HELP! Router plunged all the way into work during carve

Hi All,

Brand new to cnc and I was doing a carve and maybe 2 cuts in the z axis dove all the way through the material up until the collet and then tried to move. Needless to say it freaked me out. Any idea what could be going wrong. The z axis also makes weird noises when i try and adjust it up and down any more than .01 while setting it to home.

Any help or ideas of what to check would be appreciated.

Weird noises most likely mean stalled motor which makes it “loose steps”.
Sort the Z-motion before you preceed to carving

Post your GRBL settings for $102, $112 and $122

Also check the black delrin block that connect to the threaded row/screw that it isnt secured too tightly to the backplate, it may skew and make it more difficult for the threaded rod/screw to rotate with minimum resistance.
There have also been cases where to delrin block threads are too tight for the screw to move freely, running it back’n’forth with a hand drill helps. Grease too suitable for POM/Delrin;)

Thanks. I will give that a try this evening. Pretty scary watching your machine plunge itself into your work and then try and move.

You should be able to turn the top pulley by hand with the power off. When turning by hand check to be sure the Z axis turn smoothly over the full range of Z motion.

Also check to be sure your top Z pulley is tightly secured to the shaft with the set screws. It is very common for these screws to be loose which allows the shaft to turn independently of the pulley which will cause lost steps and really scary problems like you saw.

When I try and turn by hand it is not easy to rotate and not very smooth? So is something too tight? do I need to put some lube on the screw? :thinking:

Dry Lubricant. Oils and Grease attract sawdust and gum things up.

What could be too tight? That would cause binding?

There are several things that can cause the Z axis to bind

  1. the eccentric nuts are too tight causing the v-wheels to nut turn. Be sure you can spin each v-wheel with your thumb

  2. the threaded rod is not straight, this will cause the delrin nut to bind, If the v-wheels all spin easily then your threaded rod may have an issue.

  3. the delrin nut is binding on the rod. You can fix this my running the nut up and down the rod several times, you can also apply some PTFE dry lube to the threaded rod.

  4. The belt may be to tight, unlikely but you can check by simply removing the belt and seeing if the top pulley turns easily.

  5. There may be an assembly problem with Z axis. Be sure you put it together correctly.