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ISSUE — Track Axis Trips Due to Thermal Expansion of Rack (Hot Outdoor Environments)

CONFIRMED RESOLVED BOTH BOLT PRECISION TRACK

Summary

In hot outdoor environments, aluminium track expands at a higher rate than the steel rack gear, causing the rack joint between track sections to misalign. The track carriage encounters mechanical binding at the joint, overloading the amplifier and tripping the axis. Realigning the rack joint using the rack alignment block resolves it immediately.

Symptoms

  • Track axis trips repeatedly during moves after extended time in direct sun
  • Issue appears after the rig has heated up — not present early in the day
  • Track movement appears normal but axis keeps tripping
  • Rack joint alignment is visually misaligned relative to track

Systems Affected

  • Bolt on Track (Sebastian Opitz — confirmed outdoors in desert)
  • Any track-mounted system used in high-heat outdoor environments

Software Environment

BOTH

This is a hardware/mechanical issue — not software-version dependent.

Possible Causes

  • Aluminium track expands at a higher rate than the steel rack gear as temperature rises
  • This differential expansion causes the rack joint (where track segments join) to become misaligned
  • The track carriage encounters mechanical binding at the joint → amplifier overload → axis trip
  • Particularly pronounced in desert environments or direct midday sun

Solutions

Solution A — Realign the rack joint using the rack alignment block

CONFIRMED BOTH

Contributor(s): ~ Sebastian Opitz — 2022-09-16

Steps

  1. With the robot stationary and motors disengaged, visually inspect the rack joint (where two track sections meet).
  2. Use the rack alignment block (also called "comparator" by Peter Rush) to align the rack across the joint.
  3. Ensure the rack gear is flush and continuous across the joint.
  4. Re-engage and test the track movement.

Notes

"Realigning the rack joint (with the rack alignment block) fixed the track axis tripping repeatedly." — Sebastian Opitz

The alignment tool is referred to variously as: - "rack alignment block" (Sebastian Opitz) - "comparator" (Peter Rush, MRMC) - "something something block" (Timothy Heys Cerchio)

Ask MRMC for the correct tool part number for your track model.

Prevention

Timeline

Event Date Contributor
Reported + fix confirmed 2022-09-16 ~ Sebastian Opitz
Confirmed as known phenomenon 2022-09-16 ~ Niko

Official Documentation

Document Section Notes
Precision Track Quick Start Guide — p.55: mounting the rack Track assembly / rack joint alignment Rack alignment procedure.

Flair Classic Manual — Ch.5 Setups: Axis Setup — p.33

Flair 7 Manual — Ch.5 Setups: Axis Setup — p.19

WhatsApp Excerpts

[16/9/2022, 4:02:44 am] ~ Sebastian Opitz: I've also had the rack contract differently than the track itself when shooting outside in the desert after the sun heated up the rig. Realigning the rack joint (with the rack alignment block, if that's the right term?) fixed the track axis tripping repeatedly

[16/9/2022, 4:05:03 am] ~ Niko: I think that Peter Rush called it "comparator"

[16/9/2022, 4:06:09 am] ~ Sebastian Opitz: It seems to be a common thing with big temperature changes because it's aluminium vs. steel contracting/expanding differently

[16/9/2022, 4:06:57 am] ~ Niko: Yes, aluminium dilatation factor is higher than steel

Revision History

Date Change Editor
2026-05-24 Initial extraction Tom D / Claude Code
2026-05-24 Reformatted to CSS-tag template Tom D / Claude Code