Climax Arch Bar Truck Side Frame Machining Notes

Copyright 2006

Precision Locomotive Castings

Click here to download these notes as a document file.

Machining the journal box is a good place to start. Make sure there is nothing sticking out on the front face of the flange before you put it in the vise. Face the back. Next drill and bore the hole in the back for the needle bearing.


Remove burrs, and machine the slots in the sides to fit the journal box pedestal. The slot is not totally straight, but tapered in width for clearance to allow the box to rock. This is also a good time to drill the hole for the journal box lid pin.


This is the set up for machining the top of a journal pedestal. This one has already had the slot machined in the top. Note the stop on the left hand side, this will be useful for drilling the holes. It is hard to see, but there is a rigid 6 scale used for a parallel under the casting against the back vise jaw to insure the casting is not sitting crooked.


Here the journal pedestal casting is flipped over, being readied to machine the slot on the bottom. Note the ground 3/8 tool bit in the top slot being used as a parallel. This is also a good time to drill and tap the holes that will hold the arch bars to the pedestal.


This setup is to relieve the corners of the top slot in the journal pedestal for the bend in the middle arch bar. The opposite corner of the journal pedestal must also be relieved for the bend in the bottom arch bar.



A quickly made fixture to hold the bolster pedestal upright in the vise is handy. Here is the set up for cutting the slot in the top of the bolster pedestal. Turn it over to do the other end. Both ends are drilled with this set up.


The arch bars are bent in a press. The middle arch bar is shown. This set up is for milling off the material displaced outward from the bending so the bolster pedestal will fit..


Relieving the inside of the bends of the middle bar so the bolster pedestals will sit flat.


Drilling the holes in the arch bars. Middle bar shown. Note the stop on the left hand side again.


At this point the parts begin to look like a side frame.



Add a few bolts, and it is pretty amazing how rigid the assembly becomes. The side frames go together pretty quickly to get to this point.