MSD I: Dancer Research
P16602
Hannah Micca
Dancer Tension Control Research
Patents:
 http://www.google.com/patents/US3322315 apparatus for controlling the tension in a web
o Uses air cylinders with a constant set pressure to control the dancer roll as well as an
error generator that sends a signal to adjust spool speeds to maintain constant tension
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http://www.google.com/patents/US3087663 apparatus for adjusting printing web tension
o Uses u-shaped loop for dancer and a floating roller whose vertical position sends a
signal to vary the drive speed and bring the system back to equilibrium
http://www.google.com/patents/US3556369 apparatus for maintaining constant tension in
moving strand (fibrous strand)
o Uses two rollers on a rigid pivot arm actuated using an air cylinder
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http://www.google.com/patents/US3680753 constant tension stand feeding system
o Pivot arm dancer preloaded with pneumatic cylinder of fixed pressure
o Speed is adjusted proportional to dancer arm position
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http://www.google.com/patents/US2681184 wire tension control
o Uses weighted pulley as dancer to provide tension
o Does not vary feed rate just controls length of secondary cable that supports the weight
in order to control the distance the weight travels
o
MSD I: Dancer Research
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P16602
Hannah Micca
Other Patents:
o http://www.google.com/patents/US4967973
o http://www.google.com/patents/US2544467
o http://www.google.com/patents/US3556373
o http://www.google.com/patents/US2981491
o http://www.google.com/patents/US3384322
Papers:
 Modeling and Matching Design of a Tension Controller Using Pendulum Dancer in Roll-to-Roll
Systems
o https://www.researchgate.net/publication/224237973_Modeling_and_Matching_Desig
n_of_a_Tension_Controller_Using_Pendulum_Dancer_in_Roll-to-Roll_Systems
o Derivation of equations for tension and speed, good modeling, hard to comprehend
 Fixed-Order H∞ Tension Control in the Unwinding Section of a Web Handling System Using a
Pendulum Dancer
o https://www.researchgate.net/publication/229034589_FixedOrder__H__infty__Tension_Control_in_the_Unwinding_Section_of_a_Web_Handling_S
ystem_Using_a_Pendulum_Dancer
o hard to comprehend, only partial article (full text preview)
 TENSION CONTROL AND WINDER
o http://www.dynamatic.com/pdfs/tension-control-winder.pdf
o “In a system, something must regulate FMP and something must regulate tension. A
given controller and drive, at a given moment, can regulate either speed or tension
(torque) – never both”
o Surface winders versus centerwinds: Centerwinds need to account for changing radius
making tension/feed rate control more involved
 TENSION CONTROL: DANCER ROLLS OR LOAD CELLS
o http://ieeexplore.ieee.org.ezproxy.rit.edu/stamp/stamp.jsp?tp=&arnumber=186283
o Dancer systems and load cell systems are essentially equivalent
 The Vibration and Control of Multi-Wire Saw
o http://ieeexplore.ieee.org.ezproxy.rit.edu/xpls/icp.jsp?arnumber=4370241
o Explanation of tension setting (25N) to reduce vibration effects
o The higher the tension the higher the frequency
 Observer-based tension feedback control with friction and inertia compensation
o http://ieeexplore.ieee.org.ezproxy.rit.edu/xpls/icp.jsp?arnumber=1173016
o Load cell control theory and modeling
 Control Systems Application Guide
o http://www.carotron.com/applications/ApplicationsGuide.pdf
o Control theory for reference later on
 Modeling and Control of Wiresaw Manufacturing Process
o http://dove.eng.sunysb.edu/~kao/Wiresaw/NSF-99.pdf
o http://dove.eng.sunysb.edu/~kao/wiresaw/
o Research into actual cutting process with slurry
 Understanding Dancer Tension Control Systems
o http://www.tappi.org/content/events/10PLACE/papers/whiteside.pdf
o Reasons to use dancer
 Indexing operations
MSD I: Dancer Research
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P16602
Hannah Micca
Load on the dancer sets the tension and must not change
Springs are not great because the load changes as the spring is stretch from rest position
Weights are not great because they add mass
Shock absorbers are not great because the load changes with velocity of dancer
Requirements for dancer arm
 Long enough?
 Far enough away from idler pulleys to ensure load on dancer arm doesn’t
change with motion (assume small angles)
 Arcs of 30-90 degs common
 Light as possible
o Requirements for loading device
 Independent of position
 Independent of velocity
 Independent of direction of motion
o Gain compensation calculations????
Innovative tension control with the electro-magnetic dancer
o http://www.wireweb.de/drives-and-control/innovative-tension-control-with-theelectro-magnetic-dancer_239_de/
o Explanation of electro-magnetic dancer system
THE MECHANICS OF TENSION CONTROL
o http://www.converteraccessory.com/papers/tcpaper1.pdf
o Diameter measurement control – controls torque as spool diameter decreases and
increases
o Pivot arm dancer
 Pros: simple, common, least expensive, design for any amount of storage
 Cons: bulky, momentum and inertia is a concern
o Linear dancer
 Pros: compact, large amount of storage possible
 Cons: complex, most expensive, momentum and inertia is a concern, friction
issues at cylinders
o Rotational dancer
 Pros: counterbalanced, momentum and inertial effect decreased due to
“push/pull” motion, compact
 Cons: expensive, complex, fixed storage amount
o “Momentum and inertia affect stability and accuracy of dancers. Remember a body in
motion wants to stay in motion, so dancers will want to keep moving in the direction
they are headed. This could cause the dancer to be unstable and tension spikes. Design
dancers as lightweight as possible and avoid weight loading of dancers this will greatly
reduce momentum and inertia problems”
o To avoid gravity affects have dancers move parallel to the floor
o Load dancers with weights or electric to pneumatic converter
o Dancer position sensors
 Digital potentiometers
 Encoders
 Proximity sensors
o Load cell tension control
 Pros:
 Accurate tension control
MSD I: Dancer Research
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P16602
Hannah Micca
 Many options
 High tech controls with IO for PLC interface and data acq.
 Auto-tune to eliminate manual cal
 Inexpensive, simple
 Easy to install anywhere
 Cons:
 No storage
 Tensions can be unstable
o Combining open loop and close loop systems can increase stability
 Pros: very accurate, very stable, high tech controls with IO and PLC interface
 Cons: high cost, mechanically and electronically complex
MAXCESS UNIVERSITY CONFERENCE WEEK: College of Tension Control
o http://www.maxcessintl.com/sites/default/files/documents/files/MAGPOWR_TensionD
ancerPrimer.pdf
o In depth info of “Understanding Dancer Tension Control Systems”
Webpages:
 Dancer Control (Positioning/Compensation)
o http://www.carotron.com/applications/csag-f/
o Control theory
 Improving the production process through better web tension control
o http://www.slideshare.net/Optimacs/web-tension-control-loadcells-vs-dancer-rollers
o problems due to tension control issues (too tight too loose)
 material wanders, breaks
 unsuccessful speed changes
 inadequate cut quality
 more scrap and increased downtime
 WEB EXCLUSIVE: Tension Control: Dancer Systems Defined
o http://www.pffc-online.com/webexclusives/7076-tension-control-dancer-0409
Motors:
Dancer Motor specs 1FK7085 (~$1100 used on eBay)
MSD I: Dancer Research
P16602
Hannah Micca
Spooling Pulley Motor specs 1FK7042
http://siemens.automationjet.com/dt/synchronous-servomotor-1fk7-high-dynamic-22-nm-100-k-3000rpm-3-14kw/1fk7085-7af71-1.html