Garden Railway Forum

gregh wrote: ↑Wed Feb 27, 2019 12:18 am


Questions????

Thanks Greg! Well, I did ask!

Questions? I'm sure there would be a million, but it's gonna take me a while to get my head around it. If/when I have any that are worth wasting your time on, I'll PM them rather than clog up the thread.
Thanks again.

Brilliant post Greg. Although electronics are way over my head, you have done an excellent job with the sound card. Surprising how much deeper and better the sound is when the hood is on, 100% better to my hears.

Not a question, but an observation. I think it's amazing what you have managed to squeeze into one 8 pin Picaxe - motor control and sound! The start-up and wind down sequence is really effective and it is incredible what a difference putting the lid on makes to the sound.

A couple of questions

1 How much does your r/c and sound system cost overall?
2 I think you've nailed the synthesised sounds, but I know you experimented for a while with digitised real sounds. Did you get anywhere?

Rik

ge_rik wrote: ↑Wed Feb 27, 2019 7:59 am Not a question, but an observation. I think it's amazing what you have managed to squeeze into one 8 pin Picaxe - motor control and sound! The start-up and wind down sequence is really effective and it is incredible what a difference putting the lid on makes to the sound.

A couple of questions
1 How much does your r/c and sound system cost overall?
2 I think you've nailed the synthesised sounds, but I know you experimented for a while with digitised real sounds. Did you get anywhere?
Rik

COST
In aussie dollars I spent around $33 - say 18 GBP. Not bad for radio control and sound !
But it is a bit dependent on how you buy the 'big ticket' items. Here's my breakdown...

• speaker ($8). like these: https://www.aliexpress.com/item/One-Pai ... 7801.html
  433MHz keyfob RC - I just bought two off ebay for $8 but locally could pay $15 each. https://www.ebay.com.au/p/433mhz-RF-W ... 68&chn=ps
  relay for reversing - I got 10 for $9 off ebay but would pay $5 each locally
  MOSFET - I bought 8 for $8 off ebay, but would pay $3 each locally
  picaxe and socket $5
  resistors and capacitors, veroboard $9
  amplifier, regulator, diodes, transistor $5

That excludes the batteries and the items for the headlights.

On the 2nd question about digitised sound. I have never done anything except use some 20 second sound recorder cards. On them I have recorded whistles and horns and engine cranking sequences. My mate Geof, has done a lot more - see this link page 3 where he used five of them!
http://www.trainweb.org/btr/1620%20Class.pdf

Couldn't you use one MP3 player rather than multiple sound cards?

Hi Greg
£18! Wow!
That compares with £130 for one of my set-ups. ie Deltang receiver/controller (£40), Deltang tx (£35), MLS card (£50), speaker (£5).

I'm going to have to explore making my own gear as I dodder more into my dotage. I particularly like the idea of tinkering around to create sounds, though don't have an oscilloscope so might have to go down the digitised route.

Rik

tom_tom_go wrote: ↑Thu Feb 28, 2019 7:49 am Couldn't you use one MP3 player rather than multiple sound cards?

My thinking too, based on my experiments with my railmotor, https://gardenrails.org/forum/viewtopic ... 37&t=10095

The problem is to find a way of masking the 1sec gap between tracks. I'd also like to use a Picaxe or Arduino to do the switching automatically rather than having to do it manually.

Rik

This was mentioned on the forum MP3 wise:

https://www.dfrobot.com/wiki/index.php/ ... KU:DFR0299

tom_tom_go wrote: ↑Thu Feb 28, 2019 8:20 am This was mentioned on the forum MP3 wise:

https://www.dfrobot.com/wiki/index.php/ ... KU:DFR0299

That looks useful - I like the way you can select different tracks by connecting one of the pins to ground with different values of resistor. I like things kept simple.

Sorry, Greg, hijacking your thread. Will start another one.

Rik

Just a bit more info here on why I need a ‘push-up’ loco.

Trains heading from Sandstone to Melaleuca, face a grade of 1:38, but trains leaving Melaleuca heading ‘home’ to Termite (my indoor storage) face grades up to 1:25 for about 30 metres. (When I built it I was hoping for easier grades but I got tired of chiselling through the solid rock.) This means that fully loaded trains arriving at Melaleuca from Sandstone will be overloaded if they continue. So trains must either:-
use a larger loco
split the load and leave some wagons at Melaleuca for a later train,
Add a second loco on the front, or
use a push-up loco
The section shown as 1:39 grade includes the big ‘horseshoe trestle’ curve where the line turns back on itself on a 1m radius curve, so it is really more like equivalent to 1:25.
The loads that my larger locos can haul are actually limited by this sharp curve, not the grade – long trains are likely to ‘stringline’ where the weight of the train pulling across the curve causes the wagons to tip inwards. (I use hook and chain coupling so they never come apart in a derailment !)

Stringlining can be partly overcome by assisting in the rear. ie using a loco at the rear to push.

I have set up ‘notional’ loads for my locos based on a 4-wheel wagon= ‘1’ and a bogie wagon=’2’ and divided my locos into four ‘load classes’. This is summarised in this Load Table. (Most of my locos can actually haul lots more than their ‘rated load’ but my rules make my operating more fun.)

From experience, I have set the max load around the sharp curve at ‘16’ ie 16, 4-wheelers or 8 bogie wagons. From the table it can then be seen that attaching a push-up loco at Melaleuca allows any train arriving from Sandstone to continue to Termite. Smaller trains can use an additional loco on the front if that is preferred.

In this video my ‘small’ Garratt has brought 8 bogie wagons (=16 ‘loads’) up to Melaleuca, but is only ‘allowed’ to take 12 from there to Termite.
So my new #15 pushup loco is brought in to help. Because I use chain couplings, I can tell how many wagons are being hauled by the front loco (chains stretched out) and how many are being pushed by the helper (wagons ‘closed up’). The pushup loco is not coupled to the train and to operate the train I set the Garratt at full speed (which is pretty slow) and then adjust the speed of the pushup to be pushing 2 or 3 bogie wagons. The train is moving at a scale 25 kph.

Fantastic. Love the use of a banker to assist big trains up the gradient.

Nicely explained video, Greg. Good to see the little loco in action.

Rik

I love this build. It's far better then those shop bought ones....