Hand Plane Chatter

[Steve Brooks]

This is a long shot, but it has worked for me. Assuming your plane iron 
is thick enough for the job, chatter can result from the blade not 
having enough support. It looks like your plane is sand cast iron so 
check the area wherever the blade is supported. Sometimes, in sand cast 
frames, a grain or more of sand remains embedded in the iron frame, gets 
by QC, and keeps the plane iron from bedding perfectly flat and 
supported. It only takes one grain of silica to lift the iron slightly 
or bow it even and cause chatter. If you spot any sand sticking up chip 
or grind it down carefully. There's two cents. Are we up to a dime?

-- Steve