Graver Sharpening Machines

[Dr. Jon]

In a related thread we discussed graver sharpening. With jigs such as a Crocker tool manual methods takes about 20 minutes and a WOSTEP certified watchmaker confirmed this.

Levin made a set of tools for sharpening gravers with a lathe and the Weller system uses a lathe.

I do not like using abrasives on my lathes so here are two alternative I have made.

The first in my mark 1 using a jig I made under Dewey Clark's supervision at an NAWCC course.

I made some brass adapters to directly mount a diamond resin wheel on a small motor. Graver sharpening does not not need a precisely centered wheel or even a very flat one. The little black box is the battery pack for a bright LED I added to get a better view.

The school jig, which looks a lot like the Levin jig, is mounted in a brass tube. The jig has a brass rod base which in normal use sits in a WW lathe bed.

This is a better view of the tool holder.

The groove secures the graver for grinding. I have several grinding wheel with 400, 600 and 1200 grit. I can do a graver in a few minutes starting with 400.

It is hard to cool since the coolant flies off the wheel so I use it primarily with carbide.

I used this for several years until I made up the mark 2

This is a Bergeon bracelet cutter. I bought it at an auction in box lot of tools and it was not what I was after. It came missing its splash guard and a saw blade. I removed the bracelet holder and fit a crocket tool to it. I made a replacement splash guard and this is much better. The Crocket tool mount has some slop but when pressed hard on the wheel it is very consistent in getting the face flat on the wheel. The arbor takes readily available diamond wheels. This tool is bit faster than the nark one, hs better flexibility in setting up faces to grins and is more friendly to coolants. I have not used the mark 1 since I set this one up and got it running.

Both of these tools are fairly small and have the benefit that they enable sharpening far from my lathe or watch assembly area.

A few years ago I bought a universal grinder set up in my basement far from my shop. It is harder to get fine grit wheels for this but I finally got some so I rarely use my mark 2 any more.

I think the photos are self explanatory but I can privide more information if anyone wants to try to duplicate these

 

[DeweyC]

I like it! Both replicate the function of factory made graver sharpeners (GRS) at a fraction of the cost. I like the willingness to adapt tools (Crocker) to a new purpose. Very creative. That last one is almost a Deckel SO without the rotating head!

 

[wefalck]

Some 15 years ago I bought a bracelet cutting machine for exactly the same purpose, but then did not follow the project through, because I found its bearing arrangement not very convincing. There is no axial thrust bearing (which is not needed for the original purpose of the machine, of course) and installing one, would have been rather involved. How did you deal with this issue?

I then followed another route, but this project is still unfinished. I had an odd Geneva-style headstock with a short bed lying around and started to built a grinding machine around it. However, I did not yet get around to finish the graver/turning-bit holder ... I made a couple of small grinding tables with fences for it and I can also use my Hardinge utility set on it. What is also still missing is a tilting table with fence to able to grind compound angles.

 

[Dr. Jon]

I did not even know that a thrust bearing would be needed.

I used it as it was except for adapting the Crocker tool. I just drilled a hole though its foot. It has a bit of slop and the wheel does too. I just press it towards the wheel and use the screw drive to touch it down.

The grind wheel is phenolic, diamond filled and its cutting surface moves around, so the only essential element is to enable the work to slide across the grinding wheel face. It arrangement always produces a flat grind, which looks good and is more than adequate as a cutting tool. It is Deckel like in that I can get the face angle I want but nowhere near as precise.

 

[wefalck]

I gather, if you touch up a hand-graver with a diamond-wheel, thrust-bearings would not a big deal. I had been envisaging more serious grinding of lathe tools with it, which puts both, axial and radial stresses to the grinding wheel.

 

[Dr. Jon]

That has been my experience. Hand held gravers need very good edges but the angles do not have to be precise.

For cutters going into a tool post the angles have to be withing a few degrees and I use either bench grinder and protractor or a universal grinder.