P17551: Sandia Instrumented 3D Printer
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Build & Test Prep

Table of Contents

Team Vision for Build & Test Prep Phase

The team has surpassed the goals set for MSD I, and is well into the construction of our initial prototype. In addition to completing the first set of test prints for the designed experiment, further analysis was done to establish an early set of targets for the two temperature factors. An enclosure has been designed and constructed for the printer, and testing of its effectiveness is underway. A pair of cameras have been installed and integrated with the Raspberry Pi, and will be mounted to view the print area within the next few weeks. An early sensor array prototype has been constructed, and a significant amount of progress has been made with our new printing software.

Test Plan Summary

Our test plan for our engineering requirements that need them. Each test plan includes a description of the requirement that needs testing and a flow chart describing how the test will be performed.

Test Plan 8

Test Plan 8

Test Plan 14

Test Plan 14

Initial DOE Results

In order to determine the initial print parameters for a quality Benchy print, a two-factor, three-level experiment was run with three replications, for a total of nine combinations and twenty-seven individual prints. The two factors selected were bed temperature and extruder temperature, with levels set at 10 degree (C) intervals beginning at 60 and 200 degrees, respectively. Run order was randomized for this experiment.

After the first three prints at the low bed temperature setting all failed (one print at each extruder temperature level), the remaining six prints at the low bed temperature setting were removed from the experiment, as it had been determined that the print would not succeed at that temperature.

Print Quality Scores

Print Quality Scores

The above results show clearly that the high bed temperature setting of 80 degrees results in the best quality in completed prints. While the overall quality does not improve significantly from 70 to 80, bed adhesion and warping improve greatly, while only stringing notably suffers, and not by a significant margin. The effects of the extruder temperature factor are less clear, with no significant change in quality. Four linear regression models were created, and the results shown below:

Layer Adhesion Model

Layer Adhesion Model

Bed Adhesion Model

Bed Adhesion Model

Stringing Model

Stringing Model

Warping Model

Warping Model

Each of the four model summaries show a clear relationship between bed temperature and the respective quality score, but none of the four shows a distinct relationship between quality and the temperature of the extruder.

Octoprint

Data Collection Feasibility

With the recent addition of Octoprint, we considered moving several printer features that were initially planned to be implemented in the printer’s firmware to the Octoprint engine. This was being considered for the ease of access to Octoprint (it’s a web app, available from almost anywhere) and the large amount of native data available within Octoprint. Octoprint provides a real-time temperature graph for a given print for the native elements within the printer (extruders, print bed).
Octoprint Real Time Temperature Graph

Octoprint Real Time Temperature Graph

The first issue that was discovered within Octoprint was the lack of concert data output. While Octoprint does provide a graph of real-time data, the actual data values are not outputted anywhere and are quickly discarded after a few more polls. The initial solution to the problem was to develop a plugin or modification to Octoprint that would log the output data to a csv file. While this would have been an acceptable solution to the presented problem, two scope issues where identified while attempting to find an optimal way to implement the solution. The first scope issue was since the actual code of interest was written in an unfamiliar coding language, this would make the actual implementation time significantly longer. This issue could have been worked around if not for the other issue.

The other issue proved to be much more critical. Currently Octoprint has no ability to integrate external sensor within the printer due to how Octoprint collects the data it is interested in. While this issue could possibly be solved by improving and extending Octoprint with a new implementation with these capabilities, this is very much out of the scope of our project. Since Octoprint has no ability to provide us with a superior method of logging that we need for our project, going down this avenue for csv logging was abandoned, however we will continue to use Octoprint for the remote access it allows us to the printer and the ability to change parameters on the fly.

Octoprint Parameter Options

Octoprint Parameter Options

Since Octoprint is no longer an available logging option, all ideas of extending and improving it have been abandoned. The optimal solution to our logging issue still appears to be implementing a method of logging within the printer firmware. Since this is where Octoprint receives data from anyway, we should see no difference between our Octoprint data and our printer’s log data. However, the data log that is outputted will only be available off the printer’s native SD card. In order to provide remote access to data, we plan to transfer the logs from the printer’s SD card to the raspberry pi’s SD card. This should allow us to access the file via Octoprint, allowing us to remotely access the data from anywhere Octoprint is available.

Octoprint SD File Viewer

Octoprint SD File Viewer

Subsystem Updates

Thermal Camera Subsystem

Thermal Camera Subsystem

Sensor Network Block Diagram

Sensor Network Block Diagram

Sensor Network Subsystem

Sensor Network Subsystem

Upkeep and Future Updates

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Risk and Problem Tracking

Risk Management

Risk Management

Problem Tracking

Problem Tracking

Bill Of Materials

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Plans for next phase

Gantt Chart

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Week 5 Shared Vision

At the next phase, the team will present our next set of data analysis, including plans for further testing, along with an initial prototype with integrated cameras (including thermal history), working sensor array, and new test results to confirm improvements made by the enclosure.

Three Week Plans


Home | Planning & Execution | Imagine RIT

Problem Definition | Systems Design | Preliminary Detailed Design | Detailed Design

Build & Test Prep | Subsystem Build & Test | Integrated System Build & Test | Integrated System Build & Test with Customer Demo | Customer Handoff & Final Project Documentation