Advanced Force Gauge video

New video

Find out more about our Advanced Force Gauge in the new video hosted on our website.  The AFG not only measures force from its built-in loadcell, but can also use plug in torque sensors as well.  With settable alarm limits and an RS232 interface, the AFG can be used on its own or can be built into a dedicated system.

see the video at:
http://www.mecmesin.com/advanced-force-gauge-afg

BFG product video

Basic Force Gauge video

 

BFG the video - No, not Rould Dahl's "Big Friendly Giant" but  our BASIC FORCE GAUGE for compression or tension measurements on the go or in the lab.

Follow the link to see the video at:

http://www.mecmesin.com/basic-force-gauge-bfg

 

Tornado product video

Tornado torque tester

 

 

Tornado - the portable torque tester with a big memory and small footprint.  Measure opening or closure torque, and capture "slip" and "bridge" torque on Child-resistant closures.  Set "Pass" and "Fail" limits and save or print the results.

See the new video at:

http://www.mecmesin.com/tornado-torque-tester

Advantage ITF

A tennis ball is just a tennis ball - right?  Well yes it is, fine if you just intend to play "fetch" with the dog, but if you want to play in a tennis competition then the ball has to be type-approved by the International Tennis Federation, the ITF.  Ball manufacturers have to submit samples of their balls to the ITF for testing, and there are a surprising number of different balls available from large, foam balls for beginners to high altitude balls for use when you are playing at more than 1219 metres (4000 feet) above sea-level.

As you can imagine with lots of different ball types and many different manufacturers wanting to get type-approval, the ITF need to test an awful lot of tennis balls.  Having had a previous machine built by Mecmesin several years ago, the ITF specified a new automated ball testing machine so they could cope with the demand for type-approval testing for the expanding range including the slower balls used by small children and beginners.

The new tester can be set going then left unattended to:

• Pick up a ball from the carousel;
• Measure the diameter of the ball;
• Place it on the test platform where it is compressed to measure forward and return deformation;
• Rotate the ball so measurements can be made on each of three perpendicular axes:
• Transfer the ball to a precision balance and weigh it;
• Put the ball back on the carousel; 
• Make all the calculations needed and print out a report;

The automated placement of the ball is more accurate and therefore more reproducible than can be achieved by hand, and means the ITF technicians are free to perform other tasks - maybe even take the dog for a walk...

Take a look at the video at:

http://www.mecmesin.com/automated-testing-systems

Special torque applications: dental abrasive disks

Abrasive discs are used by dental technicians to sculpt and polish dentures. The discs are spun on the technician’s motorised hand piece at speeds of up to 20000 rpm. The abrasive surface applies sculpting and polishing friction, so high torque loads are normal. In order to reduce the possibility of the disc’s two parts – centre ring and abrasive disc – separating during use, the manufacturer wanted to test the torque performance of the join between them.

The specially made adaptor/jig fits directly over the rotating drive shaft of the Vortex-i torque tester to hold the sample securely and centrally, so that drive-shaft and centre ring are exactly aligned. Once the disc is placed in the recessed holding plate (reversible to accommodate the two sizes that the disc comes in), the clamp plate is screwed down over it. A probe, which is connected to the torque-sensing transducer, is lowered till its point penetrates the centre ring and can travel no further.

This video introduces the adaptor and shows the test being set up.

The test is designed to test to destruction the join between the centre ring and the abrasive disc. Pressure from the clamp plate ensures the abrasive disc does not spin inside the jig but rotates in unison with the jig.

The jig is rotated to 90 degrees clockwise and then 180 degrees anti-clockwise. If the centre ring and abrasive disk remain aligned (the radial marking will indicate this), the join between them is good and the disc passes the test. If the quality of join between centre ring and disk is insufficient, the centre ring will rotate independently of the disc and the sample will fail.

In this picture, the post-test misalignment of the markings on the disc indicate that the outer abrasive disk has slipped around the centre ring, so this sample has failed. The torque data is exported via the Vortex-i’s RS232 port to the PC for monitoring, analysis, and storage.

Packaging: bottle cap torque testing

Torque testing of PET bottle closures is performed to identify the torque required to open a closed cap. Systematic testing informs line managers that their capping machines are applying sufficient torque to produce the necessary degree of seal - but not excessive torque, which would make opening difficult.

"Spinners" are an unwanted occurrence in capping and can be caused by materials or excessive capping torque. Normal spinners are of two types:

1. Following slip (initial break) torque, the cap's bridges do not break and the cap spins around the thread but is not separable from the bottle, resulting in a bottle whose cap is unscrewed but still attached.
2. When closure torque is applied, the lid or cap does not bind to the thread and come to rest creating a tight seal, but continues to travel. The cap spins around the thread and returns to its state prior to tightening. Subsequent tightening results in the same.

Testing closure torque alerts managers to such problems, saving costs resulting from waste, downtime, and returns.

An Orbis torque tester is ideal for simple pass/fail closure torque tests. The following describes a typical test procedure:

• An acceptable torque range is defined by registering minimum and maximum torque values (1 and 1.5 N, for example) on the Orbis. For enclosure opening tests, counter clockwise is specified (clockwise if measuring tightening torque).
• The user places the bottle on the platen, then winds in the pegs to grip it securely. This prevents the bottle rather than the cap rotating when torque is applied.
• The user zeros the display to cancel any torque detected during placement of the bottle, and then twists the cap in a counter-clockwise direction as if opening the bottle normally.
• The Orbis detects the peak torque and reports this as the torque required to open the container. If this reading is between the minimum and maximum, the sample passes. If the torque required to open the container is outside the specified range (i.e. above the maximum or below the minimum), the sample fails. The torque reading will reveal if insufficient or excessive torque was applied by the capping machines. If several samples fail, a production line supervisor would call a technician to increase or decrease the torque exerted by the capping machines.

The Tornado torque tester is capable of all the functions of the Orbis, but has an additional, vital function: tamper evident testing.

Tamper-evident closures are a standard quality feature of beverage bottles and containers of other liquids that would degrade if adulterated or exposed. Tamper-evident closures consist of two parts - a cap and a band, which are connected by a “bridge” of regularly spaced, fine plastic tags. The content of a bottle that is capped with a tamper-evident closure can be accessed only if the cap is fully rotated counter clockwise (i.e. opened). This rotation will snap the bridge, resulting in separation of cap from band. A broken bridge provides visible evidence of prior opening or tampering.

To measure the torque required to breach a tamper-evident closure, the Tornado takes two peak torque readings: “slip torque”, which is the first and normally higher reading, and “bridge torque”, which is the second, normally lower reading. Slip torque identifies the torque required to initiate rotation of the cap around the thread of the bottle. Bridge torque identifies the torque required to initiate rupturing of the bridge. The Tornado can be easily configured to report these two torque readings.

A tamper-evident test can be quickly and easily configured with a simple push-button procedure:

• %Tamper-evident is selected on the Tornado's menu screen, and a % selected (5% is the default - meaning the Tornado will identify a second peak when it detects a torque that is 5% below first peak)  
• The bottle is placed on the platen and the user winds in the pegs to grip the bottle securely.
• To cancel any torque reading resulting from bottle placement, the user zeros (resets) the Tornado.
• The user then twists the cap and continues rotating it until the bridge is broken.
• The first and second peak torques appear on the Tornado’s display and identify slip and bridge torque respectively.

The tamper-evident test reveals whether or not the cap can be removed and the bridge broken using pre-specified torque. Testing slip and bridge torque informs the bottlers that their product is leaving the production line properly sealed for integrity and consumer safety.

A Vortex-xt (pictured) motorized tester can provide much more sophisticated torque testing of container lids and caps. The Vortex-xt can output torque data in realtime to its touchscreen display/interface (Vortex-xt) or to a computer, where data can be displayed as a graph. Data and tests can be stored on the touchscreen or a computer for future retrieval. Test results can be overlaid for purposes of comparison. The grips and motorized rotation provide far greater sample stability and uniformity of torque, creating higher accuracy of results and reducing the influence of the variables that occur with manual, handheld testing.

Automotive: rotary selectors

A typical car dashboard features several rotary selectors. Temperature, vents, blowers, and headlights are operated by rotating dial-type switches. Automotive manufacturers test these components to determine whether the torque required to operate them is within acceptable limits.

A selector can be neither too stiff nor too slack. If too stiff, the driver will struggle to operate it efficiently and safely; if too slack, selection will be uncertain and slippage could result. Rotary selectors must also provide definite tactile feedback, to provide indication of the selector's position when visual contact is a problem, such as when the vehicle is in motion and the driver cannot be distracted. Working from carefully derived ergonomics parameters, manufacturers define torque ranges for their selectors. Samples of the finished component will undergo testing as part of the quality control process. The test will obtain measurement of the torque required to rotate the selector, so the test device must emulate the human motions involved and capture an accurate picture of the selector's torque performance.

In this photo, a rotary selector (temperature dial) is undergoing torque testing on a Vortex torque tester.

The long pegs grip the switch’s housing securely to the lower platen, so that unwanted movement does not influence the torque reading. Accurate torque measurement is possible only if the switch's axis, the tester's drive shaft, and the transducer are in direct alignment. While the alignment of transducer and drive shaft are engineered into the design of the Vortex and are unchangeable, the switch's axis is potentially variable, especially if the switch's surrounding housing is irregular in form. The housing must be held level and stable throughout the test. The holding mechanism could be component-specific or adjustable. An adjustable mechanism, such as that shown here, is a more economical solution for manufacturers who have a range of components and require short setup times and easy, simple reconfiguration of the test device. The Vortex's adjustable pegs and mounting table allow components of various shapes to be held level and central so that correct axial alignment can be achieved.

The switch's selector bar is gripped by the upper set of pegs. These upper pegs (also adjustable for neat, secure gripping of the selector bar) are fixed to a static platen and hold the selector immobile while the component housing is revolved by the lower platen. Together, these platens, via their fixtures, apply to the rotary selector the pinching and twisting motions performed by the human user.

The upper, static platen is connected to the torque-sensing transducer. The transducer reads the torque experienced by the switch during the test and sends this to a display or computer, where it is reported in graph form for analysis and stored.


(Axial alignment of stalk-mounted rotary selectors can be difficult, but the adjustable holding mechanism fitted to this Vortex-xt provides an effective solution.)