how to adjust a combination square?

[windbreaker]

I have a 6" rabone model 1902 combination square. It is a favourite tool, just perfect to fit in the hand and a pleasure to use for those little boxes. It has recently gone out of square. It measures a tad over 90 degrees.

Can anyone suggest how to get it back into square?

Forever grateful

Windbreaker

[Claw Hama]

Hi Windbreaker, I would remove the blade and adjuster then using a warding file or similar slim file take out a very small amount untill its sweet again. Good luck

[windbreaker]

thank you Mr Hama.

I need to be sure what exactly to file. My confusion is that, through usage over the years, some part has worn. To take a file to fix this seems contradictory. I'm concerned that if I file everything in sight it will only compound the error.

WB

[Claw Hama]

Ok to be more thourogh, slip out the blade and check both sides are still straight and not worn. If they are flaten on a sheet of glass with some wet and dry or similar system similar to flatening a plane sole etc. Put the blade back in and check for square. If it is still reading over 90 then the groove in the body must be warn at the tail end, which opens up the angle. Put the body in a vise with the slot facing up and the tail away from you and the face towards you. Slip your file into the groove and take a couple of light cuts pushing slighlty harder at the start and tapering off towards the tail where it is worn. It won't take much to get it back. The bodys on most of the old combo squares were soft cast iron which is softer than the steel blade so the bodys would normaly wear quicker than the blade. Hope all that makes sense.

[windbreaker]

thanks.
what you say makes perfect sense now . I just hope my filing can create a flat bed rather than a curved one which may damge the tool further.Thanks again.

WB