Does anyone know how the valving works and which part regulates the ability to control light hits and feather to heavier hits? I am having a tough time getting control on mine. It will hit light, then too hard then too light with lots of movement  on the treadle. Any one familiar with these machines? I love this machine but it ends up just sitting due to this problem other than texturing material. 

 

R

I'm still tuning mine up, but one thing to check is the fit of the throttle lever linkage into the throttle valve.  This should be a square shaft into a square hole.  After being used for 80+ years, mine was more like an oval shaft into a square hole.   The result was a large degree of motion of the lever before it would engage and turn the throttle valve (i.e. backlash).   A few degrees of play in the valve connection could end up being inches in the treadle.  I had to build up the corners of the throttle control shaft with welding rod and then file to fit.  

 

Also make sure it is lubed and the packing gland is not too tight.

 

Don