hunter engineering company - · pdf filehunter engineering company ... smartweight reviewed...

HUNTER HUNTER Engineering CompanyEngineering Company

New Wheel Balancing MethodNew Wheel Balancing MethodBased In Absolute Force CalculationsBased In Absolute Force Calculations

Eliminating Significant Operating Costs and Improving the DynamiEliminating Significant Operating Costs and Improving the Dynamic Balancec Balanceby Revisiting Wheel Balancing Basicsby Revisiting Wheel Balancing Basics

““This Changes EverythingThis Changes Everything…….Except the Same Smooth Ride.Except the Same Smooth Ride””

What is SmartWeight™?

• SmartWeight is a very basic yet revolutionary and patented concept which changes the way wheels are balanced.

• For almost 30 years, all balancers have calculated imbalance the same way. SmartWeight is a completely new wheel balancing method. It is not merely based on correction weight reduction to ‘zeroes’, but is based in absolute force correction and the optimal use of correction weight to eliminate vibration.

• SmartWeight reduces the significant operatingexpense of wasted correction weight and theunnecessary labor time spent attaching weightwhich is not needed. It also improvesbalancing results and solves vibration problems.This sounds impossible, but it can be provenon any vehicle. Try it!

• SmartWeight is the first balancing business casewhich exclusively reduces balancing service costsand increases profit margins. This new capability isunlike any wheel balancer ever introduced.

SmartWeight Reviewed by OEMs and Tire Manufacturers

Rockleigh, NJ* Volvo North America

Germany & North America* Volkswagen-Audi

Torrence, CA* Toyota USA

Cypress, CA* Toyo Tires USA

Detroit, MI* Roush Industries

Torrence, CA* Nissan USA

Akron, OH* Micro Poise / Akron Standard-ITW

Greeneville, SC* Michelin North America

Germany & North America * Mercedes Benz

Irvine, CA* Mazda North America Operations

Fountain Valley* Hyundai Motor America

Van Buren Twp, MI* HUMMER/Ricardo Detroit Tech Campus, Inc.

Torrence, CA* Honda America Motor Company

Akron, OH* Goodyear Tire & Rubber Company

Milford Proving Grounds* General Motors Corporation

Detroit, MI* Ford Motor Company

Detroit, MI* Daimler-Chrysler AG

Findley, OH* Cooper Tire Company

Akron, OH and Nashville, TN* Bridgestone Firestone USA

Montvale, NJ* BMW North America

Current Wheel Balancing Issues

Traditional computerized “dynamic” wheel balancing has remained basically unchanged for 30 years. To understand why it has become outdated, take a look at the type of wheels and tires that existed when computerized “dynamic”wheel balancers were introduced.

The average types of wheels balanced in the 70The average types of wheels balanced in the 70’’s and 80s and 80’’s were:s were:• 13”-15” diameter and 5.0”-7.0” wide.• Virtually all balanced with clip-weight wheel flange correction.• All about the same average tire size and similar weight.• Balanced with uncoated lead correction weight with very low cost.

Wheel Balancing – Yesterday

Wheel Balancing – Today

……..today the types of tire and wheel applications have proliferat..today the types of tire and wheel applications have proliferated.ed.• Wheels diameters range from 13” to 30”. The wheel widths now vary from

5.0” to over 15” wide.• Tire sizes and assembly weight varies dramatically and are now heavier

which increases the amount of balance weight required.• Flangeless wheel designs are proliferating. Rim flanges are no longer used

for correction weight, thus creating smaller distances apart from each weight which dramatically increases the amount of weight when making ‘couple’balancing correction.

Tires and wheels today have changed dramatically, and so have the technical requirements required to balance them properly. Until SmartWeight, the same dynamic balancing calculations have been used in balancers which were introduced in the 70’s and 80’s when these types of wheels did not exist.

Wheel Balancing – Today

When balanced, the average vehicle containsat least eight wheel weights.

• Many styles of clip-weight and expensive adhesive tape weights continue to proliferate due to changing wheel designs and minimal industry standardization.

• Cost of wheel weights are quickly becoming much more expensive. Lead material costs have increased +50% since mid-2004.

• Lead usage is quickly becoming restricted and the alternative materials such as Zinc, steel and sintered polymers are much more costly to do the same job.

Current Wheel Balancing Issues

The average tire dealer:The average tire dealer:• Uses well over 2000 pounds of balance weight per year.• Spends well over $10,000.00 on balance weight per year.• Is unable to adjust quickly to the rising costs and therefore the cost

increases are eroding profit margins.• Often adds the price of a wheel balance into the cost of the tire

sale, regardless of tire-wheel application..

Wheel Balancing Facts

Circle-Bar Tire Service

Wheel Balancing Facts

A wheel balancer operator:A wheel balancer operator:• Often wastes materials by using too much correction weight.• Often wastes time by encountering repeated check spins in order to

get the balanced wheel to “zero out”.• Often risks comebacks due to incorrect assumptions created by the

balancer software which hides residual imbalance when the balancer reads “zero”.

• Often finds ways to defeat the dynamic balancing functions and unknowingly performs a poor service by static balancing alone.

Current Wheel Balancing IssuesChanging Incorrect Assumptions (Understanding SmartWeight)

Correction Weight Commonly ConfusedCorrection Weight Commonly Confusedwith Imbalance Forceswith Imbalance Forces

Many incorrectly consider imbalance in terms of correction weight which is independent of its location on the wheel, instead of the actual static and couple forces. As the forces remain constant, the size of the imbalance weight changes as the weight locations are moved to different distances and diameters.

Static and couple forces are viewedwith bar graphs. The dotted red lines are

the threshold at which the forceswill cause a vibration.


Static Correction Weight & Static Force Its important to understand that small changes in weight make largeand significant changes in the static force. As a result, small amountsof static correction weight greatly affect the level of vibration felt insidethe vehicle.

The two forces of the imbalanceare constant if the…

…….. correction weight of the imbalance changesin distance and/or diameter by relocating

them to a new position on the wheel.

Changing Incorrect Assumptions (Understanding SmartWeight)


Couple Correction Weight & Couple Force Unlike static correction weight, when couple correction weight is placedclose together, large changes in couple weight create small changes in thecouple force. As a result, large amounts of couple correction weight placedclose together (equal sized weights placed 180º apart) have little effect onthe level of vibration felt inside the vehicle.

The two forces of the imbalanceare constant as the…

…….. correction weight of the imbalance changesin distance and/or diameter.


Before SmartWeight, all computer balancer’s used the logic of “fixed correction weight rounding” which was designed to eliminate all static and couple forces regardless of the force’s magnitude. This is not wrong, however because the rounding was fixed and often the weights are now closer together, large amounts of ‘couple’ correction weight are often unnecessarily added to the wheel when the couple force is insignificant and will not cause a vibration.

The logic of “fixed correction weight rounding”and treating both forces with equal importanceresults in lost labor time and wasted wheel weightwhile it attempts to eliminate inconsequential forcesthat are not great enough to cause a vibrationwhen placed on a vehicle.


Current Wheel Balancing IssuesWheel Balancing – Current Problems

Shown in the two examples below, the same wheel balanced one time shows two different weight readings based on the varying weight locations chosen.

The balancer display shows ‘zero’ weight at the clip-weight locations. When the weight locations are changed to adhesive tape-on weight locations much closer together, the balancer then recalculates huge amounts of weight required. This is a “riddle” that frustrates many operators, wastes weight and also makes the balancerunnecessarily ‘hyper-sensitive” to tape-weight use.

Assuming the wheel on the left is properly balanced with clip-weight, then why does the same wheel on the right require two additional weights which are approximately equal and 180º apart ? The answer is the traditional balancing weight shown is not needed, a waste of labor time and a waste of correction weight.

Traditional Wheel Balancing Issues

The balancer showing ‘zero’ weight required is traditional two plane weight ‘rounding’

and hiding residual imbalance.

The same balance shows hidden residual static weight which is too high and can cause

vehicle vibration and NVH complaints.

Fixed Weight Rounding Assigned to Each Balancer PlaneFixed Weight Rounding Assigned to Each Balancer PlaneCan Hide Excessive Residual Static ImbalanceCan Hide Excessive Residual Static Imbalance

When correction weights used to balance each plane are used near thesame phase angle and the balance correction is rounded to “zero”,

a blinded static residual error may remain hiddenand create a vibration on the vehicle.

Residual Dynamic Display After Correction Residual Static Display After Same Correction

Traditional Correction Weight vs. Force Limitations

Wheel balancers have measured the imbalance forces of the wheel since the 1970’s, but have not utilized them efficiently because:

–– Limitation #1 Limitation #1 -- Wheel balancers before SmartWeight placed no limits on the forces of couple (shimmy) and static (shake).No threshold has been placed on the actual imbalance forces independently of each other measured in the tire and wheel.

–– Limitation #2Limitation #2 -- Equal importance has been improperly placed on couple and static imbalance forces. Equal importance is not necessary. Example: All vehicles tolerate more than a 4:1 ratio of couple to static correction weight (based on reference wheel of 15”x6” wheel atclip-weight locations) without vibration complaints.

–– Limitation #3 Limitation #3 -- All wheel balancers before SmartWeight have applied a fixed weight tolerance to the correction weight regardless of the weight location chosen; instead of placing limits on the imbalance forces and adjusting the weight tolerance as needed.

New New ““CorrectedCorrected”” Logic of SmartWeightLogic of SmartWeight

1. This new method of balancing computes correction weight based on the absolute static (shake) and absolute couple (shimmy) forces independently of each other.

2. This new method of balancing computes independent force limits based on the amount of imbalance forces which are known to induce excessive vibration on the vehicle. The force limits are set below the most sensitive guidelines as specified by the vehicle manufacturers.

What is SmartWeight™ Balancing?

3. In addition to traditional correction weight rounding, allSmartWeight force limits and thresholds are accessible and programmable, however the preset factory default works wellon even the most sensitive vehicles.

4. Force limits can be adjusted up or down automatically during thespin and are based on the mass (inertia) of the tire/wheel during the balance spin. This eliminates having to artificially raise correction weight rounding and performs a better dynamic correction. (Excessive residual static error is commonly encountered in truck wheel balancing due to correction weight rounding)

5. Using the default settings of SmartWeight, over 30% of wheels balanced will shift from a two plane dynamic correction to a single plane dynamic correction. This saves time while audits and reduces the couple force while optimizing the complete cancellation of static force.


The New The New ““CorrectedCorrected”” Logic of SmartWeightLogic of SmartWeight

• SmartWeight audits each vibration force in the same manner the vehicle manufacturers calculate the individual effects and thresholds of static and couple forces.

• SmartWeight correction weight reduces the couple force and virtuallyeliminates the static force. It does not merely display correction weight which is designed to cancel both forces regardless of magnitude and importance to vehicle vibration.

• Traditional fixed weight rounding is obsolete and use of correction weightalone ignores the differing effects on static and couple forces. SmartWeight adjusts the weight rounding and amount based to reduce or eliminate each force independently.

• A simple way to explain SmartWeight is "if the two balance forces which cause a vibration are not exceeded, then the correction weight is not needed.”



This is the first computerized offThis is the first computerized off--car balancercar balancerintroduced which displays a bar graph representation of introduced which displays a bar graph representation of actual static and couple forces independent of correction actual static and couple forces independent of correction

weight dimension entry.weight dimension entry.

Traditional Balancing vs. SmartWeight™ Balancing

Traditional DisplaysSmartWeight™ Display

Fixed correction weight “rounding” to “zero” and the fixed “round-off” mode are no longer needed with SmartWeight.


Traditional Displays SmartWeight™ Displays

Assuming the wheel balanced to “zero” with clip-weights as shown, why does the same balance with tape-on weight require two additional weights when the dimensions are changed? This illustrates the problem with 30 year old traditional balancing methods used on today’s wheels.In SmartWeight mode with the wheel balanced in clip-weight mode, it is also balanced in the tape-weight mode because the forces have remain unchanged and are below tolerance.


Current Wheel Balancing IssuesSmartWeight™ Balancing Limits

This setup screen shows the traditional Non-SmartWeight fixed ‘blind or rounding’ versus the SmartWeight method that no longer uses fixed values and correction weight alone. The actual forces are independently analyzed and correction weight is assigned to resolve each force individually.

Current Wheel Balancing IssuesSmartWeight™ Weight Savings

SmartWeight™ Balancing

• Significantly Save on Rising Wheel Weight Costs• Significantly Reduce Labor Costs

• Significantly Increase Balancer Ease of Use• Eliminate Short Cuts that Affect Balance Quality

• Perform a Better Overall Balance

SmartWeight™ is the Smarter Way to Balance Wheels

HUNTER Engineering Company11250 Hunter Drive

Bridgeton, MO 63044-2391 USA314.731.0000

www.weightsaver.comwww.hunter.com

hunter engineering company - · pdf filehunter engineering company ... smartweight reviewed...

Documents