Why is zero Z not 0

Troubleshooting
1

It would sure be great if Zero Z was equal to 0, rather than the disappointment of having some oddball z height saved somewhere and not displayed. I got all the way to cutting and the z just lowered into the material, (not from the gcode) and started carving its way to the starting point where it lowered the right amount from that -z.

What is the point of this if we just hide numbers inside the machine and put oddball buttons in the ui? They just dont seem to coincide with what a person would want or expect if they didnt code the software.

Is this another hopeful setting in the yaml file? I dont get it.

1 Like
2

In fact if you zero the z, and press define home it shows again -10?

1 Like
3

Sorry, so the new button “Zero-Z” just sets the actual bottom of the Z, when both Z steppers are at the bottom.

To set the “zero” for the job, you will use the up/down Z button (image) to raise/lower the z until it hits the workpeice, back up a mm, then define home here:

image

2 Likes
4

something is up, i hit to move the axis up so i can pull the bit out again, and the machine moves left that amount, its all screwed up. the second time i press it the z axis moves.

but i can hit retract all and it homes again, which is odd to me also, why doesnt home send it back to home.

1 Like
5

ok so i started all over, reset the machine, pulled the bit out, bottomed out the z axis on the motors, went into setup and pressed zero z like you said, also, what is the maximum Z travel, i noticed it is also allowed to come off the threads through the interface. maybe a warning a couple mm before going off the top during axis moves?

now my z is around a value of 40

now it went right into the board again and stopped, so i guess i got to pull it off the frame again, Ill get back to ya, i have put it on and off about 10+ times today. I think i will work on a dependency diagram or some kind of workflow that makes sense for this tool, its been a pain to say the least and I built a frame with a bunch of tools to help pull it on and off again, i can see why building a small one on a bench would be the way to go until it got working. the largest size frame is, well, a bigger issue.

1 Like
6

This is an unfortunate choice of name, it is not “Zero Z”, but rather “Z-Stop”, it tells the M4 how far down the Z-Axis it can go, before it can’t go any further.

After that is the real Z Zero, which will be relative to when you have a bit in your router. And you’ll need to set this each time you cut

1 Like
7

I’d like to see us set “z limits” (bottom and top) but there is no physical limit switch, so there is no way to know when it gets to the top in the hardware so we’d have to rely on the z-zero and a guess or setting as to the max Z height. Not impossible, but just not implemented yet.

As I’ve said before, I have felt what you are feeling now. Taking this thing on and off the frame every time it needs to get its home again is frustrating. Know you are not alone and it is being worked on.

1 Like
8

Ron Lawrence wrote:

I’d like to see us set “z limits” (bottom and top) but there is no physical
limit switch, so there is no way to know when it gets to the top in the
hardware so we’d have to rely on the z-zero and a guess or setting as to the
max Z height. Not impossible, but just not implemented yet.

grbl does support soft limits, just need to get to that point on the to-do list

David Lang

1 Like
9

I understand about limits, but if I know the bottom and dont go to high, i never hit my head and I dont need to know where the ceiling actually is. anyway, i tried to write it up step by step, i got some work to do on it but let me know where I made any mistakes and I would like to help with this, this took a bit to get to, as of writing this I got a successful sign finally.

Make sure the router is turned off before turning on the main switch if you have configured your machine that way.

Turn Maslow On

Connect to Maslow “maslow.local” or your preferred method that works

Select the Maslow Tab at the top of the page

Press the “Alarm” button to release the Alarm condition
Press Setup button

If this is the first time then press “Config” when the Setup dialog opens.

You will need a tape measure for this, one with metric may be helpful or to go from inches to mm you can multiply the inches by 25.4 to get mm.

Input your frame dimensions from anchor point to anchor point and the orientation of the unit.

Make a note of your frame dimensions (I made a plaque on my frame, but any way to remember will do)

“Vertical” is standing up so the top two belts hold the sled

“Horizontal” is if your sled is parallel with the ground

Press “Save”

Note - You can press outside the window to go back to the main screen in case you do not need to configure your machine again.

Now you begin the Maslow start procedure. (This will be performed every time you shut off the machine)

Note - If router bit is inserted in the machine and you have not calibrated it I would suggest moving the Z up a bit and removing the bit before calibration because we will still have to define the “Zero Z” point, this is not home, this is the absolute bottom of the Z travel)

  • Release the Alarm
  • Open the Setup screen
  • “Retract All” (This pulls all the belts in so watch out if they can get caught on things)
  • “Extend All” (This should put the sled in the middle of your 4 frame anchor points)
    • If this is way off, or the belts are not extended long enough to attach the top

Two in the vertical orientation then the frame has possibly not been configured correctly so check that again that your dimensions are saved.

  • Is there a bit in the router?
    • (Yes) But it is clear of the spoil board from dragging, then you may go to the next step and decide whether or not to calibrate
    • (No) or you will take it out now to set your “Zero Z” point
      • Setting the “Zero Z” point is part of your setting up procedure, so here we go.
  1. With nothing in the router collet, bring your Z down until it bottoms out on the Z axis motors.
  2. Press the “Zero Z” button on the Setup interface

Note- This is not your zero starting point for your router, this is something different, there is another spot we want to start routing called “Home”, it will also need to be set, but more on that later.

  • Is this a calibrate session?

  • (Yes)f this is the first time you have put in your frame dimensions or maybe applied an update to the yaml file, then it is time for “Calibrate” - go ahead, it will move around now and pause for calculations periodically, it will take a little while

  • (No)If the calibration was performed and your just going to make another beautiful cut on your machine then you can “Apply Tension” - well lets get routin

Congratulations on a milestone - A successful calibration or just getting ready to route again. Just refer back to these to stay on the path.

  • At this point there should have been a successful calibration and your “Zero Z” point has been saved. Next time you power up you can just follow the directions and get to this point a little faster.
  • The machine is on the frame now - do we have a bit in the router?
    • (Yes) then head to the next step
    • (No), make sure the router is off and unplugged

(if you still have the setup screen up just click outside of it to close it)

  1. Press “Z” to bring the Z menu up
  2. Press on the number area to input a number (I like 10 to start out, if it is too high you have to start over setting your Z point again because it can come off the lead screws.) If you come off the lead screws go back to setting the “Zero Z” procedures.
  3. Press “Set”
  4. Press “Up” and the machine should move the router up (10mm in this example)
  5. Repeat this until you have enough room to install your router bit, the router button helper in the “Not Shop” on the Maslow website can be a nice tool to help with this procedure. This is where I shut off the maslow before I put my hands in to install the bit in case it goes rogue, this means we need to the belt dance again (not calibrate) but thats okay. Go back into the Setup screen and “Release Tension” to allow your belts to be removed, remove them from the anchor points and “Retract All” now or when you turn the machine on again and go to Setup.

(Note)The router bit should not extend below the sled at this point. (if you have shut off the machine and realized it is not up far enough you can turn it on and connect to it, release the alarm and move the Z up, again minding that it’s not too much so you don’t have to set the “Zero Z” again.

  1. Install your bit and tighten up the collet while keeping the shaft locked and follow your router’s instructions.
  2. Unlock the shaft and I like to turn the collet a little to know it is ready and everything is out of the way, including the locking tool or collet wrench.

(Note)I have realized since writing this up that having a hole in the spoil board where I can set my “Zero Z” is a bit helpful at this stage of the game. You can add this if it is helpful to your frame later.

(Note)You should be confident your router is installed correctly and that the bit is secured and your workpiece is also secure to the spoil board. Get help now if you are unsure on any of these.

  1. Install some material to cut, knowing that our sled will need some support around the edges, so give a little if your using a little piece or add some helpers on the edges where it will need support.

  2. Turn the Maslow back on again and follow the directions to get back to where we were. Belts all installed (Retract, Extend, Install Belts and then “Apply Tension” this time) This is the most normal routine to my knowledge after you have Calibrated and set your “Zero Z”

  3. Bring your bit down using the “Z” menu, try using small amounts when it gets close so as to not lift the sled off the spoil board. (I get close and when I touch at 1mm movements, I back it off)

  4. Load your .NC file with “Load File” and then wait for it to upload and then select it in the drop down box below the play/pause/stop buttons.

  5. Put the sled where your home is in relation to your file at this time and press “Define Home” There is also the “Define Home” Selection in the Z Menu and does the same thing if you have set your XY Home and need to do the Z Home, otherwise you can set your Z when you get it in place, this will help to not scratch your material with the router bit.

  6. Turn on the router and the vacuum and press play

4 Likes
10

Bear Fulmer wrote:

Note - If router bit is inserted in the machine and you have not calibrated it I would suggest moving the Z up a bit and removing the bit before calibration because we will still have to define the “Zero Z” point, this is not home, this is the absolute bottom of the Z travel)

This is a slight mistake, since the calibration assumes that the Z axis is all
the way down, and the Z distance does affect the length of the belts, this will
cause some error in the calibration, you need to either remove the bit or change
the Z offset values to account for the extra height.

David Lang

2 Likes
11

Nice write-up!

I would edit this to say “10 mm” instead of just “10” because the Z axis can be operated in mm or in modes.

1 Like
12

Okay thanks we want to make sure it’s stripped down for calibration got you. Yeah any other changes keep em coming, I’m going to keep working on this document and try to clean it up but I kind of went through all the steps today, I did realize a little bit after messing with the z today that the belts do move a little bit and I almost asked why but I figured it out pretty quick It just it didn’t occur to me to put that in the calibration because when you first put it together there’s a lot to remember in a lot of different places. I tried to go step by step today and really hone in on the workflow and I want to make some kind of fun document I like to draw too so I hope to have some illustrations if I get time, thanks for all the help

3 Likes
13

Also if I’m not mistaken, if you just zero out the z steppers (drive them all the way down) prior to calibration, that will also get saved during calibration. My understanding is that the button is there to do it manually, but will probably move (and be renamed maybe?) to some “advanced” menu at some point.

1 Like
14

How can we better name the “Zero Z” button to make the name align better with what it does?

The goal is that the “Zero Z” button is used just one time to let the machine know where the limit of the z-axis travel in the down direction is.

The goal of the “Home Z” button is that it is used every time you change the router bit to let the machine know where the surface of the wood is.

15

Another thing I find is that the “Setup” menu is used more often than it should as a workflow. Though you need some similar options to get a job going, if you mess up those values or accidentally press some of them, you just lost another few minutes of “dancing” again, not as big an issue with a smaller frame. I would almost say to set the Z before you even put the sled on the frame so that when its finally up, your ready to do other things, i may change that order on my paper. And you may end up having to start over completely with updates it seems, with that also I have not seen updates or a changelog that identifies what is different from one version to the next, for example adding the Zero Z, was not clear when it was released or what the new procedure was, maybe these things are somewhere, I didnt find them or know after applying an update.
I would probably name it Z Motor Lower Limit or something that stays away from our coordinate system used in the job.

1 Like
16

Bar wrote:

How can we better name the “Zero Z” button to make the name align better with what it does?

The goal is that the “Zero Z” button is used just one time to let the machine know where the limit of the z-axis travel in the down direction is.

I would think that it needs to be set on every power up, just like the rehang
dance with the belts.

The goal of the “Home Z” button is that it is used every time you change the router bit to let the machine know where the surface of the wood is.

“set Z limit”
“set Z min”
???

David Lang

17

No, I got the non-volitle storage to work so it’s a one time thing.

I like this, but to me “limit” implies that the goal is to prevent the z-axis from hitting the bottom when in fact the goal is to help the math understand where the zero position is. Maybe the user doesn’t need to know that tho

18

It seems like if we now know the bottom of the steppers, can we make a config item / hardcode for the z max set to how many mms the screws allow and set limits in the firmware to not allow movement beyond those values? I think it would be great to have a command to go to top / bottom of Z (at least top, for bit changes).

1 Like
19

Bar wrote:

No, I got the non-volitle storage to work so it’s a one time thing.

it’s really for the lead screws to get turned as you are handling the sled
off the machine. Much easier than for a belt to move

I like this, but to me “limit” implies that the goal is to prevent the z-axis from hitting the bottom when in fact the goal is to help the math understand where the zero position is. Maybe the user doesn’t need to know that tho

possibly ‘identify’ rather than ‘set’???

David Lang

20

Ron Lawrence wrote:

It seems like if we now know the bottom of the steppers, can we make a config
item / hardcode for the z max set to how many mms the screws allow and set
limits in the firmware to not allow movement beyond those values? I think it
would be great to have a command to go to top / bottom of Z (at least top, for
bit changes).

enable soft limits
$S20=1
set soft limits
$130=X limit
$131=Y lmit
$132=Z limit

X and Y limits should probably be set to frame size. yes they can be set
smaller, but since you can only set the max value, not the min, that will lead
to protection only on two sides, and asymmetric behavior

David Lang

2 Likes