Gina

The great storm of a few days ago did a lot of damage to my ASC. Ripped the top off which landed the other side of the observatory upside down on the grass, seems mainly undamaged apart from a tiny mark on the dome. The rest didn't fare so well. The dew heater resistors and some of the wiring was strewn across the observatory roof and everything was full of water. That is the worse part - lens and camera were soaked. Eventually, after a couple of days of warming, the lens dried out and is now alright. The camera did not survive! Wet had go in and shorted something and destroyed it. There were signs of wet corrosion on the image sensor board. Cleaning this off didn't make any difference.

I need to work out how long the pendulum rod needs to be as it varies with gravity which depends on latitude and height above sea level. Using an online calculator gives it as 9.81098 here. T = 2π√(L/g) = 2π√L / √g 2π√L = T√g √L = T√g/(2π) L = {T√g/(2π)}^2 Locally g = 9.81098 so √g/(2π) = 0.498512815 For T=2 (period = 2x beat), L = (2*0.498512815)^2 = 0.994060106m IOW 994mm.

That's what I did with mine.

So do I! How's your goggie Kev?

Here is a screenshot of the model of the escape wheel in Slic3r. Now printing this on my Mini printer with 0.2mm layers and white PLA. Currently using a 0.4mm nozzle but this may need printing wit a smaller one. I have a 0.2mm nozzle I can use.

A new deadbeat escapement diagram.

No sun here today - mainly cloud with some rain. Should be better tomorrow.

I bought a giant tarpaulin for shelter and lots of rope! That formed a huge tent to work in. Just a roof wouldn't have sufficed as we get plenty of horizontal rain here.

I did the floor of mine before most other things - certainly before the roof.

Nice.

Here is a photo of the lampholder and LED bulb (G9 base). There are two fixing holes 0.5" apart (12.7mm) a bit bigger than 3mm (probably 1/8" = 3.175mm) so M3 bolts will suffice for fixing (one is shown in the photo). The LED bulbs are 4W, equivalent to a 40W GLS bulb and 5 of them will give plenty of light. They are the dimmable variety so I will be able to reduce the light output for watching television.

Here is a model of the gear wheel shown on the bed of my Giant 3D Printer. The grooves are to take the wires to the lampholders from the central stalk/axle/pipe which hangs from the ceiling rose. I plan to add a finial to the bottom of the axle below the spokes. I'm thinking of printing the gear wheel in translucent yellow PETG but that may change. Also, this is just a start - I have the attachments for the lampholders to add. The lampholders arrived today so I can sort out the fixings. 5x Offgridtec G9 Lamp Holder DVE and UL Listed with ISOL. Cable Lead Lamp Base Socket LED Halogen CFL

The centre light fitting in my living room is looking tired and I want to replace it with something funky that fits my interests, like 3D printing and clocks as well as astronomy, so my idea is a giant 3D printed gear wheel with five globes as shades for LED lamps. The gear wheel represents both 3D printing and clocks which contain lots of gears. The globes can represent moons or planets. Thinking about this, I guess I could add a star in the middle - I'll give it some thought.

Yes you might need some clips or clothes pegs to hold it up while you apply adhesive in strips. Or maybe someone to help you. My roof was 4ft x 8ft each side - one sheet of marine ply each side on top of the framework. Sometimes I've used broomsticks and G clamps to advantage. Or in this case I had lots of odd lengths of timber.

What I did with the apex was to lay the sheet over the whole roof and make sure there was enough extra all the way round to tuck up underneath, then fold back one side and apply adhesive from the ridge down a foot or so. Laid the rubber over the adhesive and rolled down carefully avoiding causing any bubbles. After that I worked my way down that side to the edge. Then did the same for the other side. I used a wallpaper roller to roll down the EPDM to ensure good adhesion. To spread the adhesive I use a paint roller on a long arm - the sort used behind radiators. Being water based, the adhesive was washed out of the roller with water immediately after use. It wasn't allowed to dry during application either.

Yes, the ridge is a problem with metal roofing and edges too. Best not to cut steel sheets as the ends rust as has been said. Ridge and edges are no problem with EPDM and fitting is fast and easy. Dealing with the junction between ROR and warm room roof is easier too. No problem with matching panel sizes to the roof either. Many years ago Tim and I constructed livestock sheds using timber framing and box profile roofing we bought at a local auction and basically we had to fit the timber to match the roofing panels. These were pent roofs not apex. Handling large roofing panels was difficult too, even with two of us. Had to wait for a windless day! Then it was a case of clambering up on the roof and hammering in dozens of roofing nails being careful to find the roof timbers! My observatory roofing I did on my own although the EPDM was heavy. Hence I conclude EPDM is much easier.

In that case you might like my design for a new chandelier for my living room. A very large (400mm OD) 3D printed gear with 5 globes containing dimmable LED bulbs. Planning to print it in translucent PETG. This is a top view of the model. There will be a central tube from the ceiling fitting with a finial on the bottom which will take the wiring which will be placed in the grooves out to the lampholders.

I like your "last century" ammeter ?

That's often the problem!!

Some thermoplastics such as ABS will be improved by "acetone smoothing" if you want a really nice shiny surface. Pretty much all 3D printing I do is for purely practical purposes though rather than aesthetics.

That looks very impressive James

It's certainly possible to get the top surface better than that. It's mainly a question of the amount of extrusion.

Oops - spoke too soon - wind has got up again in gusts of near gale force.

Rain has stopped and we've even got some sunshine though still plenty of clouds about. Wind has eased off a lot to just a strong breeze. No damage from this last storm thank goodness.

Printed escape wheel complete with bearings to fit an M5 bolt as axle. This is just a test model and rather rough print which needs some tidying up. I shall use a fine printing mode for the working version.