How to make shaft hole in hands 0.5 mm bigger ?

[Flubber]

I ordered a new quartz movement to replace the old Ato-Matic movement. and it has arrived. However, even though the minute hand fits perfectly on the euroshaft on the new movement the hour hand do not fit. I thought there was some sort of standard but there you go. The shaft on the movement is made of plastic and seems to be exactly 5.0 mm in diameter but the hole in the hour hand seems to be ~4.5 mm in diameter. So my question is what to do sbout it ? Is there a way to make the hole in the hand bigger ? Using some sort of reamer ? I could perhaps order new hands but I rather not. Any suggestions appreciated.

 

 

[watchweasol]

HI  Other than reaming (broaching )the hand to fit not a lot you can do,  other than new hands. Hand sizes differ according to the movement and there are a great number of styles.  There are    round shaft,   euroshaft,   "I" shaft. The I shaft and euroshaft are similar and the Min hand has an elongated fitting and the hour hand is round,    so carefull attention with a broach will probably do the job but after every turn of the broach check the fit.

[Flubber]

As I suspected then. But is it possible to make such a large hole bigger by reaming (broaching) by hand ? The hands seems to be made of a rather soft material (brass ?) so perhaps it is possible. I have no broaches or reamer tools so any suggestions on what to use (ie buy. Love buying tools albeit expensive ! ;-)

@watchweasolWhere did yo find that picture of the hands ? I think I spot the exact same model as the ones I have on my old clock there.

[watchweasol]

Hi Broaches can be bought either singly or in sets depending on what you want, they also come in varying sizes as shown in the following link   https://www.cousinsuk.com/product/0020-to-080mm-bergeon.   The picture I salvaged from ebay but the same can be found on ngclocks.co.uk   clockparts.co.uk     and also cousins uk                    cheers

[VWatchie]

2 hours ago, watchweasol said:

Hi Broaches can be bought either singly or in sets

Just wondering; provided a suitable size is available, could a jeweling tool reamer be used for this job?

[watchweasol]

I see no reason why the jeweling reamer wouldn't work as the object is to remove a small amount of metal

[rodabod]

I like tapered broaches for adjusting hands as it gives a nice gradual interference fit.

[nickelsilver]

Bear in mind an hour hand usually has a tube, and broaching 0.5mm might leave little to no tube.

[HectorLooi]

13 hours ago, VWatchie said:

Just wondering; provided a suitable size is available, could a jeweling tool reamer be used for this job?

If you are refering to a Seitz jewelling tool, I don't think there are any reamers 5.0 mm diameter. 

I don't like the idea of reaming. It removes material and weakens the tube. I would put the tube of the hand in a slightly larger hole of an anvil block and insert any tapered tool and expand the hole. If you can't find a tool that fits, take a large iron nail and file it to a slight taper of about 2%. If the resulting hole ends up too big, you can shrink it by clamping the tube in a 3 jaw chuck.

[VWatchie]

9 hours ago, HectorLooi said:

If you are refering to a Seitz jewelling tool, I don't think there are any reamers 5.0 mm diameter. 

I was, and you're right about that. I got it wrong and thought we were talking about 0.5 mm. Guess I had a senior moment 

9 hours ago, HectorLooi said:

I don't like the idea of reaming. It removes material and weakens the tube.

As a general rule I guess it's good idea to avoid removing material whenever possible. Perhaps a smoothing broach could do the job?