ParkeNd

I’m waiting for some Peco cable clips to tidy up the wires on top of the board so I’ve marked out the flow of the rails in the L section and installed the cork underlay. I might as well finish the last bits of track - 2 points and 4 lengths of flexi - this will be the fiddle yard effectively but will be “scenic’d”. The area will need two more pairs of droppers, choc blocks, and two point motors operated through one Cobalt controller. Out of this little list I have one shortage - one red 3M scotchlok. Buying through Amazon or hardware suppliers minimum qty is 50 and in some cases 100. Amazon wanted £13.50 for 50 plus £12.50 postage!!   So I’m buying 20 from Railway Scenics for £4.99 delivered - where the DCC bus kit came from. 

Took a brave step this morning - remember DCC is all new to me - and put the Dapol GWR Railcar on the programming track and gave it an address but took the defaults for all other variables. It ran first time and then stopped at the first point and the oVLd message came up and lights blinked everywhere. Luckily I had read on The Forum that reversing the +ve and -ve wires on the points controller output would fix it - it di to my relief. Had to change this on 4 of the 6 controllers and now the loco runs everywhere on the tracks in both directions. Travel across the points is incredibly smooth compared with my last layout. Very pleased. Now I need to get on with the scenics whilst fitting decoders on 15 of my 20 locos progressively - all bought used "as new" in the summer when nobody wanted them. Most have DCC connectors.

All 6 points motors are now installed and working. I love the way the points blades just slowly move between stock rails rather than the loud instant smack my old Peco points motors made. I’m now in more comfortable territory starting the scenics - again. Platform 2 is being shortened by about 1.5 “ of ramp because I don’t want to put it under the platform for fear of catching the little link - they can ping into oblivion if mishandled. 

I now have 4 of the 6 points motors installed and operating - 2 to go. The hardest part is lining up the motor and its tiny wire connector with the point itself, but I have managed it so far. The last 2 are going to be controlled by two sides of one Cobalt Controller and both will need the supplied extension leads and to go down under the board and come up the other side of the tracks. One will be easy. The other needs to sit where the ramp of Platform 2 will sit - see about 3 ins in front of the handset in the above picture - options are to shorten the platform and have a truncated flat end, or to modify the platform so that the point motor sits mostly under it. I can do either but the jury is out on which.

With the short circuit eliminated (with help) today was the day to return to fitting points motors and their controllers. Each controller will manage numerous points but nominally two - one each side of the circuit board. I’m going to use 5 of my 8 controllers for 6 points so I can stick with mostly the 150mm harness length of each points motor. I have installed and got 2 working today. The DCC Concepts Cobalt SS points system is pretty incredible - they move the blades slowly (with snap springs remove), you can adjust the travel on the controller to neatly nestle the blades against the stock rail on either side, change the direction of motion to suit preference, they change frog polarity, and can be operated by a passing contact switch although I’m using the Prodigy handset, will illuminate LEDs on a route panel, and routes can be set up. The only problem I had was the first one installed stopped moving the point blade after the second one was working. I feared I had programmed some sort of conflict of location names, but it turned out to be the little springy connector between motor and the point lever digging into the cork underlay after a few actions - easily fixed by cutting a 2mm channel in the cork. 3 of the controllers are going under elevated ground contours, and 2 are going under buildings. 

I installed a correctly modified new point this morning (fortunately a RH curve Code 75 wouldn’t fit a year ago despite me using Peco patterns and I had to buy a straight RH instead - at least I had one bit of luck) and two new pieces of adjoining flexi plus new wires, rail joiners, and IRJs. All fine according to the multimeter. Tomorrow I will wire to choc blocks and droppers checking as suggested as every wire is connected - one wire at a time.  Then I can get back to where the problem was exposed - fitting the point motors and Cobalt SS controllers. Maybe I’ve learned more by making a mistake than if I’d got it right first time. Thanks for the help. 

Problem is solved with the help of the DCC Questions and Help Board on this forum. It wasn't the point above, it was one next to it, and I hadn't cut the two links when modifying the point. So hard to find the source of the problem. I have replaced that point with a brand new one along with the two pieces of track leading off it. Tomorrow I have to connect the leads - one at a time with multimeter checks at every step. Then I can go back to what I was doing - installing the points motors. Out of interest with Peco Code 75 track on 1/16" cork the Cobalt SS motors need to mount on a Daler Board mat and use the little wire links in the packet with the green spot. The links have to be level and horizontal and it take a while to work out if you need anything under the point motor, and which of 4 configurations of tiny links you need. Thankfully I have some surgical precision tweezers - they are not manageable by hand when trying to fit them in two holes - one on the point motor and one on the point actuator with the tip cut off.

2 hours ago, ITG said:

Great. I had a very similar problem which didn’t manifest itself until I connected my ADSX points control until, because then the frog power switching was conflicting with the unmodified point blade routing of power. Like you, I had forgot to modify one point! Doh!

Took me a similar journey of exploration to identify the issue.

2 hours ago, WIMorrison said:

Dare I suggest that you also get the soldering iron hotter when soldering to the sides of the rails as this will make the solder flow rather than sit in lumps?

Thank you for all the help. I wouldn't have got this far without it. Soldering and electrics isn't my strong point - I'm a little better at scratch building buildings and the scenic. Below is a shot of part of my N Gauge layout of Parkend on the Dean Forest Railway, and then two scratch built OO Gauge buildings for this layout - made whilst waiting for the electronics. Coleford GWR station, and Cinderford GWR Goods shed shortened by 25% to fit the space I have.

Brand new point modified and installed. Multimeter says OK so far. Two new pieces of track to add tomorrow. Track was laid one year ago - had to wait this long for electronics to be delivered. Soldering better than a year ago but not my strongest suit. 

Solved!!  Thanks for all your help. Removed the point above and the two connected rails. No more short circuits across the rails. The point’s frog links were still intact - no attempt made to cut them. Stunned. I have a new point of the same type and plenty of new rails so I am going to replace this section. What a relief. 

8 hours ago, ITG said:

But couldn’t you check that without lifting the point by testing continuity between blade and frog?

Good idea. I checked it with multimeter as you propose. No continuity. Checked all the others with same result on 4 out of 5. But this one (Point2) there is continuity everywhere - bland to frog both sides - even across the insulated gap between frog rail V and next rail - both side. Rails aren’t touching. 

Working through the short circuit problem on one of the other Forum Boards with help. It isn’t the Prodigy, it isn’t a wiring error, and it isn’t an IRJ omission. Seems likely to be Point No 3 just before the straight track leading into the Good Shed. It is the only one with no continuity between L&R rails approaching the frog. Will remove tomorrow and check status of cutting link underneath. 

3 hours ago, Barry Ten said:

 

OK, have you isolated the frog by cutting the linkage under the point?

Yes. Subject to checking tomorrow that a piece of the link hasn’t folded back down under the point and remade the connection - and I’m worried that it may have done. 

1 hour ago, Barry Ten said:

 

It's looks as if the OP has cross-connected the rails to the blades, if I'm looking at the photos correctly.

 

The cross connection is across the stock rails and the point rails in the gap left in the Peco point plastic ahead of the blade pivots - not cross connected between the rails and the blades. 

1 hour ago, ITG said:

Can you clarify between exactly which two rails do you get no continuity on that point? I am thinking that if modified correctly, and with no frog power applied, it is correct that you get no continuity. Because that section of the point is isolated - it has the IRJs at one end and the modification cuts (underneath) at the other - hence can be no connectivity from either north or south of the point, meaning that the identified section has no continuity. The continuity flow will be via the physical connection of the point blade and the rail, In one set direction and depending of course in which direction the point is set.

Are you finding that every other point behaves differently?

 

Another afterthought- are you meaning the frog wire and the Cobalt controller are connected? As are the R & L to the controller? Try disconnecting all these controller connections.
Ian

The frog wire and the R & L are not connected to a Cobalt SS controller. They are neatly coiled having been brought up to the surface - not even with insulation stripped yet. I was in the process of installing the first point motor (physically but not wired) when I found the issue with oVLd by switching on the Prodigy. There is no continuity across any of the 4 rails at that point. And Yes that’s different from all 5 of the other points which have continuity across all 4 rails irrespective of point setting. 

The green wires are the frog common wire which will go to the Cobalt SS controller along with the red Left and blue Right and will automatically change point polarity. I used green for the common because it matched DCC Concepts point modification diagrams. All wires are above board now - none are dangling - I’m going to use Cobalt SS surface mounted points which are tiny. None of the track dropper wires are the wrong way round - I’ve checked. The short occurs throughout the DCC bus which is a common return and a common live back to the Prodigy. I am fairly sure that your first statements must be right - that point must be conducting between rails somehow - either because it’s faulty or, more likely my modification of that point is defective in some way. I have another Peco SLE 195 that I removed when I simplified the layout and that is perfectly modified, and I have a brand new one in its packet, so I will remove the possible problem one tomorrow and fix/replace it. 

Thanks Barry Ten. I did check continuity of every lead at the point of connecting them. But I still got burned because I hadn’t checked, and thus found out, that there was continuity ACROSS rails. Didn’t have this problem with unmodified Peco points on my N Gauge layout. 

Thanks - they are insulating rail joiners. There are IRJs on every frog rail. 

Thanks for additional comments. I feared at one stage this morning was going to be a morning of blank results. I did every test proposed. Interrupting each dropper feed (black and red at the same time) at the choc blocks left the meter beeping when applied across the ends of the bus wires) every time. None of the soldered feeds had been reversed anywhere. But clearly the red and black bus wires are shorted along their entire length. So I figured the problem had to be the track. So I went back to WIMorrison’s proposal. 

On the two photos below the short length of Point 3 marked in black felt tip pen on the board is the only place on the tracks where there is NO beep with probes between opposing rails.  So is it likely that this is the source of the problem? 

I didn't fit the suggested "capacitor/resistor" filter across the ends of the bus wires because, although I had the parts, I didn't think my length of track was long enough for the square wave to deteriorate. But if I put the red probe of the multimeter on the screw in the red wire side of the choc block that just stops it being just a wire end, and the black probe on the screw of the choc block at the end of the black wire the multimeter beeps. Same happens the other end of the bus wires.  See picture above of underside of the board.

And Yes - I already plan to disconnect and put away the Prodigy and use the meter. If I understand W I Morrison's post above then if I put the meter into Continuity mode and place one probe on LH rail and the other on RH side of rail on each length of track and point it will stop beeping when I reach where the short circuit is.

"it is easier (and less dangerous for your  command station) to use the multimeter to trace the fault. You can have set to beep and at the point it stops being that is where the fault lies."

Yes  I have half a box of track. And I also have the one metre long programming track at the front of the layout which is not powered of course and has no continuity across the left and right rails. 

Thanks for suggestions - much appreciated. If Prodigy disconnected from main line there is no oVLd message. Trying continuity across Left and Right rails anywhere on the layout produces a beep. Trying continuity between ANY left hand rail and ANY right hand rail anywhere on the layout produces a beep - even though the passenger set of rails and the goods shed set of rails are deliberately quite separate ie there is no set of points between them. Moving on to the DCC bus wires - there is continuity between left and right wires in both sets of choc blocks that terminate each end of the bus. That confuses the heck out of me - surely the choc blocks can’t be shorting?  I will upend the board tomorrow, reconnect the Prodigy with the board vertical against the wall, and disconnect the dropper wires between the choc blocks one at a time and see if the oVLd message goes away. After that there’s only replacing all 6 points with brand new ones modified again - I have 4 of the 6. I no longer have a DC controller so that angle isn’t available to me. 

PS. Every opposing pairs of points have IRJs where they meet, and the exit rails on every frog have IRJs to guard against wheels sitting across the the frog and running rails. Continuity check with multi-meter produces a beep when both left and right running rails are touched with the probes - but I can’t find a short circuit. 

Reply to DavidCBroad. Thanks for your comments. The layout size is inhibited by space available - I used to have an N Gauge layout in the same space. Sequence of construction was affected by Advance Prodigy 2 which was nil stock for over 6 months, then Cobalt SS points nil stock for a total of 9 months. So I either had to abort or mark time - my favourite activity is scratch building so I got on with the platforms and buildings whilst I waited.