Hi there, I just finished putting the Altmill 4x4 together. Iâm new to CNC and just have a few questions to get to know this machine better.
I was expecting physical limit switches on both ends of each axis to prevent crashes - am I right in assuming that the closed-loop stepper controllers act as a limit switch here? In other words - in case of an error the machine would âcrashâ in to the rubber bumpers and trigger a stepper controller error when it canât move any further? What about the Z axis (no rubber stops)? (I understand that homing on startup and correct max travel in firmware settings should usually prevent this)
In the video tutorials, G-Senderâs firmware tool has descriptive names for all the $ settings (at least the ones they show in the video). But when I tried to change my default spindle, my $395 setting, and all the $ settings after 133 are all just called âCustom EEPROM fieldâ. I did select Altmill 4x4 + Spindle as my profile. Could this be a bug? The spindle works but Iâd like to really get to know this software and how it works.
The altmill has physical limit switches but I can not recall having seen a CNC setup where these switches actually directly interact with the motors/power in order to prevent an actual crash. They talk to the controller and it is the controller that acts on that input.
There are many scenarios where the controller raises an error condition and shuts down the motors. Hitting an obstruction (such as a bumper or maybe a fixture clamp) is one reason.
The physical zero position is slightly off from the rubber bumper. If everything works as it should, the rubber bumper would never be bumped. Alas, crap happens and that is why you have a bumper.
The z axis has the limit switch but you are right, there are no bumpers. Guessing on the reason, I would say the axis has very little mass and is relatively slow speed so a bumper would likely not be needed.
Regarding the second question - yes, itâs annoying that a field is labelled âcustom eeprom fieldâ. I wouldnât call it a bug, it is done on purpose for some unknown reason. There might be documentation available for these entries but I am not aware of anything - ask Sienci tech support and maybe they can help or explain why there isnât a better field description.
I can only chime in on part of question 1 as I own a LongMill without the SuperLongBoard.
That is why only one switch per axis is needed. Once the machine is homed it knows where zero is and that it canât go beyond the max travel for that axis. Of course my machine does not have closed loop steppers so if something caused me to lose steps then my machine could still crash. That shouldnât be a problem for you with the closed loop steppers on the AltMill.
Be safe, the AltMill is a beast compared to the little 3018 that I made my beginner mistakes on. Now I only have to worry about non-beginner mistakes.
You need to connect using the grblHAL firmware, not grbl. I can see in your screenshot you are using the wrong controller. That is why you donât have proper descriptions. Itâs not a bug, just user error.
Donât believe themâŠthe ONLY thing that prevents this machine from slamming into those bumpers is the inductive sensors. There ARE NO LIMIT SWITCHESâŠdo YOU see any? I know this because the very first thing I did was crash my Z into the ball screw at the top because my inductive sensor was not sticking out enoughâŠand no, there is no rubber bumper. They tell you to make sure the sensor is behind the top of the pocket it is in but that is bolognaâŠthe ball screw passes well beyond that surface and so your sensor should stick out beyond a bitâŠbecause the ball screw passes WELL beyond it. Testing it effectively manually with a piece of metal as prescribed is just plain uselessâŠyou need to manually jog Z up till about 1/4" of the guide rails are left visible at the topâŠat this point your sensor should be tripped. If it isnât, jog down and adjust the sensor outward and repeat. I did not see a single visible limit switch anywhereâŠand there is exactly one inductive sensor on each axis.
I just got my Altmill and appear to have had the same issue as @softwareguru
The z-axis sensor had to be slightly proud of the plate, not slightly recessed, for it to work. Got plenty of error 10âs until it was setup properly.
It looks like there is about 3-4mm space between the plate and the ball screw carriage. But hard to tell from the viewing angle.
The confusion started right with DoNt BeLiEvE tHeM!!1
I like my thems to be a bit more specific. Did you ment all the posters trying to help out in this thread like micheal, jens and kgn. Or is them only one of them representing a greater evil and are you trying to warn we are being invaded by aliens, trolls or worse, a wef like entity?
Are they trying to have us crash our machines so we will keep buying new ones, thus depleting our planets resources before we can become a space faring civilisation.
Or is this a elaborate scam to somehow get us pure bloods to get a vacination against our will so they can kill us with their evil 5G signals like they did with all the sheeps that took the bait the first time.
Itâs a diversion from the fact that we never landed on the moon, I knew it!
Is it the reprillians? Itâs the bloody reptillians again, isnât it!
Who is them and what is it they are trying to make us believe?
âThemâ is the people that keep refering to an inductive sensor as a limit switch. Its like refering to a âpressure sensorâ sensor as a safety valveâŠits just not true and it is misleading. Even sienci labs eludes to âlimit switchesâ that are nonexistant. So yeah, dont believe themâŠ
The inductive sensor switches gnd to a pulled up pin when triggered. The controler reacts to this input by stopping the movement in the direction of said sensor. I call that a limit switch too.
@Spamming_Eddie@softwareguru OK, guys, Iâll leave the last couple of posts, but please keep this on topic. I will delete these posts and any others that continue in the same vein.
Letâs stay friendly and informative, please.
