Gina

Wind vane arm printed and vane added. Balance is fine Now to design and print the nosepiece.

I have some strips of sheet lead and have rolled up a piece of about 2" x 1" into a cylinder just over 9mm diameter. This weighs 27g. With the C-of-G of the vane 130mm from the pivot the C-of-G of the weight will want to be 130x11/27 = 53mm. The weight chamber will have a dome shaped plug to go in the end.

I may yet find some packaging as I clear up though I have chucked most of it out. But I have found a sheet of slightly thicker acrylic that came with the frame I used for the Moon Phase Clock and not wanted for that so I've cut a piece same size as the printed vane. Broke printed vane off its bar and weighed both and they're the same weight (11g) but at least the acrylic is flat

The wind vane print was not perfect - the vane is slightly concave. It also weighs more than I'd like - 1.8g whereas the thin acrylic sheet from the old one weighs 0.8g. The vane itself is 1mm thick. I think I'll see if I have any thin acrylic sheet - generally used for packaging.

I'm not waiting for the chip making some parts starting with the wind vane.

Tracked package containing MLX chips and delivery is scheduled for Friday by FedEx. Reason for cost of delivery and time taken is that they are coming from the USA - Memphis, Tennessee! I would have thought that Mouser UK would have UK stock when they said items were in stock!

Phew! Need a coffee break

Found one unsoldered joint and a couple of suspect joints which I re-soldered. Also, when I plugged everything in to connect RPi assembly with motor driver board I found the wiring effectively put the power input at the top instead of bottom so had to remove the buck converter, turn it round and rewire it. Of course, it would have been better on the other side of the motor drivers but that circuit was already at the edge of the board (I wired up all that before deciding to put the buck converter on the same board). Not a problem - just longer wires. Heres the new arrangement.

Yes, now decided to use the MLX90316 chip and a 6mm diameter x 4mm thick disc magnet with poles along the diagonal attached to the end of the wind vane axle. Three wires for SPI data plus Gnd and +5v connected to an Arduino Nano and one data wire plus Gnd and +5v (or +13.8v) to the Hall sensor in the anemometer. I'll probably put the Arduino in the wind sensors casing and connect to the RPi in the ASC via RxD/TxD or possibly USB.

I think it's about finished - at least it is for tonight I'll give it a careful visual checking over tomorrow and if all seems well I might apply power. I have yet to finish writing code for the RPi.

Absolutely!! With knobs on!

Still wiring up and attaching wires to the tiny crimp sockets on the connectors etc. It's a long and tedious job!

Magnets and optical sensors have been delivered. I've tried the magnets on the aluminium disc I already have and the drag is good with two magnets separated by the three plastic separators so that one half of each magnet works on each side on the disc. However, I may not use the optical sensors as I'm considering the MLX90316 Rotary Position Sensor IC which gives a highly accurate rotation angle with just a magnet on the end of the wind vane shaft and which is easily interfaced with the Arduino.

Decided to attach the buck converter to the circuit board with the motor drivers rather than having it separate. This means some connections could be wired straight across to the power side of the driver modules. A link from the +13.8v input to the motor power lines and the +13.8v on the 5pin connector. The power input Gnd connects to the Power Gnd and motors -ve. Then the +5.1v from the buck converter was taken across to the 5th pin on the 5pin power connector. The latter will now provide power to the RPi and HAT as Power Gnd, +5.1v and +13.8v. The +3.3v and Gnd from the HAT connect back to the motor driver board as the +3.3v and Data Gnd. This grounding arrangement prevents ground loops (often referred to as earth loops in the UK).

I'm back on the wiring up of the electronics.

I have decided I'm pretty definitely going to combine weather station wind sensors and ASC on the same mast.

Don't think there's much more I want to do to this until the aluminium discs come or at least the bigger magnets. This is the latest idea of how it might all look.

If I find it could do with greater damping I could possibly use both discs and three magnets.

Ordered some flat/bar magnets bigger than the ones I already have - due to arrive tomorrow :- 4Pcs Strong Neodymium Bar Magnets, Rectangular Block Neodymium Magnets, DIY, Building, Scientific, Craft, and Office Magnets-60 x 10 x 5 mm The 4" aluminium discs are due to arrive Wednesday or Thursday.

Where is the noise coming from on your printer Dave? Is it due to the pulse rate on the motors? My "Pilot" printer is very quiet with the motors plastic mounted and using quite large (25mm) plastic pulleys for the cords. OTOH the "Titan" is noisier, with the motors mounted on 6mm plywood and using 15mm metal pulleys. The small pulleys rattle and the motors resonate on the plywood. The fume extraction fan is also fairly noisy (only a 50mm one). The noise from the "Titan" would be worse without the acrylic enclosure.

The cylindrical magnets are a pair of identical ones so both the same pole on the countersunk side. But a pair of flat bar type which have each pole on opposite sides of the flat sides could be mounted in a 3D printed holder to hold them apart. If they were a tight fit in the plastic they might stay put as in the first diagram but if loose might come out and join up. The second diagram shows a solution - holding them fully.

Thanks - yes, I thought of opposed magnets either side of the disc and would probably work without the U shaped iron part. Hadn't thought of using magnets to hold the box together though.

Here is the latest design. Not to scale.

O-I-C

No, hadn't thought of that.