Pivot replacement

[HowardDeHart]

I’m having a difficult time trying to drill an arbor for a new pivot. I am using Bob’s method as shown in his lathe videos and have managed to drill into the arbor about 1/8″ but can’t get the bit to cut into the arbor any deeper. And have changed bits enough to know that it’s not the bit. Anyone have any advice? Thanks ahead of time.

Howard

[RandyBeamer]

Hi Howard,

My guess is that the arbor has become “work hardened” from the small amount of drilling you’ve done.

Evidence of that would ( possibly ) be if you weren’t getting any new swarf as you changed bits

You may need something  harder than the hubs of hell in order to drill deeper.

I’ve read where one watchmaker uses carbide dental “burr drills” for this.

Also, have you tried annealing it ??

 

Best regards

 

Randy

 

[HowardDeHart]

Thank you Randy, I hadn’t heard about work hardening. I’ll try annealing the arbor and see what happens. If that doesn’t work I’ll try and find a replacement.

[RandyBeamer]

Hope the info helps Howard,..and good luck !

 

Best regards,

Randy

[Dell]

If you use carbide drills they will drill it but be very careful because they break very easy , just drill a little bit then pull drill out brush off swarf bit more oil then drill a bit more DON’T let swarf build up and bind the drill.

Dell

[HowardDeHart]

Thank you Dell. I have purchased the carbide bits, I ordered a couple other sizes, and drilled the holes exactly as you described. The carbide bit worked like a champ. Thanks to Randy and Dell.

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