Helston Revisited

[longchap]

26 minutes ago, Andy Keane said:

The first DCC Concepts point motor fitted. One down, 27 more to go - days of fun ahead.

I have left the Peco point tie-bar spring in place on this first one so there is a satisfying snap as the motor flips the point. But is this wise? - do people generally reckon to remove the springs and just rely on the motors to hold the blades closed? Also I have screwed the motor down but the instructions talk about jut using the sticky pads to hold motors in place - not sure how this would stand up over time.

Andy

 

Hi Andy,

 

It’s generally considered that leaving the spring in rather defeats the object of using a slow throw point motor, as you loose the prototypical slow throw of the blades, plus the spring also adds undesirable resistance on the actuation bar and motor.

 

Best,

 

Bill

[Harlequin]

39 minutes ago, Andy Keane said:

The first DCC Concepts point motor fitted. One down, 27 more to go - days of fun ahead.

I have left the Peco point tie-bar spring in place on this first one so there is a satisfying snap as the motor flips the point. But is this wise? - do people generally reckon to remove the springs and just rely on the motors to hold the blades closed? Also I have screwed the motor down but the instructions talk about jut using the sticky pads to hold motors in place - not sure how this would stand up over time.

Andy

 

It takes a leap of faith to remove the spring because you'll never get it back in and you can't be sure the point motor will do the same job until you try!

 

I've got a turnout on my test layout in exactly the same state as yours, spring and DCC Concepts point motor, because I was unhappy to commit at the time. Now whenever I operate it I hate the whining, straining sound it makes as the motor fights against the spring...

 

On my Minories layout I bit the bullet and removed all the springs and it's been OK so far (using MTB point motors).

 

Edited January 20, 2022 by Harlequin

[5BarVT]

2 minutes ago, Harlequin said:

It takes a leap of faith to remove the spring because you'll never get it back in and you can't be sure the point motor will do the same job until you try!

I’ve removed all of mine (using tortoises).  A secondary effect of the peco spring is to keep the heels of the switches tight up against the closure rails (I think that’s the right term!).  I found with mine that some of the switches were wandering off towards the toes.

This time around I’ve tried to make sure the drive spring (rod) is slightly tensioned to push the switch rails back.  Others add a thin piece of plasticard between the tiebar and sleeper to hold in place.  I have some in black in case I need them.

Paul.

[TrevorP1]

59 minutes ago, Andy Keane said:

The first DCC Concepts point motor fitted. One down, 27 more to go - days of fun ahead.

I have left the Peco point tie-bar spring in place on this first one so there is a satisfying snap as the motor flips the point. But is this wise? - do people generally reckon to remove the springs and just rely on the motors to hold the blades closed? Also I have screwed the motor down but the instructions talk about jut using the sticky pads to hold motors in place - not sure how this would stand up over time.

Andy

 

Regarding the point tie bar spring. On the scenic side of the layout I removed the springs, also some of the fiddle yard area. I then thought "what if I left them on?" so the remaining 10 or so I've left the springs on and they've been working fine for the last 2 - 3 years.

 

On the visible areas it's nice to see the point blades slide slowly across, so I'd definitely take them off there. In the the fiddle yard it's nice to hear the point 'click' across and you know it's gone. In theory the motor has an easier time without the springs but... 

 

On the sticky pad front, I just used the pads to hold the motor while I screwed it down. The pads may be quite OK but some of mine would be an awful lot of bother to replace if the pad failed for some reason.

[Andy Keane]

Thanks everyone for the very useful comments. I think to start I will leave the springs in on the yard points. On the one I have fitted, because my base board is only 6mm thick, I have the fulcrum plate right at the top of the motor so the leverage helping the motor is quite significant and also this gives plenty of room for the wire link to act as a leaf spring, so that the motor can move while winding up pressure on the tie bar.

In the station throat I have a fully hand built point assembly with no springs to start with so that is easy - the motors will have to deliver the closure on their own. Down at the far end  of the station the three points in the run-around complex are all Peco code 75 bullhead points and they don't have hinges on the blades, so we will have to see what works best for them. Not sure how much experience there is around RMweb on taking springs out of those points though. If anyone has done it I would appreciate hearing on how it went. They will be the last three I do so plenty of learning on the job before I get there. Given it seems to take me the best part of an hour to fit each point motor and I have not even laid the track for the station its some way off. And I may well get distracted running locos up and down my yard sorting wagons anayway. I am expecting my 14xx back from YouChoos over the coming weekend with its sounds, headlamp and stay-alives all working, which will clearly deserve extensive testing, particularly of the whistle.

Andy

[longchap]

41 minutes ago, Andy Keane said:

Not sure how much experience there is around RMweb on taking springs out of those points though. If anyone has done it I would appreciate hearing on how it went.

 

My current Newton Regis layout is my first with slow motion point motors (Tortoise) and I've removed the springs in all six motors with a small electrical screwdriver and a pair of small side cutters. Use the screwdriver to prise up the metal tabs of the spring cover and lift the cover off, then use the side cutter, or other similar tool to grab and remove the spring, then refix the cover and bend the tabs back down. Easy peasy and takes a couple of minutes for the first one, then a little quicker when you get into the groove.

 

Have fun,

 

Bill

[Andy Keane]

I am currently deep in the process of wiring up my NCE DCC system. The kit I have provides 5 amps to run both my track wiring and my accessory bus for points and signals. I will have 28 point motors and 10 signal motors when I am done plus about seven locos parked around the place but with probably only two ever moving at once. Some on board lights and sounds though. Do people think 5 amps is enough or should I split the fiddle yard and station and provide 5 amps to each separately - easy enough to do with an NCE SB5 power booster but maybe its overkill? Or I could use a power booster to split the power to the track and the accessories with 5 amps each. Given I will be setting routes in one go that will ask perhaps seven or eight points to change at once, perhaps a dedicated supply to the accessory bus might be wise? All views much appreciated.

Andy

[Harlequin]

44 minutes ago, Andy Keane said:

I am currently deep in the process of wiring up my NCE DCC system. The kit I have provides 5 amps to run both my track wiring and my accessory bus for points and signals. I will have 28 point motors and 10 signal motors when I am done plus about seven locos parked around the place but with probably only two ever moving at once. Some on board lights and sounds though. Do people think 5 amps is enough or should I split the fiddle yard and station and provide 5 amps to each separately - easy enough to do with an NCE SB5 power booster but maybe its overkill? Or I could use a power booster to split the power to the track and the accessories with 5 amps each. Given I will be setting routes in one go that will ask perhaps seven or eight points to change at once, perhaps a dedicated supply to the accessory bus might be wise? All views much appreciated.

Andy

 

Hi Andy, The accepted wisdom is to always power your track and accessories separately, with separate overload protection in each circuit, so that when a loco runs into points facing the wrong way, you can still operate the points to release the problem.

Edit: Not necessarily separate power supplies - just overload protection.

 

Edited January 23, 2022 by Harlequin

[Andy Keane]

Phil

Yes I see that. But if I split my existing 5 amp supply and feed the track through a dedicated circuit breaker I was hoping that would deal with track shorts while leaving the accessory bus live or will that not work? I am mainly worrying if 5 amps will deal with route setting over a run of DCC concepts point motors while also driving two locos.

Andy

[Harlequin]

9 minutes ago, Andy Keane said:

Phil

Yes I see that. But if I split my existing 5 amp supply and feed the track through a dedicated circuit breaker I was hoping that would deal with track shorts while leaving the accessory bus live or will that not work?

Yes, that's perfect.

 

9 minutes ago, Andy Keane said:

 

I am mainly worrying if 5 amps will deal with route setting over a run of DCC concepts point motors while also driving two locos.

Andy

Not sure. You need to tot up all the current draw of everything that might possibly be operating at the same time and add a bit more for safety.

 

[St Enodoc]

40 minutes ago, Andy Keane said:

Phil

Yes I see that. But if I split my existing 5 amp supply and feed the track through a dedicated circuit breaker I was hoping that would deal with track shorts while leaving the accessory bus live or will that not work? I am mainly worrying if 5 amps will deal with route setting over a run of DCC concepts point motors while also driving two locos.

Andy

I do just that but also have a circuit breaker on my accessory bus. Belt and braces.

 

You should have no problem with route setting and driving two locos at once but check the DCC Concepts manual (or email them) to check the current consumption - active and passive - for the motors you are using..

[5BarVT]

Another factor is whether your locos are sound: they are significantly thirstier, even when stationary. 
If you’re using stall motors, they actually draw more current when stationary than when moving, so an easy test of what they draw is to measure the current once you have connected all of them to the accessory bus.  N.B. This doesn’t need them to be installed, just connected!

Paul.

[Andy Keane]

I am still pondering if 5 amps will do all I need, as this would need to live with potentially seven locos sitting on the layout, of which two could be moving while route setting might require 10 point motors to move and in addition I plan to use this power to fire up the dozens of MERG current sensors and a set of NCE AIUs to link the data back to JMRI. If it gets to be an issue it’s a simple fix to add another dedicated power supply for the accessories but the NCE 5 amp addon is over £200 so a big call. I shall rely on my trusty Fluke multi-meter to arbitrate in due course.

I have also made some other progress over the weekend. I have a couple of point motors and most of the wiring of the corner board set up. I have the NCE Power Pro mounted and a couple of their circuit breakers in place. I also have it all talking to JMRI on my laptop and can now operate points using the touchscreen of the laptop on the track plan. This also allows routes to be easily defined and I have written some code to take JMRI routes and set these up in NCE backup format so the routes can be committed to the NCE gear as well. This means routes can be operated either from the JMRI screen or by selecting them on the cabs. The only issue is if you have too many defined they can become confusing on the cabs as they have to be referred to by number, while on the JMRI screen I can add text describing what each route does and also see directly which points will get operated. I have yet to test that the AIU ouputs can be used to flag track occupancy to the JMRI display but hope that will work too.

Just waiting to get the sound and light fitted 14xx back from YouChoos.

Andy

ps - in other news I now have a second grandchild as of this evening - a girl this time!

Edited April 6, 2022 by Andy Keane

[Andy Keane]

1 hour ago, 5BarVT said:

Another factor is whether your locos are sound: they are significantly thirstier, even when stationary. 
If you’re using stall motors, they actually draw more current when stationary than when moving, so an easy test of what they draw is to measure the current once you have connected all of them to the accessory bus.  N.B. This doesn’t need them to be installed, just connected!

Paul.

Paul, I currently hope to add sound to the whole fleet so it may well be I have to add extra power. I know some don’t like sound on OO scale locos but I am a sucker for a steam whistle.

Andy

 

[5BarVT]

Assuming your 5A is man enough for your locos, a cheaper way to get an extra 3A for an accessory bus would be a SPROG Booster.  (£60 plus power supply.)  
i think you said you were using MERG DTC8s (I use DTC2s), they run off DC anywhere between 5V and 12V, so I would be careful before shoving DCC into them.  At 16V on the PSU stabiliser capacitor, a DCC signal could be pushing it a bit close!  Now, if you can get 5V (say) out of your AIU, then no problem at all as that’s what I do with my SSB units and it works fine.

Paul.

[Andy Keane]

22 minutes ago, 5BarVT said:

Assuming your 5A is man enough for your locos, a cheaper way to get an extra 3A for an accessory bus would be a SPROG Booster.  (£60 plus power supply.)  
i think you said you were using MERG DTC8s (I use DTC2s), they run off DC anywhere between 5V and 12V, so I would be careful before shoving DCC into them.  At 16V on the PSU stabiliser capacitor, a DCC signal could be pushing it a bit close!  Now, if you can get 5V (say) out of your AIU, then no problem at all as that’s what I do with my SSB units and it works fine.

Paul.

Paul, indeed I will have to take care with the DTC8s but the Merg sales team think I should be ok if I feed them via a diode to drop a bit of voltage first. I will investigate the Sprog booster

thanks

andy

[5BarVT]

9 minutes ago, Andy Keane said:

I should be ok if I feed them via a diode to drop a bit of voltage first.

That will work.  Or two if one isn’t enough!

Paul.

[5BarVT]

Back again!

I’ve just looked up the NCE AIU to see how it works.  Much the same as my SSB cards, in that it feeds back via the cab bus.

 

This is where I get worried about feeding the DTC from the train accessory bus.  That will put one polarity of the DCC signal into the ground connection of the AIU.  Now, IF the cab bus ground is connected to the controller ground, you’ve just shorted out one side of the H driver on the train bus output.  That has the potential to either burn out the cab bus ground wire(s) or burn out the H driver.  (It depends which goes bang first!)

 

Thats me going on how digitrax kit works, it could be that the NCE cab bus is opto isolated from the controller ground, but that’s a big IF that I wouldn’t want to test by trial and error!

 

I hope I’m not setting a hare running, but I wouldn’t want you to let out the smoke,

Paul.

 

P.S.  The design of the DTC with the current transformer is specifically to keep the track bus signal isolated from the DTC outputs.  If you’re intending to connect them together, you might as well go for a diode drop arrangement.  Even without the shorting out issue, putting a dirty track bus signal into the cab bus lines is not going to bode well for interference free operation.

Edited January 23, 2022 by 5BarVT
Added P.S.

[St Enodoc]

3 hours ago, 5BarVT said:

If you’re using stall motors, they actually draw more current when stationary than when moving

That's true of Tortoises but not Cobalts - one of the main reasons I chose them.

[Andy Keane]

1 hour ago, 5BarVT said:

Back again!

I’ve just looked up the NCE AIU to see how it works.  Much the same as my SSB cards, in that it feeds back via the cab bus.

 

This is where I get worried about feeding the DTC from the train accessory bus.  That will put one polarity of the DCC signal into the ground connection of the AIU.  Now, IF the cab bus ground is connected to the controller ground, you’ve just shorted out one side of the H driver on the train bus output.  That has the potential to either burn out the cab bus ground wire(s) or burn out the H driver.  (It depends which goes bang first!)

 

Thats me going on how digitrax kit works, it could be that the NCE cab bus is opto isolated from the controller ground, but that’s a big IF that I wouldn’t want to test by trial and error!

 

I hope I’m not setting a hare running, but I wouldn’t want you to let out the smoke,

Paul.

 

P.S.  The design of the DTC with the current transformer is specifically to keep the track bus signal isolated from the DTC outputs.  If you’re intending to connect them together, you might as well go for a diode drop arrangement.  Even without the shorting out issue, putting a dirty track bus signal into the cab bus lines is not going to bode well for interference free operation.

Paul, that’s very important info. I had not thought of it. So probs best to back to plan A with an entirely separate power supply. I was hoping to eliminate one extra power bus but I think your are right and I am best to tread very carefully.

Input much appreciated

andy

 

[Andy Keane]

23 hours ago, Andy Keane said:

Paul, that’s very important info. I had not thought of it. So probs best to back to plan A with an entirely separate power supply. I was hoping to eliminate one extra power bus but I think your are right and I am best to tread very carefully.

Input much appreciated

andy

 

Paul, what about feeding the accy bus through an isolated dc/dc converter like this:

https://uk.rs-online.com/web/p/isolated-dc-dc-converters/2233668

Would that prevent any issues do you think?

Maybe I should see if the Merg people can advise.
Amusingly these are described as railway approved.

Andy

[Andy Keane]

I am loving the simplicity of DCC wiring! And I don't even have the accy bus in place yet.

Edited April 6, 2022 by Andy Keane

[Andy Keane]

And just to help, MERG have just announced an error in the DTC8a kit you can see here - all the eight transistors need to come out and be replaced the other way around!

[longchap]

4 hours ago, Andy Keane said:

I am loving the simplicity of DCC wiring! And I don't even have the accy bus in place yet.

 

 

Me neither! I feel for you Andy, as I'm at a similar position with the underside of the baseboards getting more complicated with more wires and gizmos and I'm a DCC virgin. What fun though!

 

Bill

[Neal Ball]

14 hours ago, Andy Keane said:

I am loving the simplicity of DCC wiring! And I don't even have the accy bus in place yet.

 

I don't have the circuit boards under the railway, but I too thought DCC was going to be 2 wires and that was it.... My wiring has grown like topsy - its everywhere!

 

However I have taken a different route with regard to splitting my power consumption and chose old fashioned analogue for point control. Even the platform lights and all my signals are on separate power controllers. My accessory BUS is only used to power the autofrogs on the points.

 

 I have separate power districts, protected by NCE circuit breakers.

 

I am hoping that my Gaugemaster Prodigy* continues to cope with my expanding fleet of sound locos. (*Ive just looked it up and see that its only 3.5amp)

 

Good luck Andy, I'm sure it will be fine at Helston.