Press Fitting

This week in How to Make (almost) Anything, the class explored 3D printing and scanning. 3D printing was a topic with which I had a fair degree of familiarity. I started using a dimesion BST1200 printer my freshman year of high school, and had worked at an FDM printer company for an internship. I was therefore excited to try out the Form 1 printer I knew to be in the RPL and the CBA.

With the performance of a resin printer in mind, I designed an hourglass in SolidWorks. the hourglass featured a spiral cage around a standard profile. The hope was that that the mild translucense of the resin printer would allow for the hourglass to function. Unfortunately, all of the Form 1 printers were broken, and an ultimaker was used instead. Results are shown below.

The first thing one might notice is the degradation of the print quality as we move up and away from the build plate. This was largely due to a failure to modify the design for the change in loading profile during FDM printer vs. resin curing. I should have added a second set of cage bars propogating in the opposite direction to make the latice more rigid. A few more views of the finished print are shown below.

Erganomic Pistol Grip

With the print done, I moved into 3D scanning, which turned out to be quite a bit of fun. Commendation to the Sense scanner, the user interface was extremely intuitive, and the results impressive in resolution.

I'm captain of MIT's pistol team, competing at nationals several times during my time at the institute. Our team is proudly in posession of the Women's Collegiate National title for the second year in a row, and boast a large female demgraphic. One of the problems that the team faces is that the armory was manufactured in the mid-70s and 80s for mid to large sized male marspersons. We consequently routinely deal with pistol grips that aren't particularly well suited to the student using them. The team has consequently been pursuing 3D printing of grips, though so far to little success.

Using the Sense 3D scanner, I was able to obtain a reasonably detailed model of my hand and forearm, shown below.

Using software called MeshLab, I simplified the .stl file to a size that could be read by solidworks, and created a surface of my hand. This surface was positioned in an assembly (shown below) and then exported as a multibody part.

Using the cut with sufrace feature, The shape of the hand was cut from the grip block to create a negative. Patient cutting with the regular cut tool then removed excess material until a formed grip was available.

Some final tweaking will need to occur to smoot the mesh and roudn some of the edges, but the grip is reasonably ready to be tested, and hopefully will be printed in the near future.