V21 Cam problems/questions

[kvom]

I replicated a 2D drawing that I had previously done in MasterCam. It took longer, but in the end I succeeded. When I went to generate the g-code I observed the following issues:

1) I have two chains that share line segments. One is needed for profiling and the other for pocketing. Getting the proper chain selected for operations seems impossible. The program seems to choose a chain semi-randomly. So far the only way I see around the program is to split the drawing into two. However, I'm sure there's a way to do this as it seems a very common situation.

2) The Mach3 post seems primitive. There are no prompts for spindle speed or feed rate on tool changes, so it seems that these need to be hard-coded in the tool macros.

3) The generated profile g-code had multiple G41 without intervening G40. This is supposed to be an error, but perhaps Mach3 ignores it. (?)

4) The first G41 preceded a G02 rather than a 1-axis linear move. Once again, perhaps Mach3 doesn't care.

I'm not sure how to selectively modify the program if I change the drawing or toolpaths.

OTOH, simple CAM operations like hole drilling and simple pockets were easy.

[moldmker]

1) I have two chains that share line segments. One is needed for profiling and the other for pocketing. Getting the proper chain selected for operations seems impossible. The program seems to choose a chain semi-randomly. So far the only way I see around the program is to split the drawing into two. However, I'm sure there's a way to do this as it seems a very common situation.

2 ways to handle this, either blank the unneeded chain (a different color or layer here makes selection easier) or translate one chain up or down in Z to separate from the other chain.

2) The Mach3 post seems primitive. There are no prompts for spindle speed or feed rate on tool changes, so it seems that these need to be hard-coded in the tool macros.

Prompts are done with prewritten scripts. Did you try downloading other mach posts? Some might have a few scripts bundled with them.
To get v21 posting exactly as you want, you will need to learn about scripts.

3) The generated profile g-code had multiple G41 without intervening G40. This is supposed to be an error, but perhaps Mach3 ignores it. (?)

This might be in the setup, on the CAM side look under Setup > Contour...
Select Modify for the Comp Left/Right menus and see if there is a @l@ G40 in the Chain End window.
Are you using the Machine > Profile command to create your code?

4) The first G41 preceded a G02 rather than a 1-axis linear move. Once again, perhaps Mach3 doesn't care.

If Mach doesn't care, sounds like you don't need it, many controls don't.
Otherwise, you would need to manually add a straight segment to the chain.
A script could possibly be written to do this, but it could be pretty involved.

I'm not sure how to selectively modify the program if I change the drawing or toolpaths.

Search and destroy....You need to find the code you want to replace, highlight and delete.
Now you can either post the new code directly into the empty spot(not always a good way) or post it at the end of the program and then cut/paste it into the right location.
Always make sure the tool retracts to the Z rapid plane when making edits.

[kvom]

2 ways to handle this, either blank the unneeded chain (a different color or layer here makes selection easier) or translate one chain up or down in Z to separate from the other chain.

I set the profile chain to a different color. However, it doesn't let me select by color when I do the Machine|profile, either before or after. Seems logical that it should.

I also couldn't find how to define a layer, which would also be logical. That's what I do in CamBam (which I like, although it has other problems). As I said, I'm just learning as I try things.

[moldmker]

The different color or layer reference was just to make the selection for blanking easier (Select by Color / Select by Layer).

As you found out, it does nothing for chain-selecting overlying entities.

You need to separate the 2 chains, either by translating or blanking.

As you start using v21 and realize the processes that are required along the way, you'll pick up on ways to keep entities organized as you create them and know how they will be needed later for toolpaths.

Many times I will import a DXF and put it on it's own layer. Then just copy parts of it to a toolpath layer so I can blank the DXF layer. Then I can manipulate the toolpaths easier.

Defining layers for different tool dias. is handy as well.

v21 does work good for 2D, just need to learn the nuances. The limitations are on the 3D side and that's where v23 is stronger.

Good luck

Just reread your post: To put entities on their own layer...select them...press A to open Attribute box...under the General tab, type in or select a new layer.

[kvom]

moldmkr,

Thanks for the hints on creating layers for the various profile. Just what I needed. When I get my mill installation done I'll be interested in seeing how well the generated code works.

Everything I will be doing in the forseeable future is 2D milling.

[SBC Cycle]

The different color or layer reference was just to make the selection for blanking easier (Select by Color / Select by Layer).

As you found out, it does nothing for chain-selecting overlying entities.

You need to separate the 2 chains, either by translating or blanking.

As you start using v21 and realize the processes that are required along the way, you'll pick up on ways to keep entities organized as you create them and know how they will be needed later for toolpaths.

Many times I will import a DXF and put it on it's own layer. Then just copy parts of it to a toolpath layer so I can blank the DXF layer. Then I can manipulate the toolpaths easier.

Defining layers for different tool dias. is handy as well.

v21 does work good for 2D, just need to learn the nuances. The limitations are on the 3D side and that's where v23 is stronger.

Good luck

Just reread your post: To put entities on their own layer...select them...press A to open Attribute box...under the General tab, type in or select a new layer.

Great post :thumbsup: