I´ve just installed MACH3 on my third home-built CNC machine, 3 axis for the moment, A axis pending mechanics, harmonic drive etc.
My knowledge of the program is admittedly scratchy, but after nearly 8 years of using the 25? functions that everyone needs, and many hours of milling, I can´t find out why this is happening...
So here´s the thing; if I need to press RESET on the MACH screen, after say an MDI g-code entry, the machine stops...ok up to here. But when I press Reset again to unlock MACH, the DRO´s mysteriously all go to zero, hence I lose my position.
This didnt happen on my other two machines, so any help offered I will be very grateful.

Thanks,

Frank

Hi,
its been a while since I used Mach3, I now use Mach4, which is very similar and that's is what happens when you RESET the machine.
This causes a crash stop, whatever moves in the motion buffer are aborted, and consequently Mach no longer knows where it is.

Try using <FeedHold>. It stops the machine but it consumes the last of the movement data in the motion buffer and so when it stops it knows
where it is. You can hit <Cycle Start> and the machine will carry on. You actually have to stoip the job if you want to jog, ie you cannot jog
around while in FeedHold.

Craig

Hi,
if you want to jog around in the middle of a job then hit <Feed Hold>. The machine will stop, but you may notice a very short delay, that is Mach
consuming the last of the trajectory data that's already been issued. Typically the delay is 0.2 to 0.5 seconds, so hardly noticeable. Now that the machine
has stopped hit <Stop>. This stops the Gcode program and releases the Code interpreter/trajectory planner to Mach. Now you can jog around or do as you require.
If you now want to restart the job that you previously stopped you'll have to use <Run From Here>. You really need to read that closely, then read it again and then
a third time!. It works but has caused more crashes than any other feature of Mach. There is a procedure and you MUST FOLLOW IT EXACTLY or you will have trouble.

Craig

Thanks Craig, and apologies for not relying before, I wanted to visit my old partners shop and check what happens exactly when I push reset on that other (MACH3) machine, before answering you, cause I´m convinced it doesnt retest DRO´s to zero.
That said, your answer makes complete sense...there could be a loss of position, and so it resets to 0 just in case the machinist doesnt realise this, if the difference was small. And your advice is good; Feed Hold instead of E Stop, but not always possible, obviously.
My old partner is finally available tomorrow so i will chk that machine just for further info.
Thanks again!
Frank

Hi,
I don't have an Estop on my machine, I have a big <FeedHold> button. I don't like that Mach loses reference when you hit <Stop> or <Reset> or <Enable/Disable>,
so I have a <FeedHold> button instead. Sure, it takes up to an extra 180ms to stop (draining the motion buffer) and the spindle does not stop, although you can
have the spindle stop on <FeedHold>. I fid it perfectly adequate and have done for ten years.

Craig

Hi Craig, sounds good, is it a physical button, or the screen button? i would like to install them, physical buttons in a box I mean, so as to not have to go running to the screen everytime I want to Run Cycle, Pause, Feed Hold, whatever....but is secondary on the priorities list at the moment. I have seen videos where guys do it, so it´ll happen...

Hi,
its a great big red stop button, its just that its a FeedHold rather than an Estop.

After quite some years I've found that there are actually not many buttons that I use regularly.

<CycleStart>, <FeedHold>, <GotoWorkZero>, <ZeroX>,<ZeroY>,<ZeroZ>,<LoadGcode>,<LoadRecent>,<CloseGcode> are the most common ones.

I've used Mach4 and an Ethernet SmoothStepper for eight years. I've made my own breakout board with all three of the ESS ports developed so I've plenty of spare
inputs. Probably more importantly Mach4 has a a really strong set of GUI editing tools. If I really wanted I could make a stripped down Mach screen. That would allow
the use of bigger screen buttons and that would in turn allow the effective use of a touch screen.

Truth is though the just standard Mac4 is perfectly usable as is....I really don't need to fiddle with it. What I do need to do is finish my fifth axis and convert my fourth axis
to a trunnion table. Always something to do......but you have to prioritize what you want to do ....or you just go around in circles.

Craig

Sounds great, something I could implement.
Mach4 I´ve seen conflicting reprots...some dont like it over Mach3, you obviuosly do.
I used Leadshine Easy Drivers, they have encoders.
A touch screen is on the list too, but first FINISH THE MACHINE  ; - ))
Fifth axis??? Thats really where I want to go...but again, first, an rotary A axis, and eventually a trunnion and later B and C on there own head. My previous machine for milling tech foams, polystirene etc,  had a rotary, and theres loads can be done with some creative programming.
But thats big talk for me at the present. FINISH THE MACHINE, get it up and running, with an eye to doing even stone or local alabaster, sell...the big word a sculptor needs to do.
I will watch your space for news of fifth axis!
Frank

Hi,

Mach4 is very much more flexible, especially the highly editable GUI, and this was done deliberately to get OEM customers. That power and flexibility does come at a cost,
and those whom do have the stomach for that sort of challenge seem to find any excuse to deride the advantages of Mach4.

https://www.machsupport.com/forum/index.php?topic=42891.msg278176#msg278176

Download it and try for yourself.

Craig