Insulation Measuring and Cutting Module

The goal of the project is to design and build a module that scans a work order, determines a desired length, measures insulation to that length, and cuts it without any human input required.

=Project Definition=

The purpose of this project is to create an automated process that accurately measures and cuts insulation to desired tolerances, while minimizing cost and time.

Background
A large amount of energy is spent on heating the fluids that run throughout airplanes. Insulation is used to reduce this cost and decrease the chance of component failure due to unwanted heat transfer. In order ensure that all components function properly this insulation must fall within a certain tolerance. Currently in the Boeing Tubing, Duct, and Reservoir Center there is not an automated process for cutting expensive insulation to a desired length, which leaves the task open to inconsistencies and human error. Our client would like to minimize

Deliverables
Design a system which can accept a barcode input to automatically set length of tube insulation cut. The system will pull the insulation through the measuring system free of human intervention, then cut the insulation to size. Module will then fully eject cut insulation from system.

Functional Requirements
Module will be encased and safe for all human operators. Module will cut insulation to a tolerance of +/- 0.3" of desired length. The operator should not have to physically cut or measure any insulation throughout this process. This system should take less time than the current method of cutting. Intake insulation smoothly and not get caught or stuck. Keep insulation loaded once a new box has been placed inside of it. Measure and cut insulation to a desired length. Fully eject insulation from contraption. The system should know when there is no insulation in the system and act accordingly i.e. stop and notify the operator. Able to make angled cuts based on the bends in the tube.

Cutter Requirements
The cutter must be able to cut straight through the insulation without debris. The cutter may not alter the insulation’s integrity. The cutter must be able to cut through insulation that is 2.5”-3” OD. Cutter must be reusable for 100,000 cuts and easy to replace. Optional: Must adjust the angle cut based on the bend in tube.

Scanner Requirements
The scanner should be the standard model used by The Boeing Company (provided by Sponsor). Scanner must connect to system through a USB. Scanner must be able to differentiate barcodes and input length measurements to system correctly. 3 numbers, a letter, 4 numbers, a – and anywhere between 1 number and 4 numbers.

Measuring Requirements
Measure the insulation within +/- 0.270” tolerance. Measure insulation at maximum 118”. Measure insulation at minimum 3.5”. The systematic error should be no more than 1%.

Electrical Requirements
Wiring will be grounded and insulated properly. All wiring will be soldered into a circuit board. Circuit(s) will be put into a case to protect them from environmental and human factors. Contraption will be able to plug into a 120V AC socket.

Software Requirements
Interface touchpad with measurement system to allow length input. Interface scanner with measurement system to allow length input. The software should use the information from the touchpad/scanner to control measuring/cutting systems. Program has a consistent output for a given input. Must be able to be constantly and easily updated with new barcodes.

Spatial Requirements
Module length will not exceed 6’. Module width will not exceed 2’. Module height/width ratio will not exceed 1/3. Measuring and Cutting mechanisms will be visible from outside the unit. The module will have easy access to the circuitry and mechanical components for maintenance.

Safety Requirements
Pinch Points will be marked. All sharp edges will be covered or marked. Emergency Shutoff button will be functional. Mechanism will not run or initiate unless all casing is in the correct place.

Cost Requirements
All costs will fall within the budget provided (See budget for cost specifics). The time spent by each individual on this project will not affect the livelihood of said individual. Team members will not spend personal funds on this project.

Schedule Requirements
GANTT Chart will be a live document and updated bi-weekly at a minimum (See GANTT Chart for schedule specifics). The project will be turned into The Boeing Company by May 2020. Work will not be done over Thanksgiving, Christmas, or Spring Break periods unless agreed upon by team members.

=Design Considerations=

Team Insulation Station decided to split our project into four main systems: Programming, Intake, Measuring, and Cutting. In this section you will see the process of selecting which method we would use to complete the tasks needed to be completed by each system.

Programming
For this project, we will be using a Raspberry Pi microcontroller. The programming load has been split into two different goals. The first goal was to create a successful scanner program that inputs a scan into our system for future use. This future use will be to extract the scanned data and use it to determine the cut length for different work orders. The second goal is then to program the system to run the intake system, measure a specific length, and cut insulation to the desired length. It is the programming system's job to ensure smooth operation of all programmed systems.



Intake
The three initial intake concepts consisted of: The Horizontal Squeeze Method, The Hinged Wheel Method, and The Linear Wheel Method. The Horizontal Squeeze Method utilized two wheels mounted to rotate horizontally, and they would be tensioned to squeeze insulation through. The tensioning was deemed necessary because the system needs to be able to work with two different sized insulation diameters. One wheel would be the driving wheel, while the other wheel would measure the length of insulation that had gone through it using an encoder. This method was not chosen because the horizontal tensioning seemed to be too difficult and there were more efficient ways to accomplish our desired task. Next, we looked into a Hinged Wheel Method. In this case, the wheels would rotate vertically, and the top wheel would be hinged and weighted. This weight allows there to be a constant pressure on the insulation, regardless of which diameter is used. However, it creates an unnecessary moment on the size of insulation that the wheels do not perfectly line up with. Thus, we decided on a Linear Wheel Method. This method has two wheels mounted to rotate vertically, and the bottom wheel is fixed. The top wheel is attached to a linear bearing, so it is adjustable for different size diameters. Also, it allows for easy loading of insulation.



Measuring
The measurement system looked at three different options. These options were: A rotational encoder, a Linear Cable Encoder, and an Infrared sensor. The linear cable encoder did not work for this project because it could not measure lengths greater than 50 inches, and we need to be able to measure up to 120 inches. The infrared sensor was not used because it was much more difficult to program than a rotational encoder. Thus, our team decided upon a rotational encoder. However, after the Boeing design review, we have decided to use just a stepper motor to measure to our desired values, and if that is not accurate enough we will invest in an encoder.



Cutting
Three different cutting methods were brainstormed and considered designing this system. They were: a guillotine, a turkey knife, and a heated wire. The turkey knife method had already been employed at Boeing manually, so we knew that it worked. However,it produced a very jagged cut. The two methods that our team worked on were the guillotine method, and a heated wire cutter. For the guillotine method, a large blade would vertically push down onto the insulation and use pressure to cut it. For the heated wire, a thin wire is essentially short circuited to get very hot. As it is pushed down through the material, the wire melts the insulation and cuts it. We determined that the heated wire cutter was the way to go because it is more effective than the guillotine and a lot less force is needed to accomplish the cut.

System Designs
From the start, we knew that we wanted an enlcosed system with separate stages of all pre-mentioned systems. Our first very rough drawing of this concept is shown below. From the initial thought, we designed a hinged wheel intake system with a heated wire cutter.

After reflection on the hinged wheel and how it changes the moment on the insulation, we changed the design to the top wheel on a linear bearing. This allows both wheels to always be tangent to the insulation, regardless of diameter. It also made the design more compact.



= Project Learning =

In the early months of our project, we learned a lot about project management and design setup. We learned how to properly set up a budget, a GANTT chart, a Product Requirements Document, and a Design Validation plan. On September 30th, 2019, Team Insulation Station took a trip to the Tubing, Duct, and Reservoir Center (TDRC) at the Boeing Factory, and fully learned about their problem and what they needed to do. They developed professional communication skills with real-world engineers. From our research, we have learned that the insulation to be cut is non-toxic when cut with a heated wire, and we have honed in on our CAD modeling skills. Please see attached project learning statements for more in depth information.



=Final Design=

The final CAD Modeled design for our project is as follows:

The key features of this piece are the 3D printed wheels as well as linear bearings that the top axle will be mounted to. An encoder is connected to the top axle and measures the revolutions of the wheel while taking slip into account. The power box is where all of the electrical components will be housed, and it easily accessible with a hinged top. There is a lid to the frame that allows for easy maintenance. The base plate has handles on it so that the contraption can be moved if it needs to.

=Validation=

Below is our Design Validation Plan. Not included are the Result and Design Recommendations because tests have not been run yet.

=Team Members=

=Additional Documentation= Project Schedule

Meeting Minutes

Presentations



Client Interview