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Metric trapezoidal (ACME) thread lead screw help

SShep71

Cast Iron
Joined
Sep 17, 2014
Location
San Diego, Ca
I am working on what I hope is the last repair to bring my Guifil press brake back from the dead. The ram stroke has a interesting method of CNC control, the travel is controlled through a mechanism that is driven from a 20mmx5mm trapezoidal (near ACME)lead screw. The one on the machine is bent and is causing issues with the controller. I want to make a new lead screw but the pitch "5mm" is not a standard pitch for the diameter. The component that rides on the screw is a large and complex hunk of bronze so converting the system to a standard ACME screw is off the table. Is there a source for 20mmx5mm lead screw out there? I tried all the "go-to" places but the odd pitch is giving me hell. I do not have a tool to cut the thread on my lathe, I don't have a gauge to allow me to grind a proper 30deg trapezoidal thread either. I have one on order, but it is weeks out. Does anyone out there have any suggestions on where to source a length of 20mmx5mm lead screw? The part is less than 300mm overall length.
 

gregormarwick

Diamond
Joined
Feb 7, 2007
Location
Aberdeen, UK
It's definitely single lead? 20mm P5 is more common on TR multi start screws.

Just buy an insert and screwcut it? All the big names have TR full profile inserts.
 








 
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