Romer I Holdridge Radial/Radius Grinding Fixture Spin Index Type

Ball end mill sharpening instructions are at the end:

I can't find the operator instructions at that site. I can get a 2 page pdf parts breakdown, but I couldn't get to anywhere that was specifically following Breakdowns/Sharpeners shown in the URL.

Under the Parts & MSDS tab there is a listing for the E90i Operator Instructions, but it's actually the 2 page parts breakdown list.

I also couldn't get the video to dislay, but I wouldn't expect it to be very useful.

The problem is hack/spitWindows crapVista and it's security risk countermeasures. With any normal OS, I could just click the link and view the pdf, and choose to save it, or Save Target.

FWIW, the Holemaker Sharpener looks like a great machine, but limited in it's use.

That doesn't sound like a Vista problem, more like browser(shrug).

Give Opera a whirl. See:

You don't need to use its email or news group features. Watch yourself too when installing and don't let it take over as "default" for anything just yet. See if you can get use to it first. It is HIGHLY customizable, if you don't like something about the interface/looks most likely it can be changed to your flavor.

It still uses ini files for most all of its settings, very little use of the Windows registry. In other words, easy to delete/get rid of if you so choose.

I expect that you're correct, Leon. It's just what was on this Compaq box when I bought it, never expecting to still be using the hack/spitMS junk that was in it.

I've got the stuff to put together another 3 GHz machine, just lacking the gumption, due to my extreme prejudice of dealing with software of any kind.

If there was a computer built like an old mechanical typewriter or adding machine, I'd be oiling and cleaning it regularly.

Do you have any old badly chipped tip end mills which you would like to turn into either ball end mills or radiusing cutters?

That is what this does with the aid of a T&C grinder.

I doubt that it would be much use for indexing workpieces on a mill. Not strong enough.

And it may well have a fitting for feeding air into the sleeve around the spindle, to turn it into an air bearing. This is common on the ones for sharpening the side edges of an end mill -- slide it along, and let it ride on the finger to keep the flute at the right height.

Enjoy, DoN.

There is no air bearing, DoN.. just ball bearings for rotation (no sliding), and definitely not built for indexing on a mill.

Making ball endmills is probably the best use for it, and that would probably be interesting to do. It might be useful for grinding lathe cutting tools with convex or concave shapes.

Perfectly radiused ends on chuck key handles, heh. Gotta go write up a contract proposal for Jacobs.

There is -- the Babbage "analytical engine". They weren't able to complete it in his lifetime, but they have since done so.

And yes -- It would love to be oiled.

Enjoy, DoN.

Indeed so -- for a while at least.

You would need a square collet of the right size (of course), and the ability to raise or lower the grinding head to the right position to match the needed relief on the cutter. That would be a nice secondary use for it.

Only if you can talk them into making their key handles seriously hardened. Mild steel is a bit of a problem with a grinder like that -- unless you can find the right stones in the right shape for the material.

Enjoy, DoN.

What you mentioned about the needed difference in center height for grinding radiused lathe cutting tools is correct, DoN. Yep, square collets for holding lathe tools.

That's what I think is a bit strange about this grinder accessory to begin with. I don't have a T&C grinder, but I don' recall seeing any with wheel height adjustments.

The operating instruction sheets have a couple of diagrams (not photos of an actual installation on a T&C grinder), indicating the need to have the grinder wheel center line below the center line of the cutter being sharpened. A difference in height would also be required for relief angles on ball endmill flutes, so I suppose that the maker is suggesting (not specifically stating) that some shims or special fitting would be required for installation. As I pointed out in the description, I didn't purchase this new, but instead, I got this from a seller that said it was a customer return. So it may have originally had other mounting parts with it when new.

The instruction sheets just state; for use with all universal T&C grinders. I haven't decided what I'll use this radius accessory for yet, or what type of grinder I might use it with.

The diagonal of 1/4" is very close to 9mm. You can use a ball-nosed end mill in a boring bar holder to turn an inside radius, or grind the tool for an outside radius with a tapered die grinder stone held vertically. This gives a good smooth-cutting finish if not an exact radius.

The Delta Milwaukee Toolmaker's head raises and swivels on a round column. I think proper T&C grinders have a knee like a milling machine.

Any surface grinder should work. I haven't been able to free the spindle adapter on my Toolmaker to swap dressed wheels, so I sharpen tools underneath the wheel like a normal surface grinder. The homemade horizontal tooth stop is a short piece of old hacksaw blade, offset to

A small radius or bevel on the corners of an end mill makes it stay sharp much longer. I use the back relief setting on the end mill fixture to grind a flat 30 degree bevel. A small radius would look better and not leave a stress riser on the work.

The Toolmaker is like a Shopsmith or Smithy, a multipurpose combination that will do many different jobs poorly. In addition mine is very worn, but it still sharpens tools well enough for my home shop. Tool making is an art I'm a long way from mastering.

Jim Wilkins

Thanks for the additional info, Jim. I had read that grinding the sharp points off of endmills would keep them sharper longer, but haven't tried it yet. The idea of radiused cuts sounds very beneficial where a 90 degree corner isn't required.