Atlas O RS1 stuttering issue

I can't say I have seen this exact issue but know this engine has TAS EOB. EOB does exhibit some odd startup and slow speed behavior. If you go to the TMCC section of the forum, to the last sticky on the first page you can scroll down until you find the TAS EOB full installation instruction manual. Download the manual and near the end are various keystrokes you can try, some of which are used to try and smooth out the startup behavior. Worth a try.

My first thought was this was a driveline issue but the fact that it smooths out after a few seconds sort of rules that out.

Pete 

Some of the Atlas RS1 models were standard TMCC without speed control.  RS1 may have been one of the first EOB speed control models.  If you can see the flywheel with optical sensor, it has EOB.  

EOB installation manual from the OGR files.   Adjustments are near the end.  Adjustments/setting and control, ( starts Page 28 of this manual). They are lengthy, be patient.  Click on the underlined phrase to link.   Note:  Clean wheels and contact pick-ups are the start point.  These RS1 models tended to have a lot of paint on the wheels and wheel flanges . IMO,  Mike CT.  

The speed ramp-up, start, is not linear, more like exponential, takes a while to get use to this, IMO,  Mike CT. 

One of the problems, this late date, is that adjustments were done with a Cab1 handheld remote.   I don't have Legacy, I guess you would have to attempt adjustment in Cab1 mode.  Early to mid 2000, a long time ago.   

I have the exact same trouble with CNJ RS1.

Seems after I run it for awhile it straightens out...its like it has to “warm up”.

@Norton posted:

"I can't say I have seen this exact issue but know this engine has TAS EOB. EOB does exhibit some odd startup and slow speed behavior." "My first thought was this was a driveline issue but the fact that it smooths out after a few seconds sort of rules that out."

Pete 

Pete, we have an Atlas engine with EOB TMCC and it exhibits the same behavior and not had a chance to attempt the manual adjustments. The ones with equipped with ERR don't seem to have any issues.

ERR has always worked well for me. Unfortunately upgrading from EOB or SAW pretty much requires scrapping all the TAS boards. I tolerate the oddball behavior of EOB until it dies, then I will get rid of it.

Pete

One other thing about these Atlas RS-1s is everything is very crammed inside and these have to be one of the hardest engines to get apart without breaking something. Besides the screws there are numerous hidden tabs.

Because they are so crammed its common for wires to rub on the flywheels. This may have something to do with the low speed stuttering but it will take some effort to verify that.

Pete

Billbarman,

I have an Atlas RS-1 of the same generation as yours and had the same problems with it. Stuttering at low speeds and seemingly working OK after running it a while. It is equipped with EOB. It's not an EOB problem, its a power pickup problem.

I contacted Atlas when I first got the engine and Bill S. told me they had found something wrong with how the wheels were made which caused them to have power conductivity problems between the wheels and the outside rails. Their solution was to clean the wheels and then apply their conductive lubricant to the wheel tread. I did that and it helped, however it didn't take long for that lubricant to wear off and the stuttering problem returned.

Some years later I bought an Atlas dummy SD35 which came with an extra geared wheelset (I guess in case you ever wanted to power the unit). I installed that wheelset and transplanted another wheelset from the SD35 into each truck of the RS-1. Again the stuttering problem improved but I still had problems with power dropouts going through some Atlas switches and through somewhat dirty track.

Some years later again I found a junker later production RS-1 with two pickup rollers on each truck. This time I transplanted the trucks off the junker to my older RS-1. Problem fixed! The engine runs reliably at low speeds with no warmup running and no stuttering.

So my solution was to replace the original trucks with ones from a later production engine with extra pickup rollers. Not a very practical or easy answer to the issue. Getting the newer trucks would be difficult and actual work involved replacing them is not easy and would require another long explanation. The RS-1 has got to be the most difficult to work on engine I've ever encountered and mine has been a lemon until relatively recently. If you want a recommendation from me, it would be to sell it and if MTH made an RS-1 in the roadname you want, buy that.

Ken

 I ordered 2 of the very first Atlas RS1’s offered. The good thing. One never made it to the dealer. These were pre EOB.  Worst running engine I’ve ever owned. Had probably 4 useable speed steps. Thought of going with EOB. Before I decided the engine locked up. No fault of the engine. A piece of ground foam lodged in the exposed gears. While diagnosing I figured I’d remove the shell. After a half hour I gave up. I knew then this engine wasn’t a keeper. I ended up trading it for a DCS set.

 I love the looks and sounds of the early Alco’s. I’m sure the newer Atlas versions are much improved if they have 4 pickup rollers and ERR. I’ve since acquired 3 MTH versions. Maybe not at the detail level of Atlas. I have to agree with Ken. Great runners and sound at an attractive price.

After reading this thread I got my early RS1 out for the first time in about 5 years and ran it. Started right up and ran slowly like ERR Cruise for about a foot, stopped then started on its own and ran another foot and stopped. Turned off TMCC and saw it was drawing about 4 amps in conventional and running very slow even at 12volts so I took it apart.

Found one of the axle bearings had gummed up. Applied some oil and worked it in and now it draws .7 amps running light with the smoke off. Much better. That might be another thing to check especially if you can monitor current and see its over 1 amp. Traction tires are close to the brake shoes but were not rubbing.

Back together. I guess this what they are capable of. TAS EOB with single pickup roller on each truck.

Pete

Always loved that engine Pete. It should’ve been!

Jim, our friend Bob could make it a reality. Just start an MTH version instead. Maybe request one from MTH. They have been doing a lot of obscure roads lately.

Pete