Wadkin BRA - play in wedge lock

[Guineafowl21]

This is the machine:



And here is the 45-90-45 locking mechanism:


There is rotational play in the arm even when the wedge locking lever is firmly located, and this is the case for all three positions, even the rarely used left mitre. So I think the problem is in the lever wedge, not the column cutouts.

The wedge does not bottom out radially, ie there’s a good gap between it and the bottom of the column cutout.

Using a marker pen, I can see the contact patch is at the lower edge of the wedge, so the play is at the top (greatly exaggerated in diagram - it’s about 0.1mm each side:



Should I be marking the contact patch and filing to improve the fit, or perhaps run the wedge surface on a diamond plate, with pressure on the high end, to maintain flatness, or something else?

 

[Trevanion]

Is it definitely the locking lever in the cutouts that has play, not another part of the machine such as the column mounting being ever so slightly loose?

Also, has the lever worn at all where it hinges? Any sort of wear there would surely have a similar effect to what you’re describing.

 

[Guineafowl21]

Is it definitely the locking lever in the cutouts that has play, not another part of the machine such as the column mounting being ever so slightly loose?

Also, has the lever worn at all where it hinges? Any sort of wear there would surely have a similar effect to what you’re describing.

I sprayed a little WD40 round the column where it enters the boss, then wobbled the arm and used the shine from the fluid to assess play - hardly any.

There doesn’t seem to be any movement of the lever shaft, but I’ll check again.