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Jacob Franz[edit]


About Me[edit]

I am a third year undergraduate student at Michigan Technological University majoring in Mechanical Engineer. I joined Open Source Hardware Enterprise Fall 2016. I am the lead on the Granulator MKll project which is apart of the C3 Grant. I also help with any machining that needs to be completed for OSHE.

Enterprise Fall 2016[edit]

Ford College Community Challenge Project:

This semester I started working on the Ford C3 Grant Project. My main project was to design a belt cover for use on the plastic granulator. I also collaborated with Peter Gorecki and Walker Nelson in the early stages of designing the new plastic granulator. During this time we brainstormed ideas of cutting methods, potential design features, and what test, and calculations will need to be done. The main design goal for creating a belt cover was to have the cover be 3D printed using a Open Source 3D Printer, as well not having to do any modifications to the current machine. My design uses the 4 preexisting holes on the legs. In order to attach the 3D printed parts to the machine it will require new parts to fit through both the 3D printed part and legs. Currently The main components of the Belt cover are designed and on the waitlist to be printed at the start of next semester.

Bill Of Materials for adding on belt cover (added on to original BOM):
4 - 3/8" x 4" Course thread bolts
1 - 3/8" coarse thread locknuts
4 -1/2" x 5/8" x1" Steel Spacers
4 - 3/8" Washers
PLA Filament

Enterprise Spring 2017[edit]

The enterprise had received a Prusa i3 MKll kit this semester which I had assembled the printer and did maintenance work when the printer had issues. Also, I helped with the production of the husky statue's this semester.

Granulator MKll[edit]

The Granulator MKll was a continuation from what Peter Gorecki and Walker Nelson had designed. This semesters task was to build the design model. We have not completed the granulator as of now due to unforeseen obstacles such as having to work around machine shop hours and having to wait for parts. Due to manufactures not replying for request for quotes for the granulation blades we had to make our own blades. All the parts besides the blades that required machining were done using drill press, corded drill, and an angle grinder. So far one of the issues that we have found with the initial design is with the granulation screen. Because when we cut the pipe in half there was tension in the pipe which changed the dimensions. The granulator is close to being fully assembled. I am planning on completing the assembly over the summer as well perform testing and make adjustments. I will update the Spring 2017 work section after completion of machine.

Enterprise Fall 2017[edit]

This semester I have continued assembling the Granulator MKll and have also attended most of the recruiting events. Currently the granulator is almost completely assembled. I have started working on the electrical components am am currently waiting for the necessary parts to arrive to complete the wiring of the machine. I have designed the new granulation screen and vacuum adapter piece to work effectively with the new design. I worked with Daniel Seguin for heat treating the granulation blades as well stress relief heat treatment of the new pipe. Aubrey Woern and I have decided on fully enclosing the machine in plywood to protect users from the belt, and other moving parts, as well to give a barrier between the machine and the surrounding incase of a catastrophic failure. The panels will be cut out within the next month and installed soon after the start of the Spring 2018 semester. We will also be designing and 3D Printing extra covers to enclose parts of the machine that remain outside of the wooden panels.

Granulator MKll Update[edit]

Errors with Design Found[edit]

-15 Amp Circuit Breaker originally called for has been removed and will be replaced with a 15 Amp Inline GFCI extension cord

-Granulation Screen will deform significantly if you cut it in half without doing the proper stress relief heat treatment

-Corner seals 3D Printed part does not seal the gap between metal plates and the Body

-Server Rack is smaller than one depicted in the CAD Model

Design Changes[edit]

-Granulation Screen holes have been removed to reduce machining time

-New 3D Printed Granulation Screen vacuum adapter and screen insert [Pending success]

Recommendations For Machining[edit]

If you do not have access to CNC mills that can drill holes precisely in each part I would highly recommend 3D Printing hole pattern jigs to help assist with getting holes drilled in the correct locations. We did not use this method at all while machining the parts however, while building I noticed that there are inaccuracies when measuring by hand with calipers either due to the drill bit wandering when first making contact or the accuracy of our marking device. A stress relief heat treatment is necessary for cutting the granulation screen pipe in half in order to reduce the amount the pipe will deform. The heat treatment guidelines for the pipe that worked for the pipe used was 1 hour at 600 degrees Celsius. The temperature and duration can be found online for the particular steel you are working with. If you do not have access to a commercial furnace a DIY furnace that can melt aluminum, keep temperature from mid 500 to 600 degrees Celsius for 1 hour, and the pipe can fit in it.

Enterprise Spring 2018[edit]

This semester I have finished the assembly of the Granulator MKll. Currently the granulator is fully operational and has successfully granulated plastic. Future work to be done includes running more plastic through the machine, painting plywood panels for a more finished look, look into adding on a fly wheel.

Granulator MKll Update[edit]


Safety Features Added[edit]

-Fully enclosed the machine in plywood to protect users from the belt, and other moving parts, as well to give a barrier between the machine and the surrounding incase of a catastrophic failure.

-Added a belt cover for the small section that is not covered by the plywood.

-Limit Switch mount so when the chute is open the machine will automatically turn off.

-PVC cap to prevent plastic from coming back up and coming out of the shoot.

-Endcap for the portion of the side panel that has a whole due to the part of the shaft that extends past the plywood.

Design Changes[edit]

-Granulation Screen holes have been removed to reduce machining time. Instead the granulation screen now will have a rectangle cut from it where the 3D Printed insert will go.

-New 3D Printed Granulation Screen insert (Printed in PETG) worked for small plastics but eventually broke when 100% infill PLA was put into the granulator. New insert utilizing 26 gauge steel to line the part of the 3D print that interacts with the blades with increased spacing between holes to hopefully increase the strength [Currently testing this method]. If this fails either a stronger material like Nylon with carbon fiber reinforcements will be tested.

-Vacuum adapter to connect with the new granulation screen insert. And to fit the vacuum hose without an adapter.

-The electrical box was mounted to the plywood and a 40mm hole was cut for the motor and limit switch wires to go through.

-Designed seals printed with NijaFlex in order to reduce the amount of plastic that "spills" out of the system.


I am interested in Open Source Machines such as 3D printers and CNC Router Mills. I am also interested in the ways that 3D printing and other supporting technologies will help push the ways we go about our daily lives and how they can help make our day to day tasks easier and more efficient.


Assembled 2 Prusa i3 MKll Kits, Built a variant of the Athena 3D Printer, Troubleshooting 3D Printers