You could try shims of drinks can metal between bar and housing to take up some clearance and hopefully restore clamping – no risk of machine damage with this try, and virtually no cost.

First step is to pull it all out and give the bar and clamp a really good clean. Not just wiping but appropriate solvents too.

Counterintuitively roughing up the surface to "key" things doesn't help. Smooth with maximum mating surface area does the trick. Might be worth applying a very thin layer of blue or, probably better, a solvent based felt tip pen mark or two to verify that you have good contact everywhere.

Best to investigate and sort things properly rather than resorting to quick'n dirty shims to fill the gap. Once shimmed you can never go back.

When used in an environment with oils floating around occasionally moved cast iron components seem to get a bit slippy so clamps loose the holding power. Doesn't matter how careful you are to clean the mating components. If the Gremlins so decree it does happen. Takes a fair few years but if you are on the list they will get you.

For me the major disadvantage of synthetic coolants is that this sort of thing happens much faster and much more frequently!

Clive

Equally confused. picture would help.

Steve.

I've done some sleuthing.

This is a Tom Senior "Light Vertical" where the head is mounted on the end of a round bar.

Bob,

I would be checking either of the two clamps aren't cracked if it was lifted by the support when you bought it.

Don't shim anything, that type of clamp relies on everything being the 'right' size, levering the slot open to get a shim in might crack it.

If the clamps are undamaged hopefully it's just oil in the wrong place.

I would be wary of just removing the studs on a light vertical, the motor makes it top heavy and it could rotate unexpectedly with bad results. I would put a bar in the spindle and raise the knee until blocks could be secured to the bed each side of the bar to restrict any rotation.

The clamps on the LV at the museum only require tightening about 12 ftlbs to fully secure the top end.

There should be a gap of about 1/16" in the clamps where the bolts go through, it should be obvious if the casting is fractured at either, or both clamping points. Also, the two SHCS which secure the head to the bar should be checked for tightness, if loose the head can move about slightly.

Edited By old mart on 26/10/2020 14:24:16

Old Mart and Clive – thank you for pointing out my over-simplification. You are indeed right to point out that the top is top (edit – I meant too heavy, but the typo is appropriate!) heavy for a one man lift at that height and reach. . My defense is that I thought it self-evident not to undo both clamps together. Even that's not as simple to do as say – if the clamps aren't holding!

I like the idea of sticking something suitable in the taper and restraining the other end laterally!

My contribution is to caution against trying to withdraw the top bar out of the two clamps without having the clamp bolts in position, and just snugged up to stop the split clamp opening. It would be all too easy to allow the overhanging weight etc to crowbar the nearer clamp open as you bring the bar etc. forward out of the rear clamp. Ping!

I'm looking forward to hearing how this pans out.

Rgds to all our Senior citizens.

Simon

edit for typo

Edited By Simon Williams 3 on 26/10/2020 16:35:15

Ah, a picture which explains everything. The pairs of clamps touching are the prime suspects, strange that both sets should fail to clamp at the same time. This type of clamp is featured on the Light Vertical quill, the drill mill quill, the drill press and the lathe tailstock, all four of the machines at the museum lock perfectly.

Steve.