Gina

Also, following from my Giant Wall Clock where the gears from the stepper motor that drives the seconds wheel produce a lot of noise from the teeth, it occurs to me that the motor gear and 64t epicyclic drive gear will probably also make a noise. This is pointing back to a ratchet system where any noise would be on a 2s cycle like the clock itself.

Yes, a very rich region.

True!!

Hope your back gets better soon Dave. Good luck.

To allow for the different timing the motor gear can have 16 teeth instead of 25 and drive the pendulum and strike auto-wind as well as the main clock.

Might change the timing to the stepper motor to give a rotation speed of 2s per revolution and save a gear or two. I can do this with an Arduino sketch - here is a first attempt. // Filename :- Pendulum_Longcase_Clock_v2_2019-11-14 // Software timing from RTC using polling // #include <DS3232RTC.h> //http://github.com/JChristensen/DS3232RTC #include <Time.h> //http://www.arduino.cc/playground/Code/Time #include <Wire.h> //http://arduino.cc/en/Reference/Wire (included with Arduino IDE) // boolean lastSqWave = 0; boolean ledON = 0; int sqwPin = A6; int stepPin = 6; // STEP pin int enPin = 12; // Enable pin int ledPin = 13; // Internal LED pin // void setup() { pinMode(stepPin, OUTPUT); pinMode(enPin, OUTPUT); pinMode(ledPin, OUTPUT); digitalWrite(enPin, 0); // enable pinMode(sqwPin,INPUT_PULLUP); // RTC timing pin RTC.squareWave(SQWAVE_1_HZ); // 1Hz square wave } // void runClock(void){ for (int i = 800; i >= 1; i--) { // count 800 pulses in half second ie. 3200 micro-steps per two seconds digitalWrite(stepPin, 1); delayMicroseconds(10); // Make STEP pulse 10μs long digitalWrite(stepPin, 0); delayMicroseconds(600); } // 1600×610 = 976ms ledON = !ledON; digitalWrite(ledPin, ledON); } // flash LED on & off (for testing) // void loop(){ boolean sqUp = ((analogRead(sqwPin) > 500)); // read logic level of 1Hz square wave if (sqUp != lastSqWave) { lastSqWave = sqUp; runClock(); } // Call runClock on both edges of RTC square wave } // End

Here is an Arduino sketch. // Filename :- Giant_Wall_Clock_v2_2019-11-14 // Software timing from RTC using polling // #include <DS3232RTC.h> //http://github.com/JChristensen/DS3232RTC #include <Time.h> //http://www.arduino.cc/playground/Code/Time #include <Wire.h> //http://arduino.cc/en/Reference/Wire (included with Arduino IDE) // boolean lastSqWave = 0; boolean ledON = 0; int sqwPin = A6; int stepPin = 6; // STEP pin int enPin = 12; // Enable pin int ledPin = 13; // Internal LED pin // void setup() { pinMode(stepPin, OUTPUT); pinMode(enPin, OUTPUT); pinMode(ledPin, OUTPUT); digitalWrite(enPin, 0); // enable pinMode(sqwPin,INPUT_PULLUP); // RTC timing pin RTC.squareWave(SQWAVE_1_HZ); // 1Hz square wave } // void runClock(void){ for (int i = 1600; i >= 1; i--) { // count 1600 pulaes in half second digitalWrite(stepPin, 1); delayMicroseconds(10); // Make STEP pulse 10μs long digitalWrite(stepPin, 0); delayMicroseconds(300); } // 1600×310 = 496ms ledON = !ledON; digitalWrite(ledPin, ledON); } // flash LED on & off // void loop(){ boolean sqUp = ((analogRead(sqwPin) > 500)); // read logic level of 1Hz square wave if (sqUp != lastSqWave) { lastSqWave = sqUp; runClock(); } // Call runClock on both edges of RTC square wave } // End

One thought was to apply a time correction every so often to keep the clock in time. ie. using the 32KHz (actually 32768Hz) gives a ratio of 10.24 for 3200 microsteps per second so a correction of 24 counts per 1000 or 3 in 25. Another thought is to generate pulses controlled by the Arduino clock such that a number of them finish just short of the fixed time. eg. produce 3200 pulses in just short of a second and use the 1Hz square wave to restart the sequence. The 1Hz is a symmetrical square wave so timing can be taken from both edges resulting in two smaller gaps in the pulse train to the motor rather than one larger one each second.

Unfortunately, the 25:32 gears that provide the 1 second drive to the seconds wheel are far from quiet in spite of being accurately printed. There are possible ways of improving the gears such as helical teeth but this mainly applies to machined gears. Printed helical gears will be rough due to the layers. Consequently, I'm looking into the possibility of just using code in the Arduino sketch. The RTC module is capable of producing square waves of 32kHz, 8192Hz, 4096Hz, 1024Hz and 1Hz. The stepper motor has 200 steps per revolution or 3200 steps/rev with 16x microstepping. The TMC2100 only does "quiet" in 16x or 4x microstepping.

Me too at times!! Unfortunately, I don't know enough about NAS drives to help. There should be Open Source software I would have thought. After all, it's only a collection of hard drives plus an OS (often Linux) and software.

I think it's nice to see what other members look like, particularly when you can't get to gatherings. Should update my avatar I guess (grey hair)...

Wish I'd known, I could have explained it years ago.

Oops - just realised the strike wheel and shaft rotates anti-clockwise when striking so the winding has to be clockwise.

I get vertigo just looking at that photo!

Nice!! Very nice!!!

Thank you - I may need it!! One benefit of PI is that all the image processing can be done in one package. As I recall, PS only did the post-processing whist other software was needed for stacking and aligning etc.

This is amazing stuff - I have enough trouble with ordinary imaging!!!

I did have PI working for me a couple of years ago it seems from my posts but feels like I'm starting again! I used some excellent tutorials then - must find them again. I do have the book though.

Me too!

Just to rub salt in the wound, it's a beautiful sunny morning here. But guess what's forecast for later and tonight - yup - cloud and yet more rain!!

One idea is a 64 tooth ratchet wheel which is driven from the pendulum pushing system. This would be connected to the strike shaft through 6:1 gearing and a "free wheel" (like on a bicycle). A lever/pawl from the pendulum drive would be arranged to engage with the 64t ratchet wheel during the wind-up period - being started by a cam on the hour shaft and stopped by the weight being wound to the top of its travel.

I've found the stars tend to disappear if the moon is in the field of view but you can see any clouds. Any moon in the FOV will ruin any view of the stars or Milky Way in the same way as with narrower fields except of NB imaging with Ha filter.

I don't bother about the flare outside the image area from bright lights - it doesn't matter and only occurs with things like the moon in night settings and sun for daytime. The flare from the glass surfaces across the image are a nuisance but there's nothing you can do AFAIK. Top quality lenses are coated to reduce this but the sun and moon are too much!

I get lens flare too with a very bright light source like the moon or sun.

But you can use images instead apparently. I seem to remember removing stars in PI that would have used layers in Photoshop. The machine that had PS on died and I lost it. GIMP does layers though.