Spectrum DCC/Sound 3 trk Shay & insulated frog turnouts??

[Jim in Oregon]

My son & I are in process of building an HO layout and have the trackwork completed.
Code 83 Atlas flex track and Atlas #4, 6 & #8 INSULATED frog turnouts.
The largest "unpowered" length on the #8 turnouts is 2" in length, the other frogs are shorter.
All track joints soldered, underway is bussed with power to bus drops every 36".About 75 linear feet of HO track ona 6'x8' board with some 2% grades.
Track is clean, engine wheels and car wheels are clean, all NRMA gauged RP25 metal wheels.DCC controller is the NCE Power Cab.Most of the other DCC decoder chips are TCS.
I have an older DCC ready Spectrum 3 truck Shay that I installed a TCS decoder in a while back and it runs fine.
I recently got the new Spectrum 3 truck Shay with DCC & Tsunami sound.
What a great sound system!
We are in the process of gently breaking this new loco in and find that it stalls on many of the insulated frogs, esp at the slower speeds like scale 5 mph.A touch and the sound starts again and the engine goes.
Now the questions:

I was under the impression that the 3 truck Shays picked up track power from all three trucks which if true, puzzles us.It shouldn't stall even on the largest 2" insulated side of the #8 turnouts...but it does. IF we are running faster, say scale 15 mph, it goes over the insulated frogs OK.
Do you think IF we enable and set up the "dither"feature on the decoder that this might cure this annoying problem?
My older Shay doesn't do this.I have checked and the new sound equipped Shay is mechanically and electrically right with all trucks powering the motor thru the board-decoder.Trucks are not screwed onto the frame too tightly, allowing just a bit of rock 'n roll'when underway.
Any other suggestions?ALL his other larger 3 axle modern locos run fine on the layout and the trackwork is as perfect as humanly possible.Thanks for your thoughts, Jim & Caleb

[mattyg1306]

Jim,

Although I can not offer assistance or a remedy, I will say that I have had this rather ironic problem with ALL of my 5 Shays, and NONE of them are the newer tsunami sound version, but rather all are the older version (got quite a deal on most of them when the sound version was first announced.).  Also, like you, when I speed the engine up it does seem to cure the problem, and have wondered why the engine doesn't move well over the insulated frog while other engines with only two power wheel sets do it without problem.  I usually just "gun it" when I come to a switch, but this is annoying to have to sit and watch everytime it goes through a turnout, and if anyone has a solution, I also would like to hear it.  This is truly an ironic problem, because Shays are known (especially here in West Virginia) to go through lots of switches and switchbacks and over roughly layed track...they just aren't behaving like the prototype in this case, I guess...

[Jim in Oregon]

Matty, Thanks for the reply.
I have checked the points, point rails etc and the track is truly powered well and properly EXCEPT for the length of the insulated frogs on the turnouts.One thing I noticed on the Atlas Customline turnouts is that the frogs themselves are a full .005" higher than the rail on either side.
In other words, a steel straightedge laid atop right or left rail and over the frog will have the straightedge NOT touching both rails and frog..it'll be up and off one side of the track rail or the other.
SO, IF one has a truck whose left or right wheels get atop the frog AND the engine trucks ahead or following are attached stiffly, this can actually lift the whole engine frame so the OTHER wheel sets lift off the powered track causing a pause at best with flicker of lights or a stall at lower speeds.

Not sure why Atlas and Shinohara designed the turnouts this way..?

Anyhow, I CAREFULLY draw filed the frogs down several thousandths to get them more the same height as the adjacent rails and this helped.
I may need to go farther but it is painstaking work when one has over 16 turnouts already installed-soldered in place.

I have played around with the attachment of the trucks to the frames on my Shays so there is more, or less 'wobble'.
My common sense tells me that IF the Shay picks up positive rightside power from ALL the right side wheels on the three trucks AND negative left side power from all three trucks left side wheels that there's no reason the Shay should EVER stall on a 2" or smaller frog that is effectying only right or left side wheels of ONE truck.

But it does.
Maybe it's in the way the power is routed from pickups to board-decoder and engine??
I don't know and was hoping the Bach Man would offer some insights.
IF Bachmann( and Rivarossi AND Mantua AND others who make the steam locomotives are NOT building their locomotives so that ALL right side wheels pickup power from RS track and ALL left side wheels are not picking up power from LS track rail, THEY SHOULD BE.

Couldn't cost 50 cents more for the materials and labor to do this once the engineering was done for the parts and it was added to the production line operation.
Not all modelers who go to DCC want to wire the turnout switches and/or buy expensive switch machines just to be able to run a prototypical operationand cross an insulated frog turnout.

We are patiently breaking in the new Spectrum Shay and after sufficient time, will set it up with the Dither function so the engine sees tiny impulses of power even at low speed .This is the CV58 setting for frequency.
The we set the Dither "KICK" which is CV 57.This is the voltage of the 'kick' that the engine sees based on the how often frequency setting.
Using Dither function is recommended for older locotives that can be a bit hinky in their acceleration or speed curves and helps smooth them out.
For decoders that have a BEMF factory set function, generally the BEMF( back electromotive force) function is disabled to enable the Dither..which is more able to be fine tuned.
..This I hope will help alleviate the problem.

Anyhow, IF the BACH MAN or others who understand this issue have possible solutions we have not considered, please chime in.
Thans, Jim & Caleb

[richg]

I do not have this loco but have heard about this issue before. Below are two photos I found concerning what looks like this loco. The contact points for the truck power might be the issue.
I remember something similar in the older MDC/Roundhouse Climax/Boxcab locos and some people used #30 wires instead of the contact setup. A little corrosion can develop on the copper strips.




Rich

[Doneldon]

An easy workaround might be to put a capacitor in the system so the loco can cheat its way across the troublesome frogs.

[richg]

An easy workaround might be to put a capacitor in the system so the loco can cheat its way across the troublesome frogs.

Just sticking a capacitor in is not straight forward.

I have not seen a factory equipped with the Tsunami so I do not know if there is a stay  alive capacitor for the factory equipped models.
I do know the Tsunami decoders I and others have installed have a 250ufd stay alive capacitor that comes with the decoder but usually we have to add at least another 1000 ufd capacitor right across the 250 ufd capacitor and have to include a 100 ohm resistor and a diode or the decoder cannot read back to the controller.
Good and clean pickups, plus clean track is the best solution.

Below is a link to the stay alive issue. Store the link in Favorites. To my knowledge, the link does not address factory installations.

http://www.members.optusnet.com.au/mainnorth/alive.htm

Rich

[Jim in Oregon]

Don & Rich, Thanks for the interesting inputs.
Having spent the past 35 years in the electrical industry, I understand capacitors-capacitance pretty well..just not on such a small scale..
Basically, the capacitor setup supplies stored energy to carry over 'emergency' power to sound portions of the system and also if properly sized and the voltage-currenbt draw and duration are acceptable in parameters, to bridge track power gaps caused by dirty track or 'dead frogs'.

Sort of a miniature "uninterruptible power supply" for the DCC locomotive.
This all makes sense to me.It's the installation and sizing configuring that I need to study up on and consider.

When we decided to get into DCC, I wondered what the differences were in decoders from various mfgrs besides price, name and number of functions and milliamp capacity..

Looks like there are some mfgrs that are a bit more ahead of the curve in this regard.
Gotta wonder why more decoder mfgrs don't build in this feature..Mfgring price?space restrictions?
Lack the engineering technologie folks?
Jim