Category Archives: Tools

This page describes the various tools that I have made in order to make watch parts.

Slotting head tool holder

I’ve had the slotting head for the Aciera F3 for a few months but haven’t used it yet, mostly because I haven’t had any tooling or tool holders for it. Now I want to cut an internal key way to fix a wheel onto its shaft, so it was time to make some tooling. 

The slotting head has a 12mm hole for a tool holder but I didn’t have any 12mm diameter steel, so I started with a 16mm bar. The result is shown below. From left to right: parallel 12mm shank to fit in head; 16mm collar; top end of the 4mm slanting hole for the cutter, tapped for a 5mm grub screw so that the amount of protrusion of the cutter can be adjusted by pushing it out; head of 5mm grub screw for clamping the cutter (this does go below the surface when tight).

4mm diameter tool steel bar held in the holder, from which I shall grind or mill a cutter for a piece of 1/8″ square section key steel. 

It’s certainly not the neatest tooling I’ve ever made, not helped by the design of my dividing head (in which I’d planned to hold the piece on the mill while drilling the various holes) not allowing me to hold the piece in a collet, since the draw bar would foul the table [correction: I later discovered that the drawbar can be removed once the collet is secured, so I could have used the dividing head]. There was also insufficient clearance under the vertical head to allow me to use a chuck on the dividing head, so the piece was simply held in a vice and all angles set by eye. 


Aligning the centring microscope

I had been having problems when trying to cut pinions, ending up with misshapen leaves as if the cutter was off centre. The centring scope had been used to centre the cutter each time so this was suspect number one. 

A quick search on the web for the maker of my scope, Aubert, revealed they were still in business. They even provide instructions for their current scopes on their website ( 

Initial inspection of my scope failed to find the four adjustment screws, Continue reading Aligning the centring microscope

Clarkson Mk1 Tool & Cutter Grinder

This grinder was picked up for not much at an auction but since then has sat in the workshop unused. My plan is to use it for sharpening end mills and also for shaping and sharpening lathe tools. 

It came with a few accessories including the centres visible in the photo above and the universal head. 

Unfortunately the head only has one sleeve, shown removed in the photo below. One plan is to make a new sleeve, 1 1/2″ OD to fit the Continue reading Clarkson Mk1 Tool & Cutter Grinder

Mandrel for wheel cutting

I wish to cut multiple copies of the same size wheel in one go, so that I have spares in case of in inevitable mistake, and also so that I may end up with most of the parts for more than one watch with little additional effort. This means making up a mandrel to hold multiple wheel blanks for the wheel cutting process, instead of just using a superglue arbor for a single wheel.

The design of my wheels, with circular Continue reading Mandrel for wheel cutting

Making a W12 wax chuck

In order to hold various parts, such as the barrel and balance wheel, for machining, I wanted a wax chuck. I briefly considered making a brass copy of a W12 arbor but decided that was going to be a lot of work and difficult to get accurate. After all, part of the idea of the wax chuck is that I can swap the part between the Schaublin 70 lathe and the Aciera F1 mill without losing concentricity through any remounting.

Eventually Continue reading Making a W12 wax chuck

Worm drive for wheel cutting on the Aciera F1

At last, more progress on the tool making. After breaking the cutting tool while making the hob for the worm wheel, I started looking around for off-the-shelf worm drives. A low backlash one came up on eBay for $100 including a stepper motor, so I jumped.

My original plan with the bought drive was to bore out the centre of the worm wheel so that it would fit on the spindle of the direct dividing head (or indexing head) of the Continue reading Worm drive for wheel cutting on the Aciera F1

Making a worm drive – making the hob

After some deliberation, I decided that I would attempt to make my own worm gear and wheel for my electronic indexing device. While it’s possible to buy the gear and wheel from companies such as HPC, the low backlash type that I want commands a high price. Besides, it’s an interesting project in itself.

Some searching on the web got me the basic calculations for the sizes of gear and wheel, based on my desired ratio of 36:1. This ratio was Continue reading Making a worm drive – making the hob

Electronic indexing for wheel cutting

The basic principle of wheel cutting does not seem complicated. Starting with a blank the correct full diameter for the number of teeth, a cutter is used to shape the gap between two teeth. The workpiece spindle is then rotated by the angle corresponding to the tooth width and the cycle repeated until the desired number of teeth have been formed.

The workpiece spindle rotation is typically controlled either using direct indexing, where a detent acts on a disk with the same Continue reading Electronic indexing for wheel cutting

New ratchet wheel for the Hauser 333

The Hauser 333 was made for cutting gears for street lamp timers, or so I have been told. It does this by having a ratchet wheel with the appropriate number of teeth attached to the workpiece spindle. A worm drive motor is constantly trying to rotate the workpiece spindle spindle through a clutch. The clutch slips until a solenoid releases the pawl, allowing the ratchet wheel to rotate until the pawl catches on the next tooth.

When it arrived in my workshop Continue reading New ratchet wheel for the Hauser 333

Making parts

It’s a small step forward but it feels like I’m making some progress – I’ve made a punch and die set to cut wheel blanks.

The idea of cutting lots of circles from thin titanium by hand didn’t appeal, so I made a punch and die from tool steel. The steel turned surprisingly easily with a satisfyingly good fit between punch and die. The parts were then hardened by heating with a small blow torch and quenching in cooking oil. The punch Continue reading Making parts

Latest progress


Practical work has been minimal recently due to changing lathes from a Pultra setup to a Schaublin setup. This has meant making a number of new tools (such as a flip-over graver rest) and welding up a new bench on which to put the lathe and overhead drive.

In the meantime, significant progress has been made on the CAD, some of which is shown on the Concept page.