The Geeky Nerdy Project Page

[Maclir 1,057]

Geeky nerdy information about myself... my hobby is model railroads.  I have an extensive collection of HO scale trains, mainly US models, the Delaware, Lackawanna and Western, Erie, and Erie Lackawanna lines, from the North-East USA, plus some New York Central passenger trains.  I'll be at the clubhouse running some trains later today.  If anyone is interested, I can post pictures and all that...  but it's pretty geeky... 

[Kupar 13,318]

3 minutes ago, Maclir said:

Geeky nerdy information about myself... my hobby is model railroads.  I have an extensive collection of HO scale trains, mainly US models, the Delaware, Lackawanna and Western, Erie, and Erie Lackawanna lines, from the North-East USA, plus some New York Central passenger trains.  I'll be at the clubhouse running some trains later today.  If anyone is interested, I can post pictures and all that...  but it's pretty geeky... 

I'd be interested 🙂  Is everything digitally controlled these days, or is there still old-fashioned circuit-switching in the layouts?

[Maclir 1,057]

7 hours ago, Kupar said:

I'd be interested 🙂  Is everything digitally controlled these days, or is there still old-fashioned circuit-switching in the layouts?

Digitally controlled - each loco has a small circuit board with a processor chip called a 'decoder' - so each loco has a distinct address, and on your controller, you first 'acquire' a loco by it's address, and your commands (speed, direction, turn on lights, ring bell, blow horn, etc) are sent encoded on the track power to that loco address.   I've just come back from the club running one of my engines.

[Kupar 13,318]

Excellent - and the modelling of the cutting looks good - do you make things from scratch? Lichen for bushes and that sort of thing?

[Maclir 1,057]

13 minutes ago, Kupar said:

Excellent - and the modelling of the cutting looks good - do you make things from scratch? Lichen for bushes and that sort of thing?

That is at our club's layout - the First Coast Model Railroad Society, in Jacksonville, Florida.  We have a web page - http://fcmrs.club/

[Kupar 13,318]

Wow - that's a big layout! Really nice.

[gldenwetgoose 21,443]

Interesting chat on digital model railway control...   In my childhood days of my Dad and I building layouts it was always analogue  - although fairly advanced with a Regulator / Brake control, zone isolation and separate shunting controllers.  All his design.

But we both aspired to the Hornby Zero-One system...   able to digitally control 16 different locos on the same track.  The future in 1979!

https://dccwiki.com/Hornby_Zero_1

[likesToLick 10,216]

20 hours ago, Kupar said:

Here are the circuit diagram and parts list for those interested.

Looks like it is using a tunable beat frequency oscillator to add a signal to the amplified ultrasound,  thus producing a beat frequency that lands in the human audible spectrum.  Is that right?

[Kupar 13,318]

20 minutes ago, likesToLick said:

Looks like it is using a tunable beat frequency oscillator to add a signal to the amplified ultrasound,  thus producing a beat frequency that lands in the human audible spectrum.  Is that right?

Exactly so. A heterodyne circuit 😊

[Kupar 13,318]

Assembled (a nice, neat and tidy PCB layout - thanks Magenta Electronics), tested and, afaik, working (inasmuch as it picks up the ultrasonic component of test signals from the jangling of keys). A final report when the bats next make an appearance in the garden.

[Kupar 13,318]

OK - a quick report. It works. I saw a bat flitting around the garden last night and went out with the detector, scanning up and down the frequencies until I could her the clicks from the speaker. At pretty much exactly 30kHz, there it was - irregular 'wet slapping' sounds of the bat's echolocation signals. Coupled with the size of the bat I could see, and the flight path around our garden, I identified the bat as a Serotine bat https://www.woodlandtrust.org.uk/trees-woods-and-wildlife/animals/mammals/serotine-bat/  

I plugged a little audio recorder into the headphone socket of the detector, turned the gain down (the headphone output is a little loud for the recorder input) and later opened the recording in Audacity, reduced the circuit noise and looked at the waveform and spectrogram. 

This is only the first attempt, but I am pleased with it. Note that in the spectrogram below, the frequency scale is all wrong because Audacity is processing the audible detector output not the ultrasound signal. If anyone really wants to hear the recording, let me know.

[Sophie 24,364]

4 minutes ago, Kupar said:

OK - a quick report. It works. I saw a bat flitting around the garden last night and went out with the detector, scanning up and down the frequencies until I could her the clicks from the speaker. At pretty much exactly 30kHz, there it was - irregular 'wet slapping' sounds of the bat's echolocation signals. Coupled with the size of the bat I could see, and the flight path around our garden, I identified the bat as a Serotine bat https://www.woodlandtrust.org.uk/trees-woods-and-wildlife/animals/mammals/serotine-bat/  

I plugged a little audio recorder into the headphone socket of the detector, turned the gain down (the headphone output is a little loud for the recorder input) and later opened the recording in Audacity, reduced the circuit noise and looked at the waveform and spectrogram. 

This is only the first attempt, but I am pleased with it. Note that in the spectrogram below, the frequency scale is all wrong because Audacity is processing the audible detector output not the ultrasound signal. If anyone really wants to hear the recording, let me know.

Omg that is awesome! 

[Maclir 1,057]

On 3/27/2022 at 5:20 PM, gldenwetgoose said:

Interesting chat on digital model railway control...   In my childhood days of my Dad and I building layouts it was always analogue  - although fairly advanced with a Regulator / Brake control, zone isolation and separate shunting controllers.  All his design.

But we both aspired to the Hornby Zero-One system...   able to digitally control 16 different locos on the same track.  The future in 1979!

https://dccwiki.com/Hornby_Zero_1

with analog (old style DC), you drive the track.  With DCC, you drive the individual engines.

[Sophie 24,364]

I'm not sure how interesting you guys will find this (or if you will find it interesting at all) but I thought I would share anyway.

Recently I purcharsed a vinyl cutter, a Silhouette Portrait 3, and there are LOTS of free SVG files on the internet for me to download and cut out to my hearts content. SVGs are great because they are scalable without losing quality. However... the Silhouette software requires a paid version to open SVG files, but it does allow you to open a PNG. I could convert the files manually one by one but that is time consuming and rather boring, I could probably find some software to do it but where's the fun in that? So I made my own in Python, it does exactly what I want it to, no more, no less.

The script I wrote takes any SVG file in the directory, converts it to PNG and then saves it in a seperate directory, all with the click of a button. I can convert 100s of files in mere seconds, it would take me hours to do it manually. The code is below for anyone interested. Basic, but effective.

import cairosvg
import os 

def main():
	path = 'C:\\Users\\Sophie\\Pictures\\SVG'
	files = os.listdir(path)
	for file in files:
		if file.endswith('.svg'):
			filename, extension = os.path.splitext(file)
			cairosvg.svg2png(url=file, write_to=f'PNG//{filename}.png')

if __name__ == '__main__':
	main()

 

[Kupar 13,318]

6 minutes ago, Sophie said:

I'm not sure how interesting you guys will find this (or if you will find it interesting at all) but I thought I would share anyway.

Recently I purcharsed a vinyl cutter, a Silhouette Portrait 3, and there are LOTS of free SVG files on the internet for me to download and cut out to my hearts content. SVGs are great because they are scalable without losing quality. However... the Silhouette software requires a paid version to open SVG files, but it does allow you to open a PNG. I could convert the files manually one by one but that is time consuming and rather boring, I could probably find some software to do it but where's the fun in that? So I made my own in Python, it does exactly what I want it to, no more, no less.

The script I wrote takes any SVG file in the directory, converts it to PNG and then saves it in a seperate directory, all with the click of a button. I can convert 100s of files in mere seconds, it would take me hours to do it manually. The code is below for anyone interested. Basic, but effective.

import cairosvg
import os 

def main():
	path = 'C:\\Users\\Sophie\\Pictures\\SVG'
	files = os.listdir(path)
	for file in files:
		if file.endswith('.svg'):
			filename, extension = os.path.splitext(file)
			cairosvg.svg2png(url=file, write_to=f'PNG//{filename}.png')

if __name__ == '__main__':
	main()

 

🙂 That looks simple and elegant. And have you made some nice stickers and things? 

[Sophie 24,364]

1 minute ago, Kupar said:

🙂 That looks simple and elegant. And have you made some nice stickers and things? 

Not yet but I am planning to! I had a great idea for my water bottle the other day so that will be happening soon.

[Kupar 13,318]

3 minutes ago, Sophie said:

Not yet but I am planning to! I had a great idea for my water bottle the other day so that will be happening soon.

Excellent!

[gldenwetgoose 21,443]

Love it @Sophie  - You have the coolest geeky projects.   I may be grovelling enormously ahead of our European roadtrip next summer - just two caravans and a camper so not like a bulk order.

[gldenwetgoose 21,443]

Just for a bit of fun, since this thread has been dormant for a while.

What's the height of the table?  From floor to tabletop?    And in best school tradition, don't forget to show your working out...

[avatar 381]

2 hours ago, gldenwetgoose said:

Just for a bit of fun, since this thread has been dormant for a while.

What's the height of the table?  From floor to tabletop?    And in best school tradition, don't forget to show your working out...

Oh, you just gave me a nice reason to try out the built in stylus that came in my new phone, since I really don't feel like getting out of bed for a pen and paper.

Please excuse my handwriting, basically T means table, Tu means turtle and C means cat. 

Edited February 14, 2023 by avatar

[Kupar 13,318]

5 hours ago, avatar said:

Oh, you just gave me a nice reason to try out the built in stylus that came in my new phone, since I really don't feel like getting out of bed for a pen and paper.

Please excuse my handwriting, basically T means table, Tu means turtle and C means cat. 

VG. ✔️

[Kupar 13,318]

I was looking at this thread the other day too, and thinking that we hadn't posted much here recently ... clearly the winter (for us in the northern hemisphere) obviously hasn't been a particularly productive time when it comes to tinkering around with nerdy projects.

But here's a not-very-geeky/nerdy contribution, just because I love an Excel chart. This is for my attempt to do 2800 press-ups in February. I confess part of my motivation is to see the chart develop over the month lol. (The dip is a couple of days' rest after I gave blood 🙂.) 

 

[Alfresco 11,606]

3 hours ago, Kupar said:

I was looking at this thread the other day too, and thinking that we hadn't posted much here recently ... clearly the winter (for us in the northern hemisphere) obviously hasn't been a particularly productive time when it comes to tinkering around with nerdy projects.

But here's a not-very-geeky/nerdy contribution, just because I love an Excel chart. This is for my attempt to do 2800 press-ups in February. I confess part of my motivation is to see the chart develop over the month lol. (The dip is a couple of days' rest after I gave blood 🙂.) 

 

That's way too much exercise!!   No way could I do that, but maybe it should inspire me to at least do a bit more than I do!  Nice chart though.

[Euro 345]

Perhaps a step beyond geeky-nerdy...?

Backyard foundry.  Simplistically... That is melting metals at quite high temperatures and pouring them into a mould to make a metal object. A Metal Casting. Might take the form of something aesthetic of functional or a bit of both. Eg a plaque.

In the way I do it now, started a few yrs back wanting something that at the time that seeming nobody could-would  do for me, at least at a sane price. Long story, but interesting journey.

Not a hobby as such, just something I now do from time to time. Not everybody's idea of fun doing weird dangerous industrial stuff in the back garden. But I kinda like doing it 🙂

A couple of pics to give the idea..

 

A Bronze metal pour at  circa1150dec C ( 2100degF)

A plaque casting fresh out the mould in Aluminium but way too hot to touch for a while. The lumpy bit sticking out of the side is the left over bit where the molten metal was poured in from.

A finished and painted plaque

 

[likesToLick 10,216]

6 hours ago, Euro said:

Backyard foundry. 

Hey,  brilliant!   I really want to learn to do this one day.   My hobby is learning milling and lathe work in my home machine shop,  and casting would go with this really well. 

A bit scared of handling crucibles though,  as I have problems with my back and I would not want it to cut loose at the wrong moment.