peeled off right before final assembly.
And then it was time for more welding…
One of the construction methods I used was to weld 1.5in long #6-32 stainless steel flat head screws to the backs of the leters and a few other pieces in the design so that many parts of the design are bolted on and the screws / spacers set the layer heights / stand-off of may parts in this sign.
And then painting. The inside of the main body got a flat white rattle can dance. The front face got several coats of a flat black with light wood block sanding in-between. Like the powder coating steps, during the painting steps the threaded studs that have been welded on are covered in painters’ tape before painting to keep the threads clear of paint.
I had not run that stainless across the buffing wheel yet and already, just in contrast with the flat black paint, it pops…
All the rest of the parts of the sign are powder coated instead of being painted. I used some high temperature tape to cover / protect the threads during the powder application / reflow process.
I’ve used this particular silver powder on a few projects, and I particularly like it. It has a rought / speckled finish looking like extra worn pitted but bright aluminum. (Like it had just been freshly media blasted with heavy / coarse media.) The finish scatters light in all directions which works well on a lighted sign. They stopped making the particular red I used for this project about a year after I did this project. Too bad, I liked it.
So then it was time for a power supply and the installation of some LEDs.
There are two sets (rings) of LEDs pointed in-ward to light up the sign and lettering, and there is a 2’nd set pointed outward that lights up the wall around the sign to make it really stand out and catch your eye.
And then the faux neon… It fits into this welded steel support ring that slides on from the back of the sign.
Layer all this in and here is what you get… There is a wood-stove down in the corner of the studio and this sign is hanging on the fire brick up above the mantle. The camera I was using is pretty easily over saturated by this frequency of blue light, so the photo doesn’t tell the full story that the eye can see much more easily. That entire part of the wall glows blue and really draws one’s attention.
An interesting note, scroll back up and look at the beautiful blue on the powder-coated letters ~6photos above, and then compare them to the same letters installed on the sign below where they appear almost black. This is the over-saturation in ‘blue’ light that I was mentioning. One’s eyes have the dynamic range to see both, where the processing in the camera sensor just cannot deal with it.
I made a 2’nd one of these that hangs at the bottom of the stairs outside the studio. It is in an easy spot to grab off the wall when taking the robots to a show… The close up shot below is of that 2’nd sign and you can see some of the layering. Rather than make that many tiny parts on the lathe I used black nylon PCB spacers to adjust the spacing of the various components. The chromed #6-32 acorn-nuts are a bit of over-kill, but I like it and purposfully designed those screws to come through to the front of the sign as a design element, rather than having them hidden, out the back, like all the rest in the design.
I’ve mentioned in a few posts on this forum that I use the AVIDcnc all the time, and this is just one of those projects that tells that story.
Well, …, that was the project, I hope someone here finds it interesting or likes it. I sure had fun making the sign and it is a great conversation piece as people are walking into the studio, at least until they see the robots. 
-Kenneth
