# Figuring out accuracy **URL:** \ **Category:** Troubleshooting\ **Created:** [August 3, 2025, 8:12pm UTC](https://forums.maslowcnc.com/t/figuring-out-accuracy/24654 "2025-08-03T20:12:14Z")\ **Posts on this page:** 4\ **Page:** 1
**Author:** ![Tore](https://yyz1.discourse-cdn.com/flex031/user_avatar/forums.maslowcnc.com/tore/32/25202_2.png) [@Tore](https://forums.maslowcnc.com/u/Tore)\ **Post date:** [August 3, 2025, 8:12pm UTC](https://forums.maslowcnc.com/t/figuring-out-accuracy/24654/1 "2025-08-03T20:12:14Z")
I cut this yesterday and wonder if it could be belt tension that leads to the issues. The lines are not straight and the holes are a little out of placement . The dimensions are 50mm x 200mm so it’s kind of small for the Maslow. ![20250802_213544](https://canada1.discourse-cdn.com/flex031/uploads/maslowcnc/original/3X/c/1/c17330358f9866fa4acf667f813616b71b3c3301.jpeg) I used the same feed rate from my earlier cuts. Around 800 with 12000rpm(600W Spindle). The flute is a “once used” 3.175mm uncut I believe. I got nice chips and no expensive sounds. As I’m just getting back in the game and haven’t checked any info on the newest upgrades, I wanted to do the cut with the config that worked last use before upgrading. Therefore, firmware version is 1.01 and my index.html is still at 0.88. ---
**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:** [August 4, 2025, 4:14pm UTC](https://forums.maslowcnc.com/t/figuring-out-accuracy/24654/2 "2025-08-04T16:14:53Z")
Belt tensions could for sure be an issue. Are you seeing them too tight or too lose? ---
**Author:** ![Tore](https://yyz1.discourse-cdn.com/flex031/user_avatar/forums.maslowcnc.com/tore/32/25202_2.png) [@Tore](https://forums.maslowcnc.com/u/Tore)\ **Post date:** [August 4, 2025, 7:05pm UTC](https://forums.maslowcnc.com/t/figuring-out-accuracy/24654/3 "2025-08-04T19:05:53Z")
Not really. They all seem pretty fine to me, but I’m suspecting the z offsets are wrong, so I’m gonna look at that next. Just to be sure about that: 1 - The routerchuck(without bit) should be all the way down, flush with the bottom of the sled. Does the length of the spindlechuck has any say in this? Since I have a 600W spindle, it’s much longer than on the Dewalt. 2 - The offset is the measured distance in height between the top side of the belt at the arm(A), and the top side of the belt at the anchor(B) 3 - Z offset = (Distance from ground to B) minus ( Distance from ground to A) What angle they are, or what level they are compared to the height at the arms, have nothing to say for the math in this case? I also noticed a little dip on the sled at the start of changes in direction, so I’ll try to see if I can get it more slippery. ---
**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:** [August 5, 2025, 1:47am UTC](https://forums.maslowcnc.com/t/figuring-out-accuracy/24654/4 "2025-08-05T01:47:55Z")
Tore Westre wrote: > Not really. They all seem pretty fine to me, but I’m suspecting the z offsets > are wrong, so I’m gonna look at that next. Just to be sure; The offset should > be the measured distance in height between the top side of the belt at the > arm, and the top side of the belt at the anchor? correct, and this includes the wasteboard and workpiece (you can also measure from the bottom of the belt end to the bottom of the anchor if that’s easier) > What angle they are, or what level they are compared to the height at the arms, have nothing to say for the math in this case? what level they are compared to the height of the arms is what the Z offset is all about. if you get too close to the anchor with the anchor below the arm, the arm will flex down and cause some grief (this is why some of us advocate for anchors that are close to the height of the arms, as long as you can keep the anchors solid enough) David Lang