Master Watchmaker, Clockmaker and Jeweller (since 1981)
rolex omega panerai iwc patek and other fine watches by Nicholas Hacko Sydney
Suite 403, Level 4, Culwulla Chambers
67 Castlereagh St. Sydney 2000 NSW Australia
Phone: (02) 9232 0500     Fax: 02 9233 2273

Do It Yourself Project:

Seiko 7S26 for Novice Horologists

In August 2011, a group of watch enthusiasts started their journey into horology following an online tutorial. The goal of this project is to assist the watch hobbyist in disassembly and assembly of a Seiko 7S26 mechanism.

Due to a number of requests, we have now set up a dedicated mailing list for the Seiko DIY course participants. The mailing list will serve to allow better communication between 'students' and allow the rest to follow the progress of our project. The group is not moderated so please focus posts on topics related to the DIY project: assembly tips, general observations, help requests, tools and parts exchange, project photos and DIY comments.

Mailing list: SEIKO 7S26 DIY Mailing list home page
To join please click above link or send a blank e-mail to

Chapter 1

Let's get started! Introduction, choice of the movement, which one to buy, model reference number.


Chapter 2

Essential tools required for disassembling and assembling a watch. Recommendations for a workbench.


Chapter 3

Identifying the calibre, reference and serial numbers, and bracelet adjustment. Plus some frequently asked questions.


Chapter 4

Pulling a watch apart - and even putting it together - is not that difficult at all. What is challenging for many novice horologists is the deeper understanding of how a watch works, Or more precisely why it is constructed the way it is.


Chapter 5

As we are getting closer to disassembly of the Seiko 7S26 watch mechanism, now is the perfect time to get familiar with a very basic concept of automatic (or self-winding) movement.


Chapter 6

Disassembly - case / bracelet / movement extraction


Chapter 7

Now that we got our movement out of the case, we are ready for more serious disassembly.


Chapter 8

Disassembly of the Seiko 7S26 Automatic Winding System - "The Pump"


Chapter 9

In this chapter we will continue with the disassembly of the Seiko 7S26's remaining units, starting with components in the power source unit, then the oscillator and then we will disassemble the counter or train wheels. In addition, the last step is to pull apart remaining components in the time and calendar setting assembly.


Chapter 10

This chapters deals with disassembly of the mainspring barrel and mainspring cleaning and lubrication. Before you undertake disassembly of the mainspring barrel, there are a few things to note...


Chapter 11

In this chapter, you will learn a couple of concepts related to components re-assembly. It also contains a few exercises to help build your confidence and skills to a level which will allow you to undertake more complex procedures later on.


Chapter 12

Continuation of Chapter 11. Assembly of train wheels and the escapement.


Chapter 13

In this chapter we will commence assembly of our Seiko 7S26 movement.


Chapter 14

Assembly of train wheels.


Chapter 2: Tools

For the list of recommended tools: tweezers, screwdrivers, hand removal tool, movement holder etc. please watch the below video. 

VIDEO #1: The 10 essential watchmakers tools

VIDEO #2: How to select, shape and sharpen screwdrivers?