Category Archives: Injection Molding

Proposed Projects for the 2015 Minneapolis/St. Paul Mini Maker Faire

The call for makers for the first Minneapolis/St. Paul Mini Maker Faire is now open.  I thought I would throw my hat into the ring to present a few projects. I picked out a few projects for which I will show some of the intermediate steps.  The projects I have chosen have built upon each other over the years.  The projects presented below are the projects I proposed in my Maker Faire call for makers application I will edit as needed as the mini maker faire approaches.

Injection Molding Machine

My injection molding machine was made using plans from the book Plastic Injection Molding Attachment for the Drill Press by Vince Gingery. This book features a small injection molding machine that relies on an external mechanism to push the ram.  Generally the external mechanism is a drill press.  For my machine I have fitted the molding machine on an arbor press. The temperature control is accomplished using a purchased PID controller, thermocouple and cartridge heaters.  The use of an external mechanism for load application and purchased components for the thermal management makes the remaining parts of the injection molding machine a simple piston with the necessary features to interface with the purchased components.  I plan to have the injection molding machine producing small parts during the Mini Maker Faire. More information on my injection molding machine and molds is available on my Home Plastic Injection Molding web page.  As shown in this YouTube Video the injection molding machine was in part made using my Gingery Lathe which is another project I plan to display.


Gingery Lathe

A Gingery Lathe is a lathe made based on the book The Metal Lathe by David Gingery.  Gingery Lathes are often started by makers that are trying their hand at aluminum casting.  In the past very few working lathes could be found on the Internet. The number or working lathes seems to be increasing.  My lathe is by no means perfect but it is an example of a functioning lathe that I continue to use.  I plan to display wood patterns I used in the process of casting the lathe parts out of aluminum.  My aluminum foundry which I used to create many of the lathe parts is another project I plan to display.


Aluminum Foundry

Casting aluminum opens a world of possibilities for makers and hobbyists.  Aluminum casting can produce very strong aluminum components using a pattern made from wood or other easy to work with material.  In addition the aluminum used for the castings can come from many sources including old aluminum frying pans and broken lawn mower engines.  Since the material comes at little or no cost I even use cast billets from my foundry for making the molds used with my injection molding machine mentioned above.  My foundry setup is based primarily on information from but once again Gingery publishing also has a great resource in the form of the book The Charcoal Foundry by David Gingery.  I plan to show my foundry tools and some castings in various stages of completion.  My foundry setup includes welded crucibles which brings us to the last project I hope to show at the faire, my home made arc welder.


Home Made Arc Welder

The final project I plan to show is my first home made arc welder.  The arc welder is made from re-wound microwave oven transformers and some standard arc welding cable, a ground clamp and electrode holder.  Various web sites detail the process of rewinding the transformers scavenged from old microwave ovens to achieve a voltage that will work for stick welding.  I plan to show my completed welder and microwave oven transformers (MOTS) in various stages of the rewinding process.  I also plan to show my steel crucibles that I made using my home made welder.


See You at the Faire

Of course if you see me at the Minneapolis/St. Paul Mini Maker Faire you are also welcome to stop by and chat about my CNC software (F-Engrave, G-Code Ripper, Dmap2gcode) or ScorchCAD (OpenSCAD clone for Android)

Newton’s Cradle

Newtons Cradle GIF

Over the Memorial Day weekend I made this newton’s cradle for my kids.  I used some 5/8 inch ball bearings I had left over from another project.  Instead of trying to drill into the bearings I choose to injection mold a plastic ring around the bearing.  This allowed me to tie the strings to the injection molded plastic part rather than directly to the ball bearing.  Below is a picture of one of the ball bearings with the ring molded around it (and the aluminum mold).  The plastic was molded right onto the bearings inside the mold.

Newtons Cradle Mold

I used fishing line to tie the bearings to the frame.  The fishing lines for each bearing are passed through a small holes in the top board and wrapped around a screw.  Turning the screws on the top board adjusts the length of the strings to fine tuning the alignment of the bearings.  Aligning the bearings is critical to getting good performance from the newton’s cradle.

Newtons Cradle Closeup

The injection molded collar for the bearings was designed on my Android phone using ScorchCAD while I was at one of my kids baseball practices.  I exported and STL file for the mold from ScorchCAD and created the g-code file for my CNC mill using MeshCAM.  So unless someone protests I am claiming I made the first physical part from a part designed from start to finish on a smart phone using ScorchCAD.  A screenshot of the ScorchCAD part is shown below.

Newton ScorchCAD