View Full Version : Tool Changes, what am I doing wrong?

phil m
12-04-2011, 06:52 PM
I tried to do some tool changes for the first time, didn't work. I first used a 3mm drill bit to cut a few holes then switch to a router bit to cut a contour, you can see that written down on the two layers in the properties. When I started the CNC, the drilling happened then after that it switched right away to the routing without stopping for changing the bit (i.e. it tried routing with my drill bit)

What do I have to do to get the machine to stop so I can manually change the bit and set the axis' again?


12-04-2011, 07:32 PM
I don't use mad cam but with out a tool changer you need to look at stuff a little different.

What I do is assign each tool path such as drilling, routing, part cut out to a separate file.

I run the drilling file when it stops I would then change to a router bit and run the next file.


Dan B
12-05-2011, 05:23 AM
Did your tools have different tool numbers?

Let's start with that. We do tool changes all the time with madCAM, so we can rule out the program as being the source of the problem.


phil m
12-05-2011, 05:50 AM
Probably not, I don't even know where to number the tools. Can anyone be so kind as to give me a point by point beakdown of what I need to do with MadCAM to do tool changes or point me in the direction of a decent tutorial on it?

Dan B
12-05-2011, 05:59 AM
Please see the attached screenshot from the madCAM help file. Does this help?


12-05-2011, 07:31 AM
Dan - great stuff as always

Phil - great to see you found your way here :cheers:

in my current workflows, and since I don't have a tool changer in my system (dream for some distant day when I have a spindle vs. a router head) I export tool paths based on the operation I plan to perform. in some cases I combine several steps with a common tool into a single export. in cases where I want to utilize one of several options within an otherwise common part (say I want to have the ability to choose a pickup configuration within a common body shape) I export up to the point where I would choose the unique feature selection and then export out each of my choices individually.

I'm sure there's a better way, but until I decide I have time to dive into scripting so I can author a quick interface to choose my options upfront, it works for me ... and it serves to help ensure I don't utilize the wrong tool for the current cutting path

the ROI on a spindle and tool changer are too small at this time to offset the time spent manually changing out cutters. someday ... someday :wee:

all the best,


Dan B
12-05-2011, 07:38 AM
Okay, maybe I misunderstood what the issue is here. Since this is the second post mentioning how to work without a tool changer, I'm guessing I'm the one that missed the point.

If you want to post-process so that each path is a separate code (so you can manually change the tool) then simply shut the layer off with the path you don't want and post. Then turn that layer back on, and the others off, change to a new file name (1000.nc, 1001.nc for example) then post again. You will get separate toolpaths for each layer.

Displaying all the layers with paths is a great way to create a concatenated toolpath, but is only effective with different tools if you have a tool changer.

Does this make more sense?


phil m
12-05-2011, 02:15 PM
Maybe i just don't understand how tool changing works. Can I just create one nc file that will have some sort of command to bring Z back up and stop moving so I can manually change a bit, reset the Z level in Mach and then press the start or hold button for the program to continue on its merry way?

Or do I need to post process a separate nc file and load that up in Mach each time i want to use a different tool?

I haven't found any info on any of that in the help files/videos/tutorials so far. (or will it do all that i want it to by simply numbering my tools as you show in your pic?)

Hi Rod :wave:

12-05-2011, 04:40 PM
If you haven't setup Mach3 to stop when a tool change command occurs, you will not have a stop and next path will be cut right away. Either do it the Dan-way (make multiple nc-files) or reconfigure Mach3 to really make a stop for manual tool changes.

That on the other is out of my scope, I have Heidenhain and EMC2 machines.

Dan B
12-05-2011, 04:43 PM
If you have a tool changer on your CNC machine, then the suggestion about changing tool numbers will work. If you don't, then posting each path individually is the proper procedure.

I suppose you could change your post to place an M0 (stop) at the tool change. I've never done that, but I suppose it might work. In that case, you would still need to change the tool numbers as I have shown in the picture, so that madCAM knows it needs to output a tool change to the post. Then instead of going to the turret to grab the tool, the machine would stop. I don't know if this would work, I'm kinda just thinking out loud. I would suggest you just post each path separately.


phil m
12-05-2011, 06:25 PM
I'm using a homemade cnc router, I don't have an automatic tool changer. Do I just need to change a setting somewhere in Mach3 to get it to stop automatically when it needs to change tools or should I have to live with making multiple nc files for each time I change tools?

Dan B
12-05-2011, 07:12 PM
I don't know anything about the Mach 3. Heidenhain is my main focus.

Hopefully someone familiar with the Mach 3 can chime in. However, posting each layer separately isn't that big of a deal.


12-05-2011, 07:19 PM
Hi Phil, Pretty sure there is a setting in Mach3 called "stop on tool change" or similar that you will need to enable. Then you will be able to run a full program and it will pause and let you rezero a new cutter when it picks up a new tool in the code.

phil m
12-05-2011, 07:28 PM
Sweet thanks for that i'll look into it