Postprocessor - No Entry and Exit element

[artisanicview]

Hi all.

I am trying to use a custom postprocessor for Qcad and I do face an issue with some mechanizations when I do need to use the tool to be ON the center of the line (Side/Direction). Looks like the tool it is not plunging on the start position of the profile, but instead it is skipping the first segment and cutting straight away into the board without any entry point. I attached some files for reference. However If I do use the "Outside" of the shape in Side/Direction I do not face this issue.

[CVH]

Hi,

I just took a quick look ...
Can it be that you disabled the export block of the first move in Z?

Code: Select all

    this.firstLinearMoveZ = [
//        "; [TOOLPATH_NAME]",+
//        "G0 [X] [Y] [Z] [FP] [T]; MoveZ"
    ];

I would assume that the first move is a traversing.
Followed by plunging straight down into the material.
But for that motion the export will be empty in your case.

Regards,
CVH

[CVH]

Hi,

You also disabled this.rapidMove and this.rapidMoveZ.

this.rapidMove is the traversing (rapid) above the material to the start positions of a toolpath:
- From (0.0, 0.0) to (129.5,128.5)
- From (129.5,128.5) to (129.5, 88.0)
- From (129.5, 88.0) to (129.5, 68.5)
- From (129.5, 68.5) to (129.5, 49.0)

Each followed by plunging fast (G0) to just above the material with this.rapidMoveZ.
Then the tool would plunge deeper at plunge rate (G1 + FP) with this.firstLinearMoveZ.

Remark that these CAM entities are generated with adding the profiles.
See blue dash-dots lines on layer 'rapid'.
They are omitted in the export because your block code is empty.

For an example of the sequence of exported Code Blocks see halfway:
https://qcad.org/en/qcad-cam-postprocessor


For the record: I would swap the order of the 2 profiles.
First cutting the interior details followed by cutting out the piece.
In your order the piece would be floating free when cutting the grooves.


(Again) I detect something not quite right with the compensation entry.
If your 10mm cutter plunges at (129.5,128.5) it will cut a 4mm deep notch at the top middle of your rounded rectangular piece.
I would expect the compensation to be at the outside.
It is, but it is only 1mm long and your cutter radius is 5mm ... 5-1 = 4mm overcut.


You also disabled this.linearMoveZ
This is typically used to retract the cutter to Zsafe before starting to traverse to the next toolpath.


I don't understand the writeFirstPointMoveZ function.
With a drilling toolpath intended for the first point Z move with a new feedrate.
Typically overwritten for usage with a laser.
Why would you like to disable all/certain Z-up moves for milling?
What do you expect of comparing two positions by this.zStartPosition < this.zPosition ?
This are both RVector's with an X,Y and Z component.
RVector Class Reference

but instead it is skipping the first segment and cutting straight away into the board without any entry point.

For example:
Your first slot ends at X=129.5 Y=88 Z=-2
Zup is missing (this.linearMoveZ = [];)
Traversing to the second slot at (129.5, 68.5) is missing (this.rapidMove = [];)
Plunging fast at (129.5, 68.5) is missing (this.rapidMoveZ = [];)
Plunging into the material at (129.5, 68.5) is missing (this.firstLinearMoveZ = [];)
The first motion to cut to G1 X=215 Y=68.5 Z=-2 is NOT missing at all.
Because of the omitted exports this motion starts at X=129.5 Y=88 Z=-2 and is angled 347.152° instead of horizontal.
G1 simply means: Start from where you are and goto XYZ at feedrate.

What I can't explain at the moment is the overcut at either side of the slots.
There are no CAM entities in the 18PLY_center.dxf nor motions in 18PLY_center.nc that explain those.

Regards,
CVH

[artisanicview]

Thank you for reply. I will do some adjustments and do some more tests when I will have some spare time.