ISSUE — Arm Elbow Inverting / Camera Dropping on Forward Run¶
WARNING — RISK OF PHYSICAL INJURY AND EQUIPMENT DAMAGE
This issue can cause the robot arm to invert its elbow and drive the camera toward the ground at speed. Serious injury to crew or damage to camera/robot is possible. Do not operate until this is understood. Check all trigger positions before any Forward Run.
Summary¶
A confirmed dangerous bug in Flair Classic Beta 18 (and possibly Flair 7.21) causes the Bolt arm to invert its elbow and drive the camera toward the ground at speed during Forward Run when an end trigger is placed beyond the last frame of the move. The issue is repeatable and independently reported by multiple operators. Check all trigger frame positions before any run and verify with MRMC whether a patch has been released.
Symptoms¶
- During Forward Run (NOT a shoot), the ARM axis trips hard — arm attempts to slam into the base
- In Tom D's case: the arm elbow inverts and the camera is driven toward the ground
- Robot appears to attempt a short, unexpected "go-to" type movement
- Arm trips before reaching the base (safety system engages)
- Behaviour is repeatable in Tom D's case
Systems Affected¶
- Bolt on Track (Tom D — confirmed dangerous, repeatable)
- Bolt on Pedestal (Riley Morgan — related/similar symptom, different setup)
Software Environment¶
Tom D's confirmed dangerous bug: Flair Classic Beta 18
Riley Morgan's independent report: Flair 7.21 — possibly related or a separate root cause.
Conditions That Trigger It¶
- End trigger (e.g. bloop light trigger) set at a frame position beyond the last frame of the move
- Flair Classic Beta 18
- Possibly stale trigger entries inherited from an older job, including entries set to Ends
Possible Causes¶
- Bug in Flair Classic Beta 18: When an end trigger is placed beyond the last move frame, Flair incorrectly inverts the elbow and drives the arm toward the ground
- Inactive/legacy triggers set to "ends" may also contribute — review all trigger entries regardless of active state
- Riley Morgan's case involved "diopter set to 2" — may be a separate bug producing similar symptoms
- More broadly, Target Tracking / Cartesian kinematics can have more than one valid physical arm solution; any unexpected switch between elbow-up and elbow-down configurations must be treated as a motion hazard
Solutions¶
Solution A — Remove all end triggers placed beyond the last move frame¶
Contributor(s): Tom D — 2024-06-08
Steps¶
- Open Setups -> Trigger Setup and Setups -> External Camera Setup / Camera Record.
- Before any Forward Run, check all trigger frame positions in the current job.
- Ensure no trigger is set at a frame position beyond the final move frame.
- Check normal output triggers, camera record stop triggers, bloop triggers, and any entries set to Ends.
- If a trigger must fire after motion ends, add a safe hold inside the move duration and place the trigger inside that hold rather than beyond the last waypoint.
- Update to a later Flair version if available — check with MRMC whether this bug was patched.
Notes¶
"WARNING — found a massive danger fault for Bolt on track in Flair Classic beta 18 where when an end trigger (ie bloop) is set at a frame beyond the last frame of the move, the bolt arm elbow is inverting itself and dropping camera towards the ground. Will submit error report. Dangerous problem is repeatable." — Tom D
Solution B — Audit all trigger entries including inactive ones¶
Contributor(s): ~ Riley Morgan, ~ Niko — 2024-06-08
Steps¶
- Open Setups -> Trigger Setup and Setups -> External Camera Setup / Camera Record.
- Even if triggers are disabled globally ("trigger active" checkbox unchecked), check individual trigger entries set to "ends".
- Old triggers from previous jobs may persist and become active under certain conditions.
- Review all trigger entries regardless of their active state.
- Delete any stale trigger entries from previous jobs.
Notes¶
"Check if you have some [triggers] on 'ends'." — Niko
"I do have a few [triggers set to ends], but trigger not active (checkbox 'trigger active' not clicked and triggers off altogether too) — they've been set like this for probably months from an old job." — Riley Morgan
The presence of end triggers even when apparently disabled may contribute to unexpected behaviour.
Solution C — Verify firmware fix with MRMC¶
Contributor(s): Tom D — 2024-06-08
Steps¶
- This bug was reported to MRMC in June 2024.
- Contact MRMC to confirm whether a fix was released in subsequent Flair versions.
- Do not assume this has been patched — verify your exact firmware version before operating.
Safety Procedure — If Any Elbow Flip / Drop Is Observed¶
- Stop work and keep crew clear of the robot envelope.
- Save a copy of the job under a fault name before changing it.
- Remove or disable all triggers outside the move range.
- Turn off Carts / Target Tracking and inspect the physical arm pose in axis mode before re-engaging.
- If the move uses Target Tracking, End Mount, Roll Up, Camera Orbital, or unusual lens/mount offsets, review Init Scaling - End Mount Dual Solution before testing again.
- Re-test at minimum speed with one hand on the E-stop and no payload/talent in the hazard zone.
Do not use trigger cleanup as proof of safety
Removing an out-of-range trigger fixes the specific reported trigger-related case. It does not prove the move is safe if the arm is also near an IK dual-solution boundary, an end-mount singularity, or a target-tracking configuration change.
Timeline¶
| Event | Date | Contributor |
|---|---|---|
| Warning issued — confirmed dangerous | 2024-06-08 | Tom D |
| Independent report (Flair 7.21) | 2024-06-08 | ~ Riley Morgan |
| Trigger-on-ends check noted | 2024-06-08 | ~ Niko |
Official Documentation¶
| Document | Section | Notes |
|---|---|---|
| (No manual reference) | — | Bug report submitted to MRMC June 2024 |
Related Media¶
Media Text / Description¶
- Media 1: Dangerous arm-axis trip incident; Bolt arm attempts to invert the elbow and drive the camera downward or toward the base during Forward Run.
WhatsApp Excerpts¶
[8/6/2024, 1:24:04 am] ~ Niko: There was a warning sent by Tom David from Australia about an issue that feels like yours
* WARNING - found a massive danger fault for Bolt on track in Flair Classic beta 18 where when an end trigger (ie bloop) is set at a frame beyond the last frame of the move, the bolt arm elbow is inverting itself and dropping camera towards the ground. Will submit error report. Dangerous problem is repeatable. ****
[8/6/2024, 12:51:50 am] ~ Riley Morgan: Hi. Anyone running 7.21? Serious issue. Will submit bug report ASAP, hopefully this has been remedied? Upon clicking forward run (NOT shoot!) ARM axis tripped out hard after trying to slam itself into the base. It tripped before it got there luckily.
[8/6/2024, 12:54:20 am] ~ Riley Morgan: Using diopter set to 2 (I've had weird trip issues with diopter setting before) and syncing from cam
[8/6/2024, 1:25:04 am] ~ Niko: Check if you have some [triggers] on "ends"
Related Issues¶
- See also: Safety Systems chapter
- See also: Robot Safety chapter
- See also: Init Scaling — Resolving Dual-Solution Conflicts in End Mount Target Tracking
- See also: Move Finishes But Flair Stays in Post-Roll for Many Seconds
Revision History¶
| Date | Change | Editor |
|---|---|---|
| 2026-05-24 | Initial extraction — DANGEROUS flag applied | Tom D / Claude Code |
| 2026-05-24 | Reformatted to CSS-tag template | Tom D / Claude Code |