Feb 21, 2018
This posting will show the final fabrication and finish work that went into the Boca Bearing Sliding Geared Puzzle. I will have a final posting with high quality, still shots of the finished piece.
For starters, I need to make a platform or base for the puzzle. Up to this point it has basically been a rough steel frame that slides around on the table when you move the pieces around. I have a tendency to collect handles, wheels, feet, risers and other useful or decorative parts of furniture so I had 4 rubber-bottom bolts with nuts that used for adjustable feet.
I needed the feet to be able to lower all the way. This means the nut will need to screw on all the way to the head so I would have to thread the rest of the bolt. The nut will then be welded on the base as seen below.
This is the main base. It used to be a home made stand for a table mount drill press. I shortened it by adding new pieces of channel (the horizontal pieces seen at the top and bottom of the picture above) and then cutting off a few inches including the old channel.
You can see the nuts welded to each corner for the feet.
The channel is tapped with a 10-32 thread for bolts that will hold the main frame.
Main frame attached to base.
Here, the top is folded down close to the base for a lower profile during transportation. The hinge shown above is from an old treadle sewing machine and is connected by a 10-32 bold that screws directly into the channel cross-members. You can also see the bolt (foot) coming through the nut on the lower right hand side of the picture.
The "kickstand" comprises of two folding arms that I cut from an old steel table that was in my scrap pile. Each was welded to the frame at one end and then at the other ends they were bridged by welding a steel rod between the two.
Above the kick stand, surrounding the edge of the frame is another frame made of welded 1/2 steel angle. This frame fits over the main frame to keep any puzzle pieces from being removed or falling out. It is drilled with 4 3mm holes while the main frame is tapped with 4 holes to receive 3mm bolts.
Now that the main fabrication is complete, it is time for finishing. For the control box, main base and small frame, I used "traffic grey' powdercoating from Powder Buy the Pound to achieve an industrial feel on the piece.
The powder gets sprayed on around 15-20 psi and goes into the oven around 400 F.
After it cools to room temperature, its ready to handle.
The main frame that holds the puzzle pieces will not be powder coated. Since the hinges move against each other and the panels slide agains the steel, the powder coating will likely crack and flake off. I also wanted to have a little contrast between parts so I used a Slate Black Patina from Sculpt Nouveau. I also need to seal it so it does not continue to rust so I used their Clear Guard Matt Black.
I sandblasted it, made sure not to touch it with bare hands so I did not transfer oil and dirt back onto it and then sprayed the full concentrate patina onto the surface. You can dilute the patina with water to conserve it and to get a more rusty color.
The patina is basically a red/black rust so it has a fuzzy texture to it. I used some super fine steel wool to remove the loose "fuzz" and am left with a blackend surface similar to gun bluing.
To hold the color and prevent rusting I then apply the clear guard using a spray gun.
The lacquer darkens up and unifies the color of the patina while also protecting it.
For the main surface, I did not apply a lacquer but carnauba wax found at the auto store . Since the wood panels are riding on 4 bronze rods (bushings), the wax will help the panels slide. If I use the lacquer, then it will just scrape off, the wax will protect and lubricate.
I have already fabricated the aluminum handles but I need to clean them up, remove burrs and finish them.
I start with a file to round off the edges and worked up to 320 grit sandpaper for smooth finish.
Here is a shot of the raw panels before adding Teak Oil for a natural looking finish.
The oil makes the grain pop out and darkens the over color as seen above. I use paste wax on all 4 edges of each piece to help them glide against one another.
To help keep all the handles, nuts and bolts tight, I use a little threadlocker purchased from the auto store. Now it is time to re-assemble everything.
Here you can see the finished puzzle with the control box. I want to add a couple decals but that is about it. The puzzle has been a challenge since I have not build one before and there were several obstacles to over come, but that is what made it such I a blast to make.