double slip and bo-bo diesels...

[bluedepot]

hi everyone

i have installed my first ever double slip. i have used a dual frog juicer. all routes out have insulated rail joiners.

it needs more testing, but it seems to be working well with class 08 and 50, but sometimes the bo-bos (class 24, 25, 27) stop bang on the middle of the slip and the layout starts buzzing!! this occurs about 1 in 4 passes in one of the route settings and maybe 1 in 10 for the alternative route settings. as you can imagine this is v maddening!

any suggestions???!!

i will test again later on with some other classes of loco... 

cheers for any advice in advance!!


tim

[Dr Al]

Check all the central rails and point blades are actually powered - the frogs must be actively switched. Also, check for clearances - is there a short being created between wheel backs?

Cheers,
Alan

[bluedepot]

thanks alan - i think it may be clearances as it is sporadic and only happens with bo-bos...

tim

[Dr Al]

If you've anything shorter wheelbase (e.g. 0-6-0, shunter, 08, etc) try them - they will show dead areas more readily. Or go over every part with a voltmeter to check every blade, rail that should be powered is powered. Assuming that's all ok then you can look to other issues. But given you only see in short wheelbase locos, it's the first suspect in my book.

Cheers,
Alan

[jpendle]

Some questions.

1) DC or DCC?
2) Which model/brand of Frog Juicer?
3) Why did you opt for Frog Juicers rather than accessory switches to control the frog polarity?

Thanks,

John P

[bluedepot]

hi

my 08 runs over it fine.

it is dcc, tam valley juicers... i just found juicers worked v well to prevent short circuits on my old layout (on standard electrofrog points) so thought id use them again.

i'll test again toninght if i get a chance and see if i can discover what causes it.

cheers for your help


tim

[red_death]

It sounds like a short created by modern wheelsets falling into the frog crossing. You can try packing small bits of plasticard into the frog? There were details of how to do that on here or one of the N gauge Yahoo groups.

It is the problem of old track designs with finer wheelsets.

Cheers Mike

[bluedepot]

thanks for tip!

it is code 55 peco track

i suppose doing this to all frogs might help achieve smoother running through points as well


tim

[jpendle]

i suppose doing this to all frogs might help achieve smoother running through points as well

tim

In my experience, using long radius code 55 points, I have had no issues with any of my diesel/electric models running through points. BUT my Pendolinos (thanks Mike & Ben  ) all derailed taking the straight route through a single slip on my layout until I added some plastic strip and slightly re-aligned the slip versus the connecting tracks. The trailing power car derailed when pushing the train, it ran through the slip fine on its own, and when pushing carriages, but not when the leading car was pulling at the same time. None of the other locos or MU's that I tried had this issue, but then again none of my other stock has two motors.

On closer inspection I can see that the gaps on my Code 55 single slip are considerably larger than on any other points that I have and this is why the slips are more prone to cause issues with finer scale wheelsets.

Regards,

John P

[Izzy]

I believe the main problem is that the wheelbase of the bo-bo's roughly matches that of the two frogs and both fall into them at the same time. I found the same issue with the standard BR 20t brake van. They would 'ground' both wheels in the two frogs at the same time and get stuck in them.

I eventually changed to 2FS. That cured the problem.........but is of course not everybody's cup of tea....

Izzy

[Dr Al]

Frog drop shouldn't cause shorts (the whole frog and check rails should only be one polarity), but may cause conduction issues if it lifts other wheels off track. The loco should not stall though - none of my Bo-bo's do. I'd check that all loco wheels are actually picking up properly - if some wheels aren't actually picking up due to dirt or poorly adjusted pickups are in play, then that may be affecting things.

Cheers,
Alan

[PLD]

Just a thought; as it is apparently only Bo-Bo locos that encounter this issue, is it that the wheelbase of these mid-length locos is such that simultaneously they have one bogie on each frog, so the frogs are effectively electrically connected together via the loco circuitry, and this causes some conflict between the Frog Juicers (possibly inducing a 'false positive' in one) and in effect they both try to resolve the same short thereby inducing another short??

Can one frog be totally isolated (effectively making it behave as a dead frog) then try the locos through the slip...

[bluedepot]

thanks for all the excellent suggestions on this! people on here are so knowledgeable - without this forum i would have given up with n gauge by now!

yes the bo-bos i tried are about the same length as the double slip - so it could be some conflict with both frogs in contact with both wheel sets at the same time. or it could be frog drop.

i will disconnect one of the frogs completely later on and re-test and see what happens.

cheers

tim

[ntpntpntp]

.. my Pendolinos (thanks Mike & Ben  ) all derailed taking the straight route through a single slip on my layout until I added some plastic strip and slightly re-aligned the slip versus the connecting tracks. The trailing power car derailed when pushing the train, it ran through the slip fine on its own, and when pushing carriages, but not when the leading car was pulling at the same time. None of the other locos or MU's that I tried had this issue, but then again none of my other stock has two motors.

Interesting, as one of my twin motored Liliput multiple units is showing signs of doing the same through one of my single slips. I also have a recently purchased SudExpress Co-Co diesel that seems to like to split itself on one of the double slips on my loco depot that's under construction.  I've not had time to investigate in great detail yet as to whether it's a B2B problem or just ineffective check rails.  I have enough other stock that works perfectly fine, but it is annoying.

[BR Signalman]

I also use the Tam Valley Frog Juicers. In the instructions which came with them, (Which obviously, I cannot find!), there was a bit about frogs being too close together, which could cause a conflict in the device. I have noticed though that the V2 instructions on the Tam Valley site do not mention this now.