Trains constantly slow down and speed up

[Steventrain]

Like the title says, both of my locomotives are constantly shifting speeds. Ive changed the track layout, where the controller plugs into the track and the problem still persists. Both my locos, track, and controller are somewhat new, so I’m confused as to why this is happening. I thought it might be because of kato trains and tomix controllers not meshing well, but my other tomix train has these problems too and this problem only started happening a few months ago.

 

power unit: tomix 5517-pu-n-du101-cl

trains: kato 2017-7 c62, tomix 98769 hikari rail star

 

[bill937ca]

Have you cleaned the track?

 

Cleaning UNITRACK:
Kato recommends using a plastic compatible liquid cleaner. For stubborn spots, paint or glue on the rails, we recommend a soft rubberized abrasive “eraser”. Track cleaning cars are also available. Some are designed to use liquid cleaners, some with abrasive rollers or pads, and some equipped for both. We do NOT recommend constant use of abrasives. You can find any of these cleaners and cleaning tools at your local Hobby Shop or Hobby Supplier.

 

Items not recommended include: sandpaper, steel wool & cleaning pads (used for cleaning pots and pans), and any liquid not compatible with plastic, or is of a caustic chemical compound.

https://katousa.com/keeping-your-track-and-trains-clean/

Edited September 29 by bill937ca

[bill937ca]

Previous track cleaning threads. Track cleaning is just one of basics of model train operation.

 

 

[cteno4]

Steve,

 

Tomix controllers for the most part work fine with Kato trains and if it was a issue it wouldn’t be slow down and speed up like that. 
 

Slowing up like that is usually caused mainly by two things; dirty track, wheels, and contacts and voltage drops.

 

Have you tried cleaning the tracks well with a low dielectric contact cleaner like wd40 contact cleaner (not regular lubricating wd40)? Most of the black gunk that builds up on track is oxidized metal that is created from microarcing from the wheels to the track. The microarcing is facilitated by high dielectric stuff like water and alcohols (traditionally used to clean rails) that end up in the micro pores of the rails and wheels. Using a low dielectric contact cleaner helps displace the high dielectric stuff with low dielectric stuff and reduce the microarcing and also protect the track into the future.

 

At times also some of the internal contacts in the train can also get dirty and/or out of alignment and will slow down and speed up depending on the movement of the mobile contacts on the wheels and bogies.

 

Voltage drops occur mainly from the track joints. Here small amounts of contaminants in the joiner and rail end joints give a bit of resistance and thus voltage drops. A few questions on this:

• When you moved your power feeds around did you notice the slowdown/speedup areas followed the changes at all? If it’s due to voltage drops then the train should speedup around the power feeds.
• How many power feeds do you have and what is the length of your track in the layout?
• Have you tried using any other trains or power packs?
• Have you tried concentrating your power feeds to one side of the layout to see if it runs well in the power feed side?

This is the same car that took the drop from the high place and got a crack in the shell? If so this could be from something now getting out of alignment in the power train of the motor chassis. Some motor cars with age and running will get a bit stuttery in their running. This is harder to suss out and usually is fixed by totally tearing the motor car mech apart and cleaning everything and carefully reassembling it to see if you can isolate any problem contacts, parts, or alignments. Unfortunately it’s the sort of skill you have to learn by trial and error and just doing it. There are lots of YouTube videos out there showing opening up motor cars and disassembly in general and sometime you get lucky and find one on your train exactly to follow.

Try track cleaning with the proper high dielectric contact cleaner first and let’s look at your power feed number and location.

 

jeff

[cteno4]

The WD40 contact cleaner has been like magic on our club tracks! Isopropanol was our old go to but it would get you into a vicious loop of leaving isopropanol behind to cause more arcing and more crud to clean! I did one heavy cleaning a few years back of the club modules and usual member modules and now it’s just a light wipe a couple of times a year and little is there.

 

Another clue to microarcing causing crud is i find some areas where scenery (streets around rails) and some track joint areas that are not nice and flat and engines sometimes will get a tiny pause or tips is where you see gunk appear the first and heaviest. 

 

jeff: