Tool post height

[Howard LewisParticipant @howardlewis46836]

That is not unlike one that I made to cut a semi circular thread with a 4 mm pitch!

A good variation on the theme!

Howard

[brian jones 11Participant @brianjones11]

Nice pix very informative

Erm looks like i could bodge up a pair of long nosed pliers?

[VicParticipant @vic]

This is the one I made about ten years ago.

[brian jones 11Participant @brianjones11]

Thats a work of art for sure.

 

something puzzles me here the tool doesnt seem to have any clearance angle either for side or centre feed, not like a convention horizontal tool for the same duty. its supposed to stop the tool edge rubbing against the work, pls advise

maybe the phto isnt clear

 

I think someone mentioned drgs

Edited By brian jones 11 on 12/07/2021 21:47:12

Edited By brian jones 11 on 12/07/2021 21:49:18

[VicParticipant @vic]

Does this help?

[brian jones 11Participant @brianjones11]

Yes that helps to get my head around the 3d geometry

Notice how the clamp nut is not sitting square on the tool piece, needs a little land there on the other side to bring it level – in this CNC world? Those carbide holders within microns

I am knocking up a 3d model to understand the concept better – purely jpgs no dimensions – not wishing to plagiarise, that compound angle on the top face is the secret and you would definitely need a purpose made grinding jig to maintain accuracy. Only one face to grind!

but its a fascinating concept, I never heard of it before but £130 for the full English – I havent got my regular tooling working properly yet

[VicParticipant @vic]

A couple more. People have asked in the past about interrupted cuts and whether the cutter moves – no, I’ve not had this happen so far.

[egaParticipant @ega]

Vic:

What is that beautiful finish?

[VicParticipant @vic]

Posted by ega on 13/07/2021 11:06:49:

Vic:

What is that beautiful finish?

Ha ha, lots of folks ask that! It’s just sand blasted then waxed to stop it rusting. I use the same finish sometimes on most metals including Alloy, Steel, Brass and Titanium.

[brian jones 11Participant @brianjones11]

Al alloy, brass sand blast you are avin a giraff

Ive been studying that angle, its very tricky all 3 axes x y z are skewed for clearance and the top angle sloped for cutting rake

Did you calculate these yourself and draw them up

without cnc – machining by hand – a real work of art IMHO

Edited By brian jones 11 on 14/07/2021 05:35:49

[VicParticipant @vic]

Posted by brian jones 11 on 13/07/2021 20:44:52:

Al alloy, brass sand blast you are avin a giraff

Why?

[brian jones 11Participant @brianjones11]

Not being of the arty crafty persuasion, I didnt think of decorative metal finishings

Pratt and Witney have all the gen on blasting Mg Alloys – well thats rocket science

Grease is my coating of choice.

[Anthony KnightsParticipant @anthonyknights16741]

Here's my contribution.

See "Mikes Workshop"

**LINK**

[JohnFParticipant @johnf59703]

My contribution as well — I "borrowed" Vic's design — one of the nicest I have seen and made this a couple of years back – have a sketch somewhere !!!!

[VicParticipant @vic]

Very nice John. I like the finish, one of my scribing blocks has that. What do they call it?

[brian jones 11Participant @brianjones11]

This concept was invented around 1888 in America mid west. Its been reinvented many times gaining prominence in the '30s

For all its claims its always been a mystery why it never caught on

Even today with cnc to tackle the tricky angles you would expect more presence?

Mystery

Perhaps the Carbide mafia have overrun the potential?

Its fiendishly difficult to visualise yet clearly simple to use and easy to sharpen – whats not to like – £130

Some worthy machinists have made some excellent examples

[JohnFParticipant @johnf59703]

Posted by Vic on 14/07/2021 10:41:27:

Very nice John. I like the finish, one of my scribing blocks has that. What do they call it?

Hi Vic, "colour case hardening" its case hardening using bone charcoal, to achieve the finish the case is not very thick but enough to be wear resistant — been practising and the tool was a prime candidate !

John

[Kiwi BlokeParticipant @kiwibloke62605]

The mottled colouring is the result of uneven cooling of the case at the quenching stage – for dramatic results, quench in water which has air bubbling through it. Otherwise, you get a dull, fairly uniform grey. Popular technique in the gun trade.

Edited By Kiwi Bloke on 14/07/2021 11:15:46

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