Why Didn't Live Steam Take Off?

[phil-b259]

9 hours ago, billbedford said:

 

The smart way would have pick-ups feeding a rectifier that charges the battery. That way, any current on the track, however intermittent it was would help keep the battery charged. As for DCC, it really is 90s technology and most of it can be handled by the transmitter software.

 

DCC might be '90s technology' as you put it - but its a technology that is been heavily embraced by the modelling community a large - and is not going to disappear overnight regardless of what else comes along.

 

Its worth remembering that sometimes 'superior' formats do not always win - much comes down to market penetration (VHS versus Betamax for example)

DCC has the other advantage is that its backwards compatible with DC - for any radio controlled / self powered model, making it backwards compatible is going to be essential if the new technology is going to achieve a substantial market share and thus mainstream RTR manufacturer support.

[34theletterbetweenB&D]

11 hours ago, billbedford said:

Nope, you are looking at RC as an add-on. When RTR RC comes to market it will have to be a self-contained system - plug-and-go, if you like...

Yes, and it is waiting for the equivalent of a Bernd Lenz, who provided the package on which current DCC is based, to provide an equivalently competent package for r/c + battery, that will persuade the active manufacturers to adopt and promote this system.

 

11 hours ago, billbedford said:

...So there is no need to use 12v motors, 3.4v will match the output of the battery and give an acceptable running time...

The elephant in the room defeats this. 'Everyone' has 12V motored kit. Since that is the customer base, the r/c + battery system has to accommodate, or fail to win acceptance. There will be no general take up for anything but 12V. (And as above, the higher voltage brings the advantage of less current, and that's a significant benefit for the miniature electronics on the loco that will have to manage power supply.)

[Richard Lee]

22 hours ago, wasdavetheroad said:

snip...

 

My vision of the future is a system that can work on track or battery power and seamlessly switches between them. Charging the battery from the track should be included which means the battery can be considered a large stay alive with unlimited capacity. This would allow for considerably simpler wiring as there would be no need to wire the fiddly bits of the layout.  Track/battery switching has already been demonstrated in BlueRails first board which was too large for most OO locos. There next board should be  a lot smaller with more features.

 

What we will end up with is a system that allows you to run your locos on track power, either DC or DCC, battery or a combination of them. Radio control will be the norm and it already demonstrates the capability to have hundreds of locos on your layout if you wish.  ...snip

If I understand the last couple of Protocab newsletters, Protocab seems to be getting to be able to seamlessly flip between track power and battery, recharging the battery when there is track power.  They are still in pre-production mode for this, with a discount for pre-orders.  That said, Protocab is an expensive way of controlling your locos.  If I was brave enough to try radio control battery power I would be tempted to look at Deltang as well, as a cheaper option.

[34theletterbetweenB&D]

12 minutes ago, Richard Lee said:

If I understand the last couple of Protocab newsletters, Protocab seems to be getting to be able to seamlessly flip between track power and battery, recharging the battery when there is track power...

It's coming alright. There does seem to be some inherent resistance in development of r/c + battery to accepting the requirement for significant adaption to the model railway application to maintain all present control system advantages.
The baseline understanding has to be that backward steps are not acceptable.

 

Most significantly, the rails are intrinsic as the guidance system. So have the option of using the plain track for the recharging capability as standard, 'the wires' are necessarily ever present, and there are added benefits to this approach:

only a small battery is required to carry the loco over the dead points, a minute of run time is going to be enough;

no need to ever handle the loco for recharging, it just happens automatically through the plain track;

the model is always ready to go when the layout is powered, exactly as with the existing systems;

finally it doesn't preclude those wanting large battery / dead track / off track / inductive recharging, from making that choice, if that's their preferred hair shirt.

 

The r/c protocol needs to be sufficiently advanced that one control unit can operate an effectively unlimited number of locos and accessories, exactly as with DCC. Nonsense such as 'binding' to a handset with a  capacity of a dozen locos is just that, nonsense in the model railway environment.

[wasdavetheroad]

3 hours ago, 34theletterbetweenB&D said:

Yes, and it is waiting for the equivalent of a Bernd Lenz, who provided the package on which current DCC is based, to provide an equivalently competent package for r/c + battery, that will persuade the active manufacturers to adopt and promote this system.

 

The elephant in the room defeats this. 'Everyone' has 12V motored kit. Since that is the customer base, the r/c + battery system has to accommodate, or fail to win acceptance. There will be no general take up for anything but 12V. (And as above, the higher voltage brings the advantage of less current, and that's a significant benefit for the miniature electronics on the loco that will have to manage power supply.)

12V motors are no problem. surprisingly I found even my express locos would achieve over  scale 60mph hauling 12 Mk1 coaches ( I have setrack curves in the fiddle yard) and that was at 9V via a voltage booster. I think the good haulage capacity of the converted locos is down to having no rail pickups. My Lima class 20's can pull 20 coaches which surprised me, a replacement gear train would be nice though.

 

Backwards compatibility is easy if you leave the rail pickups in place and isolate them.

[wasdavetheroad]

1 hour ago, Richard Lee said:

If I understand the last couple of Protocab newsletters, Protocab seems to be getting to be able to seamlessly flip between track power and battery, recharging the battery when there is track power.  They are still in pre-production mode for this, with a discount for pre-orders.  That said, Protocab is an expensive way of controlling your locos.  If I was brave enough to try radio control battery power I would be tempted to look at Deltang as well, as a cheaper option.

Yes, Protocab is expensive compared with Deltang which is not plug and play but has a lot of different products and IMO more options than Protocab. the upcoming BlueRail product looks as if it could be a winner, not the DCC adapter one but the stand alone product which will be part of a well known DCC sound chip range, no idea who though and it will be expensive.

[Pandora]

On 04/11/2019 at 08:18, Pete the Elaner said:

There was a system in the early 90s which worked as you described, marketed as 'Dyna-drive'.

It used a centrifugal clutch to drive a flywheel which was conencted to gears in 1 bogie.

Due to its configuration, I believe it was only available for Diesels & Electrics.

It disappeared around the same time DCC became popular. I don't think that was a coincidence.

I have seen Dyna-drive in action ,at first sight it was the answer to a prayer, the flywheels permitting power-off coasting for several feet , but then early adopters found the system too fragile and  too temperamental for general use,  from memory, a collision with the buffer stops could cause expensive damage to the drive train. 

Edited November 5, 2019 by Pandora

[Reorte]

20 hours ago, The Johnster said:

This is only true in hard water areas where the water comes from a calcarious aquifer such as limestone or chalk which can be dissolved into even very mildly acidic groundwater.  These areas consist of the most populous parts of England; London (which is supplied from an artesian aquifer on the chalk downs that surround), The Midlands, Yorkshire, and Lancashire.  In Cardiff, where water is sourced from the sandstone Brecon Beacons, we have no problems at all with scaling despite the continued enthusiastic attempts to sell us Calgon...

Where I work (Stockport) we have kettles constantly boiling for tea and coffee. This is a soft water area, from reservoirs up in the Pennines (not the limestone part), but there's still a tiny bit of scale in those heavily-used kettles.

[Pandora]

Here is a controllable animation of the Prius drivetrain, a drivetrain comprised of a planet and sun gear sytem and two motors  which act as either motors or generators .

By moving the 3 sliders (start with the slider for MG2)  you can simulate the  electric motors mg1 and mg2 rotating evenly at  rpm way above  their magnetic cogging rpm or stall rpm, ( and  threfore  both MG1 and MG2 developing steady useful torque ) and the output shaft rotating seamlessly over the range from dead crawl to high speed in either forward or reverse.

 

http://eahart.com/prius/psd/

Edited November 5, 2019 by Pandora

[34theletterbetweenB&D]

12 minutes ago, wasdavetheroad said:

... I think the good haulage capacity of the converted locos is down to having no rail pickups...

That's a myth, pure and simple.

 

Where the pick up design is good, in the bronze alloy wipers self sprung onto the powered wheelbacks style, traction is dependent on the weight on the driven wheels. If the motor has enough torque to slip the wheels when the loco is held back, then the pick up wipers cannot be significantly affecting haulage. I would invite anyone doubting this proposition to take a Bachmann 9F, Heljan O2, Hornby Britannia or Oxford N7 out of the box, couple a full size trainload on, and observe the ample traction despite them all having pick up wipers, with the capacity to take such a trainload to well above scale speed.

 

A very clear exception was the Lima 20 which had the draggiest pick up design imaginable to act as 'brakes' on the 4:1 reduction of the traction tyred drive: relatively thick metal plates resting in a slot on an internal wheel boss. But this is an old design from a low grade and deservedly defunct manufacturer, hardly relevant now.

 

 

 

 

[Pandora]

On 04/11/2019 at 04:51, PatB said:

I know nothing about the Toyota CVT system, but one arrangement which I can see being, at least, possible in the model scales is that adopted by the GWK car company in the early C20th. 

 

Basically, the motor drives a large, smooth faced flywheel. A shaft running at right angles across the flywheel carries a wheel with a high friction rim. This bears against the face of the flywheel and so is driven. If you move this wheel across the face of the flywheel you can vary the effective gear ratio between the motor shaft and the driven shaft. With the driven wheel near the centre of the flywheel you get a low (numerically high) ratio, rising as you move the driven wheel towards the flywheel's rim. 

 

Very simple in principle, efficient (no belt losses) and doubles as a right-angle drive, which most models need to incorporate anyway. I don't know if it could be made compact enough to be useful, but it doesn't feel impossible. 

I believe the   early builds of  the famous  Wickham P-Way self-propelled  Trolley used such an arrangement for the drive transmission

Edited November 5, 2019 by Pandora

[The Johnster]

I don’t believe pickup wipers affect haulage more than a very minimal amount, but they act as a physical brake.  Ye canna change the laws’o fezzicks as we’ve already established, Jim, and the drag shows it’s maximum effect on wheel movement at the lowest speeds when the motor is drawing the least current.  My RTR locos perform as well as anyone has a right to expect from volume produced models engineered down to a competitive market price,  but even the best of them cannot start absolutely perfectly smoothly from rest like a real loco does.  

 

Hence the desire to have the power source aboard the loco, the effectiveness of which is nullified as soon as one needs to supply current from the track for control.  If this can be overcome, one still has to eliminate friction in the transmission. 

 

I believe the Golden Path To Enlightenment will be direct drive in the form of brushless electric motors whose drive shafts are the driving axles of the loco, possibly with ‘boosters’ on trailing axles, in conjunction with on board battery and NFC control.  No gearing at all, and no pickups, so absolutely no drag or friction. No current is needed at all in the track, but such a scheme would allow for track circuiting and panel train detection, possibly interlocked digitally with the points and signals.  Steam outline models could have full working detail between frames. 

 

Motors small enough for this already exist in T gauge, and might be capable of low enough revolutions if freed from the drag of the gearing.  Not gonna happen in my lifetime...

Edited November 5, 2019 by The Johnster

[Hitchin Junction]

16 hours ago, billbedford said:

 

Nope, you are looking at RC as an add-on. When RTR RC comes to market it will have to be a self-contained system - plug-and-go, if you like. That means that it can be built with a clean slate. So there is no need to use 12v motors, 3.4v will match the output of the battery and give an acceptable running time. Charging will either by via rail pick-ups or inductance. and there will be no need for a DCC chip on the loco as all that logic is probably superfluous, but could be handled by the controller/transmitter. (as some current US rc systems do)

 

You need to explain how you can handle feedback (back emf) control purely from the transmitter if you don't have that capability  built into a "smart" receiver chip that's probably then going be almost as complex as  a DCC chip.  Or bi-directional R/C.  Also the bemf detection is going to need to be 4  times as sensitive for a  3 volt motor, as it is for 12 v motor. But the motor electrical noise will be much the same.

 

Tim

Edited November 5, 2019 by Hitchin Junction
added word "then" for clarity

[34theletterbetweenB&D]

2 hours ago, The Johnster said:

I don’t believe pickup wipers affect haulage more than a very minimal amount, but they act as a physical brake.  Ye canna change the laws’o fezzicks as we’ve already established, Jim, and the drag shows it’s maximum effect on wheel movement at the lowest speeds when the motor is drawing the least current.  My RTR locos perform as well as anyone has a right to expect from volume produced models engineered down to a competitive market price,  but even the best of them cannot start absolutely perfectly smoothly from rest like a real loco does.

 

...Not gonna happen in my lifetime...

DCC is available now.  A good quality decoder has the advantage of permanent full track power, direct connection to the motor for efficient BEMF compensation, and a suite of adjustments to exert optimum control. Better than dreaming of what might yet come, you can see your models creep smoothly in and out of motion.

[The Johnster]

No I can’t, but that’s not not because of any flaw in the technology, more that I’m a poor pensioner who can’t afford to convert his fleet (cue violins).  A constant 12v supply makes a very big difference, but it’s clearly a lot more complex than just shelling out for the controller.  There is a whole world out there of different chips with differing abilities and uses that this curmudgeonly Luddite can cope with!!!

 

As I’ve said, I’m content with the performance of current standard DC RTR, but not unaware that improvement can be made, or that DCC is last century’s tech and will almost certainly be obsolete in the fairly near future; I’m sure NFC is the way to go.  The hobby is on the way to becoming the rich man’s toy it was before WW2. 

[Pandora]

DCC is a technology capable of supporting  improvement by modular steps as as opposed to wholesale throw it away and start again!

 

in computer networking we have the long established 7 layer OSI architecture,   where you can redesign and  improve the network by substituting a better version of each layer  at a time without having to redesign the other 6.  Example, remember 48k dial up modems for the intranet? when we swapped 48k for  broadband we only changed the modem layer and kept the other  6 layers as  before.

DCC is similar,   in DCC we may exchange one layer of the DCC architecture for a improved layer of the architecture, My example is we can swap the layer  concerning rail fed power and rail fed DCC packets to the decoder by a better  layer where the decoder receives the DCC ackets by wifi and a battery  powers the decoder to pull those wagons. this means we only have to incorporate wifi into the DCC command station and wifi and batteries to the decoder and not have to rewrite all of the software for the DCC packet protocols in the Command Station or Decoders.

In simple terms we can just change the path the DCC packets take to get to the decoder,  we cease to send them through the dirty rails and pickups, we send themby an nice clean aeriel and receive them by another nice clean  aeriel to a decoder which is powered by a battery

Edited November 5, 2019 by Pandora

[Hitchin Junction]

5 hours ago, Pandora said:

DCC is a technology capable of supporting  improvement by modular steps as as opposed to wholesale throw it away and start again!

 

in computer networking we have the long established 7 layer OSI architecture,   where you can redesign and  improve the network by substituting a better version of each layer  at a time without having to redesign the other 6.  Example, remember 48k dial up modems for the intranet? when we swapped 48k for  broadband we only changed the modem layer and kept the other  6 layers as  before.

DCC is similar,   in DCC we may exchange one layer of the DCC architecture for a improved layer of the architecture, My example is we can swap the layer  concerning rail fed power and rail fed DCC packets to the decoder by a better  layer where the decoder receives the DCC ackets by wifi and a battery  powers the decoder to pull those wagons. this means we only have to incorporate wifi into the DCC command station and wifi and batteries to the decoder and not have to rewrite all of the software for the DCC packet protocols in the Command Station or Decoders.

In simple terms we can just change the path the DCC packets take to get to the decoder,  we cease to send them through the dirty rails and pickups, we send themby an nice clean aeriel and receive them by another nice clean  aeriel to a decoder which is powered by a battery

 

Given the transport layer is basically uni-directional, I don't see much future improvement possible without a complete redesign. Driving trains via cab-view and/or robot drivers would be a tough fit.

Tim

[Pandora]

DCC packets carrying video data over the DCC system,  I do not think  video data  is supported by the DCC Standards, so yes to incorporate video data would be a lot of work and redesign of the packet rules, but  the sending  of DCC packets to a decoder in a locomotive  by a wireless antenna method, as opposed to throuigh the metal of the running rails,  I believe it is a logical and workable  progression to the current  DCC standards;

 

https://model-railroad-hobbyist.com/node/21240

Edited November 7, 2019 by Pandora