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Clock 13 progress

Clock 13 Tuning notes

As noted in my 'show and tell' post, I did a hasty initial assembly and my clock ran for about 2 days on 4lb 6oz direct weight. Then it stopped and refused to restart.

My original bearings had metal seals that seemed impossible to remove. I got some of the rubber-seal type and removed the seals and lube per the instructions. The lube was a translucent stuff reminiscent of petroleum jelly. IPA didn't seem to dissolve it, so I used acetone.

I found that the dry graphite in the bearings seemed to make them worse, though I suppose it might improve if I ran it for a while to grind up the granules. This was one of the large skate bearings. I skipped it for the rest, and am running them dry. They appear to be chrome plated, so I don't expect corrosion to be m…

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mkeveney

2月12日

Quick followup: My SP13 has now been running continuously for 6 days, with no signs of stopping. I assembled the drive weight with pulley and enough shot to give 4lb 5oz. This is less than the safety margin recommended by the instructions, but it's been running so well, I'm inclined to leave it alone for now. The pendulum swings just a hair over 2° each side. I adjusted the pendulum four times since making the drive weight, and think I now have it very close. I have not touched it in the last three days, and it's still within 30 seconds of true. Very happy with the design.

-Matt

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mkeveney

15 days ago

Countersink follow-up

I made a comment in my Show-and-Tell post, that Steve replied to.

I have more info, but the discussion makes more sense here.

> I wrote:

> One minor hiccup was that the heads of the #6 screws

> on the ratchet (clicks) were running into the spokes of the

> ratchet wheel...

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Steve

2月05日

That is interesting. I have purchased those screws in the past and don't remember the heads being oversized so much. There is a lot of variability between brands though. An 82 degree countersink is a quick solution. This trick should get added to the assembly guides.

I order screws for the parts kits from McMaster-Carr, product number 90048A151. They are specified to have a head diameter of 0.262" and usually measure close to 0.25". I keep using them because they are extremely consistent across many orders.

15 days ago

SP5B Parts on Etsy

Steve, I cannot find the parts kit for the SP5B on Etsy. Is there one? If so, can you link it here? Disclaimer: I haven't dug into the build notes and perhaps there's further info there.

Thanks!

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Steve

2月04日

The parts kit can be found at https://www.etsy.com/listing/1680180262/sp4bsp5b-easy-build-clock-parts-kit

16 days ago

Pendulum Period

This is my first clock (SP5B 2.0) and is currently breaking in. Before I write anything else, I want to publicly thank Steve for sharing his talent and passion for clocks with us. The print and build process was so enjoyable and the design remarkable. Steve's attention to detail in the assembly notes was at a level of detail I've never seen before and was obviously a engineer's labor of love. Thank you, Steve!

My clock has now run for 2 days straight and is keeping decent time! At first I had some stoppage and decided to let the entire gear train run for multiple cycles with the pallet removed and 3 lbs of weight. I swear that the gear noise softened as they ran through the cycles. Is that possible? When I put the pallet back on, the escapement wouldn't turn freely with 5 lbs and I discovered that…

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Steve

2月04日

Thanks for the kind words. A lot of effort goes into optimizing a clock for 3D printing.

The horizontal form factor of this clock stacks gears on a single arbor that can be a bit sensitive, as you found out. Once it is adjusted, the clock should run great.

Regarding pendulum length, many old clocks have a 2 second period with 1 second in each direction. This often used two gear pairs with 60:8 and 64:8 ratios followed by a 30 tooth escapement and a 39" pendulum. I believe that a 39" pendulum is disproportionately long in a small clock.

All of my clocks have shorter pendulums. This requires different gear tooth counts. For example, gear ratios of 36:8, 36:8, 36:8 and a 25 tooth escapement has a 24.5" pendulum beating 4556 times per hour. In the days of hand cut gears, the 39" example has 170 teeth to cut, while the 24.5" pendulum only has 157 total teeth and an additional arbor. With a 3D printer, the total number of teeth is an insignificant factor. I select gear ratios that allow a good overall balance. There is no difference in accuracy of a 39" pendulum compared to a 24.5" pendulum.

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