[Kosh]

...And this post is a partial vent after spending 3 hours just trying get about 10 minutes worth of machining done.....

I've been having these consistent problems with movement. I DON'T think this is a CNCRP problem per se, but since everyone here tends to have
the same hardware stack, I thought I'd start here.

First, my machine details.

CNCRP Pro 4x2, nema 23, leadshine controller, ESS, Windoze 7 PC, Mach 3 (yes, the *approved* version of it). I have the CNCRP z-axis probe. I also have their proximity sensors hooked up, and a Z-axis proximity sensor which I use for homing the machine (documented in another thread here).

Here's what I'm having issues with.

• After homing the machine and loading a program, and having set my fixture location, as soon as I hit continue, it tries to move the Z axis to 0. The command is usually "G28 G91 Z0.". This is generated by Fusion360 post processing. For some reason, it doesn't seem to really know where Z0 is. It moves all the way up and .... SOMETIMES... trips that Z axis proximity switch. I'd say it's a about 50% of the time. The other 50%, it's very close but it gets there, stops and then continues (usually wanting a tool change).
  
  
  Should I just remove that Z0 or try to see if I can get it to not generate? Why would it need to go to Z0? And is that machine zero? It's clearly not what I zeroed the bit at.
  So I usually just clear the limit switch error, move it down a bit in Z, then continue.

• Similar to the first item, after I do a tool change and tell it to continue, it tries to move Z-axis up again. I don't know why this is, there is no instruction to tell it to do that. Once again, it will hit the prox switch about 50% of the time. Have to clear it, move down, and continue.
  

• Sometimes after I tell it to continue, it moves V-E-R-Y S-L-O-W-L-Y, sometimes in all three axis'. Usually this means it has lost it's way, if I don't stop it, it will continue to try and do the next op, but usually at a high and wrong Z value, Ie it is just cutting air

• Tonight, after having this last item occur, I rewound the program and took it to the current op, did "set next line", "run from here", etc. Mach3 was just acting wonky. It would just to some weird place in the op, to to the M1/tool change spot that is expected. I tried closing and reloading the program. I restarted Mach 3, I even rebooted the the entire system. Even after doing all that, it still was acting bizarre. Finally after a couple more tries of "run from here", it started working. At one point, I told it to "run from here", only to find it back at the top of the G-codes!

• ESS runs out of data. Yeah, as if the rest aren't enough, I keep getting ESS out of data errors. Tonight, it happened right after startup. I HADN'T EVEN LOADED A FILE. Was just moving it around to set my location, and get that damn popup telling me to re-home my system. I'd just done it 2 minutes earlier. Doesn't happen a lot though.

Seems to me like something is buggier than hell here. My suspicion is Mach3. What say ye? Could it be my combo of mach3 and windows version?

I've attached the program that was giving me the issues tonight, but it is not unique to this one.

[Kosh]

OK, I did a little digging around. Seems the main issue is caused by my G28 setting. I had set G28 in the config/homing screen when I first built the machine, and Z was at 0.

I didn't think this matters, as I've seen no indication that G28 was actually working. But i found a couple of things.

- in F360, I can unselect "use G28" in the post processing dialing, that removes that G28... Z0 line completely and the problem is gone.
- However, I went into my homing setup and switched the Z value to -.25, and that also works well. Now whenever it tries to do that movement, it stops at .25 in away from
the proximity switch and doesn't trip it. Program seems to run smooth after that.

Now, if *I* was coding a G-code processor, I would set machine Z zero at the back off distance from the prox switches during homing. Don't know why they do that. Is there a setting somewhere to tell it to do that?

[LeeWay]

I don't yet use Fusion 360 on the router. Just not brave enough to try it yet. Don't actually need it yet.
As for the incredibly slow movement after some tool changes, that is what I see with Mach 3 often.

I will eventually install Path Pilot on my router I think. It will take a little research to do it, but I really like it on my Novakon mill.

My z axis doesn't home yet, so I will need an upper home switch for Z first.
Looking forward to seeing how it all works out for you.

[ger21]

Sometimes after I tell it to continue, it moves V-E-R-Y S-L-O-W-L-Y, sometimes in all three axis'. Usually this means it has lost it's way, if I don't stop it, it will continue to try and do the next op, but usually at a high and wrong Z value, Ie it is just cutting air

I've never seen this, and am guessing that it's an ESS issue.
If you ever see Mach3 doing strange things, close it and restart it before continuing.

Mach 3 (yes, the *approved* version of it)

3.043.062?

[LeeWay]

I have seen it on several machines running Mach 3 and some of them do not have Smooth Stepper.
My fix is to always add G01 Fxxx to the tool change line.
Oh and it only happened with the Z axis. Not all three.

[ger21]

I have seen it on several machines running Mach 3 and some of them do not have Smooth Stepper.
My fix is to always add G01 Fxxx to the tool change line.

That sounds like something is changing your feedrate.
If you see it running slowly, is the feedrate by chance set to 6? That's the default feedrate in Mach3, and if it gets reset, and you're using Run From Here, it may be restarting at the default feedrate.

[LeeWay]

I have researched it quite a bit. It will not do it all the time even with the same code. When it happens, it is moving much slower than 6 IPM. maybe .5 IPM. It will not do it for all tool changes. Just some and then not consistently. That is what I call a bug, though rolly pollies are faster.

[CRP]

Kosh - Good find/call on G28 - For future reference / others benefit I'll add that there is a "CNCRouterParts" POST in Fusion 360 you can use that will have defaults (such as G28 disabled) and a couple other optimizations (though otherwise very similar to the mach3 post).

Attachment 324362


-Nathan

[Kosh]

Thx Nathan.

yeah, that was the trick it seemed. I've run it 3 times now, with G28 gone and also with it there but with my own G28 co-ords modified, and none of these issues.

Never noticed the CNCRP option! Need to spend more time looking around that I'm over the learning curve (we'll near the top).

So I spent last night tossing and turning over this (partly because it was hot, windows open (we use passive cooling) and the neighbors dogs was barking till 1 am...)

The reason I've thought all along that G28 was not working on my machine, is that it NEVER moves to G28 between tool changes, except for at the end of the program.Now I know that it WAS executing G28, but only doing the Z axis for some reason.

So...
- Start - moves up to G28 Z position only
- Before tool changes... SAME
- After last op completes, moves to G28 position including X & Y.

Why would that be?

PS. for Ahren and Nathan... I donated an old jointer to our local Maker space last week, and when one of the co-founders came he wanted to check out my CNCRP Pro. They have only a buildyourowncnc there now. Turns out he'd been eyeing the CNCRP online for awhile, and it was the first time he'd seen it in person. His comment... "Looks VERY solid!". He was quite impressed. So I told him I had nothing to complain about, it's a great kit.