Atlas SD-60 help!

I have a few of these units and just lately I have had one of them begin to give me trouble. The engine has a decoder and when it is on straight sections of the layout it runs great but in corners it slows down. I have taken the trucks apart, cleaned them and all contact points with no success. I switched out these trucks with a set from another unit and it ran fine. Anyone with any clues. Your help is appreciated.

Bryan

 

Wow! I was going to post the exact question this AM. I have the same problem and tried all the same things. Only does it on right-hand curves though. Mine is non-DCC. I've even played with adjusting the wheelsets to more-narrow...nope. It's definitely a friction-type problem...not electrical conduction. I've even tried a long-term break-in run....naw, no help. I think it's the gears that protrude through the bottom that are causing it. I think that, on curves, they slide a bit laterally and rub on the sides of the holes. Not sure how to fix it...lots of gear grease does not do it : (

Russ

[ 11 January 2002: Message edited by: tehachapifan ]

 

Russ,
That makes since! When I was disassembling the trucks I had some trouble putting them back together because of a little plastic piece that hooks them together was rubbing on the gears. I had taken these apart before to weather them and ever since the problem has existed. I wonder if I could file them down some so there would be a little more room? Just a thought. I also re-gauged the wheels to make sure that they were not moving so much. I may give this a closer look. Also when mine began it was just one way until I began working with it more than it was both.
I will keep you all posted if I fix it sounds pretty common.

Bryan

 

I had the same problem with a GP 40-2.Ican't say for sure what the problem was but I think the motor itself developed too much play in in.(Take the motor out and see how much you can wiggle the shaft.)Try swapping the motor out of the one that runs fine and see if it now runs OK.If so,It is time to get a new motor.By the way,mine only slowed down on left hand curves.
Now if only I can figure out how to quiet them down.....

 

I have the same problems with my two non-DCC SD60's. First off, I don't know what kind of blackening the wheels have on them but the wheels on these two units are DIRT MAGNETS. None of my other locos get coated with crud faster than these two. The contact problem on curves is just that. A contact problem. The little leaf springs that are supposed to pick up current from the metal tabs on the top of the trucks are to long to make good contact. The only real fix for this is to solder copper strapping (wire), from the truck tabs to the chassis halves. This is one of the many things on my to-do list for the future.

 

I guess I was in the same boat. The coating on the wheels definately causes poor contact. As far as DCC locos, there is an inherent problem with contact (as well as on the GP40-2's). Our club website has some easy to follow procedures to correct this problem at: http://www.trainweb.org/nrmrc/dcc/plugnplay.html Note the problem is more of an issue if a non-factory decoder is used.

Harold

 

Trust me,check the motor.Mine ran fine for over a year,then started to slow down on curves.Swapped motors and not a problem since.All the coating gets rubbed off my loco's wheels running them with my Katos pretty fast,so I know this was not the issue,And I run straight DC,so I know (in my case)it's not a decoder proglem.

 

I didn't realize this was so common. As for the thoughts on it being the motor I don't agree. As stated earlier I place different trucks on this unit and it ran fine in the corners. Contact for the decoders is a pain I agree I have even connected the tabs with solder on some units. Not the best design. If anyone from atlas visits this forum we sure would like some answers form you all about this question.

 

Well, and I thought it was just me as well. I sat down at an exhibition last year and pulled three of my DCC SD60's apart trying to resolve this issue.

The contact's to the decoder on the top of the frame are definetly a problem, as are the contact strips from the frame to the trucks. I have been told of other modellers soldering wire to the brass nubs on the trucks to eliminate the problem.

Dirt is definately a problem for SD60s, the coating on the wheels is I believe as has been discussed the source of a lot of problems, as is the build up of corrosion on the pick up strips and trucks nubs.

 

ITS THE WHEELS! I have finally had the time to sit down and work this problem out. What I did was disassemble the trucks and pull out all the wheel-sets. Next I pushed all of them as close together in width as possible. Now using my NMRA guage I re-adjusted the wheels to scale. Only this time I only moved the wheel nearest to the gears. If you pull this wheel away from the gears it helps them ride more in the center of the axel and thus they won't rub on the plastic housing on the trucks. It solved my problem. I would error on the side of making the width more wide than narrow. Hope this helps.

Bryan

 

I think you are right bmalonef45. A customer told me that he takes the wheels apart on his Atlas locos and puts small brass washers made by Hob-Bits, (I can't remember what size he said) on the inside of each wheel. He said that this made better contact because the inside of the wheel is closer to the contact tab and brass conducts better. I have since used a Trix wheel cleaner to scrub the coating off of the wheels on my two SD-60's. I'd like to try this other technique sometime myself to see how it works.