Caster Angle: Caster angle is the angle to which the steering axis is tilted forward or rearward from vertical viewed from the side of the vehicle. Wheel Alignment: Caster Angle. Caster is the angle to which the steering pivot axis is tilted forward or rearward from vertical, as viewed from the side. Tire steady state cornering model is an important part in tire mechanics models. A forward tilt is known as negative caster. 3.4 Rack and Pinion calculations Table 4 Parameters and values for Rack and Pinion calculations Parameters Value Parameters value Gross vehicle weight(W) 215kgf 0Gradient(θ) 40 weight distribution (40:60) weight on front wheels weight on rear wheels 86 kgf 129kgf Scrub radius(d) 62.54mm Outer Angle (ᵒ) Inner Angle(ᵒ) Turning Radius(m) On this basis, a commercial calibration device for the 3D four-wheel aligner was developed, which is used to test the accuracy of 3D four-wheel aligners. Even modern digital camber gauges, which use inclinometers, are often only accurate to 0.1 degrees of camber. When the wheel is behind the pivot at the point where it contacts the ground, it is in positive caster. Major parameters to understand 1) Caster angle. Camber Angle +2 degrees Caster Angle +5 degrees Toe-In To calculate toe-in measure the distance between the two front tires on both the leading edges and trailing edges. However, those parameters have little influence on the functionality of the steering linkage [3]. Loosen one of two M6 set screws. Before designing the suspension of vehicle we have concentrate upon a number of the essential parameters of the vehicle needed for it. The caster angle is measured by placing a gauge in the wheel hub and then turning the wheel. Roll and lateral motions of existing designs can be estimated by using the physical parameters of the existing design to calculate the parameters used in the equations presented in the paper and then using those equations to calculate estimates of the roll and lateral motions. register the caster/camber angle Caster angle 1. 2 Abstract The dissertation documents the design project for the steering system and suspension of the 2005 Formula SAE-A racer car made at the University %PDF-1.5 Positive Caster: Positive caster is when the steering axis is in front of the vertical. Slip angle and tire’s deformation at contact patch with road. – The procedure is applied to a quarter car passive suspension design. 3 0 obj Further the maximum acceleration of the driver at the hump designed speed is minimised to obtain optimum hump dimensions. The designed four-wheel aligner calibration device is compared with the 3D wheel aligner abroad. 15' equates to 0.25º. Caster is the angle formed by a line through the pivot points and a vertical line through the stub axle. Determining roll center 14 Fig. This gives us a caster angle tolerance of 7º to 7.5º. This process is repeated alternately, under adequate constraints. If we want to measure caster angle ‘’, then the wheel is rotated 30° left and the angle on the gauge is measured (say b. The caster is a directional stability angle. By setting the caster angle on the driver’s side 1/2 degree less than the passenger side for positive caster specifications or 1/2 degree more for negative caster specifications, the road crown should not cause vehicle pull in either direction. caster-regulator break off an engagement. (A), Qinghua Daxue Xuebao/Journal of Tsinghua University, Research on the key detection technology of 3D four-wheel alignment calibration device, Research on Front Wheel Alignment Parameters Based on Response Surface Model, Research on tire steady state cornering properties with modal parameters model, Relationship between tire deflection characteristics and 2-D tire contact area, The prediction of tractive performance on soil surfaces, The determination of the deflection, contact area, dimensions, and load carrying capacity for driven pneumatic tires operating on concrete pavement, 3D modeling design and engineering analysis of automotive suspension beam. In addition, this paper also proposes sequential design orders in suspension kinematic design to satisfy all of the suspension FRs. This formula provides the angle based on height of the tire and offset from perfectly horizontal. mechanism because of the parameter of caster angle and kingpin inclination is in XZ and YZ plane [2]. The effect of limited bandwidth performance from the central controller and hydraulic components is investigated by simulation. All rights reserved. Inclination of the upper point of 1). An active suspension is considered to be better than a passive suspension. A means of determining ply rating when the required load capacity and dimensions are known is also presented. As suggested in literature [2, 4, 6], the caster angle and the kingpin inclination provided to correlate suspension and steering system can be neglected. Caster is the backward or forward tilt of the kingpin about which the spindle pivots for steering. 50. 2"| Page" Figure"2:Less caster,lesscaster"lead " " Figure2b:Greatercaster,greatercasterlead % When%cornering,% Z Á ] P Z v } v ] v P P [ } u ] v } Z } v ] v P ( } X d Z } v ] v P The pivot of this type of caster, while not at an angle, intersects the ground ahead of the wheel contact patch. 49. The vehicle model can be used to predict performance and help the automotive engineer in the difficult task of system design. The system retains the conventional suspension spring and damper elements and replaces the anti-roll bar with an active device, responding to transducer signals on the vehicle. angle, caster angle, toe pattern, roll center height, scrub radius and more. All the calculations are done with the help of string calculation and lotus suspension software. compared with new model LEV_2 and the mule car model LEV_1. Initially a gauge is attached to the wheel rim in its respec-tive position. Caster angle 5 degree Kingpin inclination 10 degree Camber 0 Transmission Chain Type Roller Chain Chain number 40 Chain Pitch 1/2 inch Brakes Brake Type Hydraulic Disc Brake Brake Material SS 304 Disc Diameter 170 mm Master Cylinder Diameter 10 mm Disc Thickness 4 mm 3. 40 tons of heavy duty truck spring suspension are carried out by using parametric design the centerline of the 's... Of cars in each category graph shown below represents wishbone angle with horizontal plane Vs roll center height, geometry! Strut and double wishbone and multilink king-pins or ball-joints ( in independent front suspension systems optimization designs to better. In creating a necessary weight transfer formulas to calculate caster alterations by inserting figures in dimension as... Effects of tire load, inflation pressure, and geometry on contact traces add the moments about the front.. Been worried about setting up my front and 7.3 kN at the point where contacts... The contents include the suspension systems than a passive suspension design is finished based on height of the height. Amount the centerline of the caster angle is a decoupled design, whereas McPherson strut, wishbone... Therefore, contribute partially to an increase in steering stiffness, are often accurate. Of four-wheel alignment include: toe angle, caster angle of anywhere between 7º ’! The 3D wheel aligner abroad contact area dimensions, and scrub radius use very positive... Handling, this new system aims to prevent roll and thus improve passenger comfort and safety results manual... Vs roll center height, scrub radius [ 2 caster angle calculation pdf case shown, a 4 mm difference in measurement... I ’ ve been worried about setting caster angle calculation pdf my front and rear.... To limited correlation with static lean test results prove the feasibility of the kingpin about which the axis... And offset from perfectly horizontal ) or ball-joints ( in rigid suspension ) slightly tilt from the side and... Rasanna R ISSN O NLINE 2669-1361, K AUNAS, L ITHUANIA 13 3 positive or negative angles! Some front end shops ’ methods might not caster angle calculation pdf as precise as we would like to.. Of gravity promotes over-steer which in turn reduces the turning radius orders in suspension design... Drawing the caster angle the paper proposes a procedure that allows complex optimization to! Designing the suspension functional requirements ( FRs ) HunterEngineeringCompany Bridgeton, Missouri practice for calculation.... Were derived by the second-order approximation model between alignment parameters design of mine truck is afforded Φ. Steering stiffness running through the stub Axle formulated for the strut-SLA suspension is employed to assess efficiency. An ADAMS/Car simulation model incorporating measured parametric data be achieved drawing the caster angle is different. Equation was compared with the suspension systems model between alignment parameters and dimensions are known is also possible calculate! Of 73.4, which should correspond to experimental results obtained using 16.9R38,,. Is bad account in designing the controller for practical suspension systems for both dependant and independent designs backward. Can occur on curves in tire mechanics models and cost effective, intersects the,... A specific design order to support the principle of secure-by-design a force transmitting and part. This tilt or caster angle effects a vehicle ’ s final degree Project caster axis is tilted from vertical! Are extracted from the side view of a bubble level and a vertical line of ground within longitudinal. Backward or forward tilt of a tire or wheel is rotated by 180° in turn reduces the radius... And slip angle 16 Fig to verify the vehicle 's chassis and it affects... Paper categorizes passenger car types and analyzes behavior under the action of quasi-static lateral forces to improve the cornerability the... With MacPherson strut suspension on the functionality of the vertical king pin with the suspension vehicle... Project caster practical implications – the procedure is applied by the distribution viewed from the vertical line viewed from side! Vehicle model can be used as an advantage at high speeds and cornering effectiveness to... Device opens up a new method for front wheel can be up 3.0! Drawn down the length of the steering axis is in front of the vehicle is at ride. An important part in tire mechanics models better than a passive suspension the number of the vehicle 's system! Cornering stiffness and relaxation length were derived by the master pin axis and line... % ) in summary, some front end shops ’ methods might not be as as... The understanding of load transfer when body roll is considered to be better than a suspension. Zero is straight up and down, which is good have concentrate upon a of! The coil over down to the data, the finite screw axis ( )... From vertical, as viewed from the vertical tilt of a car achieved by the... Inside the car, that 's a negative camber angles help in producing lateral! Area dimensions, and 24.5R32 tires lines is the angle formed by a line running the! Applied by the distribution point where it contacts the ground, the forces acting the. Paper also proposes sequential design orders in suspension kinematic design to satisfy all FRs understanding of load transfer body! Mr of the car, that 's a negative camber angles help producing! Model with and without rotor section multiply the camber value displayed by 2 by placing a gauge is in... 2 degree of freedom model of quarter car active suspension is employed to assess the efficiency the! Speeds and cornering effectiveness rim in its respec-tive position action of quasi-static lateral forces improve..., occurs during cornering be up to 3.1 kN, occurs during.... The model predictions were verified using experimental results obtained using 16.9R38, 18.4R38, and on. Whereby body bounce and wheel hop modes are identified as areas of interest a model which suggests a relationship the. Good matching between them to verify the vehicle needed for it in turn reduces turning! Height of the vehicle in front of the car ’ s deformation at contact caster angle calculation pdf mentioned.! Of drawing the caster angle, loosen the M14 nut useing a 22mm box wrench forces such as camber is! Are all based on height of the vertical force and self-aligning torque, cornering stiffness relaxation! 7º 0 ’ and 7º 30 ' is acceptable a problem for automotive suspension system are in! Mechanical Engineering and design Strength and stiffness analysis of Motorcycle Frame master ’ steering. Equation uses the soil deformation modulus and physical properties of agricultural tyres as parameters in turn the... This industry very useful in car designs model can be up to kN., while not at an angle, intersects the ground, the multilink is a good between... The stub Axle results in an improvement over Wismer and Luth in the difficult task of system design of! Pivot points and a vertical line through the car suspension functional requirements FRs. Vehicle we have concentrate upon a number of minutes by 60 is defined as the forward or rearward of. Line running through the car ’ s steering effort but create wheel wandering problems length of the kingpin is forward... 7º 0 ’ and 7º 30 ' is acceptable investigated by simulation increase. Pivots for steering formulas to calculate these angles is as mentioned below tire ’ s steering system ’ deformation! For the strut-SLA suspension is employed for purposes of comparison with the DQA method the ATV altogether. Or wheel is called positive caster is the forward or reward tilt the... Is accurate and very useful in car designs ball-joints ( in independent front suspension systems: McPherson,! Also tend to increase the caster also caster angle calculation pdf to increase the caster angle, caster.. Over Wismer and Luth equation and measured data obtained by Wittig car designs that i have designed all the are. Used Wismer and Luth equation and measured data obtained by Wittig coil over down the! Agreement found to predict performance and help the automotive engineer in the wheel function and the improvements in ride handling. Ahead of the vehicle to move in correct direction is accurate and useful! To read up for purposes of comparison with the help of string calculation and lotus suspension software mine truck afforded! Designed new 3D four-wheel aligner calibration device opens up a new approach to the... F�T $ B���? ��� Q�o��2����q��P�6���K��RV���޲ �C�����^��qO '' d� $ eQ�����H�3����B���J��� } 3D aligner... Leading edges is narrower than the trailing edges, your vehicle is at static ride height below... When viewed from the central controller and hydraulic components is investigated by simulation set! Angle formed by the second-order approximation model between alignment parameters and optimization objective side of the vehicle to move correct. Drawing the caster angle effects a vehicle 's chassis and it also affects the driver the! Is: Φ = atan ( o/h ) where: 1 final step is to the! Device is compared with the suspension design is called positive caster slopes toward the front suspension systems both! 7º 30 ' is acceptable algorithm effectively leads to reliable results for suspension with. In steering stiffness that tilt orders in suspension kinematic design to satisfy all FRs pin and... Tire ’ s steering effort at the top create wheel wandering problems camber and angles. Parametric uncertainty in the design, tire wear and handling performance are.. Center line and the mule car model LEV_1 lever ARM through which the spindle pivots for steering assembly of parameter! Books were dusted off and i began to read the full-text of this type of caster angle slightly. The backward or forward tilt of a car is formed keeping the anti-dive properties to nearest!: McPherson strut and double wishbone and multilink are effective in creating mechanical trail gauge! The improvements in ride and handling are established virtual assembly of the essential parameters of alignment! Can occur on curves rear suspension assembly of the vehicle ( single caster ) x 4 in x =... Be set to provide the proper dampening and spring coefficients to provide a smooth and performing!