Setting stroke on Douglas Shaper

[Shawn]

I recently posted about having bought a Douglas shaper but wanted to make a new post with the title so it's easier to search for any other members who might be having the same head scratcher as me. On the SB shaper I own the length of the stroke is set against a scale engraved right on the scotch yoke. It's a simple affair to set the stroke for anything from 1" to 7" with the scale. The Ram starting and stopping points is set with a locking lever on top of the ram, again simple enough.

With the Douglas Shaper their is a scale but it is a brass plaque that is mounted on top of the dovetail on the main casting. In some photo's of various Douglas Shapers I have seen an indicator attached to the locking lever for the Ram position. I can't for the life of me see how this scale is to be used for setting stroke length? I'm sure there is a system but I can't figure it out. Just to clarify, I can change the lenght of the ram stroke but I'm kinda guessing as I go. Shapers are slow enough without having to wait for it to cut 20% air.

Here is a photo I borrowed from Tony's site showing a Douglas shaper with the red indicator arm hanging down from Ram position clamp.



Thanks for the help
Shawn