Knocking sound on glowforge

Everytime the gf is abt to focus or centering, when it moves, i hear this knocking sound upon movement, do i need to put grease on the track? It doesn’t make any sound When is running the project though.
Is the belt loose? How do we replace the parts if it breaks?

If it sounds like someone tapping on the machine, three times, then again, and again, it’s the lens focus mechanism and completely normal.


Its not like that, everytime the gf moves to focus on the material, it makes a sound which didnt happen before, i justdescribed it as knocking sound , but i know it happens when the gf do its sudden move to focus on the material, when you hit the gf blinking light to start the project, the movement is more refined snd slower, so i dont hear any noise

would you be able to send a video of it?

To be clear: it happens after it is centered and is focusing. No knocking during XY movements? You have tested the movements of XY manually after turning the machine off?

Does it function correctly as in giving you the results you need?

Have you recently cleaned the lens? Did you take off the head and check to see if there is anything loose? The top plate of the head pops off. It is held with magnets. You can see if the angle mirror is seated correctly.

That’s all I got.

Im not sure whT is xy movement. Heres what happens,
When you turn on the machine, the first thing it will do is to focus on materials/centering etc… when the rail moves from north to south, thats when i hear the awful sound , its like rough, thats why im asking if i should out some grease on the rail, but i heard it will just collect dust.

We call the axis that the head moves left to right on the X axis and the axis the whole gantry moves back to front on the Y axis. So X and Y are the movements the head can make. Z is the axis of the lens focusing up and down, but with the Glowforge we don’t really think about it much and just call it head lens focus.

Turn off the Glowforge. Open the lid, not all the way so as not to stress the lid cable, and then pull down the front door. Take out the crumb tray. Get a flashlight and examine the rails on the left and right side. Check the belt and the little roller bearings. Make sure nothing is in the way.

Then look at the rail above the the head moves left and right on. Make sure the belt and the bearings are fine, firm and nothing in the way. It sounds like something is interering.

Moving the head left to right and front to back, look all over to make sure nothing is interfering with the movement.

Possible issues are loose belts, loose grub screws on the pulley on the stepper motor. Loose idler pulley. Dangling cables and belts here and there. Detritus on the rails.


One thing to note… If you are moving the gantry or the head manually, make sure you do so slowly. When you apply current to a stepper motor they turn… The reverse is also true. When you turn a stepper motor, as you would when moving things around in there (forward/back and left/right) the motors generate electricity and feed it back into the electronics. You CAN do bad things to them if you move things around too quickly, thus generating electricity.

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I’m so sorry to hear about the knocking sound.

I agree, checking the belt tension is always a good troubleshooting step.

When pressing lightly on one side of the belt, the other side should not move.

Like this:

(You should see an animated image above)

If the belts look as expected, could you please post a video of the laser arm when you hear the noise?

Let us know if you find anything out of place and we will follow up with your next steps.

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It’s been a little while since I’ve seen any replies on this thread so I’m going to close it. If you still need help with this or if you run into any other trouble, please either start a new thread or email