JRConsulting LLC Atwood, Colorado AN IMPROVED ROLLER BASED FLEXIBLE MEDIA PATH FOR HIGH DENSITY DATA RECORDING J Robert (Bob) Cope JRConsulting LLC 4304 County Road 31, Atwood CO 80722-9742 Phone: +1-970-522-2706 FAX: +1-775-244-9014 E-mail: jrjecope@kci.net Presented at the THIC Meeting at the National Center for Atmospheric Research-Boulder Colorado July 19-20, 2005
Mechanical Aspects of Recording
Aspects - Continued
And Lastly...
THERE ARE A LOT OF FACTORS IMPACTING Y MOTION WHERE... BALL BEARINGS ARE THE BIGGEST LIMITATION TO INCREASING TRACK DENSITIES ON ROLLER BASED TAPE PATH DATA RECORDERS.... HERE S WHY
FOR ANY DATA PHYSICAL FORMAT YOU WILL ENCOUNTER TRACK MISREGISTRATION
WHAT ARE THE CONTRIBUTORS TO TRACK MISREGISTRATION? SERVO POSITIONING ON READ BACK SERVO TRACK WRITING STRAIGHTNESS EDGE QUALITY SLITTING ACCURACY OR DAMAGE MEDIA CREEP DUE TO ENVIRONMENT CHANGES BALL BEARING NON-REPEATABLE RUNOUT (NRR) GUIDE SYSTEM ACCURACY FOR MEDIA POSITION LONGITUDINAL WAVES IN THE MEDIA-INERTIA HARD STARTS FROM SERVO SYSTEM POSITION OF MULTIPLE WRITE-READ HEAD GAPS MEDIA SLITTING VERSUS ROLLER WIDTH ETC ETC ETC...
BALL BEARINGS ADVANTAGES ARE: COSTS DUE TO MATURITY AVAILABILITY FROM MANY VENDORS STANDARD SIZES AVAILABLE ABEC STANDARDS WELL ESTABLISHED LUBRICATION NEEDS ARE WELL DEFINED RELIABILITY IS EXCELLENT
BALL BEARINGS-CONT D DISADVANTAGES ARE: - 3 PIECE CONSTRUCTION WITH CLEARANCES REQUIRED - MACHINING ACCURACY ACCUMULATES PIECE BY PIECE - ABEC SORTING VERSUS FUNCTION - PROPER LUBRICATION IS REQUIRED - LUBRICATION ADDS POSITION VARIATIONS - PROPER SPRING PRELOAD IS MANDATORY
NO INTERFERENCE ALLOWED VERY BEST MACHINING IS 6 MICRONS (0.0002 IN) NEED SOME NOMINAL CLEARANCE TO OPERATE DLT PRODUCT LINE BEARING HAVE 12 MICRONS NRR (0.0005 IN) DLT1 (BENCHMARK) HAS 50 MICRON TRACKS 25% OF THEIR TRACK BUDGET IS TAKEN UP BY BALL BEARINGS
FOUR ROLLER TAPE PATH USES 8 BALL BEARINGS NEEDS CAREFULLY DESIGNED PRELOAD SPRINGS BALL BEARING NRR IS SIGNIFICANT CONTRIBUTOR TO TRACKING BUDGET HIGH ACCELERATIONS HIT INERTIAS OF ROLLERS CAUSING LONGITUDINAL TENSION WAVES IN MEDIA A 25% CONTIRBUTION TO THE TRACK BUDGET IS HUGE
LATERAL MOTION HYDRODYNAMIC/ HYDROSTATIC FLOATING MEDIA SUPPORT ROLLER SURFACE CONTACT MEDIA SUPPORT SLIDES DOWNHILL CLIMBS UPHILL
ROLLER SURFACE AIR FILM PRESSURE BUILD AT ENTRY TOUCH DOWN AT EXIT SLOTS ALLOW LOWER FLYING AND MORE CONTACT
ROLLER FLANGE GUIDING CANNOT BUILD PERFECTLY SQUARE ROLLER PATH FLYING MEDIA SLIDES DOWNHILL CONTACT MEDIA CLIMBS UPHILL INTERMITTENT CONTACT GOES BOTH WAYS ROLLERS ARE VERY REAL CAPACITY LIMITATION
HOW TO GET MORE TRACK DENSITY USING ROLLERS AND GET MORE DATA INTO YOUR CARTRIDGE
PATENT 3,122,295 PATENT HISTORY
PATENT HISTORY- CONT D PATENT 4,337,885
PATENT HISTORY-CONT D PATENT 3,078,022
PATENT HISTORY-CONT D PATENT 4,565,495
PATENT HISTORY-CONT D PATENT 6,336,608
AN IMPROVED ROLLER BASED TAPE PATH DESIGN
PROVIDE A BIDIRECTIONAL HYDRODYNAMIC AIR SUPPLY FOR THE ROLLER ITSELF - PROVIDE EXTERNAL ROTATION TO ROLLER - SPIN IN OPPOSITE DIRECTION OF MEDIA - SURFACE SPEED OF THE ROLLER TO BE FASTER
AND, PROVIDE A HYDROSTATIC AIR SUPPLY TO THE ROLLER MEDIA SURFACE FROM PATENT 6,336,608
AND, PROVIDE AN INCLINED ROLLER SURFACE TO BIAS THE MEDIA TO A FIXED GUIDE SURFACE NON-VIBRATING GUIDE SURFACE MEDIA IS STABILIZED FOR THE BEST POSSIBLE TRACKING ACCURACY
A WORKING TAPE PATH DESIGN APPROACH 2 REEL MOTOR-4 ROLLER LAYOUT WITH 2 FIXED GUIDE SURFACES
Roller Design with 100% Hydro-Static Air Cushion
ADVANTAGES HAS BENEFITS OF PNEUMATIC AIR SUPPLY SYSTEM AND NOT THE COST OR SIZE VERY STIFF AIR FILM OVER ROLLER SURFACE AT ALL TIMES WITH NO INTERMITTENT CONTACT MEDIA IS POSITIONED FIRMLY AGAINST GUIDE SURFACE FOR BEST POSSIBLE TRACKING MORE TRACK DENSITY IS POSSIBLE, AND THUS MORE DATA CAPACITY IN THE CARTRIDGE THE CHANNEL GUYS WILL LOVE IT...
DISADVANTAGES HAS NOT BEEN BUILT OR TESTED SOME SIZEABLE DEVELOPMENT ENGINEERING EFFORT IS NEEDED TO DETERMINE: HOLE NUMBER, PATTERN, AND SIZE INTERNAL VANE SHAPE AND SIZE RATIO OF TAPE VERSUS ROLLER SURFACE SPEEDS MEASURE FRICTION OCCURENCES, IF ANY HOW MUCH TRACKING VARIATION WILL OCCUR DURING OPERATION MEASURE TRACK MOVEMENT WITH FIXED SENSOR BEST ROLLER DRIVE SYSTEM TO USE: GEARS BELTS DC MOTOR DIRECT DRIVE OTHER IDEAS
THIS TAPE PATH SYSTEM DESIGN IS WORTH INVESTING IN A SOLID DEVELOPMENT EFFORT- A RESULT WOULD BE HIGHER MEDIA CARTRIDGE CAPACITY BOB COPE