Z axis is going the wrong way!

FGSLWoodworks · November 21, 2024, 6:41pm

I have a Genmitsu 3018Pro with an upgraded Y-axis, Z-axis aluminum spindle assembly, and an upgraded spindle ( 24V Genmitsu CNC Brushless DC Motor Spindle Kit with Drive Board).
I set everything up and zeroed the X, Y, and Z axis’. I uploaded the Gcode file, and hit the “send”. Instead of raising up to move the spindle into position, it lowers (usually into the workpiece) and tries to drag the rotating spindle into position, destroying the workpiece or breaking the routing bit. This happens in both the Candle software and UGS software. Same when trying to use the “Safe Position” it thinks the safe position is into the workpiece instead of away from the workpiece.
It has been suggested that it may have to do with the dollar sign ($) codes

NeilFerreri1 · November 21, 2024, 8:36pm

First, Does the Z jog the correct direction?

If not,

What’s your $3 value?

To reverse the Z, you must first determine the current $3 value. If it’s 0-3, add 4 to it. If it’s 4-7, subtract 4.

FGSLWoodworks · November 21, 2024, 9:32pm

Yes, the Z jogs in the correct direction.
Also, the $3 value is at 0. So I should change that value to a 4?
Ummm, how do I do that? I am a quick learner, but am also a noob

NeilFerreri1 · November 21, 2024, 10:06pm

Then your Z isn’t moving the wrong direction. No need to change your $3 value.

When you click “Safe Position” can you see what command is sent.

Does your machine have homing switches?

How are you generating gcode? Can you share the first 20 lines or so of the gcode that caused the crash?

FGSLWoodworks · November 21, 2024, 10:27pm

Before we go further, let me make sure of something…is the Z+ button (Candle) used to move the spindle closer (down) to the workpiece, and the Z- for moving spindle away (up) from the workpiece?

NeilFerreri1 · November 22, 2024, 12:53am

No. I don’t use candle, but moving Z- should move the Z down and Z+ should move the Z up.

FGSLWoodworks · November 22, 2024, 1:56am

Thank you for clarifying that for me…that being the case, my Z-axis is reversed from how it should be.
I do not normally use Candle for running Gcodes, I use UGS. I know that in UGS, I can reverse the Z-axis through the setup wizard. It was a Sainsmart representative that had me reinstall Candle, so he could see what my ($) values were.
So, to answer your earlier questions, no, the Z-axis moves in the opposite direction, both when jogging, and clicking the “Safe Position” button moves the Z-axis down rather than up.
As far as “homing switches”, I am unsure what you mean. If you mean physical limit switches, then no, this machine does not have them.
Generating Gcode: I use Easel to create my Gcodes.
By the way, I really appreciate your help with this, I was becoming frustrated, and thought I had made some mistake when installing upgrades to my machine

FGSLWoodworks · November 22, 2024, 2:06am

Here are the $ values:
$0=10
$1=25
$2=0
$3=0
$4=0
$5=0
$6=0
$10=1
$11=0.010
$12=0.002
$13=0
$20=0
$21=0
$22=0
$23=0
$24=25.000
$25=500.000
$26=250
$27=1.000
$30=10000
$31=0
$32=0
$100=800.000
$101=800.000
$102=800.000
$110=1000.000
$111=1000.000
$112=600.000
$120=30.000
$121=30.000
$122=30.000
$130=200.000
$131=200.000
$132=200.000

Can you tell me where I can find what these values mean?

NeilFerreri1 · November 22, 2024, 2:20am

Wherever you can enter commands, type
$3=4

github.com

gnea/grbl/blob/master/doc/markdown/settings.md

## Getting Started

First, connect to Grbl using the serial terminal of your choice.

Set the baud rate  to **115200** as 8-N-1 (8-bits, no parity, and 1-stop bit.)

Once connected
 you should get the Grbl-prompt, which looks like this:

```
Grbl 1.1d ['$' for help]
```

Type $ and press enter to have Grbl print a help message. You should not see any local echo of the $ and enter. Grbl should respond with:

```
[HLP:$$ $# $G $I $N $x=val $Nx=line $J=line $SLP $C $X $H ~ ! ? ctrl-x]
```

The ‘$’-commands are Grbl system commands used to tweak the settings, view or change Grbl's states and running modes, and start a homing cycle. The last four **non**-'$' commands are realtime control commands that can be sent at anytime, no matter what Grbl is doing. These either immediately change Grbl's running behavior or immediately print a report of the important realtime data like current position (aka DRO).

This file has been truncated. show original

FGSLWoodworks · November 22, 2024, 2:48am

Thank you so much for this! It will be extremely helpful in configuring my machine. For the life of me, I couldn’t find these ($) value explanations anywhere (of course, I could have been searching for them in the wrong way).

MartinW.Mcclary · November 22, 2024, 12:55pm

This is a good site to bookmark too.

GRBL_Settings_Pocket_Guide_Rev_B.pdf

DarrelMiddleton · December 3, 2024, 3:44pm

FGSLWoodworks-
I had the exact same thing on my 4040 and the support team sent this to me and that resolved the issue. I hope that it helps.

Thanks for contacting SainSmart! This is George from SainSmart support. I am sorry to hear about the issue you are having with your CNC. To start things off, let’s make sure that your CNC firmware is ok. Try homing your CNC in Candle, and then type $RST=$ into the command console and hit enter. This will reset your CNC firmware to factory default. Once you have done so, try jogging the X axis up or down, does it move in the correct direction?

If so, go into Candle’s settings and use the following probing code:

G91G21G38.2Z-80F200; G92 Z14.09; G0Z5M30

Don’t just copy and paste, though, change the bolded number to the thickness of your Z probe as accurately as you can measure. It should be around 12.35 but it is always best to check. With that code in place, try probing and see how it goes. If it works without issue, does the offline controller also probe normally now?