There are various reasons why the leadins should be placed on a certain corner of the part insert if possible; here are some:
•If the Sequencing direction is Right to Left (as recommended on Kinetic machines) then placing the leads at the top left is good because it means the final segments of the cut will be along the left edge of the part, and this is generally going to be severing from "clean plate", so less chance of plate movement.
•On Platedraggers, this is especially true, Top-Left is best, particularlay on simple mostly rectangular parts: during the final cut up the left edge of the part, the plate will be stationary as the part severs.
•When cutting thick plate with flame, and especially if using a running pierce, leads should be positioned so as to have the torch moving toward the operator along the leadin during the pierce, so as not to shower the operator with hot sparks from the pierce!!!
Cutting Tools have three settings governing default leadin location tendency:
Location Tendency H Horizontal tendency (None, Left, Right)
Location Tendency V Vertical tendency (None, Top, Bottom)
Location Tendency H Weight how strong the horizontal tendency is relative to the vertical tendency (default is 5, ie we really want leads to follow Horizontal tendency MORE than vertical tendency, especially for PlateDraggers, we want those leads to the left!)
Applying lead tendency to parts is not particularly effective unless the parts are nested with no rotation. It is more effective when processing plates.
The Location Tendency H and Location Tendency V settings in combination provide the default setting for the Processing Options dialog:
When applying this tendency, PrimeCut will still attach to a corner in preference to an arc, so a part like this, with Top Left Leadin preference selected, will attach to the corner at top right as there is no corner at top left of the part:
