As many of you know we submitted a project to offering a table-top injection molding machine based on the use of hot glue sticks (plastic rods) as the raw material for molding your own parts.  You may also know that it did not meet its goals, so the seed money we were looking for to cover the costs of the design and initial production of these machines has to come from somewhere else, like our day jobs!  This is taking a little time but we’re getting there so I will fill you in.

I have been doing some prototyping recently for the DIPR project on a test machine that I threw together years ago.  It had been months since I ran it so I made some changes to it based on what developments we have uncovered recently and the end result was pretty amazing, including big reductions in screw torque for injection and simultaneously a reduction in the required clamp force to hold the mold shut.  I am going to shoot some video to show you the test machine in detail because it too is something you could make with a little help and that’s what we’re about.  If you check out this link the extruder shown at the start of the video is what grew into the test bed machine I am referring to.

This post is to tell you that we are getting closer to completing the design for the table-top machine.  What remains to be done is to refine the design of the thermal and mechanical systems, or to say it another way how many heaters do we use, what size and where do we put them along with what screw design gives us the best control and most consistent performance.  We are putting together a pressure sensor circuit to give us some real good data on what the actual forces are that we are dealing with, mainly to compare competing design concepts we have so that we can settle on the right one before moving forward.  Low forces reflect higher efficiencies in melting and moving plastic, lower forces result in lower machine costs, safer machines and more effective plastic injection molding.

In the future we will use similar pressure sensor circuits to control machine output.  This is a slick technology because changes in forces can be the information we need to make adjustment to machine settings to keep it running smoothly.  Think of it as being like cruise control on your car…

Once we have the machine design completed we will be building three prototypes in three locations to correlate test results and be certain we have a robust design and at that point we will offer completed machines and designs for sale in both manual and automatic versions.