gilbert hates me: external half-hour trip arm removal

[kinsler33]

This Gilbert tambour was supposed to go home tomorrow. It was only after I got it in its case that I noticed that the hands move too easily, which means that the cannon pinion has cracked. Okay, fine. But I can't get the plates apart because the little half-hour trip arm was secured to the rear of the minute arbor with tightly wound brass wire and has defied my every effort to remove it . I've worked on several of these clocks and never got stuck here. Any ideas?

 

[wow]

Can you cut it off and drill out what’s left? There’s a hole in the arbor, right?

 

[Willie X]

It's probably glued or soldered. A little heat and two thin screwdrivers will pop er right off.

There shouldn't be a hole in the arbor/pinion.

Place the screwdrivers evenly, on opposite sides, close to the handshaft, and twist in opposite directions. The lifting edges of screwdrivers should be on the centerline of the little lifting disc.

Willie X

 

[Thomas Sanguigni]

Liquid Wrench or Kroil it first. Let it sit a spell then give the Willie treatment. Watch adding heat, it could flare up. Is there some sort of grub screw? The photo shows something on the brass.

 

[kinsler33]

That's just it: that lever is secured on its square shaft with brass wire. There might be a hole through the arbor. Strong magnification reveals little.

I can at least repair the cracked gear--the pieces of that clutch fell out on their own--but I really want to get to all the pivots, etc. So I'll have to cut/snip/dissolve that tight little coil of brass wire. Any other suggestions? I tried a 3-corner file on it, but my hands remain certifiably useless. Mebbe a jeweler's saw might do it.

M Kinsler

 

[Willie X]

The shaft/pivot should be round, no wire. I think you have some questionable mods there?
Willie

 

[Keith Doster]

Just my two cents . . . but that part looks like it would be relatively easy to reproduce. I think as long as you don't damage the minute arbor/pivot, do whatever is needed to get that thing off. Then make another one. Maybe take some measurements prior to destruction. Dremel comes to mind. It's amazing how much trouble shows up only AFTER the movement is put back into the case.

 

[Thomas Sanguigni]

Since there is brass wire through the shaft, can you drill it out? Just replace it at reassembly.

 

[kinsler33]

More eyesight issues. I know mine are going fast but ...

Yep. Mine too. I have eyedrops to stave off glaucoma (age=75) and my ophthalmologist has been hinting at cataract surgery next year. Maybe I'm too old to bother.

 

[kinsler33]

Just my two cents . . . but that part looks like it would be relatively easy to reproduce. I think as long as you don't damage the minute arbor/pivot, do whatever is needed to get that thing off. Then make another one. Maybe take some measurements prior to destruction. Dremel comes to mind. It's amazing how much trouble shows up only AFTER the movement is put back into the case.

Yep. It is reassuring to learn that post-assembly defects happen to someone else.

I think that one of the tiny circuit board drills I use for repivoting should drill out the hole in the arbor, and I'll build a new part if necessary.

Mark Kinsler

 

[kinsler33]

The shaft/pivot should be round, no wire. I think you have some questionable mods there?
Willie

But this part must reliably trip the half hour passive strike. That's why the shaft is square.

 

[wow]

I

But this part must reliably trip the half hour passive strike. That's why the shaft is square.

I still think it originally had a pin or wire to keep it on the square arbor. It’s got to come off somehow. When you do get it off just drill a hole and put in a pin or wire.

 

[R. Croswell]

All of these that I have seen were like this one, simply pressed onto a round arbor. I don't recall ever seeing any that were wired or with a square arbor, but that doesn't mean that none were made that way, just that I haven't seen any.

RC

 

[kinsler33]

All of these that I have seen were like this one, simply pressed onto a round arbor. I don't recall ever seeing any that were wired or with a square arbor, but that doesn't mean that none were made that way, just that I haven't seen any.

RC

View attachment 738039

Yup. Round shaft, pressed on. It popped right off @5:10 a.m. The brass had been upset slightly when it was pressed on at the factory, leaving a small collar which I was morally convinced was a tightly-wrapped coil of wire.

Thank you, everyone, for tolerating yet another of my misleading fantasies.

Aargh.

Mark Kinsler