The RPX Technologies team recently had the opportunity to use the DynaVibe GX2 system to balance an Antonov 2 - "Annie" - the world's largest biplane. Our latest video shares our experience with the AN-2, showing how the dynamic propeller balancing process works.
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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
2. Speed over 15 km
3. Speed over 100 km closed course
4. Speed over 500 km closed course
5. Time to climb up to 3,000 meters
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: 405.896.0026.
Dynamic Prop Balancing Delivers Smoother Flying.
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: 405.896.0026.
DynaVibe Helps Make Aviation History
On the eve of World War II, Ettore Bugatti – the legendary sports car designer – was busy trying to build an airplane. And what a plane it was: a technological marvel in art deco; the most elegant aircraft that would ever grace the skies. Except, it never flew. Bugatti built just one of his visionary airplanes in 1939, designated the 100P, but it remained grounded with plans to fly it scrubbed because of the war. Spirited away to a hiding place to avoid being seized by the Nazis, it remained in mothballs even decades after the war. Today the restored but not airworthy 100P resides in the AirVenture Museum in Oshkosh, Wisconsin.
Enter Scotty Wilson, whose aviation career spans five decades and nearly 11,000 hours in aircraft ranging from Cubs to F-16s. He is also a certified aircraft mechanic who had a vision to build and fly a replica of the 100P. In 2013, Wilson led a team that funded the “RÊVE BLEU” (Blue Dream) project via Kickstarter. The dream became reality on August 19, 2015 when aviation history was made as the Blue Dream took its maiden flight.
The Bugatti 100P was – and is – an extraordinary airplane with an innovative, timeless design. Originally designed to fly at a top speed approaching 500 MPH, the 100P is driven by two engines located behind the cockpit, connected via drive shafts and gearboxes to two, contra-rotating propellers.
The 100P’s unique, complex power plant and propeller assemblies intensified the need to balance the propellers. RPX Technologies, the makers of the DynaVibe propeller balancing system, has been in dialogue with Scotty Wilson and the Bugatti team for a few years, reviewing the potential vibration problems of such a unique airplane. The range of possible issues with the 100P included torsional vibration, resonance and contra-rotating prop interactions not typically seen on most aircraft.
When the Blue Dream team had the Bugatti ready to run the engines leading up to the first flight, RPX met Scotty to balance the 100P’s props. Matt Dock, RPX co-founder and engineer, used the DynaVibe GX2 to perform this task, setting up the DynaVibe accelerometer on the propeller gear box, as close to the props as possible. The photo tachometer was mounted on the outside of the fuselage as pictured.
With this configuration of the DynaVibe accelerometer and phototach, it was easy to setup the DynaVibe GX2 for a non-typical installation by using the display and arrow keys to position the location of the accelerometer, phototach, propeller blades, and direction of rotation. Even with the odd angles of the phototach and accelerometer, the GX2 was able to compensate for the atypical setup and provide a great balance in minimal runs.
Before starting the balancing run, Matt did an initial spectrum analysis to determine what possible vibrations might exist in the 100P. The DynaVibe GX2 (pictured below) revealed vibration only in the prop spectra, so Scotty and Matt proceeded to dynamically balance the 100P’s propellers.
Matt and Scotty first turned their attention to the prop that rotates counter-clockwise. The initial vibration measured was significant, at 0.37 Inches per Second (IPS). Even though the 100P’s props are relatively small, the fiberglass spinner is fairly large, and custom made and therefore a likely cause of propeller assembly imbalance. During the first balancing run, the DynaVibe GX2 provided an exact solution for how much weight to add and where to add it. After three runs total, the counter-clockwise prop was balanced and Scotty observed that the annoying vibration in the panel was gone!
The clockwise rotating prop was addressed next by setting the DynaVibe GX2 up for a new balancing job. This prop was initially smoother than the counter-clockwise prop, exhibiting a vibration of .19 IPS, and after three runs Scotty and Matt easily got the vibration down to just 0.06 IPS.
With the props in balance, Scotty and Matt used the DynaVibe to check the vibration from the long drive shafts in the airframe. The Bugatti uses a pair of Hayabusa engines driving automotive style drive shafts with u-joint connections in multiple locations. U-joints typically generate a torsional vibration at twice per revolution speed. Bearing vibration was also examined, providing the Bugatti team with valuable, preventative benchmark data about these critical components.
On August 19th, with balanced props, the Bugatti 100P – the Blue Dream – finally took the air for its historic, first flight. RPX will continue to work with the Bugatti group to help with any issues in the future. Watch the exciting video of the first flight of the Bugatti 100P:
DynaVibe balanced the Bugatti and can balance your airplane too! Enter your email below to learn how:
DynaVibe is an effective tool for dynamic propeller balancing and vibration analysis. For A&P mechanics, shops and service centers, DynaVibe is also an excellent tool for boosting customer satisfaction and service revenue.
It’s not hard to understand the customer value proposition of balancing and vibration analysis – a quick scan of the DynaVibe customer testimonial page confirms the difference flying with a balanced prop assembly makes. Unlike other service procedures, fixing an unbalanced prop or a complex vibration makes a difference customers can feel.
So it is with vibration analysis. Customers that have simply lived with annoying (and damaging) vibrations are grateful when mechanics are able to isolate and fix them. And they should be: vibrations are harmful, with the potential to damage the engine, instruments and airframe. Resolving complex vibrations extend the life of the aircraft.
Shops, service centers and the mechanics have become a significant segment of the DynaVibe user population. We’ve profiled some of them in recent case studies, such as Skywest Aviation and Ascutney Air and a common theme is emerging: these businesses are using DynaVibe to deliver better service, resulting in more satisfied customers and increased revenues. It’s a scenario where everyone wins.
Adding DynaVibe to the services mix that a shop or service center provides has the following benefits:
This video shows how DynaVibe delivers these benefits to the shops and service centers that use it:
To learn more about how your shop or service center can boost profits and customer satisfaction by using DynaVibe, contact us at 405.896.0026 or firstname.lastname@example.org.
Balancing props with DynaVibe is usually pretty easy, even for first-time users. Once in a while, however, we hear from customers who are having problems balancing, so based on some support exchanges, we've put together some troubleshooting tips when the balancing process is more difficult.
Here's the typical scenario: a customer consults the DynaVibe manual, follows the instructions and adds weight where the procedure indicates, but subsequent runups show that the balance hasn't improved, and/or that the location where the weight should be added has moved. After repeated runups, there seems to be no progress being made toward getting the prop balanced.
There are a few “gotchas” that may impact how easily the balancing process proceeds.
First, make sure you are aligning the reflective blade tape with the phototach, using the position of the accelerometer as zero degrees, with the accelerometer cable pointing up to the zero degree position. Then go in the direction of rotation to the angle indicated; that's the heavy spot. When the pusher is backwards, as in a Long EZ, sometimes people get confused, but if you follow those steps, it doesn't matter which side of the plane you are on or which way the motor is spinning. Just point in the direction that the wire is coming out of the accelerometer and then go in the direction of rotation to the heavy spot (add weight opposite).
Second, RPM readings must be completely stable. If you see the RPM jump from 2200 to 1100 then back, or if you see more than a 50 RPM variation in tachometer readings, there is probably an issue with the tachometer. If you experience a tach variation of this nature, contact us and we can make some suggestions.
Third, check the spinner if your airplane has one. "Chasing" the angle during the balancing process is a classic indicator of a spinner that is shifting while running. If you can feel the spinner move by pushing laterally on the spinner, then it will be hard to balance. If your airplane doesn't have a spinner, do a very thorough job of looking for anything else that is loose: cowling rubs, exhaust pipe contact points, or anything that may be causing erroneous readings.
Fourth, are you running a long prop extension? If so, pay close attention to where you mount the accelerometer. It should be at the very front of the engine (or the very back of the engine for a Long EZ), otherwise, the accelerometer placement could give unusual results.
Fifth, check your static RPM. If your static RPM is lower than your cruise RPM, the low static RPM can be an issue if the mounts are stiff.
Sixth, and finally, the blade pitch of the prop could cause difficulty balancing, so you may need to verify the blade pitch on each of the blades to make sure they are all setup the same way. If balancing isn't going smoothly it is a good idea to verify that all the blades are pitching the same (and in track the same).
We love hearing from our customers, so if you have a question, comment or problem, please don't hesitate to contact us: email@example.com or 405.896.0026.
Paul Armstrong is the founder and owner of Skywest Aviation, an aircraft sales and maintenance company that operates out of Midland, Texas, at KMAF Airport. Skywest began operations in February 2014 and has already grown to 14 employees. “We’re aircraft mechanics – if it comes in the door, we work on it,” states Armstrong, who is also a commercial pilot, and an integral part of the flying community. Skywest works on aircraft ranging from Cessna 150s up to King Airs, Citations and Commanders. In addition, it also services Embraers through its contract with Mesa Airlines.
Dynamic Balancing: SOP
Armstrong is an advocate of dynamic prop balancing, a practice he learned early in his aviation career when the company he worked for sent him out to small fields that didn’t have maintenance shops. He would arrive to find owners lined up, waiting to have their props balanced. Today, Armstrong uses a DynaVibe GX2 to dynamically balance props that come through Skywest Aviation. “We always require a dynamic balance when we install a propeller,” says Armstrong. “When I do a prop overhaul, or remove and reinstall a prop, we do a dynamic balance on the prop or both props, depending on what we’re working on. It seems to be a pretty good calling card for us.”
Balancing & Vibration Analysis
The DynaVibe GX2 is more than just a dynamic propeller balancing solution – it also does full spectrum vibration analysis, a capability that Skywest takes full advantage of. “It’s a really good piece of equipment,” Armstrong continues. “I have used these things and found alternator problems, broken brackets. That’s one reason I sell the tool. Just because there’s a vibration doesn’t mean it’s the prop. We can find a weak cylinder – it will show up at the ½ per.”
Armstrong had previously used another vendor’s prop balancer, so when he decided to purchase a balancing system for Skywest, he was of the mind to purchase the one he was familiar with from past usage. “The cost was so prohibitive, and I couldn’t get these people to call me back,” notes Armstrong. “I was in a real rush because I had two prop overhauls I had just done, and I was trying to contract a local prop shop to do the balance. What I was charged for that was through the roof, $400 a side. That’s when I went ahead with the purchase of the DynaVibe system.”
Balancing = Profits
Since purchasing his DynaVibe GX2 in October 2014, Armstrong estimates that Skywest has done between 15 and 20 balancing jobs. While Skywest does dynamic balancing as a service, most balancing jobs are part of his overhaul package. Including balancing in this package creates value for Skywest customers and profit for Armstrong. “There is definitely hidden profit from balancing work that can’t directly be accounted for,” states Armstrong. “That machine has absolutely paid for itself. It also gives us a little bit of status, because there is only one other shop in the area – a prop shop – that has this capability. Now that we have this capability, it makes us more competitive.”
The DynaVibe GX2 is helping Skywest deliver the highest quality maintenance services to its clients. “It’s a very good preventative maintenance tool, and it’s a good troubleshooting tool,” Armstrong concludes. You can pick up other problems. It’s good for more than just prop balancing. If a shop uses it, it can bring them other work.”
DynaVibe Benefits for Skywest Aviation
Contact RPX Technologies to learn how your service center can benefit from DynaVibe: firstname.lastname@example.org or 405.896.0026.
The Airventure 2015 show in Oshkosh ended a week ago. The show was a great experience for us, and now that we’ve had a week to think about it, we wanted to share a few observations about our time in Oshkosh, what we learned and what made it so great.
Prop Balancing Awareness
Topping the list of what we learned was how many pilots and owners still don’t know what dynamic propeller balancing is, and why it’s important. Our booth in the Aircraft Spruce pavilion was in a great location, with lots of traffic. There was a steady stream of Airventure attendees that wandered by our booth, scanned our information, and popped the question: “what is prop balancing?” It was a great opportunity for us to educate attendees about dynamic prop balancing, its benefits and of course, promoting the DynaVibe as an easy-to-use, low cost prop balancer. If you are among those who want to know why balancing is important, check out and share our infographic.
Prop Balancing is Still King
In 2015, we have been working to educate the aviation community about how full-spectrum vibration analysis can help troubleshoot complex vibrations. The interest in this application of DynaVibe is growing. We are getting testimonials of owners and mechanics who have wrestled with thorny vibration problems for years that were able to quickly isolate the source of the vibration by using the DynaVibe GX2 for full-spectrum vibration analysis. That said, prop balancing is still the primary reason why people buy and use DynaVibe. We think the day will come when vibration analysis will eclipse prop balancing as the primary application for the DynaVibe GX2, but for now, prop balancing is king.
Vibration Tolerance is High
We had a few discussions at our booth that mirror our experience in the field. When discussing full spectrum vibration analysis as a means to troubleshoot complex vibrations, often the response we’d get was “I don’t need that” or “I don’t have that problem.” As we continued to describe the common scenarios and symptoms of aircraft vibration, many times the response was “I do have that problem!” It seems there are more than a few pilots and owners that have vibration problems to which they’ve become immune. They’ve simply lived with it for so long that they’ve developed a tolerance for it. Meanwhile, the vibration persists and the damage to engine, instruments or airframes continues to accumulate.
DynaVibe Price and Value
Price is what you pay; value is what you get. We continued to get validation at Airventure 2015 that DynaVibe delivers great value at a very competitive price. More than once, we did a demo in our booth for a prospect, who said “I’ll think about it” and wandered off. Later, they returned, confessing that they had been shopping our competitors who also had a presence at the show. Most of the time, they acknowledged that DynaVibe’s price performance characteristics brought them back to make a purchase.
Seeing Old Friends
Perhaps the most gratifying part of being at Airventure 2015 was the opportunity to meet with DynaVibe customers and users. In the 8+ years since DynaVibe was launched, we’ve managed to sell many DynaVibe units. It is wonderful to have our customers come by our booth to tell us about their experience using DynaVibe to get a smoother, safer flying experience.
It was a great week in Oshkosh. Thanks to everyone who took the time to visit with us. We look forward to going to Airventure next year!
Ascutney Air is a shop that provides a variety of general aviation repair services. In 2014, Ascutney purchased a DynaVibe so that it could offer dynamic propeller balancing as a service to its clients. Ascutney owner Steve Keen is an EAA tech counselor, and also flies a Cessna 172. Some time ago, he noticed that his 172 had a fairly severe vibration on landing and rollout that was getting progressively worse.
The left wheel was the vibration source, so Steve tore it down but found no problems other than an out of balance tire. He balanced the tire with a cone-type static balancer, but he could not achieve good balance when the tire was mounted on the wheel assembly. Understanding that his new DynaVibe can balance anything that spins, he set the system up on the problem wheel and balanced it, sharing that, “It worked really well!”
Steve’s experience with his 172 caused him to realize there was a business opportunity to dynamically balance airplane tires: “Out of balance tires can beat an airplane up. Tires aren’t always perfect, and static balancing may or may not work.”
Just like prop balancing, Steve understood that the best way to balance a tire is when it is mounted to the wheel assembly on the airplane, and it is spinning at takeoff or landing speed. So he built a tire-spinning device to get the wheel turning at the proper speed and he now uses the spinner and DynaVibe to balance airplane tires.
The experience Ascutney Air has had balancing airplane wheels with DynaVibe has been good for the airplane owners and the pilots the shop serves.
Balanced tires add a new level of safety. Out-of-balance tires can cause torque links to wear, or affect braking action: “Many pilots think vibration or rumbling noises are due to bad runways. They don't know that tire balance is the cause.” For example, one pilot came to Ascutney Air reporting a vibration on landing. Using the DynaVibe, Steve was able to get the tires on this pilot’s airplane perfectly balanced, and the vibration went away.
Steve credits the dynamic balancing process with generating these positive outcomes, because the process balances the entire wheel assembly, mounted on the airplane, while turning at takeoff or landing speed: “Dynamic balancing equals certainty.”
For Ascutney Air, dynamic wheel balancing with DynaVibe has created a new revenue stream for the shop. Testing to see if wheels are out of balance is easy using the wheel spinner Steve fabricated to do the balance test when the wheel is on a jack. If the wheel is out-of-balance, he hooks up DynaVibe to balance it.
Ascutney Air continues to balance propellers, and as far as balancing tires, “It’s just like doing a propeller,” concludes Steve. “DynaVibe has paid for itself more through tire balancing than prop balancing. Balanced tires make flying a little easier. There’s a huge benefit to taking off and landing with smooth tires, such as better braking.”
Shops interested in building a spinner for balancing airplane tires can purchase the plans and parts list by contacting Steve: email@example.com.
To learn more about DynaVibe or purchase one for dynamic prop or tire balancing, contact the RPX Technologies team: 405.896.0026 or firstname.lastname@example.org.
Aircorps Aviation, specializing in the restoration, maintenance, and rebuilding of vintage WWII aircraft, recently purchased a DynaVibe GX2 to perform dynamic prop balancing and vibration analysis on the warbirds that come through its shop. RPX Technologies co-founder Matthew Dock visited Aircorps Aviation to demonstrate how the DynaVibe GX2 works.
During the visit, Bruce Olson’s T-6 was analyzed and balanced with the DynaVibe system. The initial reading revealed a propeller vibration of 0.45 Inches Per Second (IPS), indicating a prop imbalance. Making some adjustments over the course of a few runs, the vibration was reduced to 0.06 IPS, reducing stress on the airplane and providing a smoother ride.
The T-6 owner, Bruce Olson, found the DynaVibe GX2 demonstration interesting beyond just the dynamic prop balancing that was done. “It made it clear to me that there are certain, other areas of that airplane that showed no vibration whatsoever. It gives me an awful lot of confidence that the engine is in good shape. Now we have a baseline for the engine, so if we come back next year and put it on the test stand, and something changes, we’ll know that there’s something going on in the engine.”
The preventative maintenance value of the DynaVibe GX2 analysis was not lost on Olson: “After having a baseline and basically finding out if there is anything wrong with my airplane, it’s like having a full physical of your own body. You now feel comfortable that everything’s okay, and there’s nothing I have to worry about… it lets us see if there’s anything going on inside that airplane that you could catch well in advance of a failure.”
Olson summarized the experience of having his T-6 dynamically balanced and getting a full-spectrum vibration analysis: “I’m very happy with what the guys did, it’s better than it was before.”
To learn more about DynaVibe and how to dynamically balance your prop, use the form below and enter your email address, visit the RPX Technologies online store or contact us directly: 405.896.0026 or email@example.com.