Need some advice on technique for reducing hour hand post height.

[k3l3k]

Hello, 

Could I please get some advise on the preferred technique for reducing the post height on an hour hand?

The aftermarket hands I sourced have posts which are too tall. The one on the minute hand is manageable but the one the hour had is too tall preventing the minute hand to completely go in (so its almost touching the crystal).

No seconds hand on the movement.

[Neverenoughwatches]

56 minutes ago, k3l3k said:

Hello, 

Could I please get some advise on the preferred technique for reducing the post height on an hour hand?

The aftermarket hands I sourced have posts which are too tall. The one on the minute hand is manageable but the one the hour had is too tall preventing the minute hand to completely go in (so its almost touching the crystal).

No seconds hand on the movement.

The hour hand tube can be filed or shaved down to size with a flat lap. You can pin the hand down for filing onto pithwood or other suitable material.

[k3l3k]

1 hour ago, Neverenoughwatches said:

The hour hand tube can be filed or shaved down to size with a flat lap. You can pin the hand down for filing onto pithwood or other suitable material.

Thanks, Do I need to protect the post's cavity? I worry crimping the cavity while filing it down.

Edited June 15, 2024 by k3l3k

[Neverenoughwatches]

1 hour ago, k3l3k said:

Thanks, Do I need to protect the post's cavity? I worry crimping the cavity while filing it down.

  My thoughts would be a tooth pick fitted tight into a staking block, paper pushed over the top, the hour hand fitted over and the toothpick cut down flush with tube then file both the hour hand and the toothpick stump.

[k3l3k]

17 hours ago, Neverenoughwatches said:

  My thoughts would be a tooth pick fitted tight into a staking block, paper pushed over the top, the hour hand fitted over and the toothpick cut down flush with tube then file both the hour hand and the toothpick stump.

Thanks, do not understand "paper pushed over the top" part.

[VWatchie]

37 minutes ago, k3l3k said:

Thanks, do not understand "paper pushed over the top" part.

I'm not sure, but I imagine that you simply thread the paper onto the toothpick so that it rests against the block. Then thread the hand (back side up) onto the toothpick so that it rests against and is protected by the paper. I don't know if this is an established method but it sounds like it's worth a try. I don't know if my description is understandable or correct but if not so, please correct me!

What is a "flat lap"?

[Neverenoughwatches]

49 minutes ago, VWatchie said:

I'm not sure, but I imagine that you simply thread the paper onto the toothpick so that it rests against the block. Then thread the hand (back side up) onto the toothpick so that it rests against and is protected by the paper. I don't know if this is an established method but it sounds like it's worth a try. I don't know if my description is understandable or correct but if not so, please correct me!

What is a "flat lap"?

Yep H that is exactly it, to protect the finish of the of the hand while it is face down on a steel block. You could stick a toothpick in a piece of wood instead of the stake block but personally i would still thread a piece of paper over the end . By flat lap i mean the flat diamaond plates , i keep using the names interchangeably but the two are different. 

I've not had to reduce the height of an hour hand tube before , but I've used similar ideas for doing other things

Clamping the hour hand by the arm seems like a good way of breaking off the head when filing.  A more simple way would be to shave the tube down on a stone or plate by rubbing it with your finger, might not get it straight though. I think you should post a picture first before trying anything. 

[k3l3k]

2 hours ago, VWatchie said:

What is a "flat lap"?

Yes, I also did not understand "flat lap".

Also, what is the best file to use for this type of work?

[Neverenoughwatches]

1 hour ago, k3l3k said:

Yes, I also did not understand "flat lap".

Also, what is the best file to use for this type of work?

Lapping plates are precision ground metal, glass and even timber disks or plates, abrasive compounds are added to impregnate and charge up the lap ready for flat lapping and polishing metal parts.  Diamond plates are sometimes called lapping plates hence my mention of the term.  Any quality small fine file should be ok, something like this from cousins. 

[k3l3k]

4 minutes ago, Neverenoughwatches said:

Lapping plates are precision ground metal, glass and even timber disks or plates, abrasive compounds are added to impregnate and charge up the lap ready for flat lapping and polishing metal parts.  Diamond plates are sometimes called lapping plates hence my mention of the term.  Any quality small fine file should be ok, something like this from cousins. 

OK.  I have these. Thanks

[Neverenoughwatches]

8 minutes ago, k3l3k said:

OK.  I have these. Thanks

just take your time and use the finest file you have , the tube will be very thin , the timber toothpick inside it will help to give it stability. Just a snug fit so as not to split the tube, watchmaking is about just the right size. Making yourself a micro diamond file from a diamond plate is well worth the effort.

Edited June 16, 2024 by Neverenoughwatches