[loddie]

Is there a way to limit the Z axis travel (retraction for clearance) when the tool is moving to another area to cut?




More info:

My machine has a limited Z travel of 7 inches. The tool blank is approximately 5" inches tall when at 0 and 90deg on an A axis. In both MadCAM 4 and MadCAM 5, I'm getting excessive Z travel for clearance on most tool paths. The machine control (EdingCNC, formerly USBCNC), will not accept the post G code files as the machine Z travel limits are exceeded. Thus, I have to manually edit all the Z clearance tool paths in the text file.

I've tried the following:

1. Setting the tool clearance (0.25"). No effect.
2. Setting the top clipping plane to just above the highest tool path. No effect.
3. Setting the Z axis home position to a low value (1") in the post process page. No effect. Not surprised as the excessive Z travel is apparent in the simulator, so I wouldn't expect the post process to change how the simulator appears.

It would be fine if it were only one or two, but with 6 tool paths, there are dozens of excessive Z travel clearance tool paths. The workflow is:

1. Import G code file into EdingCNC controller.
2. Controller identifies line code where Z travel exceeds machine limits.
3. Use Find tool in text editor to find line.
4. Edit Z travel to within machine limits and save file.
5. Reimport G code file into EdingCNC controller. It will then find the next troublesome Z axis tool path.

Repeat steps 1-5 many times until none of the tool paths exceed machine Z travel limits. If this was to repeatedly machine the same part, it would be OK, but I have to repeat this processor for every part as each is custom. So it is quite tedious and time consuming. I'm hoping there is some software setting I missed that can fix it.

Here are some images to illustrate the problem (MadCAM 4, Note how the clipping planes have no effect:

Attachment 322324

MadCAM 5 simulator:

Attachment 322328

In the EdingCNC controller:

Attachment 322330

[Gregore]

Loddie this is the second issue that your madcam is displaying a different out come than others madcam with the same or similar input .

I know mine does respect tool hight input as it causes me all kind of issues of it being too low when it Rapids from one part to another
( I wish there was a rapid hight safe setting as there is in other cam packages )

If madcam is reading the produced Gcode to create the simulator images then all of these issues could be in the post processor .

[Dan B]

If madcam is reading the produced Gcode to create the simulator images then all of these issues could be in the post processor .

The fact that you can simulate before posting tells you that it doesn't, I don't know of any CAM software that requires you to post before simulating. This is why a good post-processor is very important. Unless you have verification software like Vericut you are not really seeing with absolute certainty what is going to happen on the machine. Once you get the post tweaked and reliable, then you don't need to worry. We run a lot of machines, and the only one we run verification software is on our Hermle with a pallet system for running overnight. The reason for the verification software isn't because we don't trust our post, it's to check the movements between toolpaths.

Dan

[Gregore]

Thanks Dan I suspected that might be the case but was not completely sure ,

but back to loddies problem then it must be a setting in the machine, that gives him one thing and others another

[loddie]

The fact that you can simulate before posting tells you that it doesn't

Thanks Dan. That is what I had thought as well.

Thanks Dan I suspected that might be the case but was not completely sure ,

but back to loddies problem then it must be a setting in the machine, that gives him one thing and others another

Gregory, I don't think it is a setting in the machine. The machine has soft limits to protect the hard limits. My Z axis only has 7" of travel, and the stock material is 5". As it is 4th axis machining on almost all sides, I only need to go below the A axis (approximate middle height of part) about an inch at most. So even though the part is 5" tall, I only need about 3.5" of Z travel to machine the stock material. If the A axis is perfectly positioned in height, then that leaves about 3.5" for z clearance. While my machine is adjustable, I don't have the time at the moment to set the A axis at the perfect height to see if the Z retracting clearance tool paths are within machine limits.

It seems the only other option is to rebuild the machine with increased Z travel. Long-term I'm willing to do that, but not until I can confirm a post processor for MadCAM 5 works correctly with the EdingCNC controller. I was hoping the Z travel could be limited via in MadCAM so I would not have to manually edit a lot of tool paths and it would decrease machining time (there is no need for the Z to retract so much).

[loddie]

Actually, looking at the first image I posted above, I can see the total Z travel of the tool paths is ~6.5". So if there is no way to control Z travel in MadCAM, I can physically adjust the height of the Z axis.

[Gregore]

I think your doing something incorrectly in your setup

This is a pic of my tool path in the sim all of the Rapids have the same tool hight

Sorry upside down as I am using a iPad

[Gregore]

This pic shows how your set up should be

Put your model in the xyz center then put a line through 0,0,0 in the direction you want the rotation to be

( I have highlighted that line in yellow on mine )

Go to 4 axis function and pick the line with the pick line button press okay

Then tool path as normaL


Attachment 322914

[Dan B]

A little off topic...

Take a look at Jing. It's a free tool from Techsmith for taking screenshots. You can even save to the cloud and send links. It does short videos too.

https://www.techsmith.com/jing.html

You won't need to take pictures of your screen with an iPad. :-)

Dan

[Gregore]

normally i would not but I was lazy .... my computer that runs the cam and machine has no internet and I did not feel like using a memory stick to transfer it .

thanks for the link I will check it out

[svenakela]

At least don't hold your iPad upside down.