Newbie looking at 6040 (China CNC) for polypropylene 15mm sheet

[spluppit]

Because it's not part of the program. It's a little bit like you going for a walk in dense forest, you know where you are because you have a map, but then someone blind folds you and dumps you in a different position with no reference where you have come from.... you are then lost.

Some controllers will let you move out of position and others wont, it's highly controller dependent.

The normal thing to do is program a tool change position.

Example

Z 50.
X-100. Y100. (or were you want to tool to go for a safe tool change position)
Then a program suspend or stop.

Change tool... resume program.

But as we don't know what you procedure is, its hard to know exactly what you are doing.

Again it's not working as you think it should, but the controller is not the problem in this case.

[JAZZCNC]

Again it's not working as you think it should, but the controller is not the problem in this case.

Not necessarily.? Mach3 by default will let you Jog away between tool changes then when cycle start then go to next operation.
However, when using external controller some functions are taken away from M3 and handled by the controller and I'm pretty sure Jogging is one of them.
So if the controller doesn't handle this correctly when it hands control back to mach3 things can get screwed up.
This why Neale was seeing an issue when probing with Cslabs controller. In Cslabs case it's actually certain versions of Mach3 which changed how they worked at fault not the controller. Works fine with some not with others.

I think this could be the case here. I don't know which controller your using but might be worth trying few different versions of Mach3. I find older versions to be more stable, like neale I use 0.28.

[spluppit]

I nearly put in that i have zero experience of Mach of any kind. I was just drawing from my general experience of commercial controllers and especially ones with manual tool change like knee mills as an example. Some do accommodate out of position moves some don't. Mach will only be based on commercial controllers features. Looking at Jogaras reply from the mach forums it seems this was the case from what he said.

[Neale]

I nearly put in that i have zero experience of Mach of any kind. I was just drawing from my general experience of commercial controllers and especially ones with manual tool change like knee mills as an example. Some do accommodate out of position moves some don't. Mach will only be based on commercial controllers features. Looking at Jogaras reply from the mach forums it seems this was the case from what he said.

Whether or not Mach3, or its predecessor which then became LinuxCNC via a different development path, is based on commercial systems isn't really the issue - it supports the M6 toolchange command, and allows the user to add in a couple of macros that are called automatically before and after the toolchange itself. When it's working, it also allows things like tool-height setting using a touchplate during the toolchange, which is really useful on amateur-class machines which do not have preset calibrated toolholders and the like. It supports that way of working as well, but is a bit more flexible. However, as mentioned, when you are using an external motion controller, it can get confused if the motion controller does things Mach3 doesn't know about. I would certainly suggest trying an earlier version and general reports agree that .028 is a good bet.

[JAZZCNC]

I nearly put in that i have zero experience of Mach of any kind. I was just drawing from my general experience of commercial controllers and especially ones with manual tool change like knee mills as an example. Some do accommodate out of position moves some don't. Mach will only be based on commercial controllers features. Looking at Jogaras reply from the mach forums it seems this was the case from what he said.

Actually Mach3 isn't based on commercial controllers which is exactly why it became so popular because it did it's own thing without any of the restrictions commercial controllers imposed. However this eventually became it's downfall and why it as so many strange and wonderful habbits today.
As people requested more and more features for more and more oddball setups then because Art fennerty was such an obliging bloke it became a monster.
Each version that got released to take account of someone's request would break something for someone else. On top of this Art wasn't actually a programmer by trade just a genius who decided to have go because couldn't find a controller that did what he wanted. This meant the code was lets say less than easy to fathom for developers.
This is why so many external motion controllers fail because they don't have artsofts support and the code is mine field which tried to be All things to All machines and in lots ways won but in others failed badly.

All this said the fact remains that Mach3 DOES allow jogging in tool changes so it should work. If it doesn't then it's most likely down to the controllers plug-in.
Yes there are always work arounds but shouldn't have to in this case if the controller plug-in was working correctly.

[spluppit]

I guess what I'm saying is, why not program a simple G00 move to combat having to move out of position for a tool change manually. The controller will know where it is all the then. No reason for any errors if you do that. As you know Jazz, its a very simple and standard thing to do when required.