I could use some help

droftarts

@mac that’s great, nice and quiet too! Z problem looks like steps per mm, which I think you have set to 4000, so it is moving way more than 5mm, and so fast that it is skipping steps. Try 800, or possibly 400, which is more common for Z on these kinds of machines.

Ian

A Former User

@droftarts will do, thanks,Ian.

A Former User

@fcwilt I’ve never changed where any of the endstops are mounted. If I understand, in RRF, the X and Y endstops should be classified as “LOW”, not HIGH?”, correct?

And if I change those High to Low classifications, M119 will report that when the are depressed, they will be at Min, not Max?

RRF should change their Low and High to Min and Max, or, change their Min and Max to Low and High. The way RRF is now is creating confusion with how DWC reports the functions of endstops (min and max).

Mac

A Former User

@fcwilt that is a very good idea, and I am going to make that video today. Thanks, Frederick!

Mac

fcwilt

@mac said in I could use some help:

@fcwilt I’ve never changed where any of the endstops are mounted. If I understand, in RRF, the X and Y endstops should be classified as “LOW”, not HIGH?”, correct?

Yes

And if I change those High to Low classifications, M119 will report that when the are depressed, they will be at Min, not Max?

Hopefully

RRF should change their Low and High to Min and Max, or, change their Min and Max to Low and High. The way RRF is now is creating confusion with how DWC reports the functions of endstops (min and max).

It couldn't hurt to be consistent.

Frederick

A Former User

@fcwilt EXACTLY!

A Former User

@droftarts @fcwilt

I tried to make a video, but it just didn't work out. There are enough crimping videos on youtube already also.

We changed the steps from 4000 (which is the typical response according to Duet3D), to 400 (on Ian's advice).

I tidied up the wiring with zip ties, and now we're back at it, testing this and that.

Mac

A Former User

@mac Okay, the first bit of info I'd like to share: on the Endstops page of RRF, Z is set as Z-Probe at the location: Low end (versus High end). Because I'm not homing yet, BLTouch hasn't done anything. M119 is reporting Z: not stopped, Z probe: not stopped. (I was depressing the Z endstop - to no avail.)

Moving along here: 50mm is is 39.6875 mm in real life. I'm not going to swear by this, but the printer's moves towards the rear are relative consistent: it's 50 mm's is reality's 39.6875 mm's.

Finally, changing the steps from 4000 to 400 took care of that obnoxious noise the Z axis was making.

That's my report for today. Z sounds just as quite as X and Y. All of the axises are going the right direction.

Should I try to home Z? Nope, it's not happening. Is that because I sent the M564 H0 S0 command?

Mac

A Former User

@droftarts @fcwilt Homing update: X homed quite well, Y homed, but didn't come back far enough. When I asked Z to home, the print-head shuddered for a moment, then started to descend. Unfortunately, there was no bed beneath it for the BLTouch to sample.

So that's the latest wrinkle in all of this.

Mac

fcwilt

@mac said in I could use some help:

@droftarts @fcwilt Homing update: X homed quite well, Y homed, but didn't come back far enough. When I asked Z to home, the print-head shuddered for a moment, then started to descend. Unfortunately, there was no bed beneath it for the BLTouch to sample.

So that's the latest wrinkle in all of this.

Mac

As you may recall I home with a Z Endstop.

I use the Z Probe for:

setting the Z=0 Datum
creating heightmaps
leveling the bed

Some folks think having a Z Endstop when you have a Z Probe is foolish but I swear by it.

All of my printers have both and the all home with the Z Endstop. It can be quicker and the homing code is simpler.

Did you perhaps disable the M574 for the Z Endstop?

Frederick

droftarts

@mac change the X and Y steps per mm to 100. It is set to 80 in the last config.g you posted, but we worked out a while back that it should be 100. That should get the movement distance correct on those two.

Ian

A Former User

@fcwilt I wanted to have both. But selecting one precludes the other. Unless you know a way to have both in RRF?

droftarts

@mac you can use both, but there’s not much point. Homing with the Z endstop requires it to be configured with M574, and then a homing move of the axis to the endstop Homing with the probe does not need to be configured with M574 on Z (ie it doesnt need ‘M575 Z1 S2’ see M574 in the GCode dictionary) it just needs a move so the probe is over the bed, ideally in the centre, before running G30.

Ian

deckingman

...........and just to confuse things even more, I have neither a probe, nor an end stop. Although I guess having the hot end on a kinematic mount such that the bed touching the nozzle breaks a contact, is both a probe and an end stop.

fcwilt

@mac said in I could use some help:

@fcwilt I wanted to have both. But selecting one precludes the other. Unless you know a way to have both in RRF?

No it does not.

If it did how could all of my printers have both?

M574 can configure an Z endstop just like your X or Y endstop.

M558 and G31 configure a Z probe.

Frederick

fcwilt

@droftarts said in I could use some help:

@mac you can use both, but there’s not much point. Homing with the Z endstop requires it to be configured with M574, and then a homing move of the axis to the endstop Homing with the probe does not need to be configured with M574 on Z (ie it doesnt need ‘M575 Z1 S2’ see M574 in the GCode dictionary) it just needs a move so the probe is over the bed, ideally in the centre, before running G30.

Ian

We are going to have to agree to disagree.

Homing with a Z probe requires homing X and Y first.

And since Z hasn't been homed it's position is unknown thus you end up with four Z relative moves (2 for X, 2 for Y) to be sure it is clear of the bed while homing X and Y.

And an endstop can home faster than a BLTouch can.

So to me faster homing and simpler code is more than enough reason to have a Z endstop - it's not like it is an expensive item.

Frederick

droftarts

@fcwilt said in I could use some help:

I use the Z Probe for:
setting the Z=0 Datum

I guess you home Z first to the Z endstop, then home X, then home Y, then... probe Z?

How does that work if you have a power cut, and then resume? You have no way of knowing where the X and Y is before homing Z, which homes down onto the print.

A better use for a Z endstop is as a max Z endstop, so it can recover from a power failure without hitting the print, and then continue with the print. It can also check that the Z axis is or isn't at full height during the small relative move.

And since Z hasn't been homed it's position is unknown thus you end up with four Z relative moves (2 for X, 2 for Y) to be sure it is clear of the bed while homing X and Y.

I rarely bother homing axes individually, and generally use homeall.g. That lifts Z, homes X and Y at the same time, moves to the centre and homes Z. So it's one relative move (+5mm in Z) before X and Y is homed. So yes, there's relative move where the Z axis could hit the top of travel, but it's so rarely at max Z. And if you have a max Z endstop, that small relative move can be checked.

So to me faster homing and simpler code is more than enough reason to have a Z endstop - it's not like it is an expensive item.

Faster how? You can set the Z probe speed to whatever you want. You can do a fast probe, then a slow one, just like you do with an endstop (two speeds can be set in M558 F parameter). Faster because it's less moves? Like a second faster because it doesn't lift Z before probing? But then you set Z datum to 0 after anyway, which takes extra time?

Simpler code? Homing Z after X and Y means you can move to the centre of the bed area (where most prints are actually printed) with a G1 command, and set the Z datum with G30. Two commands. I'm not seeing where that is more complex.

Expensive? Absolutely not. But unnecessary, if you already have a Z probe, and comes with extra wiring.

What I'm trying to say is please don't encourage a newbie (ie @Mac) to go down a road that suits you, but makes it harder for him to get support with at a later time, because it's not how most people do it as far as I'm aware. That axes are homed X, Y then Z if you command G28 and don't have a homeall.g, it is clearly the intention of the writer of the firmware that it happens in that order.

Ian

A Former User

@fcwilt knowing what it can do is helpful. Knowing how to code it so it can do those things is what I need to understand. Yes, I know, read the documentation. I'm on it, but I'm also trying to answer the question I asked at the beginning of this thread. Which has not been answered yet, because if it had, my printer would be homing, which it's not.

I'm going to unplug my BLTouch now, and chock it's demise up to some kind of objection of it, even though I enjoyed watching it go across the bed of my BLV-Anet A8 during a 16 point survey.

Mac

A Former User

@fcwilt I get that, and I concur.

Still . . . I loved watching mine do it's thing.

Mac

fcwilt

@droftarts said in I could use some help:

What I'm trying to say is please don't encourage a newbie (ie @Mac) to go down a road that suits you, but makes it harder for him to get support with at a later time, because it's not how most people do it as far as I'm aware. That axes are homed X, Y then Z if you command G28 and don't have a homeall.g, it is clearly the intention of the writer of the firmware that it happens in that order.

Ian

You are entitled to your opinion but I absolutely disagree with your view of things.

Try doing this with only a Z probe:

Auto Bed Leveling

Frederick