This week I got to use the loudest machine in the OEDK. I could never place that eerie sound that reverberates through the interior but a week of other people and myself using it has familiarized myself with it. That was probably the major downside, everyone had to use it across the two prototyping classes and it was a mess to set up and get working properly.

Initially, I had planned to cut out a topographical map of Taiwan but after three hours of wrestling with VCarve and hearing horror stories of other people’s cuts failing I swapped to cutting a ‘simple‘ SVG from the noun project. The combination of the 2-hour minimum to run the machine and the sheer volume of people who needed to use the two machines meant there was no time for experimentation in the fully packed Fabman schedule.

The Carbide 3D system was easy to work with. I had chosen an image of a chemical plant in accordance with my chemical engineering major. Loading the SVG into Carbide Create and adjusting the size and toolpaths were relatively simple except for contouring, I had to fight a bit with the vector placements to prevent the contours from cutting the singular design into multiple pieces. Initializing the machine and loading the job was quite simple too though they did take very long thanks to the slow jog speed of the Shapeoko Pro.

Starting the job was when I really took in the print time: 40 minutes for the pocket and 35 minutes to contour a 3″ x 3″ image on a 1.5 in. plank of wood! It felt ridiculous that I was essentially just laser cutting and engraving on a thicker piece of wood at a greater depth yet it took more than 10 times the time, but I still ran it. I had to really babysit the machine which kept running into issues. The first and most concerning one was the spindle refusing to spin, I had reset the nozzle and restarted the jig, but it still wouldn’t turn on. Apparently, there was a separate “SPINDLE ON” button I had to press on the side. There was also a problem where the external vacuum did not have enough power to extract the sawdust so I had to stay close by vacuuming by hand.

 

 

 

 

 

 

 

 

An hour and a half later, the piece came out disappointingly. The space between the pocket was much thinner than expected, leading to thin sheets of wood in the design that simply didn’t look good. Additionally, the contour didn’t cut all the way to the bottom of the wood plank despite measuring the thickness with a caliper and selecting stock bottom on the machine.

I did not have another 1.5 hours so I quickly downloaded another noun and simplified it so two pieces could be pocketed and contoured in 40 minutes. The same problem of insufficient contour depth came up again so I had to grind away the back on a belt sander until only the tabs remained. In the process of breaking off the tabs, I accidentally broke the neck of the pipe junction and had to wood glue it back together and painted the entire thing black to hide the imperfections.

 

 

 

 

 

 

 

I’m quite disappointed with how this project turned out. The 1/8″ end mill left a lot to be desired even when it cut out the noun as intended just in terms of roughness. The strength of the CNC machine in my eyes is still the capacity to do 3D processes so I might give the topographical map another shot over Thanksgiving break when I don’t have to fight 50 people to use the machine.

Here’s the estimated cost breakdown:

Cost Type	Cost	Price	Source	Quantity	Total
Materials	3/4″x 4″ plank	$10.43/8 ft	Home Depot	10/12 ft	$1.09
	Spray Paint	$6.19 /can	Target	1/20 can	$0.31
Labor	Belt Sander	$16/hr	ZipRecruiter	1/30 hr	$0.53
	CNC Operator	$23 /hr	ZipRecruiter	2.167 hr	$49.84
Operations	CNC Machine	2.35 kW * $0.328/kW/h	Carbide 3D Community	2.167 h	$1.67
Total					$53.74

I hope the CNC Operator is much better than me at that rate.