Taking Your Own Track Measurements Measuring for the Outside Wiper Before you start measuring the outside wiper, look at your overall track and identify the clearances and contact points. Clearances are defined as sections of the track where a wiper system will never contact any other part of the base. Contact Points indicated with a red dot, are contact points where the wiper system will touch the track base as the wiper system completes revolution. These points include: steps, guards, drive gear, link belt, rollers and the base frame. 1
There are a few different types of undercarriage frames. It is important to identify which type of frame your running. The measurements required will differ between frame types. The most common frame type is an angled frame. The flat top deck heavy-duty frame is generally used with the largest excavators. Lastly smaller machines often use a block type. (All, shown below) Angled Frame Flat Top Deck Block Frame 2
Measurements: Outside Wiper Height: This measurement determines the height of the wiper. Measure in front of a top roller, from the bottom side of the shoe down to the top of where the base frame angles. Figures 1a & b. Note: Do not add extra distance to the height measurement. Figures 1a Figures 1b On a heavy duty base that has a flat deck, measure from the bottom of the shoe from tallest track section, to the outside edge of the top deck. Figure 1c. For the smaller block frame bases follow a similar measurement method. Figure 1d. Figures 1c Figures 1d 3
2) Depth Measurements: All Depth measurements are taken from the outside of the shoe measured inwards towards the base. The tools required for these measurements are a tape measurer and a straight edge. The straight edge is placed against both the bottom and top of the track as show in the below figures. Take measurements in the following locations. Track edge to base Figure 2 Track edge to track guard Figure 3 Figure 2 Figure 3 4
3) Base Frame Angle: These measurements are used to ensure that the wiper rides evenly along an angled base. If you have a flat base, this measurement is not needed. There are three tools that can help in measuring the angle of the base. A small carpenters square, a digital angle meter and a small level. Measuring using a small carpenters square: figure. You will need to record the length of each leg of the square. Note, the red section of the square MUST be flush against the side of the base. Height Measurement figure 12 Depth Measurement figure 12 The following Rise and Run Chart can help you estimate the angle of the base. Occasionally, the outside base angle and the inside base angle Figure 4a are not the same. Or there is a slight offset in the transition between the outside and inside base angles. The inside angle may be a few degrees steeper than the outside base angle. This offset is not generally sufficient to require measurements of the inside angles. However, if you observe the difference is significant. You will also need to measure the inside angle of the base. 5
Measuring using a digital angle finder: figure 13. The key to using a digital angle finder is also use a level to identify how far to open your angle. When your plumb record that angle. Next repeat the same measurement on the other track base angle. You MUST record the angle on both track sides because rarely is your machine parked on level ground. The sum of both sides divided by 2 will insure that you have measured your correct base angle. Figure 3b 6
Steps: Many medium to large excavators have steps attached to the side of the base. As long as the steps do not exceed the height of the line drawn in red in Figure 5a, there is no need to provide any step measurements. Figure 5a When steps are stacked up such shown in figure 5b, the following measurements are required. Figure 5b 7
Step Clearance: Figure 5c Generally the rear step has the shortest clearance. Measure the distance from the top of the step to the bottom of the closest shoe. Figure 5c Step depth: Figure 5d, This is how far the top of the step is from the base. Figure 5d 8
Measuring for the Inside Wiper Identify obstructions on the inside of the track. The attached figures highlight several obstructions on the drive gear side, the idler pulley side, and the rollers. Inside pinch point measurements: The drive sprocket side on the inside of the track is most commonly the shortest pinch point on the track. Figure 6a The Idler front sprocket also has a pinch point and this measurement is also need. If the height clearance of either of these pinch points is greater than 3. Measurements can be N/A There are four measurements needed. The distance from the pinch point to the bottom of the shoe. Figures 6a&b on both the rear and front pinch points 9
Distance from the outside edge of the pinch points to the inside edge of the track. Figures 6c Figure 6c Figure 6b Inside track to base measurement: Measure from the bottom of the shoe down to the base, opposite of the top roller. Figure 7 10