Having just completed the final stage of track laying, I though that I'd try to resolve an issue that has been a problem for some while.  I have one turnout out of 10 in my fiddle yard which just refuses to switch frog polarity correctly. I've used exclusively Cobalt IP Analogue motors in the fiddle yard but have ended up having to use frog juicers because of unreliable switching of frogs. So the Cobalts simply operate the point blades but polarity if switched by frog juicers. The problem seems to be that the point blades on one turnout (I have not modified the turnout to be "DCC friendly") switch the frog polarity correctly but the juicer seems to be not working correctly, or only partially, and is fighting the polarity switch from the point blades. They work o.k. in one direction, but not the other. I've fixed a new "dropper" to the frog. I've tested by putting a piece of paper between the point blades and the stock rails in each direction and I get a very limited feed to the frog from the juicer. Is it possible that the defect is with the turnout itself?  I am coming to this conclusion but am reluctant to remove the turnout and replace it, in case there is another explanation.

Dump the juicer and temporarily use an external switch. If that works consider  using the accessory switches in the Cobalt, I've never used a Cobalt but I assume it has switches built in like a Tortoise.

A juicer is overkill especially if you have wired the frog.

Regards,

John P

John
Thanks for that - I'll give one of the other switches a try. Because the Cobalts are so bulky and close together in the fiddle yard, it was difficult to position them accurately.  With the limited blade throw in N gauge this meant that some weren't switching the frog polarity reliably, even after removing the over-centre springs. That was why I decided to go for Juicers. Doing as you suggest would certainly be a good way to see if this particular turnout is defective.  In completing my layout, I reverted to non-switched SEEPs (which I find easier to position) and Juicers.  Those are all working perfectly!
Regards

Doug

Hi

Could it be that you have not got quite enough movement on the point motor so its not giving full contact on the moving rail, try lowering the motors fulcrum to give more movement. you could also try re-fitting the over centre spring, (You did keep them didn't you) the Cobolts are strong enough to move a 55 with spring.

Did you disconnect the the frog from the built in switch before connecting the juicer ?

Paul

John & Paul.

Thanks. When I installed the Cobalts, I left the over-centre springs in place.  It was after I started getting shorts that, following advice from DCC Concepts, I removed them.  There's no chance of replacing them as they were removed from on top by brute force, with the trackwork fixed down! Although I disconnected the frog "droppers" from the Cobalts, I left the Power Bus connections in place and I now believe that was part of the problem. Having re-read "An Introduction to DCC", I noticed the reference to the possibility of an internal short in the Tortoise/Cobalts due to faulty switching. I then disconnected the Power Bus connections.  That stopped the shorts when I used a redundant Mono Frog Juicer, but not when I reconnected the Hex Juicer. However, the frog switching wasn't working with either.  I then connected the problematic turnout to a different Hex Juicer output and it worked perfectly! So, it appears that I do indeed have an faulty Hex Juicer output and also a faulty Mono Juicer, as well as internal shorting in the Cobalt switch!

For my latest (last for the current layout) I have reverted to using unswitched SEEPs and Frog Juicers. In N Gauge, I find the very close proximity of Cobalts in areas of complex pointwork makes it very difficult to position them accurately.  Also the self-adhesive mounting pads don't help because they grab too quickly and make fine adjustment of position difficult.

Regards

Doug

The over centre springs go in from the top on the 55 points, I just fitted 6 new ones to mine and they are all fixed down.

Paul

I do not understand what is causing your problem, have you modified the points by cutting the links to the switch rails,then connect a wire to the frogs then to a switch. That is what the experts will tell you to do.
I have had the opposite problem to you, I had Peco motors and switches and because the points only move a small amount  the switching was eratic to say the least. I then changed to Cobalt anolouge motors with their in built switches and have not had a problem since. I have not modified my points apart from adding a wire to the frog. Where I have two motors in close proximity I reverse the motors to make more room, you have to make sure the point motor is centralised like most motors when using switches. There are more on here with problems with Seep or Peco motors than Cobalt with switching problems especially Seep, some have resorted to mounting the motor away from under the board with spacers.

Paul

Thanks. I couldn't initially work out how to remove the springs but did read that they are best removed from underneath before installation. Only the corners of the springs were visible (and then only in a very string light!) and I simply hooked them out. From what you say, it sounds as though it should have been possible to expose them before removal? I was reluctant to remove them in this way and did, in fact loosen one set of point blades by doing so.

Regards

Doug

Some of the instructions are quite confusing often tslking about removing plastic covers from the top, or metal covers from underneath, but on my 55's they come out and go in from the top.  I suspect some off the confusion is because instructional videos on YouTube etc don't always mention what gauge is being worked on and they might all be slightly different.

Chris

Thanks for your comments.  My points are completely "unmodified". The problems that I had were, I think, because of my failure to get some of the Cobalts correctly centred.  This was because with "nested" passing loops (if that makes sense) in my fiddle yard, the Cobalts were extremely close together. I could not reverse mount any because the points were too close to the edge of the baseboard. In the end, I used a mix of "conventionally mounted Cobalts, some mounted horizontally using 90 degree adaptors and some fixed to the baseboard framing. Although the Cobalts come ready centred and I wedged the point blades centrally, I still found it very difficult to accurately mount them.  The self-adhesive mounting pads did not help because they grabbed instantly and limited the scope for fine adjustment of position. I had someone assisting me by watching for the operating rods to emerge through the tie bar holes but I think that some of the operating rods were being slightly bent because of the difficulties under the baseboard.

When I started to operate the points with the Cobalt switching wired up, I began to experience short circuits with some of the points.  The team at DCC Concepts were very supportive and (although all points threw fully) they suggested removing the over-centre springs. They suggested that this might, because it would prevent sudden movement of point blades, overcome the shorting. I did remove all the springs and actually remounted a couple of the motors.  In the end, I decided to install frog juicers and these overcame all the shorting problems except for one set of points which always shorted when the blades were in the thrown position.

After much further testing (and advice from Kevin at Coastal DCC) I determined that the frog juicer indeed had one defective output (as I suspected when I started this thread).  This was tested by connecting the faulty turnout to a different juicer output. The juicer has now been replaced and all turnouts are now operating correctly with no short circuits.

Following this experience I have now reverted to the use of non-switched SEEPs with unmodified Peco Code 55 points and decided to exclusively use frog juicers for frog switching. I've just completed installing another 6 sets of points, which includes a reversing loop, using this approach. I do find it easier to install the SEEPs and they have the advantage of cheapness. Using Hex Frog Juicers brings the total cost back up, of course, but this latest installation is still cheaper overall and there is much less wiring to worry about.

Regards

Doug

Pleased to here you have it sorted, I used a hex juicer on my Peco points with peco motors before I replaced them with Cobalt motors. I still use Peco motors in my fiddle yard,most of the points are insulfrog but a couple have been replaced with live frogs with a hex juicer. They are good for a reverse loop if you need one.