Crown knurling

[jdrichard]

I made a button crown for a Pocket Watch. It is a ver simple crown but was a challenge to make by hand. I will be uploading a “howto” video soon, but here is my current problem. The crown is round and currently has “average “ grip. Any suggestions for improving the grip. I have no knurling tools.

 

 

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[khunter]

There was an interesting video on Youtube on knurling using a standard thread tap mounted in a lathe, the item to be knurled was attached vertically and allowed to spin freely, then was advanced onto the turning tap slowly, the cutting edges of the tap both cutting and turning the piece at the same time. I'll try to find the link and post it.

 

[khunter]

 

[jdrichard]

There was an interesting video on Youtube on knurling using a standard thread tap mounted in a lathe, the item to be knurled was attached vertically and allowed to spin freely, then was advanced onto the turning tap slowly, the cutting edges of the tap both cutting and turning the piece at the same time. I'll try to find the link and post it.
 

Very big thanks


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[jdrichard]

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[clockboy]

 

Are any of these useful.

https://www.ebay.co.uk/itm/Big-Lot-with-Antique-Vintage-Pocket-Watch-crowns-Watchmakers-Watch-Parts/352326262825?hash=item5208482029:g:h0oAAOSw-qVay~44

[Siro]

11 hours ago, jdrichard said:

 

I made a button crown for a Pocket Watch. It is a ver simple crown but was a challenge to make by hand. I will be uploading a “howto” video soon, but here is my current problem. The crown is round and currently has “average “ grip. Any suggestions for improving the grip. I have no knurling tools.

 

 

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I have in the past reknurled worn winding buttons with no more than a pin vice and a three square or a knife file with your ability to make a crown by hand it should be a walk in the park. Siro

[jdrichard]

 
Are any of these useful.
https://www.ebay.co.uk/itm/Big-Lot-with-Antique-Vintage-Pocket-Watch-crowns-Watchmakers-Watch-Parts/352326262825?hash=item5208482029:g:h0oAAOSw-qVay~44

I have a ton of crowns. The problem is the Tap size. Most crowns on ebay are too small.

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[Tudor]

On ‎4‎/‎10‎/‎2018 at 5:40 AM, Siro said:

I have in the past reknurled worn winding buttons with no more than a pin vice and a three square or a knife file with your ability to make a crown by hand it should be a walk in the park. Siro

This is what I was going to say... I'd also suggest you use the same spacing as the detail on the case edges to pull it all together.

[RyMoeller]

If you have a lathe (I'm assuming you do since you turned the crown) there are very economical knurling tools available on eBay.  I just purchased one a few weeks back to put a coin edge on a knob- worked like a charm.  The tools are available from China so they can take a few weeks for delivery though.

Take a look at Clickspring's YouTube channel for knurling on a lathe.  He makes everything look possible.

[jdrichard]

If you have a lathe (I'm assuming you do since you turned the crown) there are very economical knurling tools available on eBay.  I just purchased one a few weeks back to put a coin edge on a knob- worked like a charm.  The tools are available from China so they can take a few weeks for delivery though.
Take a look at Clickspring's YouTube channel for knurling on a lathe.  He makes everything look possible. [emoji4]

Can you provide a link?

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[RyMoeller]

Sure,

Here's the one I purchased:  https://www.ebay.com/itm/Single-Straight-Diagonal-Linear-Knurler-Knurling-Tool-Set-0-5mm-Pitch-Wheel-KIt/192408409882?ssPageName=STRK%3AMEBIDX%3AIT&_trksid=p2060353.m2749.l2649

You can also find some with two wheels which will create a cross-hatch pattern. 

[jdrichard]

Sure,
Here's the one I purchased:  https://www.ebay.com/itm/Single-Straight-Diagonal-Linear-Knurler-Knurling-Tool-Set-0-5mm-Pitch-Wheel-KIt/192408409882?ssPageName=STRK%3AMEBIDX%3AIT&_trksid=p2060353.m2749.l2649
You can also find some with two wheels which will create a cross-hatch pattern. 

Doesn't that single knurler cause too much pressure on the lathe bearing? Is this attached to the cross slides or hand held.

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[khunter]

35 minutes ago, jdrichard said:

Doesn't that single knurler cause too much pressure on the lathe bearing? Is this attached to the cross slides or hand held.

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These are meant for the tool holder on a cross slide, usually on a mini lathe or larger, definitely not hand held. I'm not sure how they would work on a watch lathe, but if you took it slowly then it might work ok. Yes there is a lot of stress on the bearings, these are meant for larger lathes.

[RyMoeller]

3 hours ago, khunter said:

These are meant for the tool holder on a cross slide, usually on a mini lathe or larger, definitely not hand held. I'm not sure how they would work on a watch lathe, but if you took it slowly then it might work ok. Yes there is a lot of stress on the bearings, these are meant for larger lathes.

Yes, that's a good point and admittedly I didn't really think a lot about the lathe bearing as in my case this was a one-off.  The lathe is the most expensive tool in your kit so best to take my advice with a grain of salt. 

In my case I didn't need a cross slide to knurl the knob I turned- simply bringing the knurler in contact with the nob while turned on the lathe was enough to cut the coin edge.  It took a little less than a minute but it's important to note, I was working with soft brass; here's a pic for reference:

 

[rogart63]

Think it's easier to do the knurl before doing the other things. And oil is important. And maybe this type is better for small lathes? Not as much stress on the bearings. https://www.ebay.com/itm/MINI-CLAMP-TYPE-KNURLING-TOOL-WITH-COMPATIBLE-WITH-MYFORD-LATHE-HEAVY-DUTY/263552648023?_trkparms=aid%3D555018%26algo%3DPL.SIM%26ao%3D2%26asc%3D44039%26meid%3Db39a55582c1f4be88feaa0ac537fc05f%26pid%3D100011%26rk%3D3%26rkt%3D3%26sd%3D192408409882%26itm%3D263552648023&_trksid=p2047675.c100011.m1850

[Tudor]

As long as the tool can be fixed securely, and brought into contact in a controlled manner (crossfeed), it will be OK. Knurling is like parting off pieces- you can't "hog" it. Bring the tool into contact and let it turn several revolutions (at low speed- same as parting) and then bring it in a few thousandths, spin several revolutions, repeat to desired depth.

Note you can stop the lathe to check your work, but don't back the tool out until you are satisfied with the results. Since speed should be low, oil is not a huge factor, other than ensuring the knurling tool is well lubricated so it spins freely.

Once done, back the tool out, bring the RPMs up and finish and polish the piece. Deep knurling will raise a lot of burrs due to metal displacement. You might have to use your files, then paper and then rouge to get the desired finish.

I was fortunate to get machining lessons from a tool and die maker. Ironically, he previously worked for Bulova Watch making bomb timers... Needless to say, his level of mastery of manual machining (and attention to the smallest details) is exceptional, and I again say I was very fortunate to be taught by him. Tons of videos out there I'm sure as well, but nothing beats first-hand teaching.

PS Using a live center on your tailstock will make life much easier. Normally they have a point to enter a center drill of a shaft; however there are other "point" styles including concave radius and cones which would probably suit this operation. Check McMaster-Carr or MSC for starters. Or, like my fried said: "If you need a special tool to do something, you make it." So, you might need to make a center tip the right size/shape to hold your work.

If a live center is not an option on your lathe, Chuck up the stock and apply the knurl first, then finish the shape off, so the chuck can fully support the piece for the side load of the knurling operation. This was said earlier I think too. Doing this would allow you to drill a center and support with a point live center (or dead center if that's all you have) and then the center drilled end would also be removed before final shaping. Many ways to skin a cat...

[jdrichard]

As long as the tool can be fixed securely, and brought into contact in a controlled manner (crossfeed), it will be OK. Knurling is like parting off pieces- you can't "hog" it. Bring the tool into contact and let it turn several revolutions (at low speed- same as parting) and then bring it in a few thousandths, spin several revolutions, repeat to desired depth.
Note you can stop the lathe to check your work, but don't back the tool out until you are satisfied with the results. Since speed should be low, oil is not a huge factor, other than ensuring the knurling tool is well lubricated so it spins freely.
Once done, back the tool out, bring the RPMs up and finish and polish the piece. Deep knurling will raise a lot of burrs due to metal displacement. You might have to use your files, then paper and then rouge to get the desired finish.
I was fortunate to get machining lessons from a tool and die maker. Ironically, he previously worked for Bulova Watch making bomb timers... Needless to say, his level of mastery of manual machining (and attention to the smallest details) is exceptional, and I again say I was very fortunate to be taught by him. Tons of videos out there I'm sure as well, but nothing beats first-hand teaching.
PS Using a live center on your tailstock will make life much easier. Normally they have a point to enter a center drill of a shaft; however there are other "point" styles including concave radius and cones which would probably suit this operation. Check McMaster-Carr or MSC for starters. Or, like my fried said: "If you need a special tool to do something, you make it." So, you might need to make a center tip the right size/shape to hold your work.
If a live center is not an option on your lathe, Chuck up the stock and apply the knurl first, then finish the shape off, so the chuck can fully support the piece for the side load of the knurling operation. This was said earlier I think too. Doing this would allow you to drill a center and support with a point live center (or dead center if that's all you have) and then the center drilled end would also be removed before final shaping. Many ways to skin a cat...

Very very very and another very good explanation and a big thanks. I was planning to knurl prior to forming the piece. I bought a two wheel knurling tool so all good. Will report progress.


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