Help Fitting New Hands

[Tracy]

I purchased some (90-150 Blue Dauphine) hands (P/N 86.9142) from Esslinger. I wanted to verify that I ordered the correct size. I am new to watch repair—but am an experienced machinist so I am ok with measuring using calipers.

I measured the hour wheel on my Raketa (Movement 2614.H) at: 1.549mm (.061”) and the cannon pinion dia. at .965mm (.038”). I ordered the new hands size .90mm and 1.50mm (90-150) assuming that because the shafts are slightly larger their diameter would provide an interference fit for the smaller diameter hand holes.

hour wheel shaft is 1.549 – 1.50 hand hole = .049mm interference fit.

 minute dia. is .965 – .90 = .065mm interference fit.

 Are my assumptions correct about the interference fit? Did I order the correct size? 

When I try to fit the hands to the hour wheel/cannon pinion I cannot get them started. I have no trouble getting the old hands to fit??  I even tried to fit the new hands upside down (because of the flange created when the mfg. stamped out the hands/hole) and still could not get them started. Any advice would be helpful.

Thanks, Tracy

 

 

[noirrac1j]

10 minutes ago, Tracy said:

I purchased some (90-150 Blue Dauphine) hands (P/N 86.9142) from Esslinger. I wanted to verify that I ordered the correct size. I am new to watch repair—but am an experienced machinist so I am ok with measuring using calipers.

I measured the hour wheel on my Raketa (Movement 2614.H) at: 1.549mm (.061”) and the cannon pinion dia. at .965mm (.038”). I ordered the new hands size .90mm and 1.50mm (90-150) assuming that because the shafts are slightly larger their diameter would provide an interference fit for the smaller diameter hand holes.

hour wheel shaft is 1.549 – 1.50 hand hole = .049mm interference fit.

 minute dia. is .965 – .90 = .065mm interference fit.

 Are my assumptions correct about the interference fit? Did I order the correct size? 

When I try to fit the hands to the hour wheel/cannon pinion I cannot get them started. I have no trouble getting the old hands to fit??  I even tried to fit the new hands upside down (because of the flange created when the mfg. stamped out the hands/hole) and still could not get them started. Any advice would be helpful.

Thanks, Tracy

 

 

Hello Tracey,

Welcome to the forum. I think your calculations are correct, but the measurements may be off. Here is what I found for the Raketa movement you've specified:

 As you can see, the hour hand is specified at 1.60mm and the minute hand 1.04mm.

I buy from Esslinger all the time, and you can send the hands back. Try to get some closer to what you need especially that minute hand. You don't want to force either hand onto its shaft, and in my experience, forcing that minute hand if it doesn't fit will result in bending both hands in the process.

J

[clockboy]

Strange as they should fit. You are correct they are fitted by a interference fit. I am not sure what the interference fit should be. You need to measure the old hands. The essayist way is to insert a brass/steel pin into the old hand & mark & measure where they sit.

PS What method are you using to fit the hands.

[noirrac1j]

10 minutes ago, Tracy said:

I purchased some (90-150 Blue Dauphine) hands (P/N 86.9142) from Esslinger. I wanted to verify that I ordered the correct size. I am new to watch repair—but am an experienced machinist so I am ok with measuring using calipers.

I measured the hour wheel on my Raketa (Movement 2614.H) at: 1.549mm (.061”) and the cannon pinion dia. at .965mm (.038”). I ordered the new hands size .90mm and 1.50mm (90-150) assuming that because the shafts are slightly larger their diameter would provide an interference fit for the smaller diameter hand holes.

hour wheel shaft is 1.549 – 1.50 hand hole = .049mm interference fit.

 minute dia. is .965 – .90 = .065mm interference fit.

 Are my assumptions correct about the interference fit? Did I order the correct size? 

When I try to fit the hands to the hour wheel/cannon pinion I cannot get them started. I have no trouble getting the old hands to fit??  I even tried to fit the new hands upside down (because of the flange created when the mfg. stamped out the hands/hole) and still could not get them started. Any advice would be helpful.

Thanks, Tracy

 

 

Hello Tracey,

Welcome to the forum. I think your calculations are correct, but the measurements may be off. Here is what I found for the Raketa movement you've specified:

 As you can see, the hour hand is specified at 1.60mm and the minute hand 1.04mm.

I buy from Esslinger all the time, and you can send the hands back. Try to get some closer to what you need especially that minute hand. You don't want to force either hand onto its shaft, and in my experience, forcing that minute hand if it doesn't fit will result in bending both hands in the process.

J

[rodabod]

Sometimes it helps to broach the opening of the hand collet with a pin, just to get it started when fitting. New hands can be quite tight to fit (eg. new Omega hands often take a lot of pressure to fit).

[clockboy]

You could broach out the hands you have purchased.There is a vice dedicated for this job see pic.

[Tracy]

I don't get the logic. If the shafts measure 1.549mm and .965mm respectively, why would the spects for the movement call for 1.6mm  and 1.04mm? That's like saying I have an axle shaft that's 1, 1/2" in diameter and I'm going to press a bearing on to it that has an inter race diameter of 1, 5/8"---there is no press/interference fit and the bearing would just slide into the shaft????

I get that the movement spects call for 1.6mm and 1.04mm hands however they should be too large. Is there an alternate universe for watch hand measurements?

I do like the idea of using a pin to broach the hands to get them started.

Also, If I try to reuse the old hands (hour hand was a little loose) any way to tighten it up a bit??

Thanks for all the help/advice.

 

 

[digginstony]

Hi and welcome.
I constantly order new hands even the size quoted from a tech sheets only to find they are too tight ! I suspect the problem is they are aftermarket affairs and the quality is dubious.
If you try to force the hands on, not only can you damage the hands, you could push the jewel out or alter the "End Shake"
Using a pin to widen the inside diameter is sort of ok but it's better to ream them.
Esslinger should stock an appropriate set of Reamers but not the Cutting triangular type, you want the Pusher type.
You can also buy boxed selections of watch hands of varying sizes which will always be useful to have.

Sent from my SM-G920F using Tapatalk

[digginstony]

I don't get the logic. If the shafts measure 1.549mm and .965mm respectively, why would the spects for the movement call for 1.6mm  and 1.04mm? That's like saying I have an axle shaft that's 1, 1/2" in diameter and I'm going to press a bearing on to it that has an inter race diameter of 1, 5/8"---there is no press/interference fit and the bearing would just slide into the shaft????
I get that the movement spects call for 1.6mm and 1.04mm hands however they should be too large. Is there an alternate universe for watch hand measurements?
I do like the idea of using a pin to broach the hands to get them started.
Also, If I try to reuse the old hands (hour hand was a little loose) any way to tighten it up a bit??
Thanks for all the help/advice.
 
 

Sorry I missed the second part of your enquiry.
Yes it's possible to renovate your existing hour hand. You will need a staking set but make sure it's not the cannon pinion that is loose.
2 methods I've used with my staking set.
1. With the hand shaft upwards place a hollow stake with a rounded edge over the bore diameter but larger than the bore. Gentle tap on the stake will displace the metal and decrease the bore .
2 . Using a pointed stake closer to the bore, tap gently which will displace metal and cause a forward protrusion of metal inside the bore diameter, which should grab onto the cannon pinion

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[noirrac1j]

1 hour ago, digginstony said:

Hi and welcome.
I constantly order new hands even the size quoted from a tech sheets only to find they are too tight ! I suspect the problem is they are aftermarket affairs and the quality is dubious.
If you try to force the hands on, not only can you damage the hands, you could push the jewel out or alter the "End Shake"
Using a pin to widen the inside diameter is sort of ok but it's better to ream them.
Esslinger should stock an appropriate set of Reamers but not the Cutting triangular type, you want the Pusher type.
You can also buy boxed selections of watch hands of varying sizes which will always be useful to have.

Sent from my SM-G920F using Tapatalk
 

@Tracy I know you've mentioned your experience as a machinist, but it really is easier to buy hands that are the correct size. It will save you a LOT of potential trouble. As @digginstony has already stated, I also have found that ordering hands by technical specs STILL results in hands that are too tight and have to be worked a little with a broaching pin or staking set if you have one. Do you know what happens when you make incorrect hands fit? They work for a while, then when you start wearing the watch, will start to lose grip whenever they feel like it.

J

[digginstony]

Hi and welcome.
I constantly order new hands even the size quoted from a tech sheets only to find they are too tight ! I suspect the problem is they are aftermarket affairs and the quality is dubious.
If you try to force the hands on, not only can you damage the hands, you could push the jewel out or alter the "End Shake"
Using a pin to widen the inside diameter is sort of ok but it's better to ream them.
Esslinger should stock an appropriate set of Reamers but not the Cutting triangular type, you want the Pusher type.
You can also buy boxed selections of watch hands of varying sizes which will always be useful to have.

Sent from my SM-G920F using Tapatalk

Ooops I meant set of broaches not the triangle cutting type

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[digginstony]

Just not to confuse the OP. I've done a couple of photos.
The thing needle is a a broach. The other is a reamer.
The reamer fits into a jewellers tool as shown on this photo

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