# Belts become loose on any axis movement **URL:** \ **Category:** Troubleshooting\ **Created:** [September 3, 2024, 3:26am UTC](https://forums.maslowcnc.com/t/belts-become-loose-on-any-axis-movement/22203 "2024-09-03T03:26:46Z")\ **Posts on this page:** 20\ **Page:** 1
**Author:** ![kyleschoen](https://yyz1.discourse-cdn.com/flex031/user_avatar/forums.maslowcnc.com/kyleschoen/32/26163_2.png) [@kyleschoen](https://forums.maslowcnc.com/u/kyleschoen)\ **Post date:** [September 3, 2024, 3:26am UTC](https://forums.maslowcnc.com/t/belts-become-loose-on-any-axis-movement/22203/1 "2024-09-03T03:26:46Z")
Fresh calibration, everything looks good. Corners are robust and I measured the frame very precisely. I retract, extend, mount the Maslow, and tighten the belts – they feel great and taut. Then if I move the Z axis, or any axis really, the belts loosen up, especially BL and TR. Same thing happens if I start a cut, the first thing it does is loosen the belts. I can go back and have the Maslow tighten the belts again, but same issue if anything moves. Is this normal? There’s a lot of play in the machine. Here’s an example of the BL belt (tried to aim it down what should be the centerline of the belt): ![IMG_9702](https://canada1.discourse-cdn.com/flex031/uploads/maslowcnc/original/3X/2/e/2e9e3c5e225f01f2745eb4022c23566d7a8799a8.jpeg) ---
**Author:** ![dlang](https://yyz1.discourse-cdn.com/flex031/user_avatar/forums.maslowcnc.com/dlang/32/859_2.png) [@dlang](https://forums.maslowcnc.com/u/dlang)\ **Post date:** [September 3, 2024, 3:59am UTC](https://forums.maslowcnc.com/t/belts-become-loose-on-any-axis-movement/22203/2 "2024-09-03T03:59:30Z")
When you did the calibration, was the router all the way to the bottom? David Lang ---
**Author:** ![kyleschoen](https://yyz1.discourse-cdn.com/flex031/user_avatar/forums.maslowcnc.com/kyleschoen/32/26163_2.png) [@kyleschoen](https://forums.maslowcnc.com/u/kyleschoen)\ **Post date:** [September 3, 2024, 4:11am UTC](https://forums.maslowcnc.com/t/belts-become-loose-on-any-axis-movement/22203/3 "2024-09-03T04:11:02Z")
Yup. And I removed the vacuum attachment. ---
**Author:** ![kyleschoen](https://yyz1.discourse-cdn.com/flex031/user_avatar/forums.maslowcnc.com/kyleschoen/32/26163_2.png) [@kyleschoen](https://forums.maslowcnc.com/u/kyleschoen)\ **Post date:** [September 3, 2024, 3:51pm UTC](https://forums.maslowcnc.com/t/belts-become-loose-on-any-axis-movement/22203/4 "2024-09-03T15:51:31Z")
Do I need to set the Z stop after bottoming it out as well, before calibration? After calibration the Z stop number was off. ---
**Author:** ![anna](https://yyz1.discourse-cdn.com/flex031/user_avatar/forums.maslowcnc.com/anna/32/22688_2.png) [@anna](https://forums.maslowcnc.com/u/anna)\ **Post date:** [September 3, 2024, 4:47pm UTC](https://forums.maslowcnc.com/t/belts-become-loose-on-any-axis-movement/22203/5 "2024-09-03T16:47:11Z")
During calibration the machine should set the ZStop automatically. Are you seeing the message about the Z stop during the calibration process? It should say “setting Z stop” or something similar after one of the pauses where it calculates. If not you can set it manually and you may need to upgrade firmware ---
**Author:** ![kyleschoen](https://yyz1.discourse-cdn.com/flex031/user_avatar/forums.maslowcnc.com/kyleschoen/32/26163_2.png) [@kyleschoen](https://forums.maslowcnc.com/u/kyleschoen)\ **Post date:** [September 3, 2024, 5:07pm UTC](https://forums.maslowcnc.com/t/belts-become-loose-on-any-axis-movement/22203/6 "2024-09-03T17:07:52Z")
I’m running v0.83, so pretty recent firmware. I bottomed the Z axis out before calibrating, but noticed when it was done the Zmin/Zm on the dashboard tab was like -34mm when it should be zero. Not sure if that’s causing the issue or not. Didn’t save the calibration log so no idea if it said it was setting the Z stop, but I can save the log next time. ---
**Author:** ![kyleschoen](https://yyz1.discourse-cdn.com/flex031/user_avatar/forums.maslowcnc.com/kyleschoen/32/26163_2.png) [@kyleschoen](https://forums.maslowcnc.com/u/kyleschoen)\ **Post date:** [September 4, 2024, 1:39am UTC](https://forums.maslowcnc.com/t/belts-become-loose-on-any-axis-movement/22203/7 "2024-09-04T01:39:43Z")
Did _another_ calibration made sure the Z was all the way down and still running into the same issue. Kinda stumped here. I bought it second hand, maybe the PO manually put in some weird settings? Here’s a video post calibration, showing the tightness of the belt, then jogging the Z up 10MM and how it loosens up. The calibration log was lost because the machine froze then overwrote the file when I saved again, but here’s the log of moving the machine in the video. Wondering if that “BL: -7.321” Is the issue. Maybe the BL calibration isn’t quite right? [Maslow-serial 3.log](https://forums.maslowcnc.com/uploads/short-url/6LqWPAJ2wdYxIKvPo6LmrDyp3M7.log) (1.8 KB) ---
**Author:** ![dlang](https://yyz1.discourse-cdn.com/flex031/user_avatar/forums.maslowcnc.com/dlang/32/859_2.png) [@dlang](https://forums.maslowcnc.com/u/dlang)\ **Post date:** [September 4, 2024, 3:44am UTC](https://forums.maslowcnc.com/t/belts-become-loose-on-any-axis-movement/22203/8 "2024-09-04T03:44:41Z")
all of the calibration and setting is in the maslow.yaml file, so if you replace that, it eliminates anything that was set before. what is the contents of your maslow.yaml file after the calibration? (all we need is the Maslow\_\* lines) David Lang ---
**Author:** ![kyleschoen](https://yyz1.discourse-cdn.com/flex031/user_avatar/forums.maslowcnc.com/kyleschoen/32/26163_2.png) [@kyleschoen](https://forums.maslowcnc.com/u/kyleschoen)\ **Post date:** [September 4, 2024, 5:01am UTC](https://forums.maslowcnc.com/t/belts-become-loose-on-any-axis-movement/22203/9 "2024-09-04T05:01:13Z")
Here’s the calibration data and full file below. Appreciate your two cents if anything looks off. ```auto board: Maslow name: Maslow S3 Board meta: Maslow_vertical: true maslow_calibration_grid_width_mm_X: 2000.000000 maslow_calibration_grid_height_mm_Y: 1000.000000 maslow_calibration_grid_size: 9 Maslow_tlX: -7.800000 Maslow_tlY: 2409.899902 Maslow_trX: 2924.800049 Maslow_trY: 2407.500000 Maslow_blX: 0.000000 Maslow_blY: 0.000000 Maslow_brX: 2925.100098 Maslow_brY: 0.000000 Maslow_tlZ: 0.000000 Maslow_trZ: 144.000000 Maslow_blZ: 97.000000 Maslow_brZ: 75.000000 Maslow_Retract_Current_Threshold: 1300 Maslow_Calibration_Current_Threshold: 1500 Maslow_Acceptable_Calibration_Threshold: 0.450000 ``` [maslow.yaml](https://forums.maslowcnc.com/uploads/short-url/mHkl9YVTc3F571rnwCtfFLWVbTi.yaml) (5.2 KB) ---
**Author:** ![dlang](https://yyz1.discourse-cdn.com/flex031/user_avatar/forums.maslowcnc.com/dlang/32/859_2.png) [@dlang](https://forums.maslowcnc.com/u/dlang)\ **Post date:** [September 4, 2024, 5:49am UTC](https://forums.maslowcnc.com/t/belts-become-loose-on-any-axis-movement/22203/10 "2024-09-04T05:49:26Z")
Ok, that looks reasonable. As you were doing the calibration, were the belts tight at every point of the calibration? David Lang ---
**Author:** ![kyleschoen](https://yyz1.discourse-cdn.com/flex031/user_avatar/forums.maslowcnc.com/kyleschoen/32/26163_2.png) [@kyleschoen](https://forums.maslowcnc.com/u/kyleschoen)\ **Post date:** [September 4, 2024, 5:57am UTC](https://forums.maslowcnc.com/t/belts-become-loose-on-any-axis-movement/22203/11 "2024-09-04T05:57:58Z")
When it starts the bottom belts go fairly slack. After the first few calibration points they tighten up more. I can take a video tomorrow if that helps. ---
**Author:** ![bar](https://yyz1.discourse-cdn.com/flex031/user_avatar/forums.maslowcnc.com/bar/32/10_2.png) [@bar](https://forums.maslowcnc.com/u/bar)\ **Post date:** [September 4, 2024, 4:49pm UTC](https://forums.maslowcnc.com/t/belts-become-loose-on-any-axis-movement/22203/12 "2024-09-04T16:49:37Z")
Thanks for the video! That is super helpful. It’s great to be able to see how slack is slack, it’s a hard thing to describe. > [@kyleschoen](#): > > Maybe the BL calibration isn’t quite right? I think that this is exactly what you are seeing. The calibration seems slightly off on that arm. You can try running the calibration again and if that doesn’t fix it, you can try upping this setting and then running calibration. ![image](https://canada1.discourse-cdn.com/flex031/uploads/maslowcnc/original/3X/2/f/2fb9a426cd7f06f1c37956816acd280808a46c3b.png) That sets how hard the belts pull during calibration and so it indirectly sets how tight the belts are when moving around since if we calibrate by pulling harder if there is any flex in the frame it will be taken into account. ---
**Author:** ![kyleschoen](https://yyz1.discourse-cdn.com/flex031/user_avatar/forums.maslowcnc.com/kyleschoen/32/26163_2.png) [@kyleschoen](https://forums.maslowcnc.com/u/kyleschoen)\ **Post date:** [September 4, 2024, 5:06pm UTC](https://forums.maslowcnc.com/t/belts-become-loose-on-any-axis-movement/22203/13 "2024-09-04T17:06:07Z")
Thanks guys, I’ll give that a shot. Also have a theory that the magnets might be loose. I bought it assembled and one belt was broken, when I disassembled to fix it a magnet fell out of the plastic sensor gear. So I might pull it apart and re-glue them all. I ran an extend and tighten cycle a few times and the axis were all close to zero, so that might not be it. However, would give some peace of mind. ---
**Author:** ![bar](https://yyz1.discourse-cdn.com/flex031/user_avatar/forums.maslowcnc.com/bar/32/10_2.png) [@bar](https://forums.maslowcnc.com/u/bar)\ **Post date:** [September 4, 2024, 5:21pm UTC](https://forums.maslowcnc.com/t/belts-become-loose-on-any-axis-movement/22203/14 "2024-09-04T17:21:19Z")
> [@kyleschoen](#): > > I bought it assembled and one belt was broken, when I disassembled to fix it a magnet fell out of the plastic sensor gear. So I might pull it apart and re-glue them all. That is 100% a cause for concern. > [@kyleschoen](#): > > I ran an extend and tighten cycle a few times and the axis were all close to zero, so that might not be it. However, would give some peace of mind. This is the right test for that so if it looks good maybe not the issue, but for sure something to keep an eye on. ---
**Author:** ![kyleschoen](https://yyz1.discourse-cdn.com/flex031/user_avatar/forums.maslowcnc.com/kyleschoen/32/26163_2.png) [@kyleschoen](https://forums.maslowcnc.com/u/kyleschoen)\ **Post date:** [September 5, 2024, 3:19am UTC](https://forums.maslowcnc.com/t/belts-become-loose-on-any-axis-movement/22203/15 "2024-09-05T03:19:31Z")
Pulled apart the BL reel and looks like the cable is wedged into the gear shoulder when fully retracted. This can’t be normal, right? ![IMG_9735](https://canada1.discourse-cdn.com/flex031/uploads/maslowcnc/original/3X/c/c/cc2636ebef646066e9bfccaac8a3c945520e48a9.jpeg) The magnet looks fine though. Also, @bar do you have any spare top router clamp assemblies? The bolt heads popped through on the Z axis support side. Wonder if they need a little more material under the bolt heads in the next version. ![IMG_9734](https://canada1.discourse-cdn.com/flex031/uploads/maslowcnc/original/3X/c/8/c895512c9b4a48d3013b2e6959e9dbced6a0cab1.jpeg) ---
**Author:** ![kyleschoen](https://yyz1.discourse-cdn.com/flex031/user_avatar/forums.maslowcnc.com/kyleschoen/32/26163_2.png) [@kyleschoen](https://forums.maslowcnc.com/u/kyleschoen)\ **Post date:** [September 5, 2024, 9:54pm UTC](https://forums.maslowcnc.com/t/belts-become-loose-on-any-axis-movement/22203/16 "2024-09-05T21:54:46Z")
Might have something useful here @bar — I replaced all 4 belts and recalibrated. It’s still loosening up the BL on any movement, but when I run the tighten command, it’s showing BL as about -8MM and change out. It happens after a jog and a re-tighten command, or hitting re-tighten multiple times in a row w/o a jog. Post calibration log snippit: ```auto Calibration complete Calibration values: Fitness: 0.5535789097949809 Maslow_tlX: -9.4 Maslow_tlY: 2408.7 Maslow_trX: 2930.5 Maslow_trY: 2406.4 Maslow_blX: 0.0 Maslow_blY: 0.0 Maslow_brX: 2927.1 Maslow_brY: 0.0 A command to save these values has been successfully sent for you. Please check for any error messages. [MSG:INFO: Setting z-stop position] [MSG:INFO: Calibration complete] Jog: X100Y100 [MSG:INFO: Measured waypoint 0] [MSG:INFO: Center point deviation: TL: 0.201 TR: 0.097 BL: -8.540 BR: -2.077] [MSG:INFO: Center point deviation: TL: 0.201 TR: 0.097 BL: -8.540 BR: -2.077] [MSG:INFO: Center point deviation within 15.000mm, your coordinate system is accurate] Jog: Z10 [MSG:INFO: Measured waypoint 0] [MSG:INFO: Center point deviation: TL: 0.174 TR: 0.124 BL: -8.363 BR: -0.252] [MSG:INFO: Center point deviation: TL: 0.174 TR: 0.124 BL: -8.363 BR: -0.252] [MSG:INFO: Center point deviation within 15.000mm, your coordinate system is accurate] [MSG:INFO: Measured waypoint 0] [MSG:INFO: Center point deviation: TL: 0.161 TR: 0.076 BL: -8.189 BR: -0.354] [MSG:INFO: Center point deviation: TL: 0.161 TR: 0.076 BL: -8.189 BR: -0.354] [MSG:INFO: Center point deviation within 15.000mm, your coordinate system is accurate] ``` Full log: [Maslow-serial (1).log](https://forums.maslowcnc.com/uploads/short-url/3CYnBArXmSH0YsXGNsvmOIJoljC.log) (22.8 KB) maslow.yaml [maslow (1).yaml](https://forums.maslowcnc.com/uploads/short-url/sL1lc5oOP5InMFtZ2B56svnNzIb.yaml) (5.2 KB) ---
**Author:** ![bar](https://yyz1.discourse-cdn.com/flex031/user_avatar/forums.maslowcnc.com/bar/32/10_2.png) [@bar](https://forums.maslowcnc.com/u/bar)\ **Post date:** [September 5, 2024, 10:15pm UTC](https://forums.maslowcnc.com/t/belts-become-loose-on-any-axis-movement/22203/17 "2024-09-05T22:15:01Z")
Good insight! That is a good indication that something in the calibration process which is going on with the bottom left belt, but it doesn’t narrow it down too much what exactly it is that is happening ---
**Author:** ![kyleschoen](https://yyz1.discourse-cdn.com/flex031/user_avatar/forums.maslowcnc.com/kyleschoen/32/26163_2.png) [@kyleschoen](https://forums.maslowcnc.com/u/kyleschoen)\ **Post date:** [September 5, 2024, 10:23pm UTC](https://forums.maslowcnc.com/t/belts-become-loose-on-any-axis-movement/22203/18 "2024-09-05T22:23:28Z")
It’s a second-hand unit, the belts and belt gear ring were pretty thrashed so I changed them last night. Inspected everything and made sure the gears were not too tight — seems to run better now. The frame is built to spec with some extra cross bracing and sitting at a 15° angle from vertical. I also updated the firmware to v0.83. Do you think any settings could have persisted from the previous owner despite a firmware update? Looks like he had some trouble with it and possibly changed some settings. Here’s one of his threads [M4 Calibration Questions - #47 by KDB](https://forums.maslowcnc.com/t/m4-calibration-questions/20154/47) ---
**Author:** ![dlang](https://yyz1.discourse-cdn.com/flex031/user_avatar/forums.maslowcnc.com/dlang/32/859_2.png) [@dlang](https://forums.maslowcnc.com/u/dlang)\ **Post date:** [September 5, 2024, 10:35pm UTC](https://forums.maslowcnc.com/t/belts-become-loose-on-any-axis-movement/22203/19 "2024-09-05T22:35:47Z")
go through a few cycles of extending and retracting the belts. Look at the values that are displayed for each belt after they are retracted. If any of them are significantly non-zero (more than 1-2mm, usually they should be down in the 0.1mm or below range), then you have a problem with an encoder. It could be a magnet not glued well enough, the magnet in the wrong place, or something else. David Lang ---
**Author:** ![dlang](https://yyz1.discourse-cdn.com/flex031/user_avatar/forums.maslowcnc.com/dlang/32/859_2.png) [@dlang](https://forums.maslowcnc.com/u/dlang)\ **Post date:** [September 5, 2024, 10:36pm UTC](https://forums.maslowcnc.com/t/belts-become-loose-on-any-axis-movement/22203/20 "2024-09-05T22:36:29Z")
All of the settings are stored in the maslow.yaml file, so when you replace that with the latest in an upgrade, you eliminate all prior settings. David Lang [Next page](https://forums.maslowcnc.com/t/belts-become-loose-on-any-axis-movement/22203.md?page=2)