Making a .12mm carbide drill bit for repivoting

[@bangy55]

Thank you. I was just sitting here looking at my small box of used dental carbide burrs wondering where I was going to get a 0.18mm drill bit to make a new tube for a Valjoux 7750 hour counter. Amazing how difficult it is to source 7750 subdial hands. They should grow on trees. I'm not kidding, by the way. All I need now is a grinding attachment for my old Rivett cross slide. I guess it's time to stop putting that move off. My dentist gave me the burrs over a year ago. I really do appreciate your sharing this video. Cheers.

[@cs-electronic]

Puh that is a nerve wrecking work. There are for sure many attempts needed to get one out? The result looks good!

[@s.spencertenagodus8051]

Thank you. A generous gift of your experience and time to a novice clock restorer who has just had a disastrous experience of a broken standard carbide bit in the cannon arbor. Next time I will try to make a similar single cutting point. Thanks again.

[@cyrilmatiassevitch1173]

I am a dental technician by profession and fixing watches is purely a hobby for me. Certainly, because of my basic profession I often use old dental technical drill burrs to either make some tools or to shape some replacement parts out of, such as pivots, balance staffs or winding stems. It is essential to first make sure that the drill burr's shank part is made of appropriate quality steel that can be hardened as there is a lot of drill burrs whose shanks are made of otherwise useless metal. All-carbide drill bits are very good for shaping gravers and cutters out of for turning on a lathe. And there is a wide range of diamond tipped burrs and diamond coated discs of different degree of abrasion we use in dental labs that I find extremely useful and handy when shaping and/or sharpening things in watch fixing. By way of disclaimer just in case: As mentioned above, I am just a self-taught enthusiat and the comment comes from my personal experience and may be found totally useless and grotesquely wrong by more experienced and/or professional viewers!!)))

[@repivot2253]

Interesting perspective. Thanks for sharing. I sometimes use old burrs in my lathe/cross slide for boring holes out to larger I.D.s. Carbide is preferable when working steel, but I've never used the shank for anything.

[@cyrilmatiassevitch1173]

Yes, I know there are some special steel ingots pros buy from watch parts and tools suppliers in order to turn pivots, staffs, stems and the like (I have forgotten the name of that sort of steel, maybe they call it "silver steel"..?) Being half lazy, half frugal, I have not ordered any yet..) That's why I started experimenting with old dental technical burrs (they have considerably longer shanks than dental clinical ones). If they are made of carbon steel and thus can be hardened, tempered etc., and most importantly, I have LOTS of them scattered all over the place, I suppose it is worth a try!)) But certainly I can't guarantee that the balance staffs ( especially their pivots) I have turned out of such shank material are going to last for years, if not decades, as compared to the proper type of steel. I started this watch fixing hobby about 4 years ago and came to tuning things on a watch maker's lathe about 2 years ago so I can't yet talk about remote results of my creativity!))

[@cyrilmatiassevitch1173]

P. S. And, by the way, thank you very much for sharing your knowledge and expertise with other people! It is totally thanks to you and other people like you, who do not hesitate to share their skills, that I am able to work with watches to the extent that I do, having learnt from scratch!)

[@garyprice8490]

Awesome honest coments are always welcome here. People like you are very, very rare. Glad to have read your input!

[@georgewolf7063]

Ah! This is what I was looking for! ;) Thanks for posting this!

[@theodavies8754]

Carbide micro drills are 3.2mm shank. It works well to break them close to the end of the flutes and regrind. Also works well for making centering drills. Would not recommend using full length micro drills. My setup is a boley pivot tool in the compound slide of a 350mm lathe with a 8.75 binocular microscope. Tungsten micro drills are available down to 0.1mm. WD40 is the best cutting fluid I've found with a 000 sable brush. Just keep breathing and zone in. Plan out distractions.

[@CarlosGeraldi]

you are awesome! thanks for sharing

[@BobT-b7k]

Anyone know how you cut diamond lapping disks into strips like done here?

[@nuevohermes]

Thanks !

[@colsanjaybajpai5747]

Very useful , thank you so much

[@defcon2691]

Cuantos usos se pueden hacer con una broca sin perder el filo???

[@profviniciusclaro]

Excelent! Thanks a lot!

[@wilkosoft]

Most useful - thanks

[@Qwerty-cb1ti]

A question - how do you know if a dental burr is carbide or not. Is there a visible line separating the carbide tip from the rest as with the carbide drills for electronics?

[@repivot2253]

Good question. I only use carbide tipped dental burs, and yes ther is a clear line where the carbide is attached to the steel shank.

[@Qwerty-cb1ti]

@@repivot2253 thanks. By the way recently I was successful at making a roller jewel from a broken electronics carbide tipped drill. I ground and polished the tip to 0.58mm and ground to a semicylinder. it was for a 1920 railroad Longines. Having the drill held on the watchmaker lathe made it possible to work on the tip using diamond flowers and the grinding attachment. After cutting off the tip I was Very content with the result. Cousins has no 0.58 roller jewels, apparently Seitz suspended manufacturing this dimension.

[@jonka1]

Wow!

[@Manga2limaelimao]

Que legal!