DynaVibe Blog

Selecting the Right DynaVibe System

Thursday, November 05, 2015

Perhaps you’ve had enough of the vibration that makes flying uncomfortable, or is damaging your airframe, avionics or engine.  Or maybe you want better performance, recapturing horsepower lost to vibration.  Perhaps a friend who has dynamically balanced his or her prop recommended that you do the same.  Whatever the reason, you’re ready to make an investment in a prop balancer, and a Google search has led you here.  Which DynaVibe system is right for you?

RPX Technologies currently offers three models of its DynaVibe propeller balancing system.  Here’s what you need to know about each one in order to choose the one that best addresses your needs.

DynaVibe GX2

The DynaVibe GX2 is the state-of-the-art, flagship solution in the RPX Technologies product line.  This unit comes with two accelerometers, allowing users to dynamically balance propellers while also providing full-spectrum vibration analysis capability.  When prop balancing, the DynaVibe GX2 automatically calculates a recommended weight solution for achieving balance, unlike the DynaVibe Classic.  This feature helps users complete the balancing process faster than is typically possible with the DynaVibe Classic, sometimes in as few as two run-ups. For mechanics, shops, repair stations and service centers where time equals money, this more efficient balancing process is highly desirable.

A more advanced feature of the DynaVibe GX2 is its vibration analysis capability.  When troubleshooting more complex vibrations, those caused by something other than a propeller assembly imbalance, spectral analysis is essential.  It allows users to pinpoint the source, distinguishing between vibrations caused by a combustion issues (e.g. weak cylinder), prop wash induced buffeting, alternator imbalance, and many other sources of vibration.  Instead of wasting time and money on trial-and-error maintenance procedures, the GX2 identifies the vibration source.  The GX2 has a report generation feature to simplify printing or sharing its vibration analysis data.

DynaVibe Classic

The DynaVibe Classic is the original prop balancing system offered by RPX Technologies.  If balancing a propeller or other rotating machinery is the only thing you need to do, the Classic model does an excellent job at the most affordable price.  When it comes to the dynamic balancing process, the main difference between the models is that the Classic does not automatically calculate a weight solution.  The implication is that the user may need a few more run-ups to complete the balancing process.  The DynaVibe Classic does not offer full-spectrum vibration analysis.

DynaVibe Roto

DynaVibe Roto is a version of the DynaVibe Classic with some features specifically for rotorcraft.  This unit comes with two accelerometers, one for lateral vibration and one for vertical vibration.  It also includes an integrated remote control “push-to-talk” switch that can be mounted on the stick for controlling the DynaVibe unit.  The DynaVibe Roto will also dynamically balance propellers on fixed-wing aircraft.

Summary

This table provides a quick reference to help select the right DynaVibe system to meet your needs:

If you would like to learn more about selecting the best DynaVibe model for your needs, simply enter your email address in the form below, email us with your question at sales@rpxtech.com or call: 479.708.8779.

Enter your email address to learn more about selecting the best DynaVibe for your needs:     

Dynamic Prop Balancing Adds Service Revenue

Tuesday, November 03, 2015

Our new infographic shows how mechanics, repair stations, shops and service centers can make more money by adding prop balancing to their service mix with DynaVibe:

Enter your email address to learn more about offering dynamic prop balancing services:     

Using DynaVibe to Balance Rotorcraft

Monday, October 26, 2015

DynaVibe can balance rotors as well as propellers, and key to accurate rotor balancing is proper placement of the lateral and vertical accelerometers as well as the phototach sensor. 

Lateral Accelerometer Placement

The purpose of the lateral accelerometer is to measure the mass imbalance that occurs once per rotation (1-per) of the rotor.  The best way to measure the mass imbalance is to maximize the sensitivity to the mass imbalance while minimizing sensitivity to other vibrations. 

To do so, mount the lateral accelerometer as high as possible on the rotor mast to maximize sensitivity.  It’s also preferable to mount the accelerometer on a rigid structure.  If the accelerometer is mounted on a bracket or other secondary structure, that structure may absorb vibration or modify the signal due to structural resonance.  Furthermore, to maximize sensitivity, orient the accelerometer so that it is sensitive to the axis of minimum rotational inertia.  For rotorcraft, this is usually the roll-axis, hence the reason for laterally mounting this accelerometer.

To minimize non-mass vibrations, point or align the accelerometer through the rotor shaft.  If the accelerometer is mounted ahead of or behind the main rotor mast, then the accelerometer will receive vibration from the main rotor imbalance plus vibrations from any torsional vibration.  This occurs frequently in analyzing engines: the vibration signature will change if the accelerometer is not pointed through the rotating element.

When measuring mass imbalance, a key area of focus is measuring the vibration when there is minimal forward airspeed.  If the two blades are not identical in lift and drag, then blade asymmetry will cause a 1-per vibration. Measuring the mass imbalance at high forward speeds will cause the sensor to register both the mass imbalance and blade asymmetry.  For this reason, it is best to collect mass imbalance data while in a step decent, power off.

When the lateral accelerometer and phototach are setup correctly, and the forward speed component of the 1-per vibration is eliminated, then balancing the rotor is just like balancing a prop.

Phototach Sensor Placement

Position the phototach so that it has a clear view of the rotor system, making sure that it is at least six inches away from the reflective tape target to get a good signal.  A piece of reflective tape is applied to rotor system so the DynaVibe computer can determine the relative position of the blades to the vibration signal received by the accelerometer.  The phototach position is determined by the polar charts that you will be using, the manufacturer's recommendation, or by talking with a DynaVibe team member.

Vertical Accelerometer Placement

The purpose of the vertical accelerometer is to measure vertical hop and pitch axis vibration.  This requires placing the vertical accelerometer in the forward cabin as pictured.  If vertical hop is present at the 1-per, then its cause is blade asymmetry.  If it is present twice per rotor rotation (at the 2-per), its cause is the advancing blade lift and drag.  It’s usually possible to correct a 1-per vibration through tracking: making tracking better or worse depending on the blades.  The 2-per vibration, however, is generally difficult to eliminate.  For helicopters, DynaVibe engineers recommend using trim tabs to adjust the forward flight 1-per vibration.

For rotorcraft balancing, the full spectrum analysis capability the DynaVibe GX2 provides is excellent for troubleshooting.  However, even the basic balancing capabilities of the DynaVibe Classic provide all that is necessary for rotor smoothing.  The only frequencies requiring analysis are the prop, 1-per rotor, and 2-per rotor, which are within the scope of the DynaVibe Classic feature set.  What also facilitates accurate rotorcraft balancing is expertise and knowledgeable customer service of the DynaVibe team.

Learn more by visiting the DynaVibe Rotorcraft FAQ.

DynaVibe is easy and economical to use for prop and rotorcraft balancing.  For mechanics, shops and service centers, it adds profit to the bottom line.  To learn about using DynaVibe to dynamically balance propellers and rotors, enter your email address below, visit the RPX Technologies website, or call:  469.708.8779.



Enter your email Address here to learn more about using DynaVibe with rotorcraft:     

The Bugatti 100P Flies Again

Thursday, October 22, 2015

DynaVibe was on hand to support Scotty Wilson's second flight with the Bugatti 100P when he returned to Oklahoma's Spaceport at Burns Flat to continue flight-testing.  The Bugatti needed new props after its historic first flight due to a brake failure on touchdown.  The DynaVibe team joined Scotty to balance the two, new propellers on the Bugatti and continue the flight-testing program for this innovative and historic airplane.

Having previously balanced the Bugatti (click here to learn why dynamically balancing a prop is important) for its inaugural flight, a location for mounting the accelerometer was already determined.  It was quick work to install the DynaVibe accelerometer and phototach on the Bugatti.  Balancing the contra-rotating propellers started with the rear engine / rear propeller.  The initial balancing run revealed that the rear prop required 27 grams of correction weight, which when added, brought the propeller imbalance down to 0.09 Inches Per Second (IPS).  The front propeller was then balanced down to 0.10 IPS by adding 18 grams of weight.  Shortly afterward, the Bugatti successfully took to the air once again.

DynaVibe has balanced the Bugatti 100P, the world-record breaking Anequim, warbirdsReno Air Racing team aircraft, the AN-2, the world’s largest biplane, and it can balance whatever you fly, delivering better performance and a smoother flying experience.  To learn how easy and economical it is to dynamically balance your prop with DynaVibe, enter your email address below, visit the DynaVibe online store, or call:  469.708.8779.


Enter your Email Address to learn more about dynamically balancing your airplane:     

DynaVibe Minimizes Equipment Wear-and-Tear for Alaska DOT

Thursday, October 15, 2015

DynaVibe has a long association with aviation as an affordable system for dynamically balancing propellers.  The principles of balancing, however, apply not just to propellers, but any device that spins.  The Alaska Department of Transportation is using a DynaVibe Classic system to keep brush cutting and snow removal equipment operating at peak efficiency. 

The idea to use DynaVibe came from an employee in one of the shops who was an A&P mechanic and had experience using the system to balance propellers and rotors.  Aware of DynaVibe’s ability to achieve precision when balancing, he started using the system to balance a brush cutter that had a rotating head.  When Lon Needles, shop foreman of the Transportation Department's State Equipment Fleet, heard about this, he asked this employee to come and demonstrate how it is done.

“This equipment will hit rocks and things and get out of balance, and it will shake the guys out of the cab,” said Needles.  The balancing demonstration was enough to convince him that they too needed a DynaVibe to balance the brush cutters in their shop.  Once the DynaVibe was in their possession, Needles began to wonder what other equipment they could balance with it.

“We have our snow blowers here,” continued Needles.  “Valdez averages 300 inches of snow a year; Thompson Pass, just up the road a little bit, gets 700 inches per year, so we use the heck out of our snow blowers.  If they hit a rock or something, it can mess them up, so we balance the spinning rotor in there with DynaVibe too.”  

The impellers in these machines are heavy, perhaps weighing as much as a ton.  “When they get out of whack, I’ve seen them sit there and bounce the whole head off the ground.”  Needles shares an experience about a brush cutter that was so out of balance that “it would literally shake the coffee out of the operator’s coffee cup.”  After balancing this equipment, “you could barely see a ripple with it running wide open.” 

The value of keeping these machines in balance is less wear-and-tear – for both the machine and the operators.  “When a machine is not sitting there vibrating, it’s smooth; it takes the fatigue away from the operator, and while I can’t prove it, I think it takes the metal fatigue away from the machine.  Nuts and bolts aren’t trying to come apart.  It’s noticeable.” 

By spending the time to balance, Needles and his team are able to eliminate virtually all the vibration from the spinning components of their machinery.   The snow blowers are balanced about once a year; the brush cutters about twice per year or as needed.  It takes about an hour to balance a machine. “Anything that spins, we seem to be able to balance it,” Needles concludes.  

For a free, no-obligation consult with us about your balancing application, enter your email address below.

Email Address  :     

Balancing = Profits

Monday, October 05, 2015

At RPX Technologies, we routinely hear stories from service centers, shops, or repair stations that use DynaVibe to deliver service.  These stories have a common theme:  using DynaVibe to offer dynamic balancing service brings in more business, generates greater profit, and increases customer satisfaction.

It doesn’t take much balancing work to create a fast payback on purchasing a DynaVibe GX2 system for balancing and vibration analysis.  Just doing three dynamic balancing jobs per month provides payback in less than 5 months and adds almost $7,000 in profit during the first year.  The following table summarizes the DynaVibe business case:

Under the same balancing workload assumption of three jobs per month, opting for a DynaVibe Classic provides payback in less than two months and delivers over $9,300 in first year profit!

It’s typical for a shop that uses DynaVibe to complete a prop balancing assessment for every airplane that comes in for service.  If the prop is out of balance, owners are given the option to have it dynamically balanced, and often they accept.  What’s also typical is that once a shop begins offering dynamic balancing service, owners will bring their planes in for that reason alone, and often other maintenance issues will surface during the visit. 

Shops, service centers and repair stations that use DynaVibe to offer dynamic prop balancing enjoy a number of benefits:

  • Dynamic balancing is a great “calling card” that attracts business to the shop.
  • Customers are often amazed at how smooth their airplane flies after balancing.  DynaVibe helps create very satisfied, loyal customers.
  • In addition to prop balancing, the DynaVibe GX2 can identify other vibrations from other, more complex sources.
  • Offering dynamic prop balancing improves the status and credibility of the shop or service center.
  • DynaVibe is an excellent preventative maintenance tool, allowing mechanics to get baseline vibration surveys for comparison during future maintenance.

The DynaVibe system is easy and economical to use, adding profit to the bottom line.  To learn about using DynaVibe to dynamically balance propellers, enter your email address below, visit the RPX Technologies website, or call:  469.708.8779.

Email Address  :     

Recovering “Lost” Horsepower

Wednesday, September 23, 2015

Vibrations Steal Energy

There are many benefits to dynamically balancing the prop assembly and removing vibrations associated with propeller imbalance.  Often talked about benefits include smoother flying with less wear on the engine, instruments and airframe.  These benefits have enormous value, as they reduce fatigue on the plane, pilot and passengers, while extending the life the airplane.  They are reason enough to keep the prop assembly in good balance, all the time.

Another benefit of dynamic prop balancing is performance.  When an imbalance introduces a vibration, energy is spent shaking the airplane instead of moving it.  With a finite amount of horsepower available to propel the airplane, a vibration uses some of it in a destructive way, leaving less available for propulsion.

The percentage of horsepower lost to vibration may seem small.  Look at it this way: suppose a propeller imbalance is costing 2 percent of an engine’s horsepower.  This 2 percent is going into shaking the airplane.  If that airplane has a 200 HP engine, in this scenario 4 HP is lost due to vibration.  To provide some perspective, this loss is the equivalent of hooking up a lawn mower engine to the airplane’s crankshaft to do nothing more than shake the airplane!  That’s how much energy a propeller imbalance can direct into the crankshaft bearings and the rest of the airplane. 

Fortunately, it’s not difficult to recapture this “lost” horsepower.  Dynamically balancing the prop assembly allows most or all of the horsepower lost to vibration to once again go toward flying the airplane.  Using the DynaVibe GX2, you can easily determine if a prop is out of balance, and also get a solution for how much weight to add, and where to add it to achieve good balance.  To learn about using DynaVibe to dynamically balance propellers, enter your email address below, visit the RPX Technologies website, or call:  469.708.8779.


Enter your Email Address to get a link to our balancing video :     

National Championship Air Races 2015

Tuesday, September 15, 2015

Several teams using DynaVibe to get peak performance

Qualifying for the National Championship Air Races in Reno, Nevada began this week, and DynaVibe is part of the strategy to win for teams in three of the six classes.

Vito Wypraechtiger flying the Scarlet Screamer is currently the second-fastest qualifier in the Formula One class.  In the Biplane class, Tom Aberle flying the Phantom set a new world record of 284.454 mph, breaking the previous record of 274.091 mph set in 2014.  Steve Hinton flying Voodoo, a modified P-51D Mustang and the 2014 Unlimited gold champion at Reno, is currently the top qualifier in the Unlimited class.  “The DynaVibe helped us win the national championship air race in Reno,” said Bob Button, owner of Voodoo Air Racing speaking about the 2014 win.

Each of these racing teams is using DynaVibe to help their aircraft achieve peak performance.  By dynamically balancing the propeller assembly, owners can recapture RPMs lost due to vibration.   Testimonials from DynaVibe users speak to gaining RPMs on the top end after dynamically balancing their props.

Vibration uses horsepower, so when a vibration is eliminated, that horsepower can work to move the airplane faster instead of shaking it.  Consider this scenario: a vibration that was costing 2 percent of the engine's horsepower to shake the airplane is recaptured through the balancing process.  To put this into perspective, it is roughly the equivalent of hooking up a lawn mower engine to the crankshaft to do nothing more than shake the airplane!  A prop imbalance can direct a significant amount of energy into the crankshaft bearings and the rest of the airplane.  After balancing, that horsepower is no longer "lost" due to vibration, but available to help win races.  In the air racing world, 2 percent can be the margin between winning and losing.

The benefits of a dynamically balanced prop assembly are not limited to racing aircraft.  Any airplane can experience smoother, safer flying with less wear on the airframe, engine and instruments by balancing the propeller.  To keep up with the action in Reno, visit the race reports website.  To learn about using DynaVibe to dynamically balance propellers and analyze other vibration sources, enter your email address below, visit the RPX Technologies website, or call:  469.708.8779.


Email Address  :     

Anequim Races to 5 World Records

Saturday, September 05, 2015

DynaVibe Balances the World’s Fastest Four-Cylinder Airplane

Editor’s Note: Special thanks to Craig Catto, founder of Catto Propellers, for providing key input and photographs for this story

The Anequim Project, a group of students and professors from Brazil's Universidade Federal de Minas Gerais (UFMG), has built and flown the world’s fastest four-cylinder airplane.  Anequim comes from the Brazilian name for the shortfin Mako, the fastest shark in the seas, a fitting namesake for the airplane that gobbled up title to five world records during recent flights in August:  multiple speed records over various distances as well as a new fastest time-to-climb record.

Here are the world records the Anequim Project now owns:

1. Speed over 3 km with restricted altitude

  • Previous record: Nemesis DR-90 - 466.83km/h (Jon Sharp)
  • New record claim: 521.08km/h

2. Speed over 15 km

  • Previous record: Nemesis DR-90 - 455.8 km/h (Jon Sharp)
  • New record claim: 511.19 km/h

3. Speed over 100 km closed course

  • Previous record: W.Air Race - 389.6 km/h (Richard Young)
  • New record claim: 490.14 km/h

4. Speed over 500 km closed course

  • Previous record: VariEze - 387.4 km/h (Klaus Savier)
  • New record claim: 493.74 km/h

5. Time to climb up to 3,000 meters

  • Previous record: Pushy Galore – 3 minutes and 8 seconds (Bruce Bohannon)
  • New record claim: 2 minutes and 26 seconds

Powering Anequim is a four-cylinder Lycoming IO-360 modified by Sky Dynamics, connected to a custom propeller built by legendary prop designer Craig Catto, whose propellers have helped set numerous world records.  Craig has used the DynaVibe Classic propeller balancing system for several years.  At Airventure 2015 in Oshkosh, Craig connected with RPX Technologies co-founder and engineer Matthew Dock, who explained the benefits of the second-generation DynaVibe GX2.  “I thought this would be the perfect time to upgrade to the GX2 unit with the upcoming Anequim world record speed and time to climb record attempts in Brazil,” said Catto.  “I was able to acquire one of the new GX2 units the week before leaving to support the Anequim Team on their record attempts.”

Catto and his team made a total of 8 propellers for the Anequim Project.  Prior to balancing the Anequim, the pilot reported that the engine propeller systems were operating smoothly.  “We really did not know how ‘smooth’ was smooth,” said Catto.  “So we performed a simple propeller vibration analysis and found that we could improve the balance by simply removing one of the mass balance washers that was attached to the fly wheel.  We removed one An970-3 washer and brought the balance into the ‘excellent’ range.  We felt this was important especially on the 500km record attempt, where the 11/1 compression electronic ignition engine built by Sky Dynamics was going to be operating at full throttle for what would be right at one hour.”

Catto was pleased with how easy it was to dynamically balance Anequim’s propeller, removing it as a vibration source so that any other change in engine circumstances during the record attempts would become more evident to the pilot.  “The new GX2 will not only perform a simple propeller dynamic balance, but even a full spectrum vibration analysis.  With the new unit, Catto Propellers can now perform these services for its customers and others at the facility at KJAQ.  We are happy to say that DynaVibe was a part of our wonderful experience taking part of the world records set by the Anequim Team.”

DynaVibe can help your airplane achieve record-setting performance too! To learn how, enter your email address below or contact RPX Technologies at: 469.708.8779.

Email Address  :     

Case Study: Base Leg Aviation

Wednesday, September 02, 2015

Dynamic Prop Balancing Delivers Smoother Flying.

Background

Vic Syracuse owns and operates Base Leg Aviation out of Mallards Landing Airport (GA04) in Locust Grove, Georgia.  Base Leg Aviation serves the sport aviation community, providing DAR Services in a seven-state area, avionics and instrument panel service, inspections, test flights, ferry flights and other services.

Vic has over 38 years of aviation experience, and he has built 10 award-winning aircraft.  An EAA Technical Counselor, he also writes the monthly “Checkpoints” column for Kitplanes Magazine.  With over 8,000 hours of total time, Vic has a wealth of experience and wisdom to offer his customers.

Dynamic Prop Balancing

Vic purchased a DynaVibe prop balancing system at the Sun ‘n Fun fly-in in April, 2015.  He initially offered dynamic propeller balancing as an adjunct to other services, but balancing work is getting more regular as word gets out.  “I have flown many different airplanes and can really tell a difference in balanced props. There appears to be less cracking around baffles and engine compartment accessories, and passengers and myself seem less fatigued after a flight.”

The DynaVibe purchase followed a demonstration at the fly-in, where Vic saw a DynaVibe representative show how easy the system is to use.  “They were very helpful at the show, carefully answering questions, and making us feel comfortable with the product and support.”

Vic’s customers feel the difference that results from dynamically balancing their props:  “On almost all of the airplanes I have done we have started somewhere around .29 IPS (Inches per Second) and ended up around .06 or less. It is very noticeable to the owner.”

To learn more about how DynaVibe can help you offer dynamic prop balancing services, contact RPX Technologies by entering your email address below, or simply call: 469.708.8779.

Email Address  :     

Questions? Contact us at sales@rpxtech.com