400 day clock spring

[Angefoh]

Hello,

I am new to this forum and hope that I can get the information I need. I have inherited a 400 day clock but with an old twisted suspension spring. I have managed to identify it as a Kundo Miniature/junior using a downloaded copy of Mervyn Passmore's excellent book "Anniversary clock identification". (see attached photos) The book also includes suspension spring size 0023" and jig measurements 80-83 mm. However on trying these measurements using the old spring I find the  pendulum is fouling the base-plate and I am unable to insert the top screw.
I know that the Horolovar 400 day book is the place I should look. Since I only intend repairing this one clock I cannot vindicate spending the £80.00 plus for a copy.
Would someone out there be able to advise as to the correct length of the suspension spring and the fork position. If not can anyone advise me on what would be the effect on making the 80mm length say 82mm so that I can mount the spring without fouling the base plate.

Much appreciation in advance

[RichardHarris123]

Hello and welcome.  I  don't know the answer but someone who does will help you soon. 

[watchweasol]

Hi. Ca you give us a post of the complete back plate so as to confirm your identification.  The kundo junior suspensions are all 0023” or .058mm lengh approx 90 mm measuring the old twisted spring is a no no as its length will be compromised by the twist.  The recommended suspension is 5E in the Terwillers 400 day book. It also gives you the block positions , top and bottom when making up the suspension.  These clocks look simple and in a way they are but and it’s a big but is they MUST be level and adjusting the beat without the correct tool is possible but not easy to achieve. There are also two styles of anchor post which have to be taken into consideration.  Suspension units are available from Cousins UK, Esslingers, and Jules Borel, timesavers in the USA.

I cropped springs to fit with no ill effect. The thickness is critical as the clock works by rotating / torsion with minimum friction. It has to be set up properly or it will not run

 

The full height of the suspension including blocks is 94mm measurement taken from the book.

[Dell]

All I do is restore & repair torsion clocks and I have just done 2 of the same Kundo juniors for customers, just moving top & bottom blocks very slightly further apart say 1/2 mm ish each would be enough, as for the fork if the clock flutters then raise the fork buy 1mm ( fluttering is dropping more than one tooth on escape wheel at once )

any problems just ask.

Dell

Edited January 6, 2024 by Dell

[Angefoh]

Hello, I have been unable to respond to the replies here due to personal issues but I appreciate the efforts that you have all made.
I have as was suggested through a minute amount of trial and error now managed to get the clock running and in fact it is running close to perfect timing according to my radio controlled quartz wall clock.

Thanks again

[Marsy]

The spring length should be 93mm between hole centre's and the fork 7.5mm down from the hole centre 

thickness of wire .0023”