Good work, JD! Repivoting is not easy. A few tips when drilling, try to set things up so you can clearly see where the drill bit enters the workpiece. Pay close attention to the material ejected from the hole. You want to see little chips or curls of metal, like when a graver is cutting properly. The moment you stop seeing these chips, you should stop drilling and figure out why the drill isn’t cutting well any more. With metallic drill bits, it usually means you need to sharpen it. If you keep the drill against the work when it isn’t cutting properly, it starts to burnish and work harden at the point where you’re trying to drill, and you want to avoid this as much as possible. Take care when resharpening drill bits to preserve the tip geometry, especially the symmetry, otherwise you can end up with a drill bit that wants to wander off centre. If you don’t have blue pivot wire in a suitable diameter, good quality music wire is available down to very small diameters and is excellent for repivoting. Not wanting to be pedantic but for the sake of clarity and accuracy - The support you’re using in the tailstock to support the drillbit is a pivot polishing and drilling tailstock runner, it is not a dog. A dog, or drive dog is a piece that attaches to the work so that it can be driven and turned between centres.
All good advice, my friend. I think I do have some very thin piano wire that might work, but I’m gonna try the blues steel first. my problem with rep pivoting has always been the depth of the whole. Very, very tricky at this size to not snap off the drillbit.
@@JDRichard The blue steel is just fine, it just needs turning down to size. If you have thinner music wire to hand, you can save yourself some work. It is very tricky to drill hard steel at this tiny scale when repivoting. Carbide tooling helps, either shortened PCB drills, or drills made from carbide dental burrs(used burrs if available are fine). There is always a risk of snapping off a drillbit, but I think you can improve your odds a bit. Most WW lathes aren’t accurate enough in terms of headstock/tailstock alignment to assure adequate alignment of the drillbit with the work. I can see in this video that your tailstock setup is too inaccurate and it would make it incredibly difficult (but not impossible) to succeed. If a drill this tiny is even 0.005mm off centre, it’s likely to break. It might seem counterintuitive, but since the drillbit is self centring (assuming it has normal geometry, and you spotted centre accurately on the work with the graver), you can actually improve alignment and reduce your chances of snapping off the drill by holding the drillbit freehand in a pinvise. By holding the drill in a pinvise you are letting the drill itself find the bottom of the female center. This avoids the deflection stresses built up in the shank of a drill rigidly held in a misaligned tailstock. Use a handheld pinvise and SLOW speed. The physics will keep the drill cutting along the axis and you will learn how to feel when the drill grabs or scrapes. If you feel it scraping, you need to resharpen. Practice this on brass rod, with no watch parts at stake and I think you’ll be pleasantly surprised. Lastly, there a fantastic demonstration of freehand drilling to repivot on UA-cam. Even if you’ve watched it ages ago, watch it again. The channel name is repivot22, and the video is called “Repivoting technique #1, collet holding lathe, free hand” The same channel shows how to make your own carbide drills from dental burrs. One last tip - whilst collets are very convenient, they don’t assure concentricity. Slight wobble due to lack of truth when drilling is best avoided. For this reason, the extra effort of using a wax chuck to assure that the work is centred is helpful. Repivoting can be done using collets, especially if you make sure you have a set in excellent condition, that aren’t sprung and haven’t been abused, but given the importance of truth in the finished pivot and the consequences of lack of truth when drilling, use a wax chuck if in doubt about your collets.
@mercuriall2810 so drilling with a tail stock runner insures that the balance is absolutely true to the indent in the runner and the drilling will go in straight. I used to do this freehand unless I use a wax Chuck of some sort to hold apart I can’t guarantee that the balance will be straight. And setting up a wax truck with a balance and the balance still attached would be a challenge. I understand all you’re saying as I did a lot of studying on this before I started actually re-pivoting shafts. I did a beautiful job on a Hamilton years ago found it worked well even when I put a cap on the fourth wheel and created a fourth wheel, pivot for the secondhand. Thanks for all your advice. I do listen and agree. again, the wobble is taken away by the use of the what I incorrectly called the dog
Why not just drill out the whole shaft and make a new replacement of the whole shaft? Drilling those thin walled holes seems like not the best solution.
Your lathe work is I use to love lathe work enjoy I would stay all day on one
Awesome video !!!!
Thanks Sonny:)
Looking good. My compliments to your increased skills in watchmaking as well as the quality of your videos.
Thank you very much for the compliment
Fascinating! The microscope makes a huge difference. You’ll have to talk about that new set-up in one of these videos.
Good work, JD! Repivoting is not easy.
A few tips when drilling, try to set things up so you can clearly see where the drill bit enters the workpiece.
Pay close attention to the material ejected from the hole. You want to see little chips or curls of metal, like when a graver is cutting properly.
The moment you stop seeing these chips, you should stop drilling and figure out why the drill isn’t cutting well any more. With metallic drill bits, it usually means you need to sharpen it.
If you keep the drill against the work when it isn’t cutting properly, it starts to burnish and work harden at the point where you’re trying to drill, and you want to avoid this as much as possible.
Take care when resharpening drill bits to preserve the tip geometry, especially the symmetry, otherwise you can end up with a drill bit that wants to wander off centre.
If you don’t have blue pivot wire in a suitable diameter, good quality music wire is available down to very small diameters and is excellent for repivoting.
Not wanting to be pedantic but for the sake of clarity and accuracy - The support you’re using in the tailstock to support the drillbit is a pivot polishing and drilling tailstock runner, it is not a dog.
A dog, or drive dog is a piece that attaches to the work so that it can be driven and turned between centres.
All good advice, my friend. I think I do have some very thin piano wire that might work, but I’m gonna try the blues steel first. my problem with rep pivoting has always been the depth of the whole. Very, very tricky at this size to not snap off the drillbit.
@@JDRichard The blue steel is just fine, it just needs turning down to size. If you have thinner music wire to hand, you can save yourself some work.
It is very tricky to drill hard steel at this tiny scale when repivoting. Carbide tooling helps, either shortened PCB drills, or drills made from carbide dental burrs(used burrs if available are fine).
There is always a risk of snapping off a drillbit, but I think you can improve your odds a bit.
Most WW lathes aren’t accurate enough in terms of headstock/tailstock alignment to assure adequate alignment of the drillbit with the work. I can see in this video that your tailstock setup is too inaccurate and it would make it incredibly difficult (but not impossible) to succeed.
If a drill this tiny is even 0.005mm off centre, it’s likely to break.
It might seem counterintuitive, but since the drillbit is self centring (assuming it has normal geometry, and you spotted centre accurately on the work with the graver), you can actually improve alignment and reduce your chances of snapping off the drill by holding the drillbit freehand in a pinvise.
By holding the drill in a pinvise you are letting the drill itself find the bottom of the female center. This avoids the deflection stresses built up in the shank of a drill rigidly held in a misaligned tailstock.
Use a handheld pinvise and SLOW speed. The physics will keep the drill cutting along the axis and you will learn how to feel when the drill grabs or scrapes. If you feel it scraping, you need to resharpen.
Practice this on brass rod, with no watch parts at stake and I think you’ll be pleasantly surprised.
Lastly, there a fantastic demonstration of freehand drilling to repivot on UA-cam. Even if you’ve watched it ages ago, watch it again. The channel name is repivot22, and the video is called “Repivoting technique #1, collet holding lathe, free hand”
The same channel shows how to make your own carbide drills from dental burrs.
One last tip - whilst collets are very convenient, they don’t assure concentricity. Slight wobble due to lack of truth when drilling is best avoided. For this reason, the extra effort of using a wax chuck to assure that the work is centred is helpful.
Repivoting can be done using collets, especially if you make sure you have a set in excellent condition, that aren’t sprung and haven’t been abused, but given the importance of truth in the finished pivot and the consequences of lack of truth when drilling, use a wax chuck if in doubt about your collets.
@mercuriall2810 so drilling with a tail stock runner insures that the balance is absolutely true to the indent in the runner and the drilling will go in straight. I used to do this freehand unless I use a wax Chuck of some sort to hold apart I can’t guarantee that the balance will be straight. And setting up a wax truck with a balance and the balance still attached would be a challenge. I understand all you’re saying as I did a lot of studying on this before I started actually re-pivoting shafts. I did a beautiful job on a Hamilton years ago found it worked well even when I put a cap on the fourth wheel and created a fourth wheel, pivot for the secondhand. Thanks for all your advice. I do listen and agree. again, the wobble is taken away by the use of the what I incorrectly called the dog
@mercuriall2810 isn’t blue steel the look that was given by a famous model on TV.
Why not just drill out the whole shaft and make a new replacement of the whole shaft?
Drilling those thin walled holes seems like not the best solution.