KGCOE MSDI
Detailed Design Review
P10505: Low Energy Printing – Cold Pressure Fusing II
Materials to be Reviewed:
- Design Change and Additions from System Level Design Review
- Prototype Design
- Prototype Drawings
- BOM
- Risk Assessment
Meeting Date:February 12th, 2010
Meeting Location: Room 78-2140
Meeting Time:10:00am – 12:00pm
Meeting Schedule:
Start Time / Topic of Review / Requested Attendees10:00am / Start of Presentation / 1, 2
Overview of Design Change / 1, 2,3
10:10am / Prototype Screenshots / 1, 2,3
10:20am / Prototype Drawings / 1, 2,3
10:25am / DAQ Function Diagram / 1,2,4
10:35am / Electrical Schematics / 1,2,5
10:45am / BOM(ME & EE Components) / 1, 2,
11:00am / Risk Assessment / 1, 2
11:15am / Test Parameters / 1,2,6
12:00pm / End of Presentation / 1, 2
Questions and comments are encouraged during presentation.
Attendees: Bill Nowak-1, Anthony Condello-2, Dr. Varela-3, Dr. Nair-4, Dr. Hoople-5, Dr. Thorn-6
Project Description:
Project Background:
In today’s industry of xerographic digital printers, customers are becoming more environmentally aware of the energy they consume while printing. To be relevant in the industry, printers must meet or exceed Energy Star and other energy certification requirements. A considerable portion of the power used by the printer is within the fusing system where heat is used to adhere the toner to the paper. To reduce overall energy consumption, a pressureonly fusing system was developed by MSD P09505 (as requested by Xerox) using two small rollers “skewed” or angled compared to the parallel fusing rollers to improve pressure uniformity. However, the previous group did not achieve consistentpressure uniformity across the fusing rollers.
Project Goal:
The purpose of this year’s project is to create a test fixture that is capable of adjusting certain key parameters to determine their affect on fusing. Using a statistically designed experiment, the team will try to gain understanding on how the parameters affect fusing and determine the optimum combination of variables to achieve complete fusing.
Objectives/Scope:
- Provide adjustability to test various parameters that affect pressure uniformity including load, compliance, skew, paper weight, and paper orientation.
- Minimize paper defects such as calendaring, wrinkles, tears, etc.
- Design the new prototype to reach a skew angle of 1.9 degrees as requested by Xerox.
- Develop a robust user friendly data capture system to determine capabilities of future prototypes.
- Perform a factorial experiment testing key parameters.
Deliverables:
- A functioning prototype
- A minimum of 3 adjustable skew angles including the requested 1.9 degrees.
- Variability to further test effects on uniform pressure via adjustments in compliance, load, paper weights and paper orientation.
- Factorial experiment results testing key parameters.
- User friendly data capturing system.
- Prototype that completely fuses print across the page while minimally damaging the paper.
Expected Project Benefits:Current xerographic printers use heat to fuse toner to the paper. Moving to a cold pressure fusing system will remove the energy required to maintain the fusing rollers at operating temperatures and make the product more energy efficient. Printer warm- up time will also be eliminated thus making the printing process faster. The benefits of this project to Xerox is the knowledge of how to achieve complete fusing using cold pressure technology to be able to implement this technology in their marketing line.
Core Team Members:
- Aniket Arora – ISE - Project Manager
- David Hatch – ME - Lead Engineer
- Jon Burville – ME
- Thomas Stojanov – EE
- Eric Wilcox– ME
Assumptions and Constraints:
The team must design and construct a prototype that provides adjustability of a number of factors that can potentially affect pressure uniformity. The team must assume that changing paper orientation will change pressure uniformity due to changes in the paper’s mechanical properties. Finally the prototype must adhere to the Abaqus model that Xerox has created and analyzed and must have a setting for a 1.9 degree skew angle as requested by Xerox.
Design Change:
Looking at the spacing of the design below our design is limited by the outer diameter of our bearings, and requirement to stay within the abacus model.
Figure 1: Space Limitations
This result is divided between two bearings. The result is there is 0.237” of material to support each bearing. We consider this too small of a space to machine safely and for our design to work effectively and safely. Considering these results, it was decided to revisit the concept selection again to see if this new information changed the results. In the table below the concept selection is summarized. From this analysis,adjustable end blocks were selected as the optimal design.For the DOE,three sets of end blocks will be made at varying skew angles (1.4, 1.9, 2.4 degrees). If testing suggest more end blocks, the simplistic design allows them to be easily manufactured at any skew angle.
Table 1: Revisited Concept Selection between Swappable & Adjustable End Blocks
Table 2: Concept Selection of DAQ System
Table 3: Concept Selection of Signal Conditioners
Bill of Materials:
Table 4: Bill of Materials Including Mechanical and DAQ Costs with respect to Gifted and Requested Totals
Detailed Design Screenshots:
Figure 2: General Screenshot of Prototype
Figure 3: Isometric view of generic endplate (no skew)
Figure 4: Section view through center of skewed rollers
Figure 5: Close up view of Endplates & Bearings
Detailed Design Drawings:
Figure 6: Assembly Drawing w/ List of Components (Page 1)
Figure 7: Assembly Drawing w/ Section Views & Detailed Views
Figure 8: Partial Drawing of Bottom Endplates complete with table detailing dimensions affect skew angle
Figure 9: Basic DAQ Diagram
Figure 10: Power Control and Emergency Stop Schematic
Figure 11: Load Cell and Signal Conditioner Schematic
Figure 12: Motor Controller Connections Schematic
Figure 13: DAQ and Power Supply Connections Schematics
Risk Assessment:
Risks / Effect / Cause / Minimize Risk / Likelihood / Severity / Importance / OwnerLong parts lead time / Fall behind schedule / Late parts order, wrong parts delivered, manufacturing issues / Order parts in week 8 of MSD I / 2 / 3 / 6 / Tom, Aniket
Cannot manufacture product / Fall behind schedule, cannot deliver product, Redesign required / Lack of skills, lack of resources, poor design / Use and review concept selection extensively / 1 / 3 / 3 / Eric, David
Missing deadlines / Fall behind schedule / Weather, alarm clock failure, illness, poor planning / Maintain communication, Share load / 1 / 1 / 1 / Aniket
Failure to achieve uniformity / Cannot deliver on customer requirement / Failure to compensate for roller deflection / Use and review concept selection extensively / 2 / 3 / 6 / Jon
Failure to mitigate calendaring / Product does not meet specification / Excessive nip pressure / Calculate nip pressure / 3 / 1 / 3 / Jon
Failure to achieve skew adjustability / Cannot meet customer requirement / Inability to manufacture parts / Design for manufacturing limits / 1 / 3 / 3 / David, Eric
Long manufacturing lead time / Fall behind schedule / Late submission of final product / Finalize design early / 2 / 3 / 6 / David
Overlooking a task / Fall behind schedule / Poor project plan / Review project plan continuously / 1 / 2 / 2 / Aniket
Failure to impress the guide / Poor grade / Deliverables do not meet standards / Stay in contact with guide, review project progress often / 2 / 3 / 6 / Team
Stress exceeds bearing load ratings / Failure in part / Stress too large / Drill at angle, change design, find large ID bearings / 1 / 3 / 3 / Eric
Current Rollers not concentric / Non-uniformity / wear / Make new ones and order round stock / 1 / 2 / 2 / Tom, David
Mess up reduction in skew rollers pins / Failure in part / Finite machining / Make new ones and order round stock / 1 / 3 / 3 / Eric, David
Risks / Effect / Cause / Minimize Risk / Likelihood / Severity / Importance / Owner
Cannot get computer / Cannot acquire data / No Availability / Use Eric’s Computer (Last Resort) / 2 / 3 / 6 / Team
Toner adheres to roller / Added pressure or thickness / Stickiness / Add scraper / 2 / 1 / 2 / Team
Paper feeds crooked / Calendaring and non-uniformity / Unknown / Make paper feed / 3 / 1 / 3 / Team
Cannot find signal conditioners / No data / Misplaced since last year / Buy them / 2 / 3 / 6 / Tom
Long lead time on signal conditioners / No data / Misplacement from last year / Order before week 1 of MSD2 / 2 / 3 / 6 / Tom
Fry DAQ / No DAQ / Too high current/voltage / Place limiter / 1 / 3 / 3 / Tom
Compliant material too soft / Inadequate compliance? / Material Properties too “soft” / Buy various materials / 2 / 1 / 2 / Team
Runs take too long / Length of time to complete testing increases / Long times to swap end blocks & other parts / ½ factorial or reduce randomization / 2 / 1 / 2 / Aniket
Test Parameters:
The system level diagram consists of five input variables:
- Paper Orientation – This is the direction the paper is fed into the fuser. This factor has 2 levels: Landscape and Portrait. These levels affect the overall print quality as the forces acting on the main rollers will change according to the length of the paper in contact with the rollers. It is expected that the portrait configuration will cause a lower deflection as compared to the Landscape configuration.
- Paper Weight – The system needs to accommodate for different paper weights. The paper weight factor has two levels: 20lb and 24 lb. The weight of the paper in the system affects the overall paper thickness that goes through the system. This thickness would affect the amount of load that is exerted on the main rollers. It is assumed that the 24lb paper would exert higher loads on the system because of greater thickness. To accommodate for these load changes, the system is designed with compliance that can adjust the load on the rollers.
- Skew Angle – The system needs to be able to adjust to a minimum of three different skew angles: 1.4°, 1.9° and 2.4°. These skew angles are defined as the angle between the top main roller and the support rollers. The skew angles concentrate the force of the support rollers towards the center of the main top roller and hence help in reducing its deflection.
- Compliance – The compliance in the system is required for adjusting to two different paper weights. It is tested under two levels: Low and High. These levels are important to decide the optimum level of compliance that would be required for the system to adjust for the different paper weights. The compliance also absorbs the ‘shock’ that the system undergoes as soon as the paper enters the rollers.
- Pressure/Load – The pressure or load is applied on the system at 4 points, two on each side of the roller. The amount of load on the system can vary from 50lbs – 150lbs for each of the four points. The load is measured by Load Cells present on all four points and a signal conditioner will be used to amplify the signal so that it is easily read in the DAQ system. The system is analyzed under 2 different load conditions: 50lbs and 150lbs of weight on the load points. These levels will help in the analysis of an optimum level for load on the system.
Appendix:
A. DAQ and Electrical Feasibility Analysis
Incoming Power:
-Power Cord is 16AWG capable of handling 22[A] at 250[V] maximum and itotal is well below this value, therefore 16AWG wiring is sufficient.
-Motor Controller, Signal Conditioners, and Power Supply also fed with individual cords at 16AWG which are capable of handling nearly four times the current than the maximum current and the same voltage constraints above, therefore 16AWG cords are sufficient.
-C13 and C14 panel mounted connectors are rated for 10[A] at 125[VAC] which is higher than even the maximum current and voltage, therefore the aforementioned panel mounted connectors are sufficient.
-Two C13 connectors will be provided on the surface of the Power Control/ Emergency Stop enclosure to allow for the Signal Conditioner Enclosure and Motor Control Enclosure to receive power.
-A C14 connector on the Power Control/ Emergency Stop and Signal Conditioner enclosures will be provided for each enclosure to accept 115[VAC] input power.
-16AWG multi- strand wiring has a standard 600[V] rating which is much higher than 115[VAC] therefore meets necessary insulation requirements.
-Signal Conditioners will require 115[VAC] power and have very low current requirements (below 1.0[A]) therefore 16AWG wire will suffice for providing power.
-A separate 115[V] receptacle will be provided within the signal conditioner enclosure to provide the first signal conditioner a point for incoming power for the AC to 12[VDC] adaptor.
-Female sockets will be provided external to the power control enclosure for the power supply and internal to the signal conditioner enclosure to provide a point for the AC adaptor for SC1 to connect to. The sockets are rated for 15[A] at 115[V] which are well beyond the limits as outlined by the current requirements of the DC power supply and signal conditioner 1.
Emergency Stop:
-Emergency stop will stop all power to the cold pressure fusing test fixture once engaged.
-Emergency stop switch is capable of handling 10[A] continuous at 600[V] which is well beyond the input power consumed by the DAQ system and therefore can handle the voltage and current specified above.
-Emergency stop also contains NC contacts which indicate to the DAQ when the emergency stop has been engaged.
Motor Control Relays:
-Maximum DAQ output value is 10.0[VDC] at 5.0[mA] which is much too small for a mechanical relay or contactor to utilize, therefore a solid- state device is required, such as sold- state relay to implement this signal for power control.
-Solid state relay accepts an input of 4- 24[VDC] for turn on so therefore the 10.0[VDC] supplied by the DAQ is sufficient
-NI recommends that the motor or it’s controller’s inputs not directly be connected to such a solid state relay or shall a high voltage signal be driven by the solid state relay- reduces risk of damage to DAQ. Therefore, a 24[VAC] circuit via a step- down transformer was implemented to account for this, driving a 24[VAC] motor contactor.
-To function the Solid state relay requires an output voltage of 19- 264[VAC], of which the 24[VAC] output signal falls in.
-The 24[VAC] transformer is capable of driving 40[VA] = 40[W], well above the required coil rating of the motor controller contactor which is 10[VA].
-The motor controller contactor is capable of driving 20[A] at 115[VAC], well above the required power inputs to the DAQ system. The contactor is normally open.
Power Supply:
-Power supply is of the DC nature easily capable of 10.0[VDC] at up to 5.0[A], far above the requirements of the load cells and DAQ total current required.
-Power supply will provide load cells 2 through 4 with an excitation voltage of 10.0[V] and much higher current than required (~.09[A] for all three) due to the load cell’s low input resistance of 350[Ω].
Load Cells:
-Load cells are capable of a 2.0[mV/V] output at full scale for each volt of input. The load cell manufacturer (Omegadyne) recommends a 10.0[V] or 15.0[V] excitation in order to implement sufficient readings. As such, the output of the load cells will require signal conditioning to be read by the DAQ.
-Full scale output is given at a load of 500[Lbs.] however a more typical value for the purposes of P10505 is 50[Lbs.]
-For the first load cell a signal conditioner (SC) exists with the capability of load cell excitation.
-For the remaining three load cells the 10.0[V] excitation will be provided by the DC power supply, in possession of P10505, to reduce cost of both the SC’s and a new power supply. This yields a relatively low current as each load cell exhibits a maximum resistance of 350[Ω].
Signal Conditioners:
-SC’s are necessary to alter the outgoing load cell voltage to a voltage that can be accurately read by the DAQ.
-The DAQ is capable of reading voltages from 0- 10[V] with an accuracy of 0.006[V], clearly too low for the DAQ to read accurately without some sort of signal conditioning
-The existing SC will power load cell 1 and has on- board load cell excitation, therefore will not require an external DC source for excitation. However, the existing SC utilizes an AC adaptor for power which will need to be interfaced with the power system.
-The remaining three load cells will require external excitation as given by the power supply at 10.0[VDC] as the current SC’s do not have an on- board excitation supply. These SC’s will require 115[VAC] input power as suggested by the manufacturer (Omega.)
-All signal conditioners are capable of a FSO equivalent to 10.0[V] which is clearly able to be read by the DAQ.
Motor Controller:
-The Motor controller is powered by a 3.0[A] (maximum) 115[VAC] source which can be readily supported through the 16AWG cords specified.
-The motor controller has an array of internal pins: 12 to 2 provides torque scaled as voltage (0- 1.0[V]), 5 to 2 provides RPM scaled as voltage (0-10.0[V]), both of which can be easily read by the DAQ as scaled voltage with respect to both torque and RPM.
-The motor controller has a visual output which can be used to correlate the outputs with voltages. Calibration methods will be required in the future development of the test plan in week 10 to verify this.
DAQ System:
-DAQ will be integrated via LabView into a PC through PCI card, Interface Cable, and I/O Block
-I/O Block consists of 16 analog inputs which equates to 8 differential pairs, capable of reading input signals from 0- 10.0[V] with a 0.006[V] accuracy. These pairs will be responsible for reading torque, RPM, load 1, load 2, load 3, load 4 and emergency stop status data.
-The DAQ will also provide a signal to turn on the solid state relay, indirectly powering the motor controller and motor, giving a 10.0[V] output at 5.0[mA] which suits the relay.
-DAQ I/O Block shall be mounted above the signal conditioner enclosure to allow for ease of connection
DAQ Input/ Control Wiring: