Author Topic: Graver Honing Jig  (Read 7413 times)

Offline Jere

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Graver Honing Jig
« on: October 31, 2009, 05:12:50 AM »
I Thought I would post a few photos of tonight's project.

As an amateur watchmaker, hand-held lathe tools (gravers) are a frequently used tool.
Shown is a handmade graver from 1/2" walnut dowel, brass tubing, and a GlenSteel 3/32 HSS lathe bit.  It was ground to a 50 degree cutting face.

To hone the face to a nice sharp edge, it can be done free hand on a bench stone, however this requires a very steady exacting hand.
Otherwise a jig of some sort can be used to hold the graver at its desired angle.  These jigs are available commercially in various forms, but I decided to make one.  The design is based on the one described in John Wilding's book titled "Tools for the clockmaker and repairer : how to make and use them."  I made some modifications to his design as he works in Imperial dimensions, and uses BA threads and his is designed for use with 3/16" gravers.  Aside from the dimensions, I will be following his methods and design.

It consists of a clamp, connecting arm, and roller pivot and a roller.  The pivot arm is cross drilled and pinned to retain the roller. 

When I made the brass thumb screw, I tried using a simple knurling tool, however, I obviously had no idea how to use it.  Any advice on how to use a simple knurling tool, specifically how to determine the diameter of the work to be knurled would help I think.  It is a single, checkered form wheel type that fits in the toolpost.  Instead I simply ran a threading tool bit into the side of the part and indexed to 30 positions, it gave a decent knurl-like result.


Some photos of finished project.


Shown in use on an India bench stone.


Closeup:


Thanks for looking,
Jere
"If only I had known, I should have become a watchmaker."  A. Einstein

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bogstandard

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Re: Graver Honing Jig
« Reply #1 on: October 31, 2009, 05:26:59 AM »
Jere,

A big welcome, and very nice work.

I hope you show a little more of what you get up to.

I do some hand graving when I want to get a shape that is not normally available, not in your sizes, something a little larger. But anything you can show us would be most welcome.


Bogs

Offline dsquire

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Re: Graver Honing Jig
« Reply #2 on: October 31, 2009, 05:34:18 AM »
Jere

Great job on those pieces. Its hard to realize how small they are until you compare them to the size of the stone. I have seen similar jigs used to sharpen wood chisels and plane blades.   :ddb: :ddb:

Thanks for showing us these items.

Cheers  :beer:

Don
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Offline Bernd

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Re: Graver Honing Jig
« Reply #3 on: October 31, 2009, 11:04:28 AM »
I Thought I would post a few photos of tonight's project.


Very nice jig. As Don said it reminds him of a chisel sharping jig, so true. Always wanted to try hand graving too. You might be just the insperation I need.

Quote
Any advice on how to use a simple knurling tool, specifically how to determine the diameter of the work to be knurled would help I think. 

Jere

A couple of weeks ago I was going through some of my older metal working magazines and came across just that subject. I'll see if I can find it again. Give me a  :poke: if you don't hear back from me in a while.

Bernd
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Offline Bernd

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Re: Graver Honing Jig
« Reply #4 on: October 31, 2009, 12:22:35 PM »
Jere,

I found the info. Scanned it for you. Can't post it on a public forum since it's copy righted. PM me your e-mail address and I'll send it to you. Tried at your web site but can't attach pictures there.

Bernd
You can't fix "STUPID".

Online mklotz

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Re: Graver Honing Jig
« Reply #5 on: October 31, 2009, 01:54:22 PM »
In the KNURL program on my page (which you're free to download), I took the approach that the circumference of the work has to be an integer multiple of the circular pitch of the knurl.

Old timers (most especially Sir John) will tell you it's all nonsense and to just mash the knurl into the work until it starts forming a proper knurl shape.

I've used both techniques and they both work.  I must admit that mashing has a certain appeal - especially so after just having botched a part in which you had two hours of work invested.
Regards, Marv

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Offline Jere

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Re: Graver Honing Jig
« Reply #6 on: October 31, 2009, 02:22:10 PM »
Bernd,  I sent a PM with my email, thanks for finding that article, I will check it out.

Marv,  I downloaded the Knurl program.  I assume that "number of teeth on knurl wheel" is counting how many teeth going around the circumference of the wheel?  I will have to go try and count them, it is quite a small knurl wheel, but once I have that information, looks like your program is very helpful.

A photo of the knurlling tool that I have, it is made by Cowells and has a 1/4" shank for holding in the tool post.  After reading various postings about knurling it appears that a scissors type tool would offer more success, however, no one seems to make one which will fit my small 1/4" tool post.  I imagine that sort of excuse doesn't fly around here, I should have made one!

Thanks for everyone's input and comments.

"If only I had known, I should have become a watchmaker."  A. Einstein

Adventures in Watchmaking

bogstandard

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Re: Graver Honing Jig
« Reply #7 on: October 31, 2009, 02:55:47 PM »
Jere,

Much larger tools will work just fine on your machine as long as you can get them around the job.

What people tend to do is buy the smallest tool that is available, and will fit the machine, then just machine the holding shank down until it fits into your own toolpost.


Bogs

Offline Jere

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Re: Graver Honing Jig
« Reply #8 on: October 31, 2009, 04:46:04 PM »
So I counted the number of 'teeth' going along the edge of the circumference of the knurling wheel.  = 65
The diameter of the wheel is 0.625"

The KNURL software outputs for several test calculations suggests that just about any 1/8" increment should work.
Tried 1/8" 1/4" 3/8" 1/2" as nominal diameters and the program outputs the same values.
The thumb screw above was made from 5/16" brass rod, which the program states should have been reduced to 0.308" for 'perfect knurling'.

So now I just need to try it again, and can no longer blame it on not knowing what diameter to use ....    :thumbup:

Jere

"If only I had known, I should have become a watchmaker."  A. Einstein

Adventures in Watchmaking

Offline Bernd

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Re: Graver Honing Jig
« Reply #9 on: October 31, 2009, 08:19:58 PM »
Jere,

I sent the files. Might be to big for for your provider. Outlook Express kept timimg out.

Check your PM box.

Bernd
« Last Edit: October 31, 2009, 09:08:08 PM by Bernd »
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Offline sbwhart

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Re: Graver Honing Jig
« Reply #10 on: November 01, 2009, 04:55:03 AM »
Hi Jere

Welcome to the forum

 You've probably seen that one or two of us have an interest in clock/watches, your contributions will be greatly appreciated.

Cheers

Stew
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