Tailstock trepanning tool - video

**Jon** · Oct 29, 2021, 04:59 PM

Tailstock trepanning tool. By Haxby_Shed. 19:32 video:

**Toolmaker51** · Oct 29, 2021, 07:02 PM

Tool of The Week, right here folks! Forget pilot drilling, cutting slugs of reusable material beats chip piles every day.
Such tools also face groove for O-Rings, rough out bearing bores, counterbores, even profile features like bosses. Generally, a trepan generates the radius cutting version of parting off; with a correspondingly curved toolholder.

PS; edit in. Frank S's tool bit concept is potentially correct; all dependent on material being worked.
My inclination would use positive triangular inserts with lots of clearance to eject chip flow.

Trepanning isn't normally pursued to great depths, but exhibit in post 1 gives that impression. It may turn out that he (Haxby_Shed) is more correctly coring. That possibility would have one bit behind other at desired full diameter, the first doing the roughing.
Via tailstock shown? Not so sure, that has a narrow footprint to counteract rotational forces x tool length.
Next stop, chatter-town...

**Frank S** · Oct 29, 2021, 09:45 PM

Originally Posted by Toolmaker51

Tool of The Week, right here folks! Forget pilot drilling, cutting slugs of reusable material beats chip piles every day.
Such tools also face groove for O-Rings, rough out bearing bores, counterbores, even profile features like bosses.

I've used tools very similar to the one in the vid on heavy turret lathes but the tail stock on your average engine lathe will never stand up to the stresses maybe with 4 cutters 2 to clear the ID and 2 to cut the OD with a positive rake angle but a straight in plunge with 2 carbide inserts using the full face width, I think he will have to support the core barrel with an attachment on his cross slide. But I've been wrong before since I don't know the material he is wanting to cut

**NortonDommi** · Oct 29, 2021, 11:50 PM

A support like this?

David Wilks has an excellent video on the making of his trepanning tools, well worth a look at a few of his videos.

**that_other_guy** · Oct 30, 2021, 06:10 PM

Wow!!!!!!

Hey @NortonDommi

It's "brino" here from that other site....

How many cutting edges in that tool?
What's the rpm? What material?

Sorry for so many questions, I just gotta pick up my lower jaw.

Thanks for the video!
You have cored out what is "big stock" to me!

Thanks for sharing this!

-brino
wait... I mean "that_other_guy"..........

**NortonDommi** · Oct 30, 2021, 10:05 PM

Hi that other guy,
Video is from an English guy called David Wilks, used to have a YouTube channel called userwl2850. He had an engineering business specialising in coring stock for further machining and making drill rig heads, now has a channel under his own name.
Here are two videos on making trepanning bars. I've put them in quotes to save space:
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"

Can you tell Brino that I have looked in a few times at the neighbors but are having too many glitches. Miss some of the neighbors too. Happy Halloween.