Home Up O-Ring Check Valve Switch Frog rebuild

 

I took on rebuilding of aluminum switch frogs for a 7.5" gauge track that I attend frequently.  They haul a large number of public passengers and the aluminum switch frogs were having to be replaced frequently.

I am milling out the center section of the worn out frog and machining a steel insert that replaces the milled out section.  This insert should last a long time.

I have a CNC mill and have made up fixtures used to machine the old frog and the new insert.  I'm guessing that, once the fixtures are in place, I can do a frog and an insert in about 45 minutes.

Each new frog style (manufacturer, frog number #9, #10, etc.) requires different fixtures and different CNC programs.  It took me about 4 days to setup for the first type (the track has several different types) but the next ones should only take me about a day or so.
 

Fixture (center) to CNC machine the center section out of the frog and cleanup the flangeway.  A finished frog is shown at the top. The four flat-head screws (zinc coated) are used to fasten the new insert to the frog.  A worn frog is shown at the bottom of the photo.

Fixture  (w/clamps) to CNC machine the new steel insert.  An insert blank (CRS) is shown above it and finished insert at the top.

Close-up of the finished insert.

Finished frog with new insert in place.

Close-up of installed insert. I'm wondering about sinking the screws a little more so that I can fill in the holes with caulk to seal out water as added precaution against corrosion.  I'll also 'bed' the insert in caulk/form-a-gasket for the same reason.

Close-up of installed insert from a different angle.

Hit Counter