Accuracy Diagnosis - External Factors

Auteur avatarGareth Green | Dernière modification 11/08/2020 par Gareth Green en cours de rédaction

External Factors that can affect accuracy on Stuga Machines

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There are many external factors that can affect the accuracy of Stuga machines. it is incredibly important that these factors are all eliminated as potential root causes.

If you do suspect that one of these factors is potentially a problem, it is equally important to be able to prove and demonstrate your suspicions clearly.

External Factor Description Common Symptoms Link to Page Affected Machines
Temperature change Profiles expand around 0.5-1.0mm per 10 degree in temperature change

If the bar temperature changes between machining and sawing, the bar expands and accuracy is compromised

Operation position randomly out Proving temperature change variance Flowlines

ZX3 / 4/ 5

Profile Width Depth of front V and Y notches depends on the profile width

Arrow head position depends on profile width (Autoflow, Microline only)

Depth of V notch incorrect on one profile only Z Transom Width Measurement All
Innaccurate welders Finished Y notch depth depends heavily on reverse butt burn-off Y notch depth correct before welding, incorrect after Y Notching machines
Incorrect link data (Y notch codes) Machine will cut to the depth that it is told Y notch depth correct before welding, incorrect after Y Notching machines
Profile symmetry The profile has not been extruded properly and transom profile is not symmetrical Arrow heads are out

Arrow heads change depending on profile orientation

T notches on transoms incorrect

Test T Transom Symmetry All
Wet profile Profile is not dry before running through machine Cut lengths incorrect

Loading problems

All
Profile left on TT overnight Operator leaves profile on transfer table overnight - machined on one day and sawn on another.

High chance there will be a temperature change

Operation position randomly out first thing in morning Proving temperature change variance Flowlines

ZX3 / 4/ 5

Bowed profile Profile is bowed outside of its tolerance range Profile does not load correctly All
Twisted profile Profile is twisted outside of its profile range Profile does not load correctly All
Parallelism of profile faces Profile faces are not parallel to each other. This causes havoc when reverse butt welding Y notches incorrect Y Notching machines
Cleanliness / Housekeeping Machine has not been cleaned properly. Increased chance that swarf can create a problem

Extraction systems turned off

V notch pattern not correct

Loading problems and timeouts

Incorrect operation positions

All
Blades / tooling Blunt blades or tooling causing inaccuracies

Non-Stuga tooling used

V notch blade buckled or missing teeth

V notch pattern not correct

Loading problems and timeouts

Incorrect operation positions

All
Customer expectation The customer expectation is too high - quoted accuracy is +/- 0.5mm Cut lengths incorrect All
Customer measuring equipment No two tape rules are the same.

Check consistency of tape rule

Cut lengths incorrect All
Operator measuring method Is the measuring method used accurate enough? Cut lengths incorrect All
Incorrect pos testing Operator is blindly changing parameters based on only one test outcome

Only change parameters if there is s consistent error

MEASURE 3 TIMES ADJUST ONCE

Incorrect operation positions All
Proper operator trained Operator changing wrong parameters of abusing machine Incorrect operation positions All
Laser lens Laser measuring system not kept clean or not set up properly Incorrect operation positions Flowlines

ZX3 / 4 with laser

Skipping the laser Operator is skipping laser measuring because of another problem on loading Incorrect operation positions Flowlines

ZX3 / 4 with laser

Accuracy of cut pieces Length of cut pieces into Ecoline will affect operation positions
Incorrect operation positions
Ecoline


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