View Full Version : List of bugs in 4.3 MadCAM

07-22-2012, 04:48 AM
I have found a couple of annoying things in MadCAM 4.3, maybe you as well?

Pencil tracing does not honor the bottom clipping pane: I was roughing and z-level finishing to a depth of 12mm - pencil tracing did dive down to the very bottom of 20mm. That won't work.
3d planar finishing does create a toolpath where there is nothing to finish. Take a box and subtract an inner box so that it becomes effectively a ring. Planar finishing will work on the shoulder - fine - but also remove material from the inner hole where there is nothing. Can be avoided easily with clipping panes.
Toolpath sometimes outside the selected region curves when using z-level with the default radius lead in. Result is, you dive with high speed into the remaining stock still left. The roughing happened inside the curve only.
With 3d roughing quite frequently the toolpath created goes into the full material although it could also lower the z axis in empty space and approach the material from the edge.
I frequently have roughing toolpathes where a radius lead in is created into the full material, then it does traverse to another place and does the entire surface including the hole it created before. I see no reason for that hole somewhere, the later toolpath just passes over it as if it does not exist. I would understand that if there is an edge or the hole is needed to reduce the amount of material cut at once but no, it is just a hole somewhere in a large surface, result would be the same without.
Although the drill has cooling turned on, the G-Code postprocessor does not add the M07 or M08 command. It used to work before and I am not aware of a change I made. And idea?
I got the impression that when you do not save the definition of a drill, just modify e.g. the xy speed without saving, it gets ignored.
When defining a drill tool you can checkmark coolant-on but it is not saved. Next time you open the same drill coolant is disabled again.

What happened to me as well frequently is that in complex pattern I did not realize that two work pieces had a minimum distance of 6.5mm only. So when milling with 6mm drill and 0.3mm stock to leave, that obviously will not work. As a result the z-level finishing and planar finishing will dive into areas that where never roughed. Not very healthy. Some kind of graphical indicator would be nice. With 2D objects you can see it at least, but with 3d there might be too many lines to recognize it.

As much as I like MadCAM, I am a bit worried as well as there was no update on it since last November.

07-22-2012, 02:41 PM
1) You are right about the clipping plane and pencil tracing. It will be a service release for this as soon as possible.

2) By default, madCAM will create toolpaths also at the bottom plane of your default box. In the Expert Level version you can use "stop at parting line". This will make the planar finishing to go only where you have surfaces. It will also automatically stop at areas on your model where you have undercuts.

3) The lead-ins collision check is against the model. If you use region curves for the roughing, madCAM has no control for the lead-ins against material that has not been machined outside the curve. It is possible to avoid this if you extrude the region curve and include the extruded surface with the model. In the expert level version you can select a 3D-model as your stock material.

4) The 3D-pocketing approaches into full material because it starts from the center of each pocket. The 3D-facing starts from the outside edge of your workpiece when it's possible. Both toolpaths makes ramp approaches.

5) madCAM always creates a ramp approach on each lead-in. This is very important when cutting hard material and it would break the cutter without them. If the length of a pocket is too short for the ramp-angle or ramp depth that you set, madCAM will automatically remove "tiny" pockets and replace them with a helix lead-in that is wide enough for the ramp angle. If cutting in soft material, you can set the ramp angle to zero degrees, but then you will have a plunge approach.

6) The code for coolant on and coolant off has to be defined in the post processor. You can edit the post processor and add two lines for coolant on and off and then use the variables for it. (see below)
M06 T"toolnr"
S"speed" F"feed" M03
G43 H"toolnr"

7) That's correct. Some of the settings like speed, feed, coolant etc. has to be saved for having affect when you post process. There is an option for this when you post process. If you select "Cutters / User Select", you will be prompted to select a cutter and you will also be able to change settings temporary without having to save the settings.

8) You are right about the coolant when saving a drill tool. It will be a service release for this as soon as possible.

The 3D-cut simulator should show the roughing and finishing and you can use different colors. If you are having trouble, please post your part here or send it to info@madcamcnc.com and we will help you.
It hasn't been an update for a while, but it will be a service release for madCAM 4.3 very soon. We have also been working on the next version for Rhino5 64-bit.


07-23-2012, 03:32 PM
Thanks Joakim, greatly appreciate your input. That thing with the parting line is exactly what I was looking for. Many other doubts you have explained as well. And for the remaining ones I will try to create examples to validate.

07-29-2012, 05:25 AM
Okay, let's talk about 3) for a moment.

I have my raw material (green) and want to cut out the shown workpiece.
see image 1

To save time I don't want to mill a box, there is no need to mill the triangular area. So I create a region curve by taking the workpiece edges plus cutter radius plus 1mm. This is then roughed - all perfect.
see image 2

Step 3 is the z-level finishing. I leave all the default (to better visualize I set the radius lead in to a greater value) and as you see, this lead in cuts into the full material outside region curve. So my request is, honor the region curve as you do with roughing. No subsequent cutting should ever be outside the region curve.
see image 3

Something related I haven't mentioned, imagine the workpiece would be a 3d element, maybe that is a wing shape. Due to the fact that traversing is set to 3mm the cutter will be raised by 3mm from the current depth if that is the maximum z level for the traverse. So to traverse from one edge of the triangle to the other it has cut into full depth of z=-10, save clearance is 3mm, so it will traverse at z=-7mm from one side to the other. It assumes that outside the region curve there is no material, but the way I have used it there is - hence it tries to cut 7mm of material at once.

Both cases are similar, the assumption is outside the region curve is empty space. I use region curves a lot to break the entire material into areas, e.g. mount the raw material from the outside and cut the inner pockets entirely. Then screw down the raw material using the pockets and cut the outer side of it.

Using a stock model does not help either, just tried out. I defined the workpiece and the entire raw material as stock. Then defined the region curve and the resulting plan was exactly the same, including the z-level lead in cutting into the full material.


In that last image and the second as well you can see the other topic I meant in 5. Roughing is supposed to go one z-level step deeper, so it mills the four holes, then moves to somewhere else and does its ramp approach to dive on milling all it should including the holes it had cut before. Why are the four holes for? Would it better to leave them aside, dive into the material once and then remove all material?

(zip file contains the example with tool paths.

07-29-2012, 05:47 AM
And regarding the last sentence, let me visualize that as well.
My goal is a very simple shape to be milled as seen in the first image. So I just leave all the default and create the full tool path - shown is the roughing one.

There is just one thing I didn't think about, the two cones are 3mm apart at the nearest point and I use a 3mm cutter. So if I would have thought about this in advance I would have known the base surface will not be 100% flat or I would need a smaller cutter. But as it did not occur to me I very likely will not see in the generated toolpath and not in the simulation but once I did cut the material.

So all I am saying is, there is nothing wrong however you could help me spotting the mistakes somehow. What about creating two layers, one with the toolpath and one with the 3d-objects the toolpath cannot cut out although it should. So in essence this layer would show the workpiece as milled minus the workpiece itself. In a perfect world this will be an empty layer, when you mill a cone it will be a lot of tiny objects.