Backplotting Rotary toolpaths

[Kylis-dad]

I'm working in Mastercam 2020, programming a complex part using a lot of rotary/ axis substitution tool paths. It's a Horizontal machine so I'm programming in the front plane. When I backplot a toolpath, the tool comes in from the back plane, the solid model rotates 180 degrees and begins it's backplot. Basically, something is 180 degrees out. Everything is posting correctly, and the verification is correct. it's just really annoying. Has anyone else ever encountered this problem?

[crazy^millman]

11 minutes ago, Kylis-dad said:

I'm working in Mastercam 2020, programming a complex part using a lot of rotary/ axis substitution tool paths. It's a Horizontal machine so I'm programming in the front plane. When I backplot a toolpath, the tool comes in from the back plane, the solid model rotates 180 degrees and begins it's backplot. Basically, something is 180 degrees out. Everything is posting correctly, and the verification is correct. it's just really annoying. Has anyone else ever encountered this problem?

Welcome to the forum. 

Yes I see this with just about every toolpath at the initial position when doing not only rotatory but also full 5 Axis toolpath. If doing one operation by itself you have to ignore the first position in backplot it is bogus. To test make a dummy point toolpath before your operations and one at the end of your operations. Then backplot all together and you will see the issue goes away. It has been annoying for almost a decade when the Moduelworks Switch was made for Verify. Back plot was rumored to be leaving, but thankfully they were just that rumors. I have a MT project right now the 1st move is 150 degrees away from the real 1st move. Switch to interpolate mode from endpoint in backplot and hit the S button. Crash fest all day long that is not real. With Transform toolpath you will also get this no matter what you do if you are back plotting step by step you will see really odd behavior in backplot. Where using a Machinesim tied to a post is about the only about 99% way to be sure what is going on in Mastercam. Using external CAV is your only other way besides running it at the machine and hoping all those bogus moves are not real.  

 

[Colin Gilchrist]

5 minutes ago, crazy^millman said:

Welcome to the forum. 

Yes I see this with just about every toolpath at the initial position when doing not only rotatory but also full 5 Axis toolpath. If doing one operation by itself you have to ignore the first position in backplot it is bogus. To test make a dummy point toolpath before your operations and one at the end of your operations. Then backplot all together and you will see the issue goes away. It has been annoying for almost a decade when the Moduelworks Switch was made for Verify. Back plot was rumored to be leaving, but thankfully they were just that rumors. I have a MT project right now the 1st move is 150 degrees away from the real 1st move. Switch to interpolate mode from endpoint in backplot and hit the S button. Crash fest all day long that is not real. With Transform toolpath you will also get this no matter what you do if you are back plotting step by step you will see really odd behavior in backplot. Where using a Machinesim tied to a post is about the only about 99% way to be sure what is going on in Mastercam. Using external CAV is your only other way besides running it at the machine and hoping all those bogus moves are not real.  

 

I haven't tried it yet, but does changing the Home Position values for the Operation make any difference Ron? I know at one point they added a 'start/end at home position' switch. I think it tells Backplot "where to go for a Toolchange".

This probably won't fix it, but worth a shot to try it out.

[crazy^millman]

23 minutes ago, Colin Gilchrist said:

I haven't tried it yet, but does changing the Home Position values for the Operation make any difference Ron? I know at one point they added a 'start/end at home position' switch. I think it tells Backplot "where to go for a Toolchange".

This probably won't fix it, but worth a shot to try it out.

Problem is the angle of the tool in relation to the start plane. I have 5 axis drilling toolpath and the Plane is top, but the 1st hole is 150 degrees from that position. When you do like I said and make a dummy point operation and backplot them together then you don't see the drill toolpath start out incorrectly, but by itself back plotted the tool is positioned incorrectly. Same thing happens is 4 axis and 5 axis toolpaths unless the start plane is identical to the operation then you don't see if, but if the tool is different than the plane and you backplot the toolpath by itself it will always be wonky. In transform toolpath doing Multi Axis work and stepping line by line in backplot you also see this.

[nickbe10]

7 hours ago, crazy^millman said:

To test make a dummy point toolpath before your operations and one at the end of your operations.

Yep. haven't done any multi axis for a while but I would always post it out and see where it "wants" to start and then give it a nudge in the right direction.... 

[crazy^millman]

6 minutes ago, nickbe10 said:

Yep. haven't done any multi axis for a while but I would always post it out and see where it "wants" to start and then give it a nudge in the right direction.... 

Curve 5 Axis in MT is my best friend since Multiaxis linking is not a part of it. Back plot save to a level and then project lines to my clearance cylinder and good to go.