Author Topic: Engraving cutter sharpening  (Read 828 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





Offline 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

Offline 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