# Secondary Kinematics **URL:** \ **Category:** Troubleshooting\ **Tags:** accuracy, calibration, frame\ **Created:** [August 12, 2025, 9:02pm UTC](https://forums.maslowcnc.com/t/secondary-kinematics/24710 "2025-08-12T21:02:18Z")\ **Posts on this page:** 5\ **Page:** 1
**Author:** ![willpuckett](https://yyz1.discourse-cdn.com/flex031/user_avatar/forums.maslowcnc.com/willpuckett/32/22652_2.png) [@willpuckett](https://forums.maslowcnc.com/u/willpuckett)\ **Post date:** [August 12, 2025, 9:02pm UTC](https://forums.maslowcnc.com/t/secondary-kinematics/24710/1 "2025-08-12T21:02:18Z")
Last week I got to pop by [ISAM](https://isam2025.hemi-makers.org) for a minute. A small router there called [Compass](https://www.compassrouter.com) was showing… You basically push it around and then it uses a couple of very short belts to adjust itself on a couple of tiny linear rails to where it needs to cut (working kinda like a Shaper Origin). It has to be manually pushed around the entire time it’s being operated… 🥴 Compass and Maslow have opposite problems–given the belt stretch issues (below), Maslow can get close, but has difficulty with cutting precision notches/tabs, whereas Compass can’t move itself around a workpiece. > [@X & Y Accuracy Analysis: Belt Stretch](https://forums.maslowcnc.com/t/x-y-accuracy-analysis-belt-stretch/23996/51): > > I think that the position of the anchor points is going to be important IE a frame which is square is going to have different forces at different points that a frame which is rectangular so I think we’re going to end up doing some trig confused I haven’t done any drawing or anything, but I thought it would be interesting just to mention the idea of a compass style router on a Maslow style sled–the Maslow belts get it close, and the small, secondary kinematic system à la Compass handles the fine location. Compass uses 4 PMW3360 sensors for location sensing. It seems like optical sensors in a dusty cutting environment could have problems, but being able to track the movement in a way that isn’t reliant on belts that change length seems helpful. Perhaps Compass and Maslow will have a love child? The Complow? The Maspass? ---
**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 12, 2025, 9:24pm UTC](https://forums.maslowcnc.com/t/secondary-kinematics/24710/2 "2025-08-12T21:24:00Z")
Compass is awesome! Cameron is a super cool guy. I am a huge fan of that project 😀 The issue with the compass type control system is that you get drift over time. The mouse sensors gradually lose track of where they are. The compass fixes that by having the user reset to a “known” reference position every minute or two, but for a work area as big as maslow we’d be losing position by the time we got to the far corner of the board 😕 ---
**Author:** ![MrN808](https://yyz1.discourse-cdn.com/flex031/user_avatar/forums.maslowcnc.com/mrn808/32/22275_2.png) [@MrN808](https://forums.maslowcnc.com/u/MrN808)\ **Post date:** [August 12, 2025, 10:10pm UTC](https://forums.maslowcnc.com/t/secondary-kinematics/24710/3 "2025-08-12T22:10:41Z")
Just spitballing…I know that inertial sensors (inertial measurement units, or IMUs) like they use for station-keeping drones have dropped in price and the affordable ones have increased in accuracy (and they’re _ **tiny** _!). Maybe they could be part of a solution? ---
**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 12, 2025, 11:49pm UTC](https://forums.maslowcnc.com/t/secondary-kinematics/24710/4 "2025-08-12T23:49:07Z")
David Negaard wrote: > Just spitballing…I know that inertial sensors (inertial measurement units, or > IMUs) like they use for station-keeping drones have dropped in price and the > affordable ones have increased in accuracy (and they’re _ **tiny** _!). Maybe > they could be part of a solution? how do they handle high vibration and high electrical noise environments? David Lang ---
**Author:** ![MrN808](https://yyz1.discourse-cdn.com/flex031/user_avatar/forums.maslowcnc.com/mrn808/32/22275_2.png) [@MrN808](https://forums.maslowcnc.com/u/MrN808)\ **Post date:** [August 12, 2025, 11:56pm UTC](https://forums.maslowcnc.com/t/secondary-kinematics/24710/5 "2025-08-12T23:56:02Z")
> [@dlang](#): > > how do they handle high vibration and high electrical noise environments? I am not sure? High vibration, at least, they should be hardened for. Last time I worked with an IMU was in 1988, and it was a massive ball with physical gyros. I think commodity ones use ring lasers, instead; they’re on-a-chip devices. Here’s one that turned up during a cursory search: [Adafruit BNO055 Absolute Orientation Sensor](https://learn.adafruit.com/adafruit-bno055-absolute-orientation-sensor/overview)