Dial Indicator Alignment Procedure The procedure for doing reverse dial indicator alignment is not a difficult one. There are several steps which need to be taken for a successful alignment job. Step 1 Familiarize with terms, techniques and procedure. *follow all safety rules and procedures Step 2 Learn about the machine you are aligning. 1. Visually check coupling, pipehangers, base bolts, coupling spacing etc. 2. Check for coupling & shaft run out. Step 3 Know the characteristics of your tool. Perform a Sag Check A sag check is a test that determines the amount an indicator bracket will sag at a given distance. How to perform a sag check: Clamp the brackets on a sturdy piece of pipe th e same distance they will be when placed on the equipment. Zero both indicators on top, then rotate to the bottom. The difference between the top and bottom reading i s the sag.
Sag will always have a negative value, so when allowing for sag on the vertical move always start start the dial indicator with a plus(+) reading. For example if you have .002" sag; when you zero your indicators on top put the needle on a +2 instead of zero to compensate for the sag.
Step 4 Prepare the machine. a. Remove all existing existing shims shims from under the feet feet -if old shims are to be used, clean them thoroughly. -always use minimum amount of shims. b. Clean the base thoroughly. -scrape and file away all rust, nicks, and burrs c. Examine the base bolts and holes. -retap if necessary -replace bolts if necessary Step 5 Clean mounting surface, file off nicks and burrs. b. Check indicators for sticking and loose needle. c. Aim indicator indicator stem stem directly toward center line of shaft. Step 6 Measurement -measure distance between the two i ndicators. -measure distance between indicator and front feet. -measure distance between front and back feet.
Step 7 Layout graph paper -mark indicator position -mark feet position. -remember to mark + and - signs (this eliminates confusion) example: graph layout
Step 8 Preliminary Horizontal Move
The horizontal move is the part of the al ignment process that aligns the shaft's centerlines from side to side. View the machine from the pump end, zero the indicators on the left, and then rotate and read on the right. Make sure that you always view the pump from the same direction in order for you to keep the left and right directions correct. There is no sag compensation on the horizontal move. For Example: the indicator on the pump reads -8 the indicator on the motor reads +10
The shafts are collinear at 1/2 the Total Indicator Reading. Using graph paper to illustrate the position. Under the indicator position mark the point that is 1/2 the indicator reading. (-4 for the pump and +5 for the motor) Connect these points and extend the line past the motors feet. This will show you how much you need to move the motor for horizontal alignment. These indicator readings mean that you need to move the motor: front foot .006" left back foot .007" left
You can avoid graphing the horizontal move by zeroing the i ndicators on the left and rotate them to right. Now turn the indicator needles half way to zero and begin to walk the motor into place by moving the farthest foot toward zero and then the nearest foot. Slowly walk the motor into place by alternating the moves until you obtain two zero indicator readings. Now begin the procedure for the vertical move. Be sure to check your equipment for sag and soft foot. Step 9 Check for Soft Foot Soft foot is a condition in which one of the feet does not sit flat on the base. The foot or the base may have been warped. When you tighten the bolt on the foot, the machinery will distort.
Parallel Soft Foot
Angular Soft Foot
How to check for Soft Foot 1. Move indicators to 12 o'clock position, depress indicators and then zero. 2. Loosen one base bolt. If indicator moves away form zero, place the amount of shims that will slide under that foot. Retighten bolt and make sure the dial indicator needle does not move. 3. Repeat this procedure for the remaining feet. Step 10 Perform Vertical Move
The vertical move is the part of the alignment process that aligns the two shaft's centerlines into their proper up and down position. Usually you will have to add or remove shims in this step. The indicators are zeroed on the top and read at the bottom. (start with a plus + reading if you need to compensate for sag) Example: the indicator on the pump reads -12 the indicator on the motor reads +8 This means that the shafts are one half the total indicator reading from being collinear at these points. Using a square grid graph paper to illustrate the position. Under the indicator position mark the point that is half the indicator reading. ( -6 for pump side indicator and +4 for the motor side indicator) Connect these two points with a line and then continue the line past the lines representing the feet on the motor. The graph now shows that the front foot needs to have a .003" shim added and the back foot needs to have a .001" shim added.
Now with your shims in place. Tighten all bolts and take and check your readings. If the readings are within tolerance than your equipment should be aligned. Step 11 Tighten all bolts and recheck indicator readings. Step 12 Remove alignment brackets. The more you become familiar with these steps the faster you wil l be able to align your machinery.
Five Basic Errors in Shaft Alignment Properly aligned shafts will do more to increase bearing, seal, and rotor life than any other single thing you can do after lubrication. Unfortunately, many maintenance departments in smaller plants still think that alignment is only needed for large, high-speed shafts on somebody else’s equipme nt. Many have no idea how to align two shafts beyond using a straight edge to get them close. Besides, the guy who sells the couplings says that the coupling can take up to one degree of misalignment and not hurt anything. That is a pretty gross figure. They are correct, though. They design couplings that will not wear out with that much misalignment. The life of the coupling, though, is not controlling here. Badly aligned shafts, and by that I mean much less than the one degree of misalignment the coupling manufacturers use, will ruin the bearings on the equipment in short order. All shafts, even low speed ones, must be aligned to within a few thousands of an inch TIR (Total Indicator Runout) if the bearings are to last for their full expected life.
Typical Types of Misalignment in Shafts There are some tremendous systems on the market for alignment. They use lasers, computers, and proximity sensors. They will practically move the equipment and install the shims. They do no good at all, though, if they are not used by trained, qualified technicians who understand what the systems are telling them. This paper does not purport to explain shaft alignment. The presumption is that the reader already has some idea of how to align shafts using a dial-indicator set. What we want to do in this paper is to point out five common errors made while aligning and what to do about them. Couplings ain’t round.
Suppose we have two shafts that are perfectly aligned but one has a coupling improperly mounted on a shaft so that there is some error in colinearity of the axes. As we approach the maching the error is only in the horizontal direction. Let’s set up the dial indicator so that it reads the outside of the coupling then rotate only the shaft on which the indicator is mounted, leaving the coupling still. When we get to position 1 the dial indicator will be extended to, say, -0.010 inches due to the error. Turning to position 2 will bring the dial indicator back to zero. At position 3 the indicator is compressed due the error and reads +0.010. If we believe that the coupling is square on the shaft and the axes are collinear we will believe that there is a TIR or 0.020 inches in the horizontal direction. Acting on that information will cause us to misalign the shafts by 0.010 inches – introducing vibration and potential bearing damage. How can we eliminate that error? By rotating both shafts together. The roundness of the coupling, the roughness of its surface, and the poor mounting will be eliminated from the readings (actually, all of those things will cause compensating errors so that only the actual misalignment of the two shafts will be indicated by the dials. A better way is to elim inate reading the coupling at all by using a tar get for your indicator that is securely mounted on the shaft. This will necessitate rotating both shafts but eliminates the need to break the coupling, even to do rim-face readings. Move the Driver This seems almost intuitive – at least if you have been in the field for any time. Yet, I repeatedly have had clients who inexplicably believed it was easier to move the driven machine. I will not argue that there is a time when the driven should be aligned to the driver. In all of industry, there are undoubtedly situations where this is better. As a general rule, though, it is better to move the driver that is not connected to your process than to move the driven that is. For example, suppose we are aligning a pump and motor. The pump is connected to the process by an inlet pipe and an outlet pipe. There are some applications where the piping is connected through flex joints but I haven’t found ver y many of them. Most of the time, the pump is hard-piped into the system. I
will make an assumption that you have corrected any pipe strain in the system. If not, then do that before trying to align the pump. You are just kidding yourself otherwise. Once the pump has been connected to the system, any attempt to move the pump to align it to the motor will induce pipe strain; whereas, moving the motor strains nothing but the flextite on the electrical connection – and it was made to be strained. If you move the pump and introduce pipe strain, you will end up with a misaligned pump as soon as you start the system up. Hot fluid, cold fluid or just the movement of the fluid will begin to flex the piping system which will, in turn, move your pump, which will in turn ruin that careful alignment you just accomplished. Threads don’t increase Strength At one client’s plant I gave a f our -hour class on shaft alignment. At the end of the class, we went to the field to practice on a 50 Hp pump. This was a pump that had been “aligned” by that crew the week before. The plant had been in service for about two years and the bearings had been failing on this pump every six months. In the middle of the class, there had been some sheepish looks and, when I questioned them, they admitted that they had never heard of angular misalignment and had only been correcting offset since startup. With information from the first pass of readings, the computer required a movement of the back end of the motor which was 0.010 to 0.015 more than the holes in the motor mount would allow. After some cursing, the crew began to disassemble the coupling and pull all the mounting bolts. I stopped them and asked what they were planning. “We have to take the motor to the shop and enlarge the holes in the feet,” was the answer. There are times when the two devices may be so misaligned that that kind of action may be necessary. Needing less than 0.015 inches is not that kind of misalignment. When you run across this situation, do this: Pull the offending bolt, take it to the shop and turn or grind the threads off in the area that is in contact with the motor foot. You can grind all the threads down to the root diameter and not effect the strength in tension at all. On a 5/8 –11 bolt the OD at the threads is 0.614 inches. The root is 0.515 inches. So, you can pick up 0.050 inches of movement with no decrease in strength by grinding the threads. Besides, I have seen many alignments where the computer moved the offending foot right back after the second pass. Enlarging the hole in the foot would have been an extreme waste of time. 2 Planes are Better Than 1
I have seen alignment techniques that suggest that the technician align first the horizontal then the vertical. I disagree with that. I believe you should be making complete passes – all four positions, and calculating both your vertical and horizontal correction at the same time. Here’s why: If the alignment is far out, it is better to correct both planes (horizontal and vertical) at the same time. Otherwise the requirement for positioning the indicators becomes too precise. Error will be introduced and you will end up bouncing around the solution for any one plane. Suppose you are nearly perfect in the vertical direction yet still grossly misaligned in the horizontal as illustrated in the above figure. If you do not place your dial indicator exactly vertically, part of the gross horizontal misalignment will be read as vertical misalignment. This will cause you to bounce around the solutions with each pass. It is better to remove the error from both planes together so that this situation does not arise. With the availability of computers, laser systems, etc. there is not reason not correct both planes simultaneously. Reverse Indicator Works Most experienced mechanics and engineers will shrug at that statement. Of course, reverse indicator systems work. My experience as a teacher and as a consultant belies that complacency. I have found experienced crews who knew nothing but rim-face techniques or who knew of RI but did not believe it worked. I had one very experienced technician tell me that RI only worked on very large shafts. To correct this thinking, I utilize a very old technique popular and needed prior to the advent of hand held calculators and computers: the plotting board technique.
In it, the distance between in the indicators is plotted as X. The distance from the B indicator and the front foot of the moveable machine is plotted as Y. The distance between the feet of the machine is plotted as Z. So, the horizontal axis is normally in inches. The vertical axis, though, is not in inches but in thousands of an inch. On the A line is plotted the TIR of the A indicator in the plane being corrected (I know, I just told you to correct both at the same time – only, we didn’t have the calculating technology back then.) The B indicator TIR is plotted on the B line. A straight line is drawn through them and extended all the way to the Rear line. The needed correction at each foot is read off the vertical axis where the plotted line intersects the “foot” lines. In the example shown the A TIR was +0.003 inches. The B TIR was +0.002 inches. The plotted line crossed the Centerline very near the Front line and crossed the Rear line at approximately –0.0015 inches. If this was the vertical plane being measured, then the front legs would need no correction and the rear legs would need a 0.0015 shim added to bring it up to the centerline. Normally, when this technique is shown to the technicians, a light bulb goes on and they are able to grasp and appreciate the RI technique. RI is not right in every situation. It is just another tool the alignment technician has for getting the job done. Its biggest advantage is ease of set up and a balanced rotor compared to Rim-Face (RF). The RI set up is balanced and will not rotate unless made to. The RF is unbalanced and will rotate to the bottom position unless held in place.
These five errors, although simple and basic to the experienced mechanic, are ones that I have found many clients making – and making without even realizing there was an error involved. Teaching these things to an inexperienced crew or to your new craftspeople will improve your alignments and make them more time efficient.
Benefits, Methods of Proper Pump to Motor Alignment
By Allan R. Budris Experience shows that many pump distress events (failures) have their root cause in the misalignment of the pump to motor. Misaligned pumps can even consume up to 15% more energy input than well-aligned pumps. Even small pumps can generate big losses when shaft misalignment imposes reaction forces on shafts, even if the flexible coupling suffers no immediate damage. The inevitable result is premature failure of shaft seals and bearings. Performing precise alignment, therefore, pays back through preventin g the costly consequences of poor alignment. Indeed, using precise alignmen t methods is one of the principal attributes of a reliability focused organization. Good alignment has been d emonstrated to lead to:
Lower energy losses due to friction and vibration Increased productivity through time savings and repair avoidance Reduced parts expense and lower inventory requirements
Further, in order to insure good alignment, the alignment must be checked and correctly set when:
A pump and drive unit are initially installed (before grouting the baseplate, after grouting the baseplate, after connecting the piping, and after the first run). After a unit has been serviced. The process operating temperature of the unit has changed. Changes have been made to the piping system. Periodically, as a preventive maintenance check of the alignment, following the plant operating procedures for scheduled checks or maintenance.
Alignment Problems
Hundreds of technical articles and presentations have elabo rated on the serious problems that are caused by incorrect alignment between the pump and driver, such as:
Coupling overheating and resulting component degradation Extreme wear in gear couplings and component fatigue in dry element couplings Pump and driver shaft fatigue failure Pump and driver bearing overload, leading to failure or short bearing life Destructive vibration events. Harmful machinery vibration is created whenever misalignment exists. Excessive pump vibration can shorten bearing and me chanical seal life.
Pump Alignment Basics
Pump shafts exist in three-dimensional space and misalignments can exist in any direction. It has been found to be most convenient to break this three-dimensional space up into two planes, the vertical and the horizontal; and to describe the specific amount of offset and angularity that exists in each of these planes simultaneously, at the location of the coupling. Thus, we end up with four specific conditions of misalignment, traditionally called Vertical Offset, Vertical Angularity, Horizontal Offset, and Horizontal Angularity. These conditions are described at the location of the coupling, because it is here that harmful machinery vibration is created whenever misalignment exists. Basic issues that must be taken into account regarding pump alignment are:
Alignment equipment sag (with dial indicators) Cold, hot or running alignment Where to make shimming adjustments (Align the motor to the pump by shimming the motor feet) Soft foot problems Type of alignment equipment
Alignment Methods
Alignment accuracy is critical to pump and driver longevity as stated above, and generally the better the alignment the longer the pump and driver bearing life. Figure 1 shows the best alignment that can expect from the three most prevalent alignment methods practiced in the industrial, worldwide.
Straight Edge and Feeler Gauges Dial Indicator Lasers-optic
Straight Edge, Feeler Gauges
This is the easiest and least expensive method of doing alignment but it is also the least accurate. Used primarily for very small pump / motor combinations where there is not enough room to use more accurate but larger alignment methods. The straight edge is laid across the flanges of the coupling hub and the feeler gauges are used between the faces of the coupling hubs. Shim changes are estimated and the alignment is attained through a process of trial & error. It is more difficult to attain the equipment manufacturer's alignment specifications through the use of a straight edge and feeler gauges.
Dial Indicators
There are two basic dial indicator methods. The Single Indicator Method uses a single dial indicator to take both the rim and face reading. You can then calculate shim changes for the motor feet to correctly align the unit. The Reverse Indicator Method uses a dial indicator on the pump shaft to read the motor shaft, and a dial indicator on the motor shaft to read the pump shaft. You can then use mathematical formulas to calculate shim changes to correctly align the unit. Although better then the "straight edge and feeler gauge method", the dial indicator method does have a few shortcomings, such as:
Sagging indicator brackets Sticking/jumping dial hands Low resolution rounding losses Reading errors Play in mechanical linkages Tilted dial indicator (offset error)
Lasers-optic Devices
This state-of-the-art system emits a pulsating non-hazardous laser beam that automatically determines relative shaft positions and conveys this information to its microprocessor. The advantages of modern laser-optic alignment devices far ou tweigh the possible initial cost advantages of other, more conventional methods. Reliability-focused pump users employ this state-of-art laser optic alignment determination method, even though it is somewhat more complicated to set up, but it can be more accurate if properly used. The laser is especially helpful when aligning shafts that are separated by more than a few inches. The laser systems also have software that is capable of calculating the shim changes required. Once familiar with it, the laser operator can align a pump/motor combination fairly quickly and accurately. The primary drawback of the laser systems is cost, and in some cases their size. Specific advantages of laser alignment tools are that: the y do not require as much operator skill; center-to-center pump alignment can be achieved without paying attention to thermal growth, since it is possible to feed in the thermal growth data for compensation; and laser alignment can allow the operator to check the pump when it is running and up to temperature, this is not possible with dial indicators. Other advantages for the laser are:
It is free of gravitational hardware sag It can work with the couplings in-place or uncoupled It is fast & easy to mount It can detect & measure the extent of a "soft foot" It feeds misalignment data to a microprocessor for horizontal and vertical corrections.
Alignment Tolerances
Acceptable alignment tolerances are a function o f shaft speed, coupling type/geometry, and the distance between the driver and pump shaft ends. The question then becomes, just how close should the pump and driver shafts be aligned? How much vibration and efficiency loss will result from the misalignment of the shaft centers? It should be noted that high-quality flexible couplings are designed to tolerate more misalignment than is ideal for the machines involved. Bearing load increases with misalignment, and bearing life de creases as the cube of the load increase, therefore, a doubling of the load will shorten the bearing life by a factor of eight.
There is generally little consensus among machinery manufacturers and users as to the allowable, and/or preferred alignment tolerances. As a minimum, the recommendation s of the coupling or pump manufacturer should be followed. Pump Alignment: Just The Facts Proper alignment of the pump shaft with the driver can reduce vibration and significantly improve reliability. For appropriate applications, the time, expertise and instruments needed t o achieve precision alignment (tolerances of less than 0.005 in) will prevent seal leakage and extend bearing life.
Depending on such factors as operating speed and coupling type, not all pumps will require such precise alignment. When assessing a plant's alignment needs, it helps to understand basic shaft alignment concepts and procedures, as well as application-specific factors that dictate the required tolerances. Effects of Misalignment
A common misconception about pump shaft/driver misalignment is that it increases bearing load, causing bearings to fail prematurely. In fact, except in cases of extreme misalignment, the resulting vibration is what damages bearings and seals. Since some vibration is normal for pumps, it is best to have an experienced vibration technician determine if the vibration is due to shaft misalignment, and whether it is severe enough to affect pump reliability. Alignment Basics
The purpose of shaft alignment is to minimize the vibration resulting from forces transmitted across the coupling. The goal is to have both shafts rotating on a common axis, referred to as
collinear. All misalignment of shaft centerlines (i.e., deviation from the collinear condition) can be described in terms of offset and angularity. Theoretically, two perfectly aligned shafts would rotate in the same axis, and if properly balanced and coupled, would not generate abnormal vibration during operation. If instead the two shafts are misaligned in the horizontal or vertical plane (o r both), or are at an angle with respect to one another, they will rotate in different axes. The amplitude of the resulting vibration will vary, depending on such factors as the severity of the misalignment, operating speed an d coupling type. In addition, the relative positions of a horizontal pump and driver can be viewed independently in the horizontal and vertical planes. Reducing alignment conditions to offset and angularity, independently in the horizontal and vertical planes, simplifies manual calculation of required "correction moves." Automated techniques for calculating corrections also use this convention. (Vertical pumps, solid couplings and hollow-shaft motors present unique concerns and require special procedures not discussed here.) Alignment (or misalignment) is measured at the coupling-the point of power transmission-not at the feet. The amount of shims to be added or removed beneath the feet does not directly indicate the alignment condition at the coupling.
Figure 1. Alignment tolerances in relation to operating speed.
Tolerances
Alignment tolerances specify how close the pump and driver shaft centerlines should be to collinear at running conditions. Offset tolerances are measured in thou sandths of an inch (or mils), centerline-to-centerline at the coupling. Angularity tolerances are expressed as pitch o r slope (mils/inch). Alignment tolerances for pumps range from the "ro ugh alignment" that a conscientious technician can accomplish with visual indicators (accuracy of about 0.02 in) to precision alignment (accuracy of 0.0005 in or greater). The latter requires an experienced technician and accurate instruments (e.g., dial indicators or a laser alignment system). Accuracy of about 0.005 in can be accomplished with a simple straightedge and feeler gauge. The degree of precision required for a specific pump/driver will depend on the pump's rotating speed, the distance between the pump and driver shafts (spool-piece length) and the application's thermal characteristics. The required precision increases exponentially with operating speed; proportionally less precision is necessary with longer coupling spool pieces. For applications where temperature changes occur during operation, evaluation of thermal effects is also needed to determine target values. Another important factor is the coupling type. Industrial users generally agree that nonsegmented elastomer boot couplings produce less dama ging vibration than jaw or gear couplings, given equal amounts of misalignment. Other kinds o f couplings fall between these extremes.
Figure 2. Offset and angular tolerances in relation to operating speed.
Alignment Procedures
Rough Alignment: When installing the pump and driver, experienced technicians will perform a "rough alignment" based on visual indicators. They also will ensure that all machine feet a re in good foot-plane and have 0.025 in to 0.050 in shims under them. Good foot-plane must be established and maintained throughout the alignment procedure to avoid stressing the machine cases. Target Values: Pumps and drivers are moving targets due to torque strains and thermal effects, so evaluation of these factors is an important step in pump shaft alignment. Just as a marksman anticipates the location of a moving target, prop er alignment procedures must predict the relative running position of the machine cases (i.e., differences between cold and running alignment positions). These target values may be determined for the relative positions at the coupling or at the feet.
Figure 3. Sample alignment target values.
Measurement:
Alignment tolerances and misalignment are measured at the coupling, where the power
is transmitted. The simplest way to measure these parameters is with a straightedge and feeler gauges. A taper gauge or caliper can also be used to measure angularity between the coupling faces. These methods can achieve accuracy of about 0.005 in, which is acceptable for many pumps that o perate at 1,200 rpm or less.
If precision alignment is required, careful use of dial indicator methods (e.g., rim-and-face and reverse-dial), including compensation for bracket sag, can achieve accuracy of 0.0005 in. This will suffice for most pumps that run at 5,000 rpm or slower. Laser alignment systems accomplish the task quicker and with m ore accuracy, eliminating math errors and other common mistakes. Most of these systems also provide graphics that show the direction of the "correction move." Regardless of the alignment method, correction moves must b e determined from measured misalignment data-whether the calculations are done manu ally, or automatically with a calculator, computer program or laser alignment system. Attempts to "guesstimate" correction moves often waste time and cause frustration.
Foot-plane: To maintain good foot-plane during the alignment procedure, both front feet should be raised or lowered the same amount, and similarly, both rear feet should be moved in equal amounts. Shim adjustments that would tilt the motor side to side should be avoided.
If a machine is bolt-bound or base-bound and cannot be adjusted sufficiently, it will be necessary to move the opposite (fixed) machine case. Most calculator and laser systems provide the means to recalculate for base- and bolt-bound conditions. Documentation: It is essential to record pre-alignment data, target values, tolerances and final aligned condition. This information can help m aintenance personnel determine when to perform maintenance tasks and spot developing problems that may otherwise result in unexpected, costly failures and downtime. The documentation features included with many alignment calculators and laser systems may not be adequate for recording data about foundations, machine feet, shims, coupling components and observations. If so, a paper or an electronic work order system should be used to capture this information (see an example data form below and click here for an enlarged version and a downloadable pdf ).
Assessing Alignment Needs
Pump and alignment tool manufacturers offer "suggested" alignment tolerances, mo st of which do not consider the coupling type. But application-specific variables make a single tolerance for pumps unrealistic. The best approach is to evaluate each installation based on operating speed, thermal movement, spool-piece length and coupling type. For a large 1,200 rpm pump with an elastomer-in-shear coupling, alignment with a straight edge and feeler gauge to precision of 0.005 in would suffice. A medium-size 3,600 rpm hot water circulation pump with a jaw coupling, however, would require precision alignment with dial indicators or a laser system. A high-temperature (400 deg F) refinery pump may have a spool piece coupling to accommodate thermal movement, and would require an operational assessment of target values. While target value assessment and precision alignment techniques could be used for any of these pumps, the required time and expense would outweigh the benefits for the 1,200 rpm pump. Thermal growth analysis also would be unwarranted on the hot water circulation pump, because the driver and pump will have similar thermal growth. Common sense dictates that evaluation of the alignment needs of individual pumps-including coupling type, thermal changes, rotating speed and spool piece length-will ensure use of the most cost-effective shaft alignment procedure. Conclusion
Successful pump alignment requires careful planning and execution, beginning with evaluation of tolerances and target values based on pump speed, thermal characteristics, coupling type and spacing. The technician must also be adequately trained and systematically document the entire procedure, including the original misalignment, the final alignment condition, and any observations related to machine reliability. The expense or sophistication of the alignment toolswhether laser, dial indicator or manual-will not produce the desired results if these essentials are ignored.
