Axle Box Timken Covers Part 2.
A distinctive feature on the Timken covers is the four studs with accompanying nuts.
I decided to add this feature to the axle boxes using dummy 12BA studs and nuts these would be glued into each corner. I ordered some 12BA nuts and bolts from EKP supplies and tried to figure out how to use the Pitch Circle Diameter feature of my milling machines DRO.
After a bit of head scratching I realised the DRO has to be in ABS mode which is effectively the base measurement axis (the DRO supports different 100 axis or rather 100 different origin (0,0) points.
Once I figured that out I used a centering indicator to line up the first axle box.
Next job is to set up the DRO.
Hitting the Down arrow moves the display to the first hole, which is roughly 5mm away from the centre in both axis. Mill table is moved until both axis read zero.
You can just about see the Red LED over the PCD button which indicates the mode. It is possible to switch the mode on and off as required. I used this later one when I realised the centring was different for some of the axle boxes :-(
Re-drilling them looks messy but the epoxy I use to stick the dummy studs in should fill the gaps.
The three not quite so good ones but salvageable.
I decided to add this feature to the axle boxes using dummy 12BA studs and nuts these would be glued into each corner. I ordered some 12BA nuts and bolts from EKP supplies and tried to figure out how to use the Pitch Circle Diameter feature of my milling machines DRO.
After a bit of head scratching I realised the DRO has to be in ABS mode which is effectively the base measurement axis (the DRO supports different 100 axis or rather 100 different origin (0,0) points.
Once I figured that out I used a centering indicator to line up the first axle box.
Here I'm checking right to left its within 0.1mm
Next job is to set up the DRO.
Axis 00 selected (ABS Mode) The X and Y axis were Zeroed using the Xo & Yo Buttons.
PCD Mode selected, Centre is same as ABS centre, hit down button.
Pitch Circle Diameter is next, 14.27mm was scaled from a photo. Relative to the diameter I turned earlier.
Four holes needed. Use keypad and enter button. (=)
Start Angle 45 degrees.The Angle is with respect to a horizontal line to the right of the centre point.
Ending Angle 315 degrees.
Hitting the Down arrow moves the display to the first hole, which is roughly 5mm away from the centre in both axis. Mill table is moved until both axis read zero.
You can see the hole layout on the vice. Positive angles are clockwise. Hence Hole 1 is the lower Right, Hole 2 is lower left, Hole 3 upper Left and Hole 4 Upper Right.
To cycle through the holes you use the UP/DOWN arrows to the right hand side of the display, here it is showing Hole 2. X and Y are reading Zero so we are bang on the right position. When you move to the next hole the X or Y reading will change and you move the corresponding handle, until both axis are reading zero again.
You can just about see the Red LED over the PCD button which indicates the mode. It is possible to switch the mode on and off as required. I used this later one when I realised the centring was different for some of the axle boxes :-(
Four boxes look okay.
On two of the boxes, holes were offset :-(
Re-drilling them looks messy but the epoxy I use to stick the dummy studs in should fill the gaps.
After counter boring, Three perfect ones with a 12BA bolt in place.
The three not quite so good ones but salvageable.
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