New Hermes CG4 cutter grinder

[Bob Fisher]

Anyone know about this machine? Is it something that I can't live without?One for sale locally for $250. Should I go for it? Bob.

[DR]

This type of grinder can be handy for doing the ends of milling cutters, drills, lathe tools, etc. It's hard to make a judgment on this particular machine without info on it. The general category of machine comes in many versions from 50 pounds to several thousand pounds.

I would ask whether it has a diamond wheel for carbide or a wheel for high speed steel. And are wheels readily available. Also, what about work holding, does it use proprietary collets or a standard size. Are square collets available for lathe tools.

[gary hart]

Bob, believe this is a grinder for sharpening single lip cutters. D-bit type cutters. Not very adaptable for doing end mills or drill bits. Good for sharpening engraving slingle lip cutters. Have one similar if not the same as this one and the only thing have used it for is making or sharpening the small D-bit cutters used for engraving.

[Mike of the North]

Here is a link to it, I saw it but it is out of my price range.
http://detroit.craigslist.org/okl/tls/2679511447.html

[DR]

Bob, believe this is a grinder for sharpening single lip cutters. D-bit type cutters. Not very adaptable for doing end mills or drill bits. Good for sharpening engraving slingle lip cutters. Have one similar if not the same as this one and the only thing have used it for is making or sharpening the small D-bit cutters used for engraving.

Is there something about the work holder or machine size that prevents end mills and drills from being done on your machine?

Here's a link to a site where a PDF for the Deckel single lip grinder can be downloaded. The PDF shows how Deckels are capable of end mills, drills, etc, etc. Of course, I don't exspect the New Hermes to be in the same league quality-wise as the Deckel, but the concept is the same. I've lusted after a Deckel single lip grinder for years, I always hope the ones at auction will go for $500 or so, but no such luck, they usually go well into the thousands.

[gary hart]

DR, believe the Deckel has a slide on the work head that the New Hermes doesn't.

[rickyb]

Anyone know about this machine? Is it something that I can't live without?One for sale locally for $250. Should I go for it? Bob.

I have this model and yes it does have limited use. It is referred to as a single point grinder and was designed for making 1/8" engraving cutters. $250 is a good price. If it has collets and grind wheels, its a bargain. Collets are 2B and impossible to find. Grind wheels are not available either.

2B collets are an internal thread draw bar with an 1/8" through hole. So even with the collets you can only chuck small length parts. I made a full set of external thread collets from drill rod and can now hold any length round up to 1/2" dia.

Stones are equally as difficult. I found some stones at a local abrasives shop and had them modified to fit. Diamond cups are available but need a sleeve to get down to the 1/2" hub diameter. At least that part was easy.

I use the grinder for pointing scribes and for making boring bars. Its easy(but slow)to grind the flat on the rod to 1/2 dia and sharpen and relieve the cutting edge.

I have not been able to devise a modification to the machine to get the extra degree of freedom to sharpen end mills.

[DR]

I have this model and yes it does have limited use. It is referred to as a single point grinder and was designed for making 1/8" engraving cutters. $250 is a good price. If it has collets and grind wheels, its a bargain. Collets are 2B and impossible to find. Grind wheels are not available either.

2B collets are an internal thread draw bar with an 1/8" through hole. So even with the collets you can only chuck small length parts. I made a full set of external thread collets from drill rod and can now hold any length round up to 1/2" dia.

Stones are equally as difficult. I found some stones at a local abrasives shop and had them modified to fit. Diamond cups are available but need a sleeve to get down to the 1/2" hub diameter. At least that part was easy.

I use the grinder for pointing scribes and for making boring bars. Its easy(but slow)to grind the flat on the rod to 1/2 dia and sharpen and relieve the cutting edge.

I have not been able to devise a modification to the machine to get the extra degree of freedom to sharpen end mills.

Not to belabor a point, but if you can do boring bars why can't you do the ends of milling cutters?

From what you've said about the collets and wheels I believe I'd pas on it as a general purpose grinder. The Deckels and Gortons and others I'm familiar with are very sought after because they are general purpose ( even though they're called single lip grinders).

[rickyb]

Not to belabor a point, but if you can do boring bars why can't you do the ends of milling cutters?

From what you've said about the collets and wheels I believe I'd pas on it as a general purpose grinder. The Deckels and Gortons and others I'm familiar with are very sought after because they are general purpose ( even though they're called single lip grinders).

To sharpen an end mill you need to be able to 1. align the cutting edge to about 1/2 degree from the end mill axis, 2. introduce the rake/relief angle perpendicular to #1, 3. feed in the end mill for the cut and 4. index to the next cutting edge. The Hermes can do 1 and 3 and be easily modified to do #4. There is no possibility to introduce the rake/relief angle #3. That is the extra degree of freedom that I mentioned was needed.

For most of us it is much, much cheaper to buy new end mills that to buy a used Deckel at $1500+.

[jreinke]

I have this model and yes it does have limited use. It is referred to as a single point grinder and was designed for making 1/8" engraving cutters. $250 is a good price. If it has collets and grind wheels, its a bargain. Collets are 2B and impossible to find. Grind wheels are not available either.

2B collets are an internal thread draw bar with an 1/8" through hole. So even with the collets you can only chuck small length parts. I made a full set of external thread collets from drill rod and can now hold any length round up to 1/2" dia.

Stones are equally as difficult. I found some stones at a local abrasives shop and had them modified to fit. Diamond cups are available but need a sleeve to get down to the 1/2" hub diameter. At least that part was easy.

I use the grinder for pointing scribes and for making boring bars. Its easy(but slow)to grind the flat on the rod to 1/2 dia and sharpen and relieve the cutting edge.

I have not been able to devise a modification to the machine to get the extra degree of freedom to sharpen end mills.

You can get the 2B collets for the CG-4/5 from Quality One Engravers for $65 which is less than half of what New Hermes sells them for. New Hermes also sells all 3 types of grinding wheels, Aluminum Oxide, Silicon Carbide and Diamond.