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ME-430 INTRODUCTION TO COMPUTER AIDED DESIGN Bicycle Chain Assembly

Pro/ENGINEER Wildfire 2.0 Dr. Herli Surjanhata

Create a new directory called bicycle_chain under \ME-430 directory. Copy all the files created for Roller Chain Assembly into bicycle_chain. You should have:

Roller_link.asm, and Pin_link.asm

Make sure to delete roller_chain.asm Here below are the subassemblies:

Roller_link.asm

Pin_link.asm

Add Pin_Link_Plate.Prt Into Pin_Link.Asm Assemble component pin_link_plate.prt into existing assembly pin_link.asm. Note that the Align Offset distance is -0.05.

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Create Two Datum Points in Pin_link.asm

Measure the inside distance between the two plates. From Analysis pull down menu, select Measure.

Note that the resulted distance is 0.34 in.

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Create a new datum plane click , and offset it from bottom inside surface at 0.34/2 = 0.17 in distance.

Create two datum points that lie on ADTM1 and the axis of each pin.

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Select the Sketched Datum Point Tool

icon .

Pick the newly created datum plane ADTM1 for Sketch Plane, and then select ASM_RIGHT datum plane as Sketch Orientation. Pick the references.

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Click to create two points at the center location of the pins.

Pick it as reference.

Pick it as reference.

Pick it as reference.

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The resulted datum points are APNT0 and APNT1. Save the assembly.

Create Two Datum Points in Roller_link.asm Open roller_link.asm, and use the same technique to create two datum points needed for assembly of bicycle chain.

Create a point here.

Create a point here.

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Measure the distance as shown to make sure we have a correct size.

Create a new datum plane ADTM1 at the middle of the roller_link.asm. Note that the inside distance between the plate is 0.25 in. Therefore the offset distance of the new datum plane from the top surface of the bottom plate will be 0.125 in.

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Create Total Assembly of Bicycle Chain Create a new assembly called bicycle_chain with default assembly datum planes.

Create a datum curve of the path that the chain should follow. Make sure that the length of the curve is a value that can be evenly divided by the length of each link.

Pick the Sketch Datum Curve Tool icon .

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Pick the sketch plane ASM_FRONT, accept default for Sketch Orientation Click the Sketch button. Sketch two centerlines (horizontal and vertical) through the origin for symmetry.

Sketch two horizontal lines of length 5 each and two Tangent End arcs of radius 1.59155 each.

To determine the length of the curve, select Measure from the Analysis dropdown menu, select Curve Length from the Type list and select Chain from the Curve/Edge list, then select the curve and make sure that the entire curve is highlighted as red. Click Accept.

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The curve length will be shown in the Results field. In this example, the curve length is 20.

Pick this curve first.

Next, press and hold Ctrl-key and pick this curve.

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Create two length ratio (LR) datum points on curve, with the first point LR = 0.0 and the second point LR = 0.025. The length ratio can be computed by dividing the link length by the overall length of the chain. In this example, LR = 0.5 / 20 = 0.025.

Click the Insert a datum

point icon DATUM POINT dialog box opens. Bring the cursor to the curve, and right click it and select Pick From List.

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Pick the curve that represents the whole curve. In this case, the second F5 curve. Make sure the whole curve is highlighted. Click OK. Datum point APTN0 is created.

Enter 0.00 for the offset of the first datum point.

Click New Point in the DATUM POINT dialog box.

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Bring the cursor to the curve at the left of the first datum point, and right click it and select Pick From List.

Pick the curve that represents the whole curve. In this case, the second F5 curve. Make sure the whole curve is highlighted. Click OK.

Change the offset for the second datum point APNT1 to 0.025. Click OK.

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Pick the two datum points by double-click one of the points, and make sure both of them are highlighted.

Pattern these two datum points around the curve by selecting , pick one of the datum points (APNT0), pick the 0.00 dimension, and enter the curve length ratio increment of 0.05. The curve length ratio increment is equal to the length ratio multiplied by 2. Hold Ctrl key and the 0.025 dimension, and enter 0.05 again for the curve length ratio increment. Enter 20 for the total number of instances. The total number of instances should be half of the total number of links because these points will represent the "pin_link.asm" part. The number of links is equal to the datum curve length divided by the link length, or in this example 40 links. Therefore, the total number of instances for this first pattern should be 40 / 2 = 20.

Select to create the pattern. This will create 40 total points around the datum curve.

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Assemble pin_link.asm and align APNT0 and APNT1 to APNT0 and APNT1 of bicycle chain respectively. Add additional Automatic (Mate) constraint by mating ADTM1 of pin_link and ASM_FRONT of bicycle chain. Then click the OK button.

Hint: When picking the datum point, select Datum Point in the Selection Filter dialog box.

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Right click PIN_LINK.ASM in the Model Tree, and select Pattern. Reference pattern will be created.

Click .

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Right-click Pattern 2 in the Model Tree. Select Suppress.

Zoom in the area of datum curve as shown in the left.

Create two more datum points as before that are offset by one length ratio, so the first point's length ratio should be 0.025 (rather than 0.0) and second point's length ratio should be 0.05 (rather than 0.025). These points will lie on top of APNT1 and APNT2 from the first pattern of points.

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Pattern these points (APNT40 and APNT41), the same as before.

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Assemble roller_link.asm and align APNT0 and APNT1 to APNT40 and APNT41, respectively. Add additional Automatic (Mate) constraint by mating ADTM1 of pin_link and ASM_FRONT of bicycle chain. Then click the OK button.

Right click ROLLER_LINK.ASM in the Model Tree, and select Pattern.

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Reference pattern will be created.

Click . Under Edit pull down menu, select

Resume -> All This will complete the bicycle chain assembly.