Focus: Prototyping and Sheet Metal
Over the summer going into my senior year, I worked in the machine shop, called the Precision Machining Lab (PML), full time. I was tasked with solving the ongoing issue of clutter and disarray around the shops 4 manual lathes. There was no organization for the tools, brushes, wrenches, or chucks. This project was one that I was given full responsibility over, from designing to prototyping to manufacturing.
There needed to be a way to easily store the tools such that they were not a danger to students and such that the shop assistants could easily see if any tools were missing or damaged. I decided to make an angled platform that was fixed to the wall near the lathes. Each of the dozen of tools could be easily visible for people of all heights, they would be safe to handle, and easier to keep track of. I got to work making prototypes and CAD models.
The two images above show the first version of the holder. It supports five tools, two files, the lathe’s hex keys, a brush, a chuck wrench, a drill chuck, and the spindle cover hanging off of the edge. I made this first prototype out of laser-cut acrylic. Here, the drill chuck, brush, and file were on the top part. The tools, hex keys, and chuck wrench were all angled down to face the lathe operator, allowing for easy access of the tools. However, in prototyping, I discovered that the files were too high up to easily reach. So, I updated the CAD model to shift them around.
The drill chuck was more out of the way in this second version and the files were easily accessible. So, I made another prototype for further iteration.
I installed the angled L stock into the wall with help from the building engineers. Using the sheet metal function in SolidWorks, I flattened the bent profile of the main lathe holder part. I laser-cut this part out of acrylic. With a heat gun and a simple MDF fixture, I slowly bent the acrylic to the correct angle. I installed this prototype onto the wall and tested it out for a few days. This provided valuable insight into design’s layout. I found that everything was in a reasonable position apart from the boring bar. The long bar extended too far up and would scrape my wrist as I reached for the drill chuck (very bad!). So for the final design, I shifted the boring bar tool over to the far left, where it would be out of the way and leave safe clearance for reaching to the flat upper level of the holder.
The next step was to move up to the final material, 1/8″ 6061 aluminum sheet metal. The manufacturing process would be similar to that of the acrylic sheet: start with a flat sheet, cut out the profiles, bend the part to around 60 degrees, then install it. Ideally, the aluminum part would be waterjet cut since it is a 2D profile. However, I did not have access to waterjet cutting, so I had to machine them on the PML’s CNC mills. I clamped a stack of 6 sheets of aluminum and milled out all of the profiles at once.
The above picture on the left show the sheet metal after milling. The holes and profiles were cut into it. The one on the right shows the same part after bending using a sheet metal brake.
The next part was a key feature that I have not mentioned yet. The lathe tools use a dovetail to remain precisely fixed in place on the tool post of the machine. In order to keep the tools in place on my holder, I replicated the dovetail that the tools would slot into.
Starting from the block in the left image, I used a Haas MiniMill CNC to mill the profile and rigid tap the holes. These threaded holes would be used to fix the dovetail part to the sheet metal holder. I then made 20 of these parts, five for each of the four lathes. Using a vise stop, I was able to efficiently run each of these parts with very little set up or fixturing time.
Finally, I was ready to assemble the completed lathe holders.
All four completed lathe tool holders were installed in the summer of 2022 and remain there nearly two years later. None of the parts have needed maintenance or replacement (with the exception of the 3D printed file rests which wore down a bit). The shop’s lathes are used by around 50 students and staff on a weekly basis and have held up to both experienced and inexperienced use.