Occasionally, in the process of putting together this fine magazine, we quite by accident come across a product or process that truly amazes us. While we were shooting the Keck motor buildup that ran in our April '97 issue, Quality Assemblies President Pete Baker insisted that we test-ride a custom bike his company had recently completed. His purpose was to enlighten us about a new modification they had used on this custom bike, the Keck motor, and several of their stroker motor assemblies.
HFB Editor Frank Kaisler and I took turns riding the
bike, and to say we were impressed is an
understatement. We both agreed that it was among the
smoothest-running solid-mounted Softail-style bikes we
had ever ridden. That its motor was 98 ci in size made
this even more impressive. Pete explained that the bike
had been modified by Sun-Tech Innovations, the same
company that makes Balance Masters®, using its active
Well, being the naturally inquisitive types we are, we contacted Chris Gamble at
Sun-Tech and asked him to share his secrets with our readers. After huge amounts of cash changed hands, he allowed us into the Sun-Tech manufacturing plant-spy camera in hand-and gave us the lowdown on this revolutionary modification and the science behind it. Basically, the process involves machining a groove into one flywheel half and epoxying in a Quick Silver-filled bladder, much like those used in Sun-Tech's Balance Masters® products.
First, a simple understanding of flywheel balancing is
necessary. Because of variations in material density and
in manufacturing and machining tolerances, no two
flywheel halves or complete assemblies are exactly
identical. Add to this the fact that the centrifugal force of
a reciprocating mass (a mass that rotates or spins)
increases in relation to its speed, and you'll understand
that an imbalance of just a few grams can cause
tremendous vibration at high rpm. In order to offset the
centrifugal force of the crankpin, connecting rods, and
piston assemblies as they move outward-away from the
flywheel's centerline-additional weight (referred to as
counterweight) is cast into the flywheels directly opposite
those parts at full extension.
The idea is that since the piston and rod assemblies create inertia in one direction as the flywheels rotate, the counterweight creates a near-equal inertia in the opposite direction, resulting in opposing centrifugal forces that move away from the flywheels' axes and thereby cancel out each other. This helps reduce the forces that contribute to vibration and the inertial load on the bearings. Remember, Newton's Law says that for every action there is an equal and opposite reaction. With us so far?
The factory-using a complex equation to estimate average crankpin, pistons, and rod assemblies' weights-calculates the amount and location of counterweight material removal on each flywheel half. Holes are drilled in the counterweight until it meets the calculated weight; then the flywheels are sent for final assembly. This is all the factory does to balance its flywheel assemblies. It explains why one Harley can vary from another in the amount of transmitted vibration it exhibits. This simple balancing method doesn't account for variations in manufacturing and machining tolerances.
Traditional Harley V-twin balancing is accomplished using
one or both of two additional methods. The first is called
static balancing. This is done by supporting the flywheels'
pinion and sprocket shaft centers, attaching a bob-weight
to the connecting rods to simulate the weight of the piston
assemblies, and allowing gravity to indicate the heavy
spots. This method is only a ball-park indicator of major
out-of-balance areas. Then there's dynamic balancing.
Using a bob-weight as described earlier, the flywheel
assembly is spun at one or two different speeds and a
computer determines what additional material must be removed from the counterweight. The machine that does this works much like the modern tire balancer you'd find in an automotive shop.
The biggest drawback to both of these methods is accuracy. Because the centrifugal force of a fixed mass increases with rotational speed, a flywheel assembly that is relatively smooth at 1,500 rpm can shake like a paint mixer above 4,000 rpm.
Here's where Sun-Tech's active balancing technology comes in. It uses a circumferential Quick Silver-filled bladder attached directly to the rotating mass. As the object spins, centrifugal forces cause the Quick Silver to migrate within the bladder to an area that is directly opposite any imbalance. The Quick Silver migrates not in a blob but in a thin bead, so it doesn't add any imbalance of its own. Since the Quick Silver is not constrained, it can move around as needed in response to changes in rotational speed-hence the designation "active balancing."
Now, you might be curious why Sun-Tech uses Quick Silver in its products. So were we. The reason is surface tension. Quick Silver has the highest surface tension of any liquid. Why does this matter?
Well, because the Quick Silver is constantly moving within the bladder. This creates friction, and friction causes wear. A liquid with a lower surface tension will eventually wear through the bladder and leak out. Quick Silver's surface tension is so high that it is the only liquid known to man that cannot adhere to glass.
Now, the Balance Masters® products have been on the market for several years. We highlighted their installation back in our September '94 issue, and they're in use on a couple of our own staff's motorcycles as well. But only recently did Sun-Tech develop a process for installing this technology directly into a Harley flywheel assembly, which they claim reduces vibration by 80 percent. This is an even better alternative for eliminating vibration at its source.
At the Sun-Tech plant in Northridge, California, the company can machine your flywheels and install the bladder without the need for complete flywheel disassembly. And once modified, your flywheels never again need balancing, even if you change pistons or rods. This technology has been proven by years of fleet use on over-the-road trucks, and carries a U.S. patent. Companies such as UPS use Balance Masters® on their truck wheels to reduce maintenance costs and tire wear. Hallcraft's Industries is even using this technology on its new "never-need-balancing" laced wheels.
If you're contemplating an engine teardown or building a
big-bore or stroker monster, the benefits of Sun-Tech's
active balancing could be the difference your bike needs
to be more Jekyll than Hyde. So, if your bike is giving you
the shakes, check into Sun-Tech's Balance Masters® or
active balancing flywheel modification. If you're still shaking
after that, we recommend you cut down on caffeine. HRB
Getting The Most From Your Tires
With Active Wheel Balancers
by Vic Cohen
Active wheel balancers have been on the market for about twenty years. Despite their many advantages, most bus converters and fleet operators still balance using wheel weights. The reason may be lack of national advertising or an understanding of how wheel balancers work.
First of all, why must tire/wheel assemblies be balanced? Many truck and bus operators do not believe radial tires need to be balanced because they are made better than bias ply tires. Actually, because radial tires are made with most of their mass on the outer circumference, even a slight imbalance will be amplified causing high vibration. Any wheel balancer acts as a counterweight to neutralize weight imbalances on the tire/wheel assembly. Wheel weights are placed on the wheel rims after a new tire is mounted. They are positioned as counter-weights, opposite the position(s) of the imbalance. If balanced carefully, they work fine at the beginning, but many factors may again cause the tire to go "out of round."
Some of these factors: (l) Minor damage to wheel, such as dents, during normal vehicle operation; (2) Minor damage to tire, such as cuts or gouges, during normal vehicle operation; (3) Uneven tire wear due to poor alignment or continuous rough conditions; (4) Tire may pick up rocks in tread.
Shortcomings of Static Wheel Balancers
There are other conditions that are not effectively corrected by wheel weights. These are of more concern to tractor/trailer rigs, tankers and auto carriers; still, they are worth mentioning as some of the effects could carry over to a bus conversion. During road operation, the trailer, at the tractor connection, tends to ride up and down. This causes tire bounce on both the drive and steering wheels of the tractor. The tires are continuously being compressed, a condition that eventually leads to tire cupping. A lightly loaded rig will tend to bounce and shake, a condition that is not only hard on the tires, but all mechanical parts and assemblies. You have probably noticed this most when passing or trailing an empty tanker-not only the violent shaking but the noise. Hard trailer braking, causing tire bounce and vibration, leads to further tire wear. Suffice it to say that there are many situations where static tire balancing (weights) can not completely do the job. The reader can probably think of others. Any condition that might change the weight distribution of the tire over the miles and years of driving will not be corrected by static wheel balancers.
Active Wheel Balancers
How much better are the active wheel balancers? Before getting into that, let's find out just how they work and how many different types of active wheel balancers there are. All of them mount so as to turn with the wheel assembly. They are usually in the form of a round metal plate mounted in some manner to the wheel assembly, with a tube filled ball bearings, shot, sand, oil or Quick Silver forming a ring around the outer perimeter. Some wheel balancers are hub mounted, and some are actually in the form of a tire fluid. The only criteria for location is that they become an integral part of the wheel assembly. The wheel assembly may consist of two or even three tires. All the wheels are locked together through the tire lugs. Corrections made by the balancer are for the entire assembly. Only one balancer is needed per assembly regardless of whether it is one, two or three tires. This does not apply to static wheel balancers. In this case, each tire must be separately balanced.
Using Quick Silver as the Active Element
Balance Masters® of Northridge, California, is the only company that uses Quick Silver as the balancing liquid. These devices are positioned behind the wheel assembly and are adaptable for all vehicles, 3/4-ton and up. President Chris Gamble demonstrated how this balancer helps to prevent tire bounce (one of its many advantages) by filling a tennis ball with Quick Silver and dropping it onto the floor from about shoulder height. The ball did not bounce at all due to the counter force created by the liquid, opposing the attempted upward thrust of the ball. In the Balance Masters® system the Quick Silver is contained in a small neoprene tube forming the outer circumference of the balancer. Because Quick Silver is essentially frictionless, there is no wear on the neoprene tube, and the balancer should never need replacing. Although other products may make a characteristic noise, the Quick Silver device is completely silent. Almost from the moment the wheel starts rolling, the liquid will assume counterweight positions to any tire imbalance. There is no "lumping effect," sometimes caused by shot-filled, hub-mounted and tire-fluid products. The Balance Masters® device is mounted directly behind the wheel assembly. They will reduce or eliminate vibration, increase tire life 50%, eliminate tire cupping, improve braking, roadability, decrease fuel consumption and reduce maintenance cost. Because the Quick Silver active wheel balance lasts almost forever, it is a one-time cost and can be reused when changing tires, wheel assemblies or even vehicles. Another product from Balance Masters® can be attached to the drive shaft. It functions in the same way as the wheel assembly device, eliminating shaft vibration and costly U-joint replacement.
Forgetting about all the mechanical advantages, what this will mean to you and your family will be a better and smoother ride, better road handling, and a less fatigued and more alert driver. If you are bringing along your best china and/or are preparing meals while rolling, and if some family members are sleeping en route, a smoother ride will be thoroughly enjoyed.
Purchasing and Installing Active Wheel Balancers
The Balance Masters® active wheel balancers may be purchased through their office in Northridge, California, or through distributors in other parts of the country. For a list of distributors, or to order, call 1 (800) 786-8324. The wheel balancers come in sets of two with each balancer installed on the right and left wheel assembly per axle. In other words, for a typical bus conversion, consisting of a steering axle, a drive axle with dual tires, and a tag axle, three sets would be required. The probable part number would be SA-303, one set for the steering axle and one set for the tag axle; DT-404, one set for the drive axle dual wheels.
This assumes a 22.5 or 24.5 ten hole wheel for all axles. The listed prices are $189 a set. There is a three-year warranty for any workmanship provided the tire wheel assembly is within the industry standards of 0.125 . Check with the company for more details and possible price changes.
The wheel balancer for the steering and tag axles (SA-303) is actually shaped like a shallow pan. Before installing, remove the wheel/tire assembly from the hub. Any wheel weights must also be removed. Place wheel balancer over lugs with outer ring (which contains the Quick Silver tube) facing inward over the hub. Replace wheel/tire assembly and torque bolts to factory specifications. For the dual wheel drive axle, remove outer wheel and place wheel balancer in front of the inside wheel over the lugs and with the larger of the two holes over the valve stem. Replace outer dual tire/wheel assembly and torque bolts to factory specifications. Consult company for further details. All installation instructions are included with purchase.
The Balance Master drive shaft balancer can be mounted on either end of the drive shaft, or in the middle. It comes in two sections clamped together. To install, simply remove the clamp, place the two sections around the drive shaft at the desired location, and replace the clamp. Again, consult the company for more details.
THE INDUSTRY'S BEST KEPT SECRET
What if there was a simple product that dramatically
reduced a motorcycle's vibration, was inexpensive,
maintenance free, and could be installed and returned
to you in a couple of days? If you're guessing, engine
balancing, you're partially right. If you're guessing
dialing in the flywheels, you're still only partially right.
The story starts back in 1979 when a washing machine
ran amuck in Phoenix, Arizona. Inventor Chris Gamble
was looking for a way to balance his washer after it
walked off the back porch. "I was supposed to watch
this thing and had to clean it all up before my wife got
home. By the time I was finished with that chore, I decided I'd put an end to this imbalance problem. I first looked into a way of liquifying lead, but that proved out of the question, so I tried Quick Silver. A naturally occurring mineral, it's a third heavier by volume than lead, remains in liquid state under most conditions, and is non-frictional so it won't wear out. Because it's a liquid it was perfect for balancing. All I needed was to design an appropriate tubing to contain it. The washing machine application I designed worked, and I began looking for other uses. This led to ultra-light aircraft which were experiencing problems balancing their props. I solved that vibration problem with one of my designs. We have several aircraft out there in general aviation which are flying with the device installed. They happily report reduced vibration even on their cockpit gauges."
The Balance Masters® device is a dynamically active counter-balancing mechanism composed of a special neoprene tubing filled with Quick Silver which is specifically fitted to a spinning part. Applications include engines, driveshaft, pumps, wheels, any rotating compoment-you name it.
The device greatly reduces vibration and its subsequent harmful effects. "Vibration will kill about anything out there...engine bearing components, shocks, wheels, tires. The vibration is what you see in the mirrors, feel in your fingers, your back, your feet. That same vibration is killing your bike," says Chris. "With Balance Masters®, we're getting rid of ultra-sonic vibration, the high pitched range of vibration which if allowed to come in contact with two pieces of material without a lubricant will weld the pieces together. The intent is to balance out the engine assembly, in other words take the vibration off the bearings which cause them to wear. The frictional wear also affects the oil between those two surfaces, heat being the enemy. If you take the vibration out you run smoother and cooler and everything lasts longer.
"The Harleys came into the picture through the truck people who had bikes. They liked how the product worked on their rigs and wanted to try it on their motorcycles. In 1988, we started applying the technology to engine flywheels after people asked what was the ultimate we could do for internal balancing. We pulled out a set of flywheels, and found we had room to directly machine the counter-balancing device into the side of one of the wheels. The liquid Quick Silver contained in the tubing seeks the correct balance for the moving part; if it senses something pulling one way, it will automatically concentrate more of its mass to the other side and pull it back to the center. The operating principle is for every action, there's an equal and opposite reaction, simple high school physics.
"We even balance clutches which people thought you couldn't do. Most of the vibration coming out of a bike is from the clutch as a result of its weight sticking out at the end of a shaft. The vibration is transmitted through the clutch into the transmission, into the frame, through the whole system. To get rid of the vibration is to extend the life of the bike and as a secondary benefit you take the vibration out of the rider. Not all bikes will experience the same reduction of vibration. But our device will get rid of the ultra-sonic range, an improvement which the rider should also notice in vibration transmitted to his body in addition to the mechanical benefits," says Chris.
How does this differ from harmonic balancing? "Harmonic balancing doesn't stop the source of the vibration but serves to dampen or mask it."
Where can Balance Masters® be applied? "Currently, we apply it to the engine on the flywheel, at the engine drive sprocket level, and on the clutch assemblies. In addition, Hallcraft Industries installs them on their custom motorcyle wheels. We also offer a bolt-on balancer that can be applied to wheels. You can save up to fifty percent in tire wear with the addition of the device."
What's the difference between a static flywheel balancing job offered by shops and Balance Masters®? "In static balancing, the mechanic drills out material from the flywheel to reach a maximum balance. Dynamic balance involves the same process except spinning the flywheel on a machine. The problem with spinning wheels is that whatever hole you drill, you're in balance for that particular speed at that particular point. The minute you drill a second hole, you're out of balance for the first," says Chris.
"Our device when located on the flywheel, located in the heart of the engine where all the bad stuff is generated, removes up to eighty percent of the vibration at all speeds."
What about applications to a brand new engine? Should you wait until the break-in time is completed? "There's a reason they call it a break-in time. Even the factory balancer stops around 500 rpm, while the engine idles at 900, not what the engine experiences in real world operation. In addition, a new motor is tight, and grinding metal right off the bat. The sooner you can install the Balancer the better, so that you're bringing the engine in, not breaking it in."
The Balance Masters® device will work on any bike Pan, Shovel, Evo, rubbermount, hard-tail. Again, it's an active system, designed to work while in use and which adjusts to whatever environment. Logically, whenever a customer plans an engine rebuild, the installation of a Balance Masters® system should be as mandatory as installing new piston rings.
How is the process handled? "The set oi flywheels can be
shipped to us. There's no need to split the wheels as we
have a special tool to hold it, so there's no down time putting
the wheels back together and truing them. We machine the
flywheels on our lathes, embed the balancer, seal it up and
epoxy it in, and send it back. You can figure on a 48 hour
The cost? Would you believe less than $250? Of course, a shop can add their processing/installation fee to that amount. Contact Balance Masters® at (800) 786-8324.
Balance Masters® can smooth things
out between you and your H-D.
Anyone who has ever ridden an unbalanced Harley-Davidson motorcycle knows the "Bad Vibes" phrase could have been coined by a disgruntled Harley-Davidson owner! These powerful, but inherently vibration-prone V-Twins (fork and blade rod arrangement on a single crankpin) can create a degree of vibration that subjects the rider of the bike to a level of discomfort few other motorcycle riders experience.
Harley experts know they can eliminate a fair amount of
these vibrations with close tolerance engine balancing,
but this extra effort and work can be expensive. Yet, if
they don't take the time to do a balance procedure, they
also know the motor may not last as long as it should.
Additionally, they may be losing five to seven percent of
the power potential of the motor.
Sun-Tech Innovations has developed a solution to this common and traditional problem for motor builders of any Harley-Davidson motor. Bad vibes can be caused by inadequate factory balancing, torsional vibrations, and all the other factors that try to shake apart any internal combustion powerplant (reciprocating or otherwise) as it runs.
It is important to remember that a Harley-Davidson, as
well as any other motorcycle, faces accumulated
imbalance from the engine, clutch and jackshafts (if they
have them), and, of course, from both wheels. In reality,
it is the total amount of imbalance a rider feels that must
be corrected to eliminate the problem!
A possible answer is this patented "Active Engine
Balancing" technology line of products for the wheels as
well as the clutch and the flywheel. These "Balance Masters®" are permanently installed in the motor, or on the motorcycle. They contain a liquid metal balancing agent that uses the centrifugal motion of the engine to find the optimum point on the rotating mass and adjusts it to maintain it in as perfect balance as man can make it!
Other devices, with solid metal balls or silicone as a balancing agent, have been tried (on external balancing devices). Both of these methods simply will not work, because of the influences of friction and changing temperatures. Sun-Tech Innovations' "Balance Master" is the first internal balancing system that balances a running engine actively. It adjusts to the motor as the dynamics of motion affect it. Piston or ring wear, which actually changes engine balance, will not affect a Balance Masters®-equipped engine. Neither will clutch wear, nor the changing position of clutch friction plates. Since the system is active, it is always in balance!
Installation is simple. If you want to place a balance master ring into your flywheel, you send your flywheel (the drive side) to Sun Tech Innovations, and the people there modify it by cutting a groove 0.438-inch deep x 0.380-inch wide in the flywheel. This is where they install the Balance Masters® device, which is permanently attached with a special high-temperature epoxy.
After installing your Balance Masters®-equipped flywheel
(or compensator, if you do not want to take your engine
completely apart), do not add external weights to the
components or add heavy metal to the flywheels. No
other balancing device(s) should be added to the
crankshaft oil either side-it will negate the function of the
Balance Master and cause problems. On a "Hot Bike"
engine, you may want to match the pistons and ring
assembly weights. On a stock engine, don't even bother doing that! Just assemble your engine with the Balance Masters®-modified flywheel, or just add a compensator, and forget it.
What about the other rotating parts on your bike-the clutch and both wheels? Sun-Tech Innovations hasn't forgotten them! It has created a series of balancing devices to fit virtually any Harley-Davidson model. Wheels, compensators, clutches, you name it-Balance Masters® probably has the application.
How good is this system? Drag racing legend Don "The Snake" Prudhomme installed one on his "Custom Chrome" high-performance Harley, and was more than just a little pleased. He also uses Sun-Tech Innovations Balance Masters® on his top fuel dragster to balance all four tires for runs at over 300 mph!
The flywheels you see here belong to Brad Lackey, ex-world champion motocrosser from the 1970s and 1980s, and one of the most knowledgeable Harley owners you will find. All engine work was done by Jacques Ellis, a highly regarded Harley tuner who has prepared several Bonneville Salt Lake Harley bikes to run in the magic 200-mph range; Ellis is installing them in Brad's bike now.
(After a break-in period, we will run the bike with vibration analysis instruments and get back to you with the results. Look for a report of this installation, plus actual instrumented road test data about the Sun-Tech Innovations Balance Master, in a future article.)
But how is the seat-of-the-pants feeling after installation?
Of the people who have tried them, we have received
everything from rave reviews to a simple "It's better now!"
The bottom line: You have to try them to understand just
how well they work. A simple installation and a few hours
in the saddle will tell you what a difference they make
on your bike.
If you don't like them, remove them and return them in good condition to Sun-Tech Innovations for a full refund. Sun-Tech knows its product is good, and that's why the company guarantees that it will perform. With a guarantee like that, you have nothing to lose-except a bunch of bad vibes you don't want anyway!
P.O. Box 9154
Canoga Park, CA 91309
Having a balanced motor is as important as having balanced tires on your car. Have you ever driven a car or truck with an out of balance tire? If so, you'll most likely remember how the vehicle shook and vibrated, but once you had the offending wheel balanced things smoothed out nicely. Well, the same holds true for engines. If it's out of balance it will shake and vibrate more than necessary. Furthermore, if you modify your motor's internal components such as installing different pistons, rods or stroker flywheels, your motor will need to be balanced again. But it is not as easy as having your wheels balanced when you change your tires. Balance Masters® set out to change that problem.
There are three basic methods of balancing a motor: static, dynamic and active. Static balancing is the old school method done by weighing each part and mathematically calculating where to remove weight from the flywheels by drilling holes in them. Dynamic balancing is achieved by installing the flywheel assembly on a computer-operated machine and spun between 200 rpm and 500 rpm (similar to a computer wheel balancer). The machine tells you where to drill the flywheel and how much material to remove. The final method is active balancing.
Active balancing embeds a small amount of Quick Silver inside one of the flywheels. It works on Newton's theory of relativity (for every action there is an equal and opposite reaction) and as the crankshaft spins the Quick Silver automatically moves to the light side to counteract the action generated by the heavy side of the flywheel.
Static or dynamically balancing a set of flywheels is similar to balancing a tire and wheel only instead of adding weight to the light side, you normally remove weight from the heavy side by drilling holes in it. Balance Masters® adds weight to your flywheels in the form of Quick Silver. In the next few pages, we will show you how it's done.
1. Chris Gamble, the driving force behind Balance Masters®, placed our flywheels on the workbench and stamped an ID number and the Balance Masters® patent number on the pinion side. This ID number can be used to identify the date they were done and which technician performed the process.
2. Next, the flywheels were mounted to a special fixture on a lathe. Then Chris wrapped a custom blanket around them to hold the rods in place and protect the assembly during the machining process.
3. Chris machined a groove into the pinion side. This is where the Quick Silver tube will be potted in.
4. The next step is to clean the machined groove thoroughly.
5. Chris mixes a small batch of specially-formulated epoxy resin and pours a thin layer into the groove.
6. This is the meat of the subject. What appears to be an O-ring is actually a hollow tube with a precise amount of Quick Silver inside. The Quick Silver moves freely in the tube so it can counter balance the motor's pulses.The Quick Silver tube is placed into the groove and seated into the first layer of resin.
7. A second layer of resin is poured into the grove covering the Quick Silver tube and cured under heat lamps for 24 hours.
8. Here is the final product ready to be packaged and shipped.
SUNTECH INNOVATIONS BALANCER
Several years ago, I tried one of Suntech's engine sprocket-mounted balancers. They are simple devices, basically a steel disc with a Quick Silver-filled ring on the outside edge. When the motorcycle is running, engine imbalances force the Quick Silver to the point in the ring where it needs to be to counter the imbalance, thereby reducing vibrations. Installation on my Sportster took less than an hour; the balancer just bolts to the face of the motor sprocket. I found that the vibration reduction effect was small but definitely noticeable. Suntech Innovations also sells active balancers for clutches, wheels, and even flywheels, but I haven't tried any of those myself.
These Sun-Tech balancers also helped lose some
the vibrations from the drivetrain.
Balance Masters® by Sun-Tech
I'll have to admit up front that I've been skeptical of any bolt-on product being able to reduce vibration in a V-twin motorcycle to an appreciable degree. So when a friend of mine mentioned he'd bought a Balance Masters® for his bike-and was very pleased with it- I wanted to know more.
John Peano loves his '83 Shovel head. He has a couple of other bikes, but the '83 is his touring bike. The belt drive and late model oil control kit make it a low maintenance bike-the major drawback is a trade-off between cruising speed and comfort. At 70 or 75 mph the bike was a real shaker; 55-60 works much better. John had tried the usual approaches to remedy the problem, but the belt final drive limited his ability to change final drive ratio. So he researched tires and learned that Avon made a tire with a larger diameter than the Metzelers he was running- larger by about 6 inches. That helped him lower the revs at highway speeds slightly.
When John had a motor rebuilt a year or so ago, he also had it balanced. But that didn't seem to help with smoothness at the rpm range he needed. Other than a mild hydraulic cam, the motor is stock. He had tried changing the motor sprocket gearing, going from 24 to a 25 tooth sprocket, but that proved too tall. His goal of achieving a 75 mph cruise remained elusive and he bought the Balance Masters® more out of frustration than anything else.
After installation John said he could tell the difference on the way to the expressway for the trial run. Seat-of-the-pants feel told him it was smoother. A longer ride confirmed that the Shovel was running smoother at a higher rpm, allowing him to raise his cruising speed in 4th gear. He can now run at 75 mph without the killer vibration he had been unable to deal with any other way.
Sun Tech, (the company behind Balance Masters®,) has been selling vibration reducing devices for years. They've been making products for over-the-highway truck operators, offering a rim mounted device that actively balances tires for the life of the wheel. Motorcycle products include flywheel balancing systems, sprocket shaft and clutch hub installations.
The company's web site includes many testimonial letters. One of those letters is from a person known and respected at IronWorks, Bill Mallinchock of Edge Cylinder. Bill has been using Balance Master products for 15 years and says the technology goes back to the aircraft industry of the early '50s, what Bill termed "viscous balancing." As a serious engine builder, Bill has gone farther than just using a compensator sprocket from Balance Masters®. He has them embed their Quick Silver tube technology in the flywheels of his big inch drag bike and other street motors he builds. Bill says the difference is amazing, and not just on a touring motor but especially on a big inch motor. According to Bill, Balance Masters® bring a lot of experience dealing with vibration to the motorcycle marketplace.
To learn more about their motorcycle related parts, check out their web site or call them.-Eddie Larson
"Master! Enemy Vibes attacking! What are your orders?"
"Quick Silver, stand-by to redistribute our forces. Check integrity of the inner seals. What is our spin pattern?"
"Outer ring idling at 3700 rotations, surges up to 4400, Master. Our propulsion unit's internal temperatures are rising rapidly. It will be ready for full power in 58 seconds."
"Activate Quick Silver. Report torque fluctuations."
"Sir! RPM's are coming in too fast! They're shaking the ship's frame!"
"Maintain balance! Damage Control, how are the main engine bearings taking the strain?"
"Only minor friction, Master. Lubrication temperature is still low, but vibration threat is minimal."
"Well done, Quick Silver! Set for full power"
"Rotations 5300 and holding. Tracking reports 10 degrees longitudinal wobble of the ship. Quick Silver is shielding the propulsion shaft from gyroscopic pressures, Sir."
"Good. Launch mode! Countdown begin... NOW!"
"Rotations 5900 ... 6000... 61... 62. Flight speed! Lift-off... Oh, no! We're hit! We're hit! The Vibes hit us with a tip strike! Major prop imbalance! This ship's gonna self-destruct...!"
"Maximum gravity shift, Quick Silver! Continue the launch!"
"Y-yes, Master. Reaching orbit trajectory... we're... we're doing it! We're climbing out of danger! Vibration attack is under control! Balance Master, you have saved our ship...!"
The cheering fades out as the camera pans outward from the spinning disk mounted beneath the propeller bolts of your ultralight airplane. The engine comes into view running smoothly followed by a swift scan along the fuselage and wings to focus finally on your own blissfully happy face admiring the view as you climb higher into the blue sky.
The final scene shows you back on the ground, reaching out with quivering fingers to touch a broken tip of your propeller, whispering, "Must've hit the grass... on take-off, probably. Guess I let the nose drop too far. I didn't even know! It should have shaken the whole plane to pieces and I didn't even know. Only the Balance Master could have saved me..."
Cut! So ends another exciting episode of "Balance Masters®: The Movie!" Well, ah, actually there isn't any movie about Chris Gamble's innovations yet. But there could be, some day. The way this guy is going, anything is possible.
Sun-Tech Innovations is Chris Gamble's company that produces the Balance Master. If you haven't guessed what the Master is by now, then re-read the script above. Okay, since you're going to peek ahead anyway then you might as well be told.
The Balance Master is a dynamically active counter-balancing mechanism which, when fitted to a spinning part, eliminates up to 80% of destructive ultra-sonic vibrational resonance. Friction between surfaces is thereby reduced, helping machinery to run cooler, smoother and last longer. It consists of a ring of liquid Quick Silver inside layers of flexible tube sealed within a steel shell. The outside is coated with black epoxy baked on at high temperatures. Applications range from aircraft propellers and turbines to motorcycle wheels, truck tires, clutch assemblies, flywheels and just about anything else that spins. Miniature versions have even been successfully tested on computer hard-drives.
Two principles of physics are involved in the Balance Master's operation. One is centrifugal force, which makes the Quick Silver 'heavier' and more effective the faster it spins. The other is Newton's Third Law of Motion, which states that for every action there must be an equal and opposite reaction. The Quick Silver automatically shifts its center of mass in the ring to compensate on the opposite side of any imbalance.
Quick Silver occurs naturally in a liquid state, because it will not easily combine with anything else. It is the only frictionless mineral liquid known to man so 'slick' with such a high degree of surface tension that it will not even stick to glass. Nor will it boil or freeze in conditions likely to be encountered by operating machinery. Since the Quick Silver cannot stick to the inside of the Balance Master's tubing, there is no friction to wear the unit out. Instead, it is free to instantly shift its center of gravity within its own mass to perfectly balance whatever force is acting on it.
Chris "discovered" the potential of Quick Silver as a centrifugal balancing agent after his wife's washing machine vibrated itself off the back porch and fell with a crash, spilling clothes everywhere. First, after cleaning up the mess, he tried to figure a way to keep lead in a liquid state long enough to re-balance the flywheel of the cantankerous machine. Eventually, he learned that Quick Silver not only stays liquid naturally but also happens to be a third heavier than the same volume of lead.
The idea of dynamic (fluid) balancing had been used as far back as 1908 by German scientists and improved by Americans in the early 1940's using steel ball-bearings in tubes filled with oil. So Chris, being an amateur-inventor familiar with such things, took the idea one step further by creating the Balance Master using liquid Quick Silver. It is now another of his 15 widely-diversified patented inventions.
Chris started Sun-Tech Innovations in 1984 as a way of helping others develop their own marketable ideas. Often he gets calls asking, "Can you do this...?" His standard answer is, "No! But I'll help you find ways to do it yourself!" He continues to practice his own advice by creating new products such as the Balance Master.
Ultralight aircraft use of Balance Masters® began in 1979 when Chris gave some sample parts to a couple of instructors to try on their propellers. The pilots weren't sure they could notice much difference at first. Then after a series of practice landings and take-offs, a student found he had somehow chipped off a quarter of an inch from the tip of one propeller blade without noticing any excess vibration! (That's where the idea for the fictitious script at the start of this article came from. It actually happened.)
The propeller Balance Master is a disk measuring less than 7 inches in diameter that fits behind the propeller. To install, simply remove the prop, slip the disk over the bolts with the flat side toward the prop, then replace the propeller and torque the bolts. After tracking the tips, run the engine at full RPM for one minute, then torque the bolts one more time and re-check the tip tracking. You are now ready to fly with an active propeller balancing system.
After refining the propeller balancers, Chris expanded further by designing Balance Masters® to fit on flywheels and starters of Rotax and Cayunna (now 2si) engines. Vibration of some two-stroke engines has been reduced by as much as 50% when both balancers are installed. The devices weigh about 4 oz. and measure less than 5 inches in diameter.
Installation takes about 30 minutes using ordinary hand tools.
Cost is $70 for the propeller Balance Master. Rotax engine Balance Masters® are $64 for the 277, 532 or 582 and $90 to fit the 377, 447 or 503 engines. They can be ordered directly from Sun-Tech's Northridge, California factory by calling 1-800-786-8324. Chris can be reached by e-mail at firstname.lastname@example.org, or you can check out his website at www:BalanceMasters.com.
Hasta hace poco, la unica forma que tenia el piloto de ultraligero de reducir a un minimo tolerable el nivel de vibraciones era equilibrar la helice a menudo, ajustar su tracking y cuidar las gomas de los silent-blocks. Estos cuidados basicos no siempre son garantia de un bajo nivel de vibraciones, porque el motor mismo, debido a su propio funcionamiento, es siempre una fuente de vibraciones, y por otra parte la helice casi nunca esta perfectamente equilibrada. Tampoco podemos evitar los pequenos desequilibrios debidos a defectos de fabricacion o de diseno, a los que se anaden los causados por el desgaste de todo el conjunto motopropulsor. Cada una de las piezas que giran o se desplazan es una fuente potencial de vibracion, y a ello hay que anadir el efecto de las resonancias, es decir, las vibraciones resultantes de la interacci6n entre distintas fuentes de vibracion. Los ultraligeros son especialmente sensibles a este fen6meno, debido a la elasticidad y ligereza de su estructura.
Un perfecto equilibrado estatico no es suflciente para eliminar las vibraciones, y los procedimientos de equilibrado dinamico raramente estan al alcance de las posibilidades de un aficionado. El piloto cuidadoso con su avion intenta ajustar las revoluciones del motor que permitan el funcionamiento mas suave durante el vuelo, aunque ello suponga una limitaci6n mas al pilotaje. Muy a menudo el piloto no puede utilizar el ajuste de motor deseado porque produce vibraciones, y debe contentarse con otro que no se adapta tan bien a las necesidades del vuelo.
Los mismos problemas de vibraciones que sufrimos en los ultraligeros aparecen tambien en aviacion comercial, automocion y maquinaria en general, y se combaten desde hace anos con amortiguadores dinamicos de mercurio. El sistema consiste en un plato metalico con mercurio en el interior que se acopla al eje de giro que deseamos equilibrar, en nuestro caso el eje de la reductora, el del ciguenal o ambos. El mercurio se desplaza por el interior del plato debido al efecto de la fuerza centrfuga y de las mismas vibraciones, situandose en la posici6n id6nea para actuar de contrapeso equilibrador. Al variar el ajuste de gases, o aparecer una nueva fuente de desequilibrio (por un desperfecto en la helice, por ejemplo) el mercurio se vuelve a distribuir adaptandose a la nueva situaci6n, por eso calificamos de dinamicos a este tipo de equilibradores.
Por fin una empresa americana ha decidido fabricar este tipo de equilibradores pensando en los ultraligeros. Su nombre comercial, Balance Masters®, engloba a los tres modelos que fabrican, uno para la helice y dos distintos para el ciguerial, segun se instale en el Rotax 582 o en los 377, 447 y 503. La instalaci6n es rapida y facil, y no se necesita ningun material adicional. En los gralicos puede Balance apreciarse la disposici6n Master para de los Balance Masters® en Rotax 582 el motor. En el caso de los Rotax 377, 447 y 503 se trata simplemente de una polea de ventilador que sustituye a la original, y en el 582 es un plato que s adapta al sistema de arranque. La instalacion en la helice es todavia mas facil, basta con colocar el Balance Masters entre la helice y el plato del motor. El grosor del plato es minimo, de forma que podemos aprovechar los mismos tornillos.
La instalaci6n de los dos sistemas distintos, el de helice y el de ciguenal, es independiente, podemos instalar sólo uno de ellos, pero conseguiremos la maxima eficacia instalando los dos.
Balance Masters® es Ull dispositivo que ha demo.strado su eficacia a lo largo de muchas horas de funcionamiento, y no sólo aumenta el confort en vuelo sino que alarga la vida del motor y de la estructura. Para mas informacion llamar al distribuidor exclusivo de Balance Masters® para Espana, Aeroplans Blaus, tel. 93 871 19 05.
2015© Balance Masters®
www.balancemasters.com | Sun-Tech Innovations LLC
P.O. Box 9154, Canoga Park, CA 91309
Tel: (818) 882-8431 Toll Free (800)786-8324