Gina

Tipping it down here but it's only supposed to be showers so hoping it will stop soon - want to do some shopping.

Well, you've well and truly christened that jacket Kev!!

The whole gear train except for some of the bearings and axles.

Seconds wheel printed etc.

I used ordinary galvanised shed door hinges.

Been raining quite heavily all day here in spite of the local forecast saying it would rain later. Having the Met Office only 20 miles away has done nothing - they still don't look out of the window!!

Yes, I've heard of that. Think I took notice when adding hinges.

A few changes.

I've got three (I think) - I'm not going out in the rain to check!! Edit - OK yes it's 3

Wet here too. Started just after I got back from shopping at our local farm shop.

Here's just the drive chain. This is just the gears and ratchet wheel without the main axle and bearings. Explanation :- Green wheel is seconds with red pinion attached Red and blue gears form the seconds to minutes reduction with the pinion above Yellow wheel driven by friction from blue gear - provides ability to set time. Pink pinion on yellow wheel drives minutes to hours reduction Orange and pastel pink gears plus pink pinion reduce minutes to hours. Red and orange gears are fixed. Green, blue yellow and pink rotate on ball bearings. The ball bearings keep the wheels aligned.

Sunny here too but cold. Hard frost this morning. Gradually warming up in the sunshine though.

I think this is just about it for the overall design. Some fine tuning to do and the parts have to be fitted to available ball bearings.

Seconds and minute hand added. Need to add another hour gear before the hour hand.

For reference hour pinion centre is 87.625mm from axle.

Minute wheel was oversize - now corrected.

CAD screenshot of clock with dial and some of the gears.

As mentioned in the initial description, this clock uses epicyclic gearing to provide the 60:1 and 12:1 reduction ratios between seconds and minutes and between minutes and hours. This is described in my DIY Skeleton Epicyclic Clock with 3D Printed Gears but I shall repeat it here. The principle involved is that when a pinion is moved round two spur gears with just one tooth difference and one gear is fixed the moving gear rotates by one tooth for each revolution of the axis of the pinion. So if the fixed gear has 59 teeth and the moving gear 60 teeth the gear ratio between the rotation of the pinion axle and the moving gear is 60:1. This is the ratio required for seconds to minutes in a clock. When the gears are different by two teeth the moving gear turns by two teeth for each revolution of the pinion axle thus if the gears have 22 and 24 teeth the gear ratio becomes 24:2 = 12:1. This is the minutes to hours ratio. However, it works out better to have more teeth and a lower modulus to make the motion smoother for 3D printed gears. Using 44 and 48 teeth gives a gear ratio of 48:4 = 12:1.

Based on some of my other clocks this will be a wall clock for my living room to go above the fireplace. It will have a dial of around 3ft diameter with a sweep seconds hand as well as the usual minute and hour hands. It will be driven by a stepper motor controlled by an Arduino Nano with Real Time Clock module to ensure excellent time keeping. Unlike other clocks it will not have any extras such as moon dial or striking, nor a pendulum. This will be of the simplest design using an epicyclic gearing principle with minimal number of parts.

I thought you could use webcams "live". I'm sure I have in the past. Otherwise CCTV for live pictures. I have one watching my yard and gates.

Model of clock "works" in case. The dial isn't really white, it's black but the CAD software adds white lines round everything.

Very nice Huw

I used SketchUp to design my observatory too.

I'll try a close-up as you suggest.

I made my observatory door from the same shiplap as I used for the walls attached to a framework of 3x2 with diagonal bracing to hold it square. The inside filled with polystyrene foam and lined wit 6mm marine ply.