Dapol working signals review

[Andy1963]

There was a 4mm version at Alexandra Palace show, can't recall if it was a home or distant GWR. Looked pretty good to me.

[Grovenor]

If I am reading the review that started this thread correctly, you feed 16v ac power to the signal via two always on power feeds and a switched return.

Not quite, you feed the 16VAC by two wires, this supply goes directly to a bridge rectifier, then a 5V regulator and onto the LED and to the motor circuit. (It does work perfectly on 12V DC despite Dapol's denial and mine is working just fine on a 9V PP3 battery). The other two wires connect to a switch contact, not any kind of return or power source, the switch contact needs to be made briefly (joining the two wires together) to make the signal run to the opposite position, a simple press to make push button is the simplest.

The signal responds to each switch operation by motoring one way or the other which is pretty similar to the operation of the point motor.

Yes

This isn't a pulse it is a switch generated power feed that the signal can use.

This is not to clear, the switch should not provide any power feed just connect the two wires briefly, ie a pulse. This triggers an electronic chip in the signal that runs the motor until it reaches the limit switch in its new position.

I will lay odds that the signal has a limit switch built in, perhaps electronic, that allows the signal to respond to each switch movement by moving in one direction or the other.

Yes it has a pair of limit switches, one for each direction of travel, these are simple make contacts soldered to the PCB, once triggered the motor runs until the limit switch in the new position makes and causes the chip to turn the motor off. The control chip has had all the identification markings removed so it is difficult to be certain of the circuit.

In MERG we have designed a replacement circuit board that will allow operation from a simple on/off switch so it will always be possible to set the signal to the desired position.

Regards

Keith

[Gordon H]

This is not to clear, the switch should not provide any power feed just connect the two wires briefly, ie a pulse. This triggers an electronic chip in the signal that runs the motor until it reaches the limit switch in its new position.

And that is the critical point, of which many appear not to appreciate the significance - each pulse on the pair of wires merely moves the signal to the 'opposite' position to that which it is currently.

It doesn't say 'go to clear' or 'go to danger' as you might reasonably expect (or demand) of a semaphore - it just says 'change position'.

As such it is indeterminate as far as any properly conceived control system is concerned. To me this represents a fundamental flaw in Dapol's concept.

[beast66606]

The fundamental flaw in the signals in the pictures is that in the OFF position they seem to point to the sky...... Every one knows that proper signals drop to the OFF position

 

You are referring to LNWR signals of course

[Steven B]

As such it is indeterminate as far as any properly conceived control system is concerned. To me this represents a fundamental flaw in Dapol's concept.

 

It's only a fundamental flaw if you want to control the signal automatically or be able to interlock it with point motors or other signals. The number of people wanting to do this will be tiny compared to the market as a whole.

 

For the vast majority who are going to add them to a normal control panel it's not an issue - train drivers will be looking at the state of the signal arm, not which direction a toggle switch is pointing.

 

If your layout is advanced enough to need positive control of the signal then you're likely to be capable enough to swap the drive circuit for the one MERG are developing or build the MSE kits and motorise them yourself.

 

It must be really frustrating being a manufaturer at times. For years modellers have been crying out for working ready to plonk signals. Now they're here we're grumbling that the control mechanism isn't perfect. Either way they can't win.

 

Happy modelling.

 

Steven B.

[Paul Cram]

I shouldn't worry too much about the manufacturers they are there to make money. If it doesn't sell then they know they need to change something. If they don't serve the customers needs then they won't make money. Simple really.

[N Gauge David]

In MERG we have designed a replacement circuit board that will allow operation from a simple on/off switch so it will always be possible to set the signal to the desired position.

 

How does this work, and will it be made available generally? What level of skill would be required to replace the original control mechanism with the merg one?

 

Cheers

 

David

[Grovenor]

It will be on test soon and once proven we will decide what to do with it. Standard MERG policy is to produce for sale to members if enough demand is established. Whether the design is put in the public domain or not is up to the designer.

The skill level is similar to fitting a hard wired decoder in an N gauge loco. There are 6 small wires to unsolder from the factory board, resolder to the new board, then you have to persuade all the bits to fit back together, and the board will need the components soldering on, surface mount components but not too small.

Regards

Keith

Edited April 14, 2012 by Grovenor

[Gordon H]

The unfortunate thing about the retro-fitting idea that you still have to buy the whole thing from Dapol at the going rate, even if you are going to throw their PCB away.

Thus there is little incentive for Dapol to make any changes themselves to correct the shortcomings that have been identified.

If Dapol can be persuaded to supply the mechanism only, so much the better, but I doubt whether they would even consider it.

[Chris Higgs]

It must be really frustrating being a manufaturer at times. For years modellers have been crying out for working ready to plonk signals. Now they're here we're grumbling that the control mechanism isn't perfect. Either way they can't win.

 

Happy modelling.

 

Steven B.

 

Well, they could always spend that little extra time thinking about the scenarios in which their products might get used. In almost all walks of life, the earlier you make the adjustments the easier they are.

 

Chris

[Etched Pixels]

Thus there is little incentive for Dapol to make any changes themselves to correct the shortcomings that have been identified.

If Dapol can be persuaded to supply the mechanism only, so much the better, but I doubt whether they would even consider it.

 

I would ask Dave Jones before assuming. Its possible they'll say no, or that you'll need to buy 500 but it may be worth asking.

[Gordon H]

I would ask Dave Jones before assuming. Its possible they'll say no, or that you'll need to buy 500 but it may be worth asking.

Ironically, I have little or no use for these signals at all myself. My concern from the start has been that Dapol failed to foresee the obvious issues that would arise from their selected control method.

Chances are that no individual would ever be in a position to place a special order for a sizeable batch of 'mechanism only' signals. It would take a consortium or another business concern to do that. Mind you, if that did ever come to pass, perhaps it would persuade Dapol to seize the opportunity and make the corrections for themselves.

For interest, the MERG replacement PCB mentioned previously has been successfully demonstrated, so it may only be a matter of time before these become available.

[whiteswan]

If it's of any interest, I've had half a dozen of the Dapol GWR signals running on a Digitrax & R&R TrainController DCC controlled layout for the past month without any problems. They are operated via a CML DAC20 accessory decoder (usually used for points), the closed and thrown outputs are linked together and go to one side of the coil of a SPNO 12v relay, the common output of the accessory decoder goes to the the other side of the relay coil. The DAC20 provides feedback to the system and R&R via LocoNet as to the state of any signal at startup each session.

 

Whenever a thrown or closed command is issued the relay (substitute for the push button) closes the Dapol signal operate circuit without fail. Because of this, once you have sync'd the signal (I use thrown for signal off and closed for signal on) it has never once lost sync with the requested operation. If ever it should fail, I'd do exactly what I'd do if a point failed to throw, just issue the command manually from the DCC controller.

 

Using vero board, half a dozen 12v SPNO relays and some terminal strip I've made up a board that links the accessory decoder to the signal yellow operating wires.

 

Caz

Edited May 14, 2012 by whiteswan

[Gordon H]

Copied from a thread in the DCC section of the Forum, but more relevant here...

 

Now you see it's just not possible to see the signal control method as anything but "an affordable, simple to install and wire, fully working signal, for the enthusiast and beginner alike".

 

 

I doubt whether true enthusiasts would see it that way. All the enthusiasts I have spoken to on the subject think it is a major blunder.

 

It was never designed to be all things to all men, certainly at that price point. Would you have paid 50% more for a signal that did all you wanted? If so great........now get your friends together and get me an order for 4000 units and I'll make you some!

 

The tragedy is that it could have been so much more to so many more men by a relatively trivial change to the design.

As to where you get the figure of 50% more to make it work sensibly, I can only suggest you review your component sourcing processes because the reality is that it would cost nothing like that sort of figure.

With an initial signal purchase price of about GBP 25, that would mean a price differential of more than GBP 12.50!

 

For comparison purposes:

The mechanism stays as-is - no differential

A double sided PCB of identical size and similar complexity is required - no differential

The same manufactured switch contacts can be used - no differential.

Now we are down to pure electronic component content - and even some of this is likely to coincide with that used already.

Basing the components on a design that is known to work and fit in the same enclosure, essentially a small microcontroller, a voltage regulator and two half-bridge drivers plus a few discrete components.

Taking 4000 off as a working figure, total electronic component cost is GBP 2.43 - including VAT!

No idea what the cost of the components in the existing design might be, but as a wild guess say GBP 1.00

So, the true differential cost is likely to be less than GBP 2 for a properly controllable signal that satisfies a whole lot more people and maintains Dapol's reputation for innovation.

I think that would have been worth it.

[DapolDave]

Hi Gordon,

 

I'm shocked that you readily dismiss all others who dare not use a control system you advocate as 'none true enthusiasts'.

 

Dapols reputation for innovation is intact thank you, and i have the sales AND awards to prove it!

 

I look forward to you designing and implementing a working signal in N or OO gauge that does truly mean "so much more to so many more men", and then selling it to a market thats in a double dip recession at an affordable price.

 

Regards

Dave

[RedgateModels]

Can I ask is there any point in continuing to hector (pun intended) Dapol on this matter? Dapoldave has made the company stance clear - they have produced what THEY think the market wants and there is no going back. MERG have come up with a modified pcb that provides the sort of control that those who wish for a different approach to control want.

 

I'm a MERG member myself and can see the reasoning behind the modified approach and might even adopt the MERG boards should Dapol produce 7mm signals, but can also see that for a lot of users a simple press button to change the signal would be appropriate.

 

I honestly can't see the point in continuing to press Dapol for a modified signal, but hey it's an open forum what do I know

[PaulRhB]

I doubt whether true enthusiasts would see it that way. All the enthusiasts I have spoken to on the subject think it is a major blunder.

Blimey that's a sweeping statement, think you need to ask the rest who support it on this thread!

It's blindingly simple for non electronically minded people, Merg have offered a solution to the problem you mention, others have operated on dcc using the decoder to prove it without problem.

Gordon you're critique of Dapol is uncalled for as you've apparently not even tried to contact them direct to suggest this or ask if the parts could be obtained separately. That is taken from your posts content.

With regards a Signalman and obviously not true enthusiast

Edited May 14, 2012 by PaulRhB

[The Stationmaster]

I doubt whether true enthusiasts would see it that way. All the enthusiasts I have spoken to on the subject think it is a major blunder.

I see I've been at the invisible ink again, along with Beast and I think PaulRhB. Mind you after more than half a century of deep interest in railway and model railways I've still yet to divine exactly what the expression 'true enthusiast' means and would love to be enlightened (on another thread - not this one, please).

 

The tragedy is that it could have been so much more to so many more men by a relatively trivial change to the design.

 

For comparison purposes:

The mechanism stays as-is - no differential

A double sided PCB of identical size and similar complexity is required - no differential

The same manufactured switch contacts can be used - no differential.

Now we are down to pure electronic component content - and even some of this is likely to coincide with that used already.

Basing the components on a design that is known to work and fit in the same enclosure, essentially a small microcontroller, a voltage regulator and two half-bridge drivers plus a few discrete components.

Taking 4000 off as a working figure, total electronic component cost is GBP 2.43 - including VAT!

No idea what the cost of the components in the existing design might be, but as a wild guess say GBP 1.00

So, the true differential cost is likely to be less than GBP 2 for a properly controllable signal that satisfies a whole lot more people and maintains Dapol's reputation for innovation.

I think that would have been worth it.

Right - simples - a replacement electronic gizmo can be put on the market for 'true enthusiasts' for under a tenner, simple to fit and clearly bound to be a commercial success.

 

In the meanwhile Dapol can continue to sell something which only needs a simple, dirt cheap, switch to operate it which is bound to appeal to many of their customers and is not impossible to use with more sophisticated ideas. Operation from an on/off switch/lever frame is no doubt a good idea in many respects but as a large percentage of modellers don't understand such things and regard the subject as 'difficult' I can see lots of benefit in doing it in a simple way. And - just like the prototype - the operator will have to watch how the signals respond to the controls and ensure they are showing the correct indication (but maybe only 'experts' - who like me write Rules & Instructions for Railways - know that?).

[Trains&armour]

I, for one, would like to applaud Dapol for bringing this on the market. When I became interested in british railway modelling a few years back I looked a long time for working british signals before I realised there weren't any! As a continental modeller RTR signals were a fact of life for me. And yes, I would have liked a feedback system that shows which position the signal is in, but I would call that a minor quibble, not a major fault. The major fault here was the fact that there was no RTR signal on the market at all, and I'm thankful to Dapol for filling that gap.

 

Regards from a still very enthousiastic British (well, actually GWR...) railway modeller.

 

Sierd Jan

[DaveArkley]

I look forward to you designing and implementing a working signal in N or OO gauge that does truly mean "so much more to so many more men", and then selling it to a market thats in a double dip recession at an affordable price.

 

Don't you go bringing commercial realities into this. You'll spoil all their fun!

[Gordon H]

I'm shocked that you readily dismiss all others who dare not use a control system you advocate as 'none true enthusiasts'.

Yes, it was an unfortunate turn of phrase used in the heat of the moment, but I still find it hard to credit that so many appear not to care about such a fundamental limitation of a brand new product in these days where widespread acceptance of deterministic electronic control systems (not just DCC) has just taken hold.

 

Dapols reputation for innovation is intact thank you, and i have the sales AND awards to prove it!

I have no issue whatsoever with Dapol's other efforts - just this one which really sticks out like a sore thumb.

 

I look forward to you designing and implementing a working signal in N or OO gauge that does truly mean "so much more to so many more men", and then selling it to a market thats in a double dip recession at an affordable price.

I have already shown above that Dapol themselves could have achieved this aim if they had chosen to do so. The figures I quoted speak for themselves.

 

Gordon you're critique of Dapol is uncalled for as you've apparently not even tried to contact them direct to suggest this or ask if the parts could be obtained separately. That is taken from your posts content.

Why would I want to contact them directly when this Forum is here for the purpose? At least here it is all in public view.

 

With regards a Signalman and obviously not true enthusiast

As a signalman, would you not expect your lever positions to directly reflect the signals you control with no doubt or uncertainty?

 

Right - simples - a replacement electronic gizmo can be put on the market for 'true enthusiasts' for under a tenner, simple to fit and clearly bound to be a commercial success.

Wouldn't it have been so much better if Dapol had designed their gizmo that way in the first place for negligible price difference, if any?

 

In the meanwhile Dapol can continue to sell something which only needs a simple, dirt cheap, switch to operate it which is bound to appeal to many of their customers and is not impossible to use with more sophisticated ideas. Operation from an on/off switch/lever frame is no doubt a good idea in many respects but as a large percentage of modellers don't understand such things and regard the subject as 'difficult' I can see lots of benefit in doing it in a simple way.

The operating method I have been advocating is no more 'difficult' to implement than the existing one. A similar 'dirt' cheap' switch is used - and it has the advantage of showing you directly which way the signal is set without needing to look at it, assuming you can.

I think we have to give the majority of modellers a bit more credit than this with regard their electrical capabilities. If things were really that difficult they would surely have given up at the first attempt to get a point to move under electrical control. Unfortunately for some, this hobby is largely reliant on electricity, so some understanding of general principles is bound to be required, though even that is not necessary in this case.

 

And - just like the prototype - the operator will have to watch how the signals respond to the controls and ensure they are showing the correct indication (but maybe only 'experts' - who like me write Rules & Instructions for Railways - know that?).

Does this mean that 'prototype' signalmen have always had line of sight to every signal they controlled? I find that hard to believe.

 

 

It is increasingly clear that Dapol are happy with their sales of these signals, so it is understandable why they are reluctant to doing anything to improve them. However, as the title of this thread is 'Dapol working signals review', it is inevitable that any shortcomings are going to be pointed out, and that is all that I have been doing - and giving reasons why, and suggesting possible alternative strategies for consideration. Sorry if that offends some people, but when an issue as fundamental as this one becomes apparent, surely it is better to highlight the situation and provide explanations for those who may not realise the consequences?

[DapolDave]

Yes, it was an unfortunate turn of phrase used in the heat of the moment,

But no apology to the modellers you may have insulted i note!

 

but I still find it hard to credit that so many appear not to care about such a fundamental limitation of a brand new product in these days where widespread acceptance of deterministic electronic control systems (not just DCC) has just taken hold.

So you deny the fact that there are many many more modellers out there (possibly leaving you in the minority) that just want an easy to wire, use and cheap, working signal, and that your still right and they are wrong?

 

I have no issue whatsoever with Dapol's other efforts - just this one which really sticks out like a sore thumb.

To you maybe, but not to the majority of modellers.

 

I have already shown above that Dapol themselves could have achieved this aim if they had chosen to do so. The figures I quoted speak for themselves.

Having gotten quotes myself for a respected 3rd party that did'nt come on a forum and approached me himself, i'd say that your figures are wrong! (but then i speak from a position of knowledge and understanding, but we wont let that get in the way, shall we)?

 

Why would I want to contact them directly when this Forum is here for the purpose? At least here it is all in public view.

How about contacting in the right forum section to start with and not one that was locomotive decoder based, and with, what i now consider to be a 'sarcastic comment'.

 

As a signalman, would you not expect your lever positions to directly reflect the signals you control with no doubt or uncertainty?

As for this, there have been times i have seen a 'pulled off signal' and they have looked neither stop or go! so i expect a signallman would on this occassion know what he signalled, and inform the driver somehow. But i'll leave that more to the signalling experts on here.

 

Wouldn't it have been so much better if Dapol had designed their gizmo that way in the first place for negligible price difference, if any?

Again i'm afraid you are speaking from a position of little knowledge, wheras i KNOW the prices, and the reasoning behind the design which a minority few seem not to be able to accept.

 

The operating method I have been advocating is no more 'difficult' to implement than the existing one. A similar 'dirt' cheap' switch is used - and it has the advantage of showing you directly which way the signal is set without needing to look at it, assuming you can.

I think we have to give the majority of modellers a bit more credit than this with regard their electrical capabilities. If things were really that difficult they would surely have given up at the first attempt to get a point to move under electrical control. Unfortunately for some, this hobby is largely reliant on electricity, so some understanding of general principles is bound to be required, though even that is not necessary in this case.

 

 

 

Does this mean that 'prototype' signalmen have always had line of sight to every signal they controlled? I find that hard to believe.

I'll leave this for those with more knowledge than i.

 

It is increasingly clear that Dapol are happy with their sales of these signals, so it is understandable why they are reluctant to doing anything to improve them. However, as the title of this thread is 'Dapol working signals review', it is inevitable that any shortcomings are going to be pointed out, and that is all that I have been doing - and giving reasons why, and suggesting possible alternative strategies for consideration. Sorry if that offends some people, but when an issue as fundamental as this one becomes apparent, surely it is better to highlight the situation and provide explanations for those who may not realise the consequences?

"so it is understandable why they are reluctant to doing anything to improve them"? Sorry but that beggars belief that you still believe that there is something wrong with our signals control system when the solid reasoning was laid out before you. Your failure to accept this is unbelievable.

 

Sorry for the bold text but it helped differentiate between your mail and my reply.

Regards

Dave

[beast66606]

As a signalman, would you not expect your lever positions to directly reflect the signals you control with no doubt or uncertainty?

 

Want and happen are two different things, for a long time a signalman has been instructed "to observe the movement of all signals".

 

Does this mean that 'prototype' signalmen have always had line of sight to every signal they controlled? I find that hard to believe.

 

You are correct of course, I look forward to your modification where you fit a working arm and lamp repeater to the signals - which is how the prototype got around this problem.

[Andy Y]

.Sorry if that offends some people, but when an issue as fundamental as this one becomes apparent, surely it is better to highlight the situation and provide explanations for those who may not realise the consequences?

 

Ok, you've done that and irritated some folk other than Dave along the way with the manner adopted. Can I politely suggest you drop the matter now.

[Oldddudders]

I am disappointed that the negativity in this thread has continued unabated. Not least because the principal - only? - complainant includes this in his rationale for decrying the product "Ironically, I have little or no use for these signals at all myself." What is ironic about that?

 

I am confident that the Dapol signals will sell like hot-cakes to the many modellers whose signalling needs have been previously largely unfulfilled - the Dapol product is that much of a step forward. As with models of every make, scale and genre, there will be those talented and imaginative folk who take the Dapol signal and make it do everything but talk - and we will all applaud their abilities. In the meantime, and in parallel with those people's efforts, the 4mm signalling market has become a better place.