TB0395 How To Test T transom Symmetry

Operator Checks for Transom Symmetry

Transom, Symmetry T_Transom_Symmetry_NO.png

Technical Bulletin

TB Number:	395
Originator:	Gareth Green
Machine:	All
Date:	19/03/18
Circulate to:	Service; Customers
Title:	How to test if T Transom is symmetrical

Do NOT check the arrow head position with a square across the small face. This has been known on several occasions to show an error on the profile, and fools the unwary into an adjustment of the central position. This happens because the narrow part of the profile has not been extruded square to the bottom face.

The Z blocks can be used to “bias” the profile under these circumstances, but this is no way a fix for the problem; the profile should be rejected.

An easy check will demonstrate if there is a profile issue:

·        Cut two lengths of profile [ ] and mark the front face

·        Turn one piece around and butt it up to the other piece, as in the picture.

This picture shows a poor quality profile where the narrow face is not centralised to the rest of the profile. The outer edges are lined up, but it is clear that the narrow edges are not.

...This is a profile quality issue is a regular problem

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