Some background. I purchased a used Atlas SD-38 at York in October of 2018. The engine is equipped with TMCC, sounds and electro-couplers. But no cruse control. There in lies the problem. When negotiating the 0-36 turnouts on my layout the engine stalls at low speed. I can get the engine to go through the turnouts only by raising the speed to a unacceptable level. Plus engine does slow some going through the curves on my layout no matter the diameter.

 

So my dilemma is. Should I upgrade the engine with a ERR board to get the low speed control and constant speed control? And can I use the sound board that is already in the engine instead of purchasing a new one? Or should I just sell this engine off and by a new one? I would probably have the same amount of money invested in the engine either way. Purchase price plus upgrades vs the cost of a new MTH or Lionel engine. 

 

Any ideas or suggestions would be appreciated.

 

Dave

Original Post

I have the SD35 too.  It would be pretty easy to pull out the TMCC board and replace it with a Cruise Commander.  When you look in the engine, if the sound board is separate than the TMCC board, you should be able to use it with no issues as mine is a Railsounds 4.0 board and I have several engines with this combination (Cruise Commander and RS 4.0 Board).

I haven’t checked that particular section of curved track since it’s in a tunnel. And I’ve checked the other curves too. They all read around 18V. My other engines without cruse control don’t seem to have this problem in the curves.  I will test it to see. BTW I did clean my track to see if that made any difference. It didn’t seem to. But I wanted to eliminate that possibility. 

I'm not sure why, but I distinctly remember the first run of TMCC Atlas O SD-35's, a PRR version in particular, would also slow going into curves on a hobby shop layout. It was the primary reason I didn't buy one.  (And, yes, I am talking almost 20 years ago.   )

Fred

You should measure track voltage with a load(loco) on it, noting if voltage drop  is consistent with what voktage drop is on the next/previous RR tracks when tested .

"Still trying to not shoot my eye out"

 

"Nursing insomnia one railcar at a time"

My aroma therapy? Smoke Pellets.

 





A different perspective- upgrading, you know your current engine is sound. 

But, based on recent experience (by myself and others) the chances MIGHT be that a different locomotive (NOS or used) might not run as well as the one you have.  Then you would have TWO unsatisfactory engines, and far less money than the cost of the ERR upgrade.

Is it an SD-35? What is the product number? Doesn't it have the TAS EOB system factory installed?

http://archive.atlasrr.com/OLoco/arc-osd35.htm 

TMCC Features:

  • EOB™ Speed control technology
  • Lionel TrainMaster Command Equipped featuring RailSounds™ digital sound system (including horn, bell diesel-roar sounds, etc.); Crew Talk (in command and more...
  • RailSounds™ operates in both conventional and command modes in 3-Rail.
  • Operating electro-couplers
C&O Allie posted:
BobbyD posted:

Is it an SD-35? What is the product number? Doesn't it have the TAS EOB system factory installed?

http://archive.atlasrr.com/OLoco/arc-osd35.htm

It depends on the model.  My SD35 (the Chessie version) had a simple TMCC board in it and no EOB.

As Marty always said "Give us the product number!!"  

Our Williams and MTH Protosound equipment have no cruise and run pretty constant speed wise.

Per Atlas' Website, this Engine has EOB.  You can make sure that the Cruise Control is enabled to see if that helps.  I don't remember the keystrokes to enter off the top of my head, but I can get them for you when I get home as I have their manual in my trainroom.  But I am wondering if the website is wrong because I did not think EOB yet existed in 2000.

C&O Allie posted:

Per Atlas' Website, this Engine has EOB. 

Trust me.  That's the first run.  No cruise control whatsoever.

Now, the odd thing. I seem to remember the center wheel sets on each axle could be blind, or possibly flanged.  Might have been a set in the box for changing them out either way. Are all 6 axles flanged by chance?

Walmart_Tom made an interesting point about wheel sets being in gauge as well.  That could be the issue.  Maybe it's in-gauge for Atlas track but is having a problem other manufacture's track?

Fred

Fred Brenek posted:
C&O Allie posted:

Per Atlas' Website, this Engine has EOB. 

Trust me.  That's the first run.  No cruise control whatsoever.

Now, the odd thing. I seem to remember the center wheel sets on each axle could be blind, or possibly flanged.  Might have been a set in the box for changing them out either way. Are all 6 axles flanged by chance?

Walmart_Tom made an interesting point about wheel sets being in gauge as well.  That could be the issue.  Maybe it's in-gauge for Atlas track but is having a problem other manufacture's track?

Fred

Fred,

That is what I thought based on the date.

Dave,

In general terms, early TMCC before Lionel added Cruise Control always slowed down on curves because having solid axles and having wheels with Traction Tires, the inside wheel and outside wheel are going the same rotational speed.  Like the squealing you hear when 1:1 trains go around curves, the engine will slow down because depending on whether the inside wheels or outside wheels have the most traction, they are trying to overcome the slowness (out side wheels) or fastness (of the inside wheels) and without the Cruise Control, the motor will be under more stress and will slow down.  Cruise Control counts the steps (or the motor amperage for ERR Cruise Commander) and adjusts the power to the motor to keep it at a constant speed.

For 1:1 trains, the squeal you hear is one of the wheels "slipping" on the rail as the other maintains traction.

So for the upgrade, look at the boards in the engine and snap a picture.  Then post it here and we can tell you what you will need for the upgrade.  

Dave,

FYI, the reason I ask for a picture is that older TMCC engines had a single board set and not a separate set.  For example, here is a board pulled out of an older Atlas Engine (RS1) which I assume is what you have, so you will need both the Cruise Commander and a new Sound Board you can get from 3rd Rail.

TMCC

Attachments

Photos (1)

Looking at the whole story, I would not recommend upgrading until you diagnose and fix what is physically causing the engine issues.  Sometimes it 's merely the newness at fault and a longer run in period is needed to loosen things up.   Otherwise, whatever the cause, an electronics upgrade will help maintain speed but be constantly straining to do so.

An ERR cruise commander can sure produce a jewel out a smooth performing tmcc loco.  Gotta have a healthy patient to begin with, though.

Bruce

Completely designed with your mind in mind.

When you say "stall," I presume you mean that the loco is still getting track power, but it stops moving because torque isn't sufficient to overcome the friction at very slow speeds.  The root cause is a poor, toy-like gear ratio combined with fairly small motor(s), and there's no easy way to change that.  As Allie mentioned, modern-era practice of putting rubber tires on both sides of the same axle doesn't help.  Yes you could install ERR or PS3 speed control, but that's tantamount to putting a big band-aid on a fairly serious wound.

Atlas wants to sell trains, and technically your loco will make it around O36.  But I'll bet most folks who buy these have O72 curves and switches, or more likely, dream of building an O72 layout.  If you're stuck with O36 and determined to run six-axle, scale-sized road diesels through that crossover, I would sell it and get something with Legacy or PS3.

Creep, coast, and pull.  We're not talking about cold fusion here.

ncdave posted:

And yes I’ve had the body shell off to see if there was a problem with the wiring.  The wiring looks OK. No binding of any kind. 

Can we see a picture of the boards in the locomotive to verify what package you have?

Ted S posted:

Yes you could install ERR or PS3 speed control, but that's tantamount to putting a big band-aid on a fairly serious wound.

This sure confuses me, as this band-aid is applied to virtually all the current command products, even down the the Lion Chief Plus line.  It's hardly a "serious wound", it's simply how it works. 

FWIW - I have an Atlas O SD35 PRR.  It also slowed noticeably going through 042 curves.  Installed a CC-M and a new radio board and it runs fine now.  These locomotives have a great foundation from which to work.  I would not hesitate upgrading another one.

Tom

Unlike the first issue tmcc type previously pictured, the configuration in your engine is easy and economical to upgrade by swapping in a cruise commander M board.  No new sounds are required so it virtually cuts the upgrade costs in half.  The new board gives you added lighting features too.

Bruce

Completely designed with your mind in mind.

Bruce is correct, the CC-M is a simple upgrade for this locomotive.  You will want to replace the R2LC as that one is the -07 software, the CC-M wants to see the -08 or later software.

Well, the CC-M is an ERR product, so 3rd Rail ERR Products is obviously the place to find that.  You'll also see the R4LC board there, it's compatible with the R2LC and has the right software.

Some Atlas, and this is one had OEM Lionel install.  So changing out the DCDR with the CCM gives you cruise.  But I do think you still have to look at the stall issue first.  No way that can't handle an O-36 curve.  Things are tight in an atlas diesel.  Does it run better with shell off.  How are gears and cleanliness.

If you switch to C08 you might have to reverse some wires for the lighting effect, since all the Atlas I have worked on used LEDs and polarity of the output will matter.   G

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