Printed Clocks

Last week I acquired SP16 from myminifactory, and promptly decided I wanted to put my own face on it: normal (arabic) numerals, but with the hour and minute markings round the outside edge as on the dials with the Roman numerals. Because.

Anyway, I messaged Steve about it, and he promptly and kindly uploaded the dial parts in .step format, making it far easier to hack my own dial onto it.

The deed was therefore done, I printed everything, and did a pendulum swing test; after 20 minutes it was still moving quite perceptibly, so I finished the build and started it up with 1.8kg of diving weights hanging directly off it. After an hour the pendulum amplitude had settled at about 4.8° each side, then it gradually increased overnight to about 5.5° after 12 hours. I assume this means it is being run in, and friction is still decreasing. Most gratifying.

I am ineffably impressed by the polished character of this design, and also of the assembly manual. It speaks of a deep understanding of clocks, design for 3D printing, and process documentation, in one professional package. There were no issues, unclear points, or problems whatsoever. I printed, built, and started it up, all completely painlessly. We are dealing with a heavyweight here.

So I intend to run it for a few more days like this, then reduce the weight to find the minimum, as suggested, then finalising the weight with pulley, before doing any serious rate adjustments.

One more thing (probably also ridiculous, but, as you have no doubt gathered by now, I am excited, and why should one not enjoy some silly excitement occasionally?): I take it you have considered higher-order block-and-tackle arrangements for the driving weight?

As I understand it, the suggested default weight configuration is in the so-called gun tackle arrangement, rove to disadvantage, which gives a factor of two reduction in force (=doubling in weight, and run-time). Adding more pulleys top and bottom would allow this factor to increase, thereby increasing the run-time by the same factor, at the cost of some complexity, and, more importantly, a concomitant increase in driving weight, which will of course strain the frame. So the real question is, how much weight do you think such a PLA frame can withstand indefinitely before sagging/creeping? What do the years of experience (and the gut feel) indicate?

Because it is so exhausting having to wind a clock every.single.week. 😊

As it is this clock has already given much joy, and is bound to still do so for a long time to come. 😁

I am much pleased.