Poly Chain Belts and Static Conductivity

Occasionally we get questions about using Poly Chain belts in a static safe environment.  The simple answer is don’t do it.  Our current Poly Chain belts use a carbon fiber cord.  This cord is static conductive, but the polyurethane that makes up the body of the belt is not.  This means that there is no way to guarantee electrical conductivity into the sprockets and then down to ground, which is necessary to dissipate the static electric charge that could build up in the system.

In the past, when the cord in Poly Chain was aramid, which is not conductive, the belts were sometimes used as an isolator.  This cannot be done any more either, as again, the current cord is carbon, and there is a possibility that an electrical charge could be conducted by the cord from one sprocket to the next.  In the rare instance where you need a belt to act as an isolator, this old construction can be ordered, but minimums and lead times will apply, and if you’ve never heard of a belt being used this way, chances are you don’t actually need it.  Like usual, please contact us if you have any questions.

Fastener Information for TaperLock and QD Type Bushings

Sometimes little things like shaft keys and bushing fasteners can halt progress when installing belt drive systems. Shaft key sizes were provided in an earlier blog post so sizes can be checked and key stock obtained before starting the installation process.  Lost bushing fasteners and wrench tool availability can also hinder progress.  Fastener sizes by bushing type and size can be found in industry publications, but not typically in concise form.

The following table provides fastener and wrench tool sizes for TaperLock type bushings ranging from the small 1008 size to the large 7060 size:

This information is very useful, as fasteners used with TaperLock bushings can be unusual and the wrench tools needed to tighten them may not always be readily available.  A hex bit socket set is needed for most TaperLock bushing installations.  And don't forget to have an appropriate torque wrench available so fasteners can be accurately tightened to the recommended torque levels.

The following table provides fastener and wrench tool sizes for QD type bushings ranging from the small QT size to the large S size:

Fasteners used for QD type bushings have hex type heads, so are quite common.  Hex type socket tools are generally available in most mechanics tool sets.  Again, don't forget to have an appropriate torque wrench available so fasteners can be accurately tightened to the recommended torque levels.

Don't let a lost fastener or an unexpected wrench tool size hinder progress when installing belt drive systems.  These tables are handy references for standard TaperLock and QD type bushing fastener sizes.  They also provide valuable wrench tool types and sizes as well as recommended fastener torque values.

Feel free to contact us at ptpasupport@gates.com or 303-744-5800 if you have any questions.

Gates Molded Notch V-belts Can Handle the Heat

Ethylene rubber is a robust material with excellent temperature and ozone resistance.  Several years ago, Gates developed and patented the technology to make ethylene rubber suitable for use in molded notch V-belts.

Gates latest molded notch single V-belt construction utilizes that patented technology to provide an allowable temperature range of -70°F to +250°F (vs. the industry standard of ‐30°F to +140°F).  The increased temperature range results in increased belt performance in high and low temperature environments. For more information on Gates molded notch V-belts, contact us at ptpasupport@gates.com or 303-744-5800.

Making the Cut: Long Length Poly Chain GT Carbon Belting

We are often asked what the best practice is for cutting our Long Length Poly Chain GT Carbon belting.  We have recommendations for not only the equipment used to properly cut the carbon fiber tensile cords with the least intrusion, but also for the location and manner in which the cut should be performed. 

The location along the belt span at which the cut is made can vary slightly depending on the clamping plate system used.  The best location to cut the belt would be in the span between two teeth given this results in the least material loss and decreases the likelihood of damage due to excess force.  In addition, the belt can be cut from the top of the tooth though care will need to be taken to ensure significant material deformation does not occur.  Finally, unless otherwise required, it is recommended to cut the belt parallel to the teeth given non-parallel cuts have the likelihood of damaging the tooth form of the belt and can cause unnecessary stress concentrations on the cut sections.

The tooling used to cut the Long Length Poly Chain GT Carbon belting at our testing lab is known as a “Guillotine Cutter”.  More specifically, a Model 600 Guillotine Cutter manufactured by U.S. Mold Machine Tool Co. is utilized (http://www.usmmt.com/).  The mode in which the Model 600 cutter applies the cutting force to the tensile cords within the belting is the most desirable given it is quick, has consistent forces and produces little to no heat.  It is not regularly advised to use a rotary cut off saw given this produces excess stress and friction on the belt which can causes the temperature to exceed the 185°F limit and result in damage to the belt.

Though each Long length belting application is different, these guidelines should get you on your way to getting your belt properly cut to size.  For any additional questions feel free to contact us at ptpasupport@gates.com or 303-744-5800.

NHRA Update: Double Win for Don Schumacher Racing at Arizona Nationals

At the recent NHRA Arizona Nationals (Feb. 22-24), Don Schumacher Racing celebrated a double win, with Tony Schumacher taking the win in Top Fuel, and Ron Capps winning Funny Car. Gates Corporation sponsors all the Don Schumacher Racing team cars. The win is Capps' 24th win with DSR and the 39th of his NHRA pro career. Capps with crew chief Rahn Tobler and assistant John Collins produced four runs Sunday between 4.037 seconds and the 4.064 he ran in the final. “This new car really likes to be planted early, and so Tobler (Crew chief) has been working on a new clutch package,” said Capps. “In (the final qualifying session Saturday), we finally found out what it really liked. And when you give Tobler a new combination that works, he’s going to ‘bracket car’ it to death,” he said of Tobler’s penchant for consistency. The combination of being runner-up at Pomona and Capps’ win Sunday moved the NAPA team to first in the Mello Yello standings after two of 24 events. “We’re starting to feel like we’re getting into the same rhythm that we were in last year when we went to six finals in a row,” Capps said. Schumacher's victory in Top Fuel was his fourth career NHRA Arizona Nationals at Firebird International Raceway and the 70th event title of his career. “The fans got their money’s worth on that run,” Schumacher said. “It was pedal, pedal, lift, pedal, straighten the car out, do it again. I loved it. It’s cowboy stuff. I enjoy that kind of race more than the record-setting ones we’ve had over the years. That still proves you have to put a driver in these cars and drive these things. We ran incredibly well all weekend. All you have to do is be a machine and do the same thing, win rounds and win rounds, but those runs are the ones that are just fun. The Top Fuel and Funny Car classes use Gates Poly Chain belts to drive the superchargers necessary to achieve the enormous horsepowers required to make the 1000' runs in 4 seconds or less. The Poly Chain belts are specifically engineered for the extreme conditions (shock loads, high loads, high accelerations, high speeds) of the application.