# Strong engraving at both ends but weak in the middle…? **URL:** \ **Category:** LightBurn Software Questions\ **Created:** [August 7, 2025, 2:38am UTC](https://forum.lightburnsoftware.com/t/strong-engraving-at-both-ends-but-weak-in-the-middle/177165 "2025-08-07T02:38:20Z")\ **Posts on this page:** 1\ **Showing post:** 20
**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:** [August 8, 2025, 6:24pm UTC](https://forum.lightburnsoftware.com/t/strong-engraving-at-both-ends-but-weak-in-the-middle/177165/20 "2025-08-08T18:24:39Z")
> [@santinif4](#): > > This was at 750 The manual and the simulation values show the laser tops out at 133 mm/s on both X and Y. You can set any layer speed you want, but the controller will not run the steppers at more than the maximum speed set in the `Machine Settings`. IIRC, GRBL uses mm/ **min** for the speeds shown in the `Machine Settings`, so you must convert from mm/ **s** when comparing the numeric values. > [@santinif4](#): > > 1% overscan The 500 mm/s² acceleration means it requires about 18 mm to reach 133 mm/s, which is likely much longer than 1% of the speed will produce, particularly for one-word-at-a-time scanning. The result is it’s proceeding at a much slower pace than you think. That makes diagnosing the problems much harder, because all our assumptions are wrong. > [@santinif4](#): > > things like these distortions Those are likely due to USB communication errors dropping out chunks of the commands. Using a better cable, typically one with molded-in ferrite cores, seems to improve the results. The `Troubleshooting` page has some suggestions: > **[USB Cables - LightBurn Documentation](https://docs.lightburnsoftware.com/2.0/Troubleshooting/USBProblems/)** > > Better software for laser cutters An earlier discussion suggests how long it takes to recover from various other non-solutions: > [@My Cherokee Beast](https://forum.lightburnsoftware.com/t/topic/107347/149): > > WOO HOO !!! I got everything working right , FINELY !!! What was the problem? It turns out to be the USB to Controller board cable was faulty. That was the only thing I failed to check and that was it. I have a bad habit of buying one to use and one to loose. When I thought about the cable being bad, I got the cable out the spare controller kit and that one worked. I feel really stupid sitting here thinking how I spent 4 to 6 weeks crying and trying to fix this thing and never though… --- _[View the full topic](https://forum.lightburnsoftware.com/t/strong-engraving-at-both-ends-but-weak-in-the-middle/177165)._