When I made my forst clock the tutor who is now quite a close friend) imparted his interest in how the "old time" clockmakera went about their craft. He showed several parts from very old clocks that displayed the evidence of how they had been marked out and then fashioned using the very basic tools of the 17th & 18th centuries….

…….Thus it came to pass (the biblical style is not an accident!) that of the 4 pinions in my first clock one is completely made by hand. The blank pinion was held in the vice and a hacksaw used to cut the channels between the leaves, then a succession of files, and finally wooden pegs were used to shape the final profiles. A piece of brass clock wheel of same module was used throughout as a 'guage' for the work.

EDIT;   I should add that I don't use fly cutters to make pionions currently….I either use Thornton cutters (I'm not an enthusiast!) when in the EFHC workshop but prefer to cut them by planing using the topslide of my smaller lathe.

Edited By Bob Stevenson on 19/09/2020 17:06:57

I make all the pinions and wheels in my clocks using shop-made cutters made from hardened/tempered silver steel. I usually cut pinions from silver steel, but sometimes I use EN8. Cutting pinions this way is a slow job. I typically run the mill at around 200rpm, and take 2 or 3 passes with plenty of cutting oil. Picture of one of my cutters and examples of wheels and pinions below.

Mike

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It's both, Martin … Much of the modern "silver steel" is more variable in quality than the old Peter Stubs material.

Hardenability and Machinability are bedfellows in this.

MichaelG.

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Hopefully ; T&A still makes it right: **LINK**

https://www.silver-steel.co.uk/about-us

Struggling to learn is normal. Some lucky souls are natural machinists, and find everything easy. Not me! Everything has to be practised, and most first attempts are iffy at best.

From a distance what you're doing looks straightforward, but there are a mass of small details to get right. Michael mentions speeds and feeds. Also, there's getting the cutting edge on the blank just right, which is a challenge, followed by heat-treating silver-steel successfully.

My experience of silver-steel is getting the best out of it is a little hit and miss. Judging temperature, how long to hold the metal steady at that temperature, and then plunge cooling without allowing steam to upset the chill are all a bit of a knack. The steel might not be hard enough, or the hardness could be skin deep, or brittle so bits of the edge flake off.

And then there are the cutting properties of properly hardened Silver Steel. It's more akin to Carbon Steel than HSS, meaning it's easy to overheat and less tough. Needs plenty of lubrication and a slower pace than HSS – another learning opportunity.

Some materials are harder to cut than others, yet another detail. EN1A is considerably better than ordinary mild steel, but I would practice on brass first.

It's not that beginners make a mess of everything, rather a few slightly off details combine into erratically disappointing results. Keep trying, and it gradually comes together. Self-teaching is difficult – much easier if an expert shows how it's done, and explains the mistakes you're making. It's a little like learning to ride a bicycle – suddenly things come together and away you go.

I have no problem buying tools and materials to get jobs done, but I enjoy learning too, despite the frustrations!

Dave

Chris

If you are going to use gauge plate to make a cutter you may be better to use the same design as shown in the Ivan Law "Gears and Gear Cutting" book, it is single point cutter made with an offset centre and has a section removed to form the cutting point and the tool section remains even after extensive grinding.

Emgee

The multi tooth cutter is best but not so easy to make as the teeth need backing off to prevent rubbing, details can be found in the Ivan Law book as well.

Edited By Emgee on 20/09/2020 10:18:37

You can still make cutters from carbon steel. Just buy a large rusty twist drill with a MT shank and make cutters from that. The larger MT shanks should yield a good number of small cutters for pennies outlay. Harden them yourself.

Yes John, I remember now after looking at the cutter I made to cut some 16DP gears for my Bantam many years ago and a closer look at your pictures shows the indexing holes.

Emgee

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We’re both right … All is well : There is peace and harmony

MichaelG.