Skip to content

Cinebot Max Track Acceleration with Arm Master Near 90° Rotate

Issue ID: MOVE-cinebot-arm-master-track-acceleration-singularity
Affected Equipment: Cinebot Max, Flair
Severity: High
Status: [CONFIRMED] - Known singularity issue

Summary

When using Arm Master mode on Cinebot Max, the track can accelerate aggressively and cause D/A overflow when the arm approaches ±90° on the Rotate axis. This can cause the entire unit to skid on the floor and trip protective systems.

Symptoms

  • Track accelerates uncontrollably when arm extends outward near 90° rotate
  • D/A overflow trips track axis protection
  • Entire Cinebot unit may skid or move on the floor
  • Occurs specifically when using Arm Master mode (not Track Master)

Root Cause

This is a known singularity in the inverse kinematics when using Arm Master mode at Rotate ±90°. At this position, the math becomes unstable and the track attempts to accelerate indefinitely to maintain the arm position.

Solution

[CONFIRMED] Primary Solution: Use Track Master Mode

For Cinebot Max operations, stick to Track Master mode instead of Arm Master:

  1. Set Track as Master in your rig configuration
  2. This allows the arm to move freely from front to back of base
  3. Avoids the singularity issue entirely

[CONFIRMED] Safety Measure: Enable Cartesian Limits

If you must use Arm Master mode:

  1. Navigate to Miscellaneous settings
  2. Ensure Cartesian Limits is checked
  3. This should provide popup warnings before entering dangerous zones

Evidence

WhatsApp Discussion (2025-03-07):

Mike Greenberg: "I was experimenting with arm master and solver on with our Cinebot Max today and as I extended the further arm out, the track aggressively accelerated, such that the whole unit skidded on the floor and D/A overflow tripped track axis. I've been trying to understand why– reading through the manual I see one reference to Rotate90. I was close to the 90 on rotate, is that relevant to Cinebots?"

Timothy Heys Cerchio: "When in Arm Master there is a further 'singularity' at Rotate ±90 where Track would accelerate indefinitely... And that is mostly why on Bolts we keep Track as master, so the arm can go from front to back of Base freely 😉"

Josh T.: "I don't think Cinebot are 100% go for arm master at the moment."

Equipment Details

  • Primary: Cinebot Max
  • Also Affects: Potentially other Cinebot models when using Arm Master
  • Software: Flair (all versions)
Source: WhatsApp Community Chat 2025-03-07