Advise

[mikeosborne6446@gmail.com]

I am about to start building a Tredecimus clock.   Would appreciate any advise from anyone who has built one about anything that helped them in their build.  

[DaveY]

I made the Trecdimus over two years ago and since then I have had several attempts at getting it to run for any length of time. I had a number of problems which were usually down to my construction and some of the solutions I now realise were probably unnecessary. However, the three main problems that needed resolving were:

Friction. Plenty of smoothing of cogs and arbors was needed, especially with the main cog of the minute arbor and the pinion on the intermediate arbor. When the balls are loaded there’s a lot of force between these two gears and I even had to file a flat on the intermediate arbour to ensure that the pinion didn’t slip.

The pendulum limiter. I could never get the timing right and found that the pendulum bar was riding over the ringstop, the amplitude would increase and the count wheel would be advanced by two steps. The drop-weight-trigger would also further advance the count wheel when returning to its up position. The clock soon stopped. I fashioned a new grub screw for the ringstop with a spare 3mm threaded brass rod about 1cm in length and moved the ring stop so that it limited the pendulum on its left swing rather than the right. I was now able to get the clock to run for several hours.

Drop weight. With an intermittent problem it was difficult to observe what was happening, but I noticed that occasionally the drop weight made a double or even triple down/up movement and the trigger sometimes flipped over which prevented the drop weight returning to its up position. This was happening so fast that I couldn’t really see what the cause was. In the end I used a thin strip of veneer to act as a sort damper spring to help keep the trigger under control. The clock has now been running for several days and, after a bit of adjustment, running reasonably accurately. Further refinement though is still needed.

I hope this is of some use.

[mikeosborne6446@gmail.com]

Hi Dave

I see you finally got approved for the forum.
Mike

[DaveY]

Hi Dave

I see you finally got approved for the forum.
Mike

Yes, but of course as soon as I posted the message the clock stopped! However, with a little be more tweaking it seems to be going ok. I noted that the drop weight is slow to return to its up position when the ball at the bottom is effectively being forced out of the drive wheel. This accounts for only two or three cycles of the drop weight. I removed the small additional weight and my own made roller, which has metal bearings fitted, from the drop weight. The effect was that the clock only ran for a few minutes, so on my version the additional weight added to the drop weight was needed. 

I noticed that the drop weight was still occasionally doing a double drop, even using slow motion video it was very difficult to see what was happening. In the end I tightened up drop weight damper that I had added and hopefully that seems to have helped.  It's still running a bit fast, 5 to 10 mins a day. I have had to move the pendulum up 20mm or so to achieve this; a few more mm is no doubt required. Anyway it's now in its final position on the piano, which in the past has always been the kiss of death as it has always stopped. This time hopefully not.

Dave

[mikeosborne6446@gmail.com]

Hi Dave

Merry Xmas and Happy New Year. I have been working on the clock for a few hours each day for the last week or so. My injuries finally got well enough that I felt like doing anything exept doing nothing. I have run into several problems to date. When working on the motor I discovered that the motor pinion did not engage with the first gear of the ball lift. I had to contact Dave who pointed out that the plate that the motor attaches to is upside down. It turned out it is not symetrical and I missed in the drawing where the top edge is flush with the sides. My mistake Not a really hard thing to correct. The other issue I am having is the fact that the bushings that Dave changed to are so long that two of them on the same are do not leave any real room to adjust so that the gears line up correctly. I am working on a solution for this. I have also noted that the length of the 3mm rods for the arbors or spacers are short in most cases. I ordered more 3mm rods from Amazon so that I can remedy this. I find the instructions to be lacking in clarity and details. Probably why I make mistakes that I have to fix. I now get most of my understanding from the 3D model that Dave sent out. I have built other clocks in the past that had much more detailed instructions to follow step by step. Hope all is well with you and yours. I see you are still tinkering with your clock from your last post.
Mike