Author Topic: Engraving cutter sharpening  (Read 986 times)

Offline chipenter

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Engraving cutter sharpening
« on: August 15, 2017, 09:07:42 AM »
I bought a set of ten tc engraving cutters from China , and have broken the tips from five so far , I made a simple jig to sharpen and put a relife angle on them , 1/2" Whit tread as it is turned in it puts the relife on , and any cutting angle is easely set , these are 20 degrees I hope these will last longer . 
Jeff

Offline awemawson

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Re: Engraving cutter sharpening
« Reply #1 on: August 15, 2017, 10:06:11 AM »
A very neat idea using a coarse thread to create the relief - I must remember that one  :thumbup:
Andrew Mawson
East Sussex

Offline Fergus OMore

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Re: Engraving cutter sharpening
« Reply #2 on: August 15, 2017, 11:25:53 AM »
I'm looking over my copy of the Norman Tinker drawings and would be delighted to see more of it.

Perhaps you could oblige?

Thank You

Norm

Offline John Stevenson

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Re: Engraving cutter sharpening
« Reply #3 on: August 15, 2017, 05:27:37 PM »
Do not try to use these cutters as is from China they are far too sharp

You need to take a single swipe with a diamond slip angled back a couple of degrees and sideways a couple so you have less of a point, more the flat you get with your 12 degree attachment

TBH I still prefer HSS for fine work, far more forgiving
John Stevenson

Offline chipenter

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Re: Engraving cutter sharpening
« Reply #4 on: August 16, 2017, 01:42:43 AM »
I was reliving the tip John but anything more than 0.2mm cut on brass and the tip went , 20 degrees gives a cleaner cut and the tip is still sharp , I will expriment further but still calling it a sucess .
Jeff

Offline chipenter

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Re: Engraving cutter sharpening
« Reply #5 on: August 17, 2017, 04:54:19 PM »
I am pleased to say the sharpend cutters work without breaking , sharpend the rest potoes show the relief ,
Norm I took some photoes of the Tinker its mounted on a Victorian Britannia lathe slide , no dials in those days perhaps thats were the term a smidge and a Nats wisker pluss outher parts come from .
Jeff

Offline chipenter

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Re: Engraving cutter sharpening
« Reply #6 on: August 18, 2017, 03:04:35 PM »
I was premature in saying no breakages tried cutting some CZ108 brass today , my mini mill did not like that at all and what it did cut looked rough antill the cutter broke .
Jeff

Offline Fergus OMore

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Re: Engraving cutter sharpening
« Reply #7 on: August 18, 2017, 05:42:41 PM »
Norm I took some photoes of the Tinker its mounted on a Victorian Britannia lathe slide , no dials in those days perhaps thats were the term a smidge and a Nats wisker pluss outher parts come from .

I must say 'thank you' for an interesting resume. I understand it fully.

I also recall the old battle between the Quorn Owners and those  with a couple of brackets- laughingly called a Tinker.

Cheers

Norm





Online philf

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Re: Engraving cutter sharpening
« Reply #8 on: August 18, 2017, 05:46:17 PM »
CZ108 is the problem and probably not your mini mill - CZ121 or CZ120 engrave much better.

I made a door plate out of CZ108 (because it's what I had handy) but engraved it with a 2 flute slot drill rather than an engraving cutter. I think you need positive rake (rather than the zero rake of your cutters), lots of clearance and lubricant to get away with it.

Phil.
Phil Fern
Location: Marple, Cheshire

Offline chipenter

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Re: Engraving cutter sharpening
« Reply #9 on: August 24, 2017, 03:19:22 PM »
I modified the holder today as it put to mutch relife on , the cut was 1.2mm wide and cut the tops of the letters that should have stood proud , bored out the threads and fitted a plain collet holder , the relife is obtained by a flat on the leading edge and grinding the rest off , I still have to put some on indexing to get the required angle , the flat can be seen in the photo .
Jeff

Online philf

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Re: Engraving cutter sharpening
« Reply #10 on: August 24, 2017, 03:37:43 PM »
I agree - it's a much easier way to grind engraving tools.

There's a useful diagram showing suitable clearance angles for different materials here: http://www.pilotltd.net/engraving.htm

Phil.
Phil Fern
Location: Marple, Cheshire

Offline Meldonmech

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Re: Engraving cutter sharpening
« Reply #11 on: November 30, 2017, 04:55:06 AM »
 
  Hi Phil
              Just caught up with this very interesting post. Like all your detailed drawings and text.
 
                                 Great info. Cheers David   

Online philf

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Re: Engraving cutter sharpening
« Reply #12 on: November 30, 2017, 05:36:16 AM »

  Hi Phil
              Just caught up with this very interesting post. Like all your detailed drawings and text.
 
                                 Great info. Cheers David   

Hi David,

The only credit due to me is in finding the link!

Cheers.

Phil.
Phil Fern
Location: Marple, Cheshire