Parallel surface - finish, start point

[MadPickinSkills]

Hello,

Is there a way to create a specific start point for a Parallel surface - finish toolpath? I know there is a check box for use approximate start point, but I was hoping to be able to have the toolpath start at the highest point on the convex surface because there is some material left over around the edges of the part and the tool (ball EM) will plunge into if it starts on the edge of the surface.

[Tyler Robertson]

Did you select the start point when you selected the surfaces?

you have to select the start point, and then use the check box

[gms1]

The angle in which you program plays into it also. Sometimes that angle determines whether you start at the top or bottom of the part.

[Odell]

I always extend my surface out half the diameter of my tool when starting a surface, or if you have roughed it down you can calculate how much to extend it so your tool doesn't gouge on the first cut.

[Colin Gilchrist]

If I understand correctly, you want to start cutting at the "high point" on the surface. Parallel really doesn't do that. It takes parallel cuts in XY at the angle you specify.

 

The "Start Point" pretty much tells the toolpath which "corner" of the surface to start at.

 

What you really want (I think) is a different toolpath. Try Surface Finish Contour.

 

This toolpath always starts at the "Top" of a surface and works downwards. You can use the "Shallow" button to add cuts by specifying a minimum stepover and minimum step down of the tool.

 

Can you post an example file on the FTP? Then we could give you better advice.

 

I can tell you that I barely use any of the "Parallel" style toolpaths anymore. There are newer toolpaths in the Mastercam arsenal that are much more efficient for machining...

[MadPickinSkills]

Hello all, thanks for the replys.

Colin,

I'll try the Surface Finish Contour path like you suggested.

 

Thanks again

[MotorCityMinion]

"This toolpath always starts at the "Top" of a surface and works downwards."

 

By default. De-select optimize, then select order cuts bottom to top.

 

Parallel is one of the smoother paths and often produces good results with surfaces that have an incline of less than 30DEG.

 

You may also be able to force a start point at the bottom of your cut and work your way up thru the aggressive amounts of stock quite painlessly.