My Escort rack and extension steering shaft arrived from Rally Design today. The shaft is 14mm x 36 splines on each end of a 380mm x 15mm shaft = £20.00. I decided to change the original design in this area to give the steering shaft more support. The modification mostly relates to where it comes out of the bulkhead by adding another bearing .
So.... I cut the shaft and joined it to the Puma shaft. I then found I had enough material left with a spline already machined on one end. I then I looked up the mechanical engineering forums and found out how to cut a spline. Amazingly I found I had all the kit already would you believe.
Set about machining the cut end and found it was made of a very hard alloy like silver steel. I have come across this in clocks, pins and small shafts before but not in any automotive context. Considering the application I was reassured it was made of this stuff for a reason. Anyway by careful technique I turned the shaft to exactly 14mm in the lathe. Then I set up the mill and cut the spline. All done with TC cutters I have already.
Result, complete success