# Designing a universal time of flight z compensator **URL:** \ **Category:** Community Laser Talk\ **Tags:** focus, movable-z, auto-focus\ **Created:** [April 13, 2023, 11:37am UTC](https://forum.lightburnsoftware.com/t/designing-a-universal-time-of-flight-z-compensator/97406 "2023-04-13T11:37:25Z")\ **Posts on this page:** 6\ **Page:** 3
**Author:** ![ednisley](https://forum.lightburnsoftware.com/user_avatar/forum.lightburnsoftware.com/ednisley/32/40455_2.png) [@ednisley](https://forum.lightburnsoftware.com/u/ednisley)\ **Post date:** [November 15, 2023, 2:24pm UTC](https://forum.lightburnsoftware.com/t/designing-a-universal-time-of-flight-z-compensator/97406/41 "2023-11-15T14:24:15Z")
> [@misken](#): > > control the bed height adjustment Unlike CNC machines and 3D printers, the Z axis in larger laser machines does not ride on precision guides. In my OMTech 60 W laser, 700×500 mm platform rides on four large leadscrews with _terrible_ concentricity. They have upper and lower bearings pressed into the steel frame, but with no attempt at precision alignment: the entire platform moves in a circle about 1 mm in diameter in the XY plane as the leadscrews turn. Bonus: the platform moves _majestically_, so attempting to track the laser head height at normal engraving / cutting speeds can’t possibly work. ---
**Author:** ![jkwilborn](https://forum.lightburnsoftware.com/user_avatar/forum.lightburnsoftware.com/jkwilborn/32/63089_2.png) [@jkwilborn](https://forum.lightburnsoftware.com/u/jkwilborn)\ **Post date:** [November 15, 2023, 3:26pm UTC](https://forum.lightburnsoftware.com/t/designing-a-universal-time-of-flight-z-compensator/97406/42 "2023-11-15T15:26:02Z")
> [@ednisley](#): > > four large leadscrews with _terrible_ concentricity I’ll have to 👍 on this. Mine wobbles all over the place… If you’ve even seen the Sadler video on the _ **Russ Spec** _ machine, this is addressed… [Cloud Ray](https://www.cloudraylaser.com/products/cloudray-cr-series-russ-oem-co2-laser-cutting-machine?_pos=1&_psq=russ-s&_ss=e&_v=1.0) link to this machine. If I knew then what I know now, I’d bought this one 😵‍💫 There is a video in the Cloud Ray ad, this is the same video on [Youtube](https://www.youtube.com/watch?v=9MZNnHtoxe0). You’ll notice these Z axes bearings have been changed out for something a bit more accurate. I think it’s worth a watch. 😸 ---
**Author:** ![TravisGood](https://forum.lightburnsoftware.com/user_avatar/forum.lightburnsoftware.com/travisgood/32/205_2.png) [@TravisGood](https://forum.lightburnsoftware.com/u/TravisGood)\ **Post date:** [November 15, 2023, 7:29pm UTC](https://forum.lightburnsoftware.com/t/designing-a-universal-time-of-flight-z-compensator/97406/43 "2023-11-15T19:29:14Z")
I own one of these and am thoroughly pleased with it. Here’s a video I made after getting it over a year ago. (It looks different because, per Russ, it’s beta unit #2.) [![](https://img.youtube.com/vi/YR798vHpupQ/hqdefault.jpg "Cloudray Russ-Spec Laser Cutter") ](https://www.youtube.com/watch?v=YR798vHpupQ) ---
**Author:** ![jkwilborn](https://forum.lightburnsoftware.com/user_avatar/forum.lightburnsoftware.com/jkwilborn/32/63089_2.png) [@jkwilborn](https://forum.lightburnsoftware.com/u/jkwilborn)\ **Post date:** [November 15, 2023, 11:47pm UTC](https://forum.lightburnsoftware.com/t/designing-a-universal-time-of-flight-z-compensator/97406/44 "2023-11-15T23:47:25Z")
Smart move… 👍 😸 ---
**Author:** ![misken](https://forum.lightburnsoftware.com/user_avatar/forum.lightburnsoftware.com/misken/32/47593_2.png) [@misken](https://forum.lightburnsoftware.com/u/misken)\ **Post date:** [November 16, 2023, 7:19am UTC](https://forum.lightburnsoftware.com/t/designing-a-universal-time-of-flight-z-compensator/97406/45 "2023-11-16T07:19:27Z")
> [@ednisley](#): > > Unlike CNC machines and 3D printers, the Z axis in larger laser machines does not ride on precision guides. Ah, ok. Since I don’t have any, I didn’t know. That’s bad. Would have been an easy possibility to offload the movement from the head to something else 🙂 ---
**Author:** ![julienrl](https://forum.lightburnsoftware.com/letter_avatar_proxy/v4/letter/j/c57346/32.png) [@julienrl](https://forum.lightburnsoftware.com/u/julienrl)\ **Post date:** [June 11, 2026, 1:26pm UTC](https://forum.lightburnsoftware.com/t/designing-a-universal-time-of-flight-z-compensator/97406/46 "2026-06-11T13:26:48Z")
Hi all, first off an extra thanks to @Colin for providing the 80$ I needed to complete one of the prototyping phases. Unfortunately my health never did get much better and bigger projects like this are just out of my reach now. I’ve been coming to term with that change in my life lately, and as part of that I will be releasing everything I had so far. I am releasing everything I had done under GPL. I do exempt the light burn team from having to continue releasing modifications if they were to make an accessory / move the project along. If anyone wants to make a commercial product out of this, I’d love to be kept in the loop / participate in a limited capacity. > **[GitHub - wBrhy2/universal-time-of-flight-z-compensator: universal time of flight z compensator for lasers...](https://github.com/wBrhy2/universal-time-of-flight-z-compensator)** > > universal time of flight z compensator for lasers and other optical scanning devices [Previous page](https://forum.lightburnsoftware.com/t/designing-a-universal-time-of-flight-z-compensator/97406.md?page=2)