CNC Coat Rack

Due to the coats in the welding area always being on the ground and covered in dirt I decided to make a coat rack to hang them on. This project is entirely CNC cut out but could probably be made using different techniques as well.

This project could be made multiple different materials but preferably something durable enough to hold up top the strains of the heavy coats being placed on it. I used 1/4" steel plates to make this rack out of.

You will need...

-One 4"x16" 1/4" section of steel plate (for hangers)

-One 4"x18" 1/4" steel plate (for backboard)

-I used #10 drywall anchors to attach the rack to the wall

-I made two racks, one from wood using a CNC laser cutter, and the other from metal using a CNC plasma cutter

I originally intended on making to the rack out of wood and se how strong it would be so I started by designing the hooks on Fusion 360 in order for it to be able cut out on a laser cutter. I used the spline tool in order to create the rough outline I wanted for the hook and then refined it from there. In order for the pins to fit into the holes on the board and not slip out I needed to create the design with very tight tolerances I made the height and width of the holes 100th on an inch larger than the height and width of the pins. This seemed perfect as the hangers were still able to fit into the holes but were not too loose that they would just slip out.

After designing on Fusion 360, I cut out my prototype on the laser cutter to see how it would look and fit together, as I originally intended the final project to be made of wood. When I was designing the hook on Fusion I used splines in order to make the curved tip of the hook. This created an issue as Inkscape, the program used to convert files to be used on the laser cutter, was not able to read the splines in the file. In order to resolve this issue, I needed to export the design from Fusion as a dxf. file and import it into a spline-polyline converter (there are multiple free options online) which converted the design into a polyline which could be used on the laser cutter. On the laser cutter, after focusing the laser, I kept all the base settings except that I instructed it to run 10 passes over the 1/4" wood for it to fully cut through. Anything less than that left parts of the outline uncut.

After cutting out the rack on the laser cutter I made sure that the pins on the hooks would fit into the slots on the backplate for the rack. This took a few tries because the tolerances of the pins and holes needed to be very precise and I did not get it right on my first or even second try. Either the pins were too small for the holes or they were too large and is was impossible for them to fit in. After I made sure they were secure I used wood glue to attach them together and painted everything to make it look better. Once the rack was complete I attached it to a larger piece of wood for testing. During the testing I discovered that there was a weak point on the hooks(outlined in the picture). In order to make the hooks stronger I had to decide whether to redesign the hooks and make the section that broke thicker or make the same design out of a different material. I chose the second option and opted to make the rack out of metal.

After my wood rack broke I shifted course and went with a metal design that would be welded together which seemed fitting as this is going to be for the welding coats in the shop. I redesigned the Fusion model so that it no longer had the pins on the end of the hooks but was instead a flat surface so that it could be welded onto any metal backplate without specific cutouts for the pins. On the plasma cutter I first had to make sure that there was enough coolant in the holding area below where the cuts were being made by topping it off with water. After that I needed to make sure that the actual cutting torch was exactly perpendicular to the pieces being cut out. Otherwise the parts will have a very slanted edge to them. After that I plugged in my USB stick with the CAM (linked below) and made sure that the origin was set in the correct place. After that I ran the CAM with the torck turned off so that I could be fully sure that the cuts were going to be in the right places and the right sizes. After that I turned on the torch and ran the program. (make sure to wear some type of shaded glasses as it is very bright)

I assembled the metal rack by welding the hooks to the steel back plate. I spaced each hook equally distant from each other, around 2.6 inches apart so that there would be enough room for the coats to hang on each of the hooks.

https://a360.co/4kGhDBQ