When the 3D printer pushes glue through the hot glue gun it determines the size of the circle it’s making by measuring how much time is spent pushing glue through the nozzle. In this way there is a direct correlation between time and diameter. The goal of making a test is to find that correlation mathematically. It will have to do with the equation already in the program but it will also be necessary to see some evidence from testing that shows actual time pushing glue and actual diameters printed. Real world testing. It will also show consistency. This test isn’t strictly necessary since the point of this printer is to prove that 3D printing isn’t magic but I do want some way to relate the numbers to real world measurables or it retakes some of the voodoo aspect.
The Arduino and shield were going to be mounted outside the pie tin due to space constraints but the most practical solution seemed to be mounting the controller on the top but slightly elevated off the bottom of the tin. The mounting holes in the board of the Arduino were metric but a #4 bolt easily passed through the opening without an excessive gap. A pressure sensitive adhesive (PSA) label was put down on the pie tin and the controller was placed on top of the label. A permanent marker marked the holes and put the holes size, 7/64, on the label. The holes were not piloted since they were such a small diameter to begin with. The PSA label was used to collect the metal shavings after the holes were drilled.
Holes marked out and size clearly labeled
The holes have been drilled
The shavings were neatly picked up
The next phase of testing is to determine the time-to-volume factor. There is already an equation which should translate linearly increasing numbers into diameters which increase by the same scale. Of course, due to the area of a circle, the time spend on different sized circles will be exponential. The test will also test for consistency and repeatability. At this point the most apparent pitfall will be the glue will reach a high temperature and lower viscosity in the nozzle while the machine is idle in order to let the freshly printed glue cool. This may make small circles larger than desirable. It may be necessary to cut power to the nozzle during idle times.
Time-to-volume and consistency test:The goal is to get a circle exactly 30mm in diameterAn array of numbers will be compiled.The numbers will be start out large.The numbers will be grouped in groups of three.Example, 100, 100, 100, 95, 95, 95, 90, 90, 90There will be a long delay after each each circle is printed to allow for cooling.The circle will be examined and measured.The array values will be compared to the diameters of the printed circles and graphed.Consistency should become evident.
- Buy #4 bolts at least 1" long
- Physically install Arduino + Shield
- Reattach heating element to hot glue nozzle
- Perform tests outlined
- Build two wheel tensioner around chain
- Test + Debug
- Revise Documentation
Journal Page 1
Journal Page 2
The rest of the posts for this project have been arranged by date.
A list showing of all the final posts of COMPLETED projects.
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