Double honing machine

[turbine712]

At the Mid-West SRP get together, there was a discussion on cryogenic freezing of metal during the heat treatment. I was reminded of this guy who uses dry ice in his manufacturing of knives. I asked Mike Blue if he knew of this guy and his machine and I couldn't remember his name. So here is the guy and his 290 lb double honing machine.

The Iceman's Double Hollowgrinder for Making Custom Handmade Knives.

[ChrisL]

Very cool. I wonder if during the design of this machine the maker researched traditional dual wet wheel grinders razor makers used? Outfit this grinder you've linked to with different sized wheels et, voila, there's your ticket to making real full and extra hollow razors/singing razors, bellies and all rather than just single concave grinds.

Thanks for posting this.

Chris L

[ChrisMeyer]

If you search through Google Patents you'll find a bunch of old patents for double razor grinders. Here are some examples;

Machine For Concaving Razors (1894)

Machine For Concaving Razors (1904)

Razor-Honing Device (1922)


I wonder if it would be cost effective to try to put one of them together?

[ignatz]

IMO That double grinder looks interesting for knifemaking, but would be overkill for razor making.

The problems as I see them are relative to producing razors (which are, in general, much more fragile and delicate than your average knife). From the photos on the maker's web site I can make the following observations:

1) There is no support rest for steadying a razor blade. Such a support is needed to rest the spine of the razor on. Such a support also needs to be vertically adjustable (in a repeatable manner) to allow for controlled, repeat grinding and hollowing operations.

2) Even if there was a support, the machine's working direction is from bottom to top. This would mean that the edge of the razor blank would be facing downwards so that the operator would not be able to judge his work in progress. (Note: All razor grinding machines I have seen to date - either in person or in videos - have the razor blank facing edge up.)

3) The speed of the belts appears to be fast, way too fast to offer control with a very small and extremely delicate razor blank. A bit of side-to-side flutter of your blade at that speed and "whoops!" a thin razor blank would be erased.

4) There is no provision for cooling of the blade. A razor blank would dangerously overheat within seconds. But even if there was some sort of liquid cooling, that very cooling would be trouble with the abrasive belts. The coolant liquid would contribute to the degradation of the belts and/or possibly introduce slippage in the drive system.

5) It appears that the opposing belt wheels cannot be adjusted during the grinding operations. Double wheel machines for razors allow for subtle changes in the distance between the opposing wheels during the grinding operation.

Of course, if one were making older, wedge-style razors and was working on the blanks with this machine prior to the hardening process, then, yes, one might see some speed advantage. But I really wonder if the machine would offer the necessary control for a razor maker.


- Ignatz

[randydance062449]

Thanks guys, that is some great info.

[Stubear]

Thanks very much for the link..! Some great info there..!

I saw a clip on Youtube about how DOVO make their blades and there is a similar machine on there for the hollow grinding. DOVO's machine uses grinding wheels though, rather than belts and the wheels are pretty small. They looked like 4"? They put the blade on the underside of the wheels, cutting edge up and there was a lever that was pushed to raise the blade into the wheels.

[0livia]

The reincarnation of Meister Wichlinghaus!
(German manufacturer of hollow grind machines)
Goood job!!!

[Mike Blue]

Good thoughts Ignatz. I don't think we ever finished going over the problems of the double wheel setup at our discussion. Each one of your points is valid.

...They put the blade on the underside of the wheels, cutting edge up and there was a lever that was pushed to raise the blade into the wheels.

Exactly, Dovo's process addresses the safety and machine issues. Aside from the speed, the first thing that McCann's double grinder will do is fling the thin razor straight down between the wheels. A chain mail apron would be a minimum garment...