Tomix EF-81 'stuttering'

[nah00]

I have a Tomix EF-81 that I got a few months that has an on and off problem. The first 10 or 15 minutes it runs at normal speed it will randomly slow down as if it's not getting enough power (lights dim and the motor sounds like it's straining) but after I run it for a while (or run it at high speed for a bit) it runs fine. It will start to stutter again after a while though (sometimes). 

 

The only other train I had this problem with was my Kato E6. It did it for about 5 minutes on and off but then I throttled it up and let it run for about 45 minutes and it never had the problem again. I've taken apart the EF-81, cleaned off the wheels and all the contacts, removed a bit of gunk from inside but I still have the problem. Do I just need a new motor or do I need to run this one in more? I've ran it for about 2 hours at high speed without seeing any stuttering but once I drop down to lower speed it will (eventually) return.

 

Any ideas?

[cteno4]

Ugh, the are the worst to figure out. You poked thru all the gears in the trucks for gunk and fibers and hairs, correct? Sometimes fibers can bind up around axles and slow down the get pushed aside with higher speed and back innat slower speeds. I've been surprised a few times when taking apart a truck that did not look too bad only to find hidding windings of carpet fiber, puzz or cat/dog hair. A pair of fine tweezers can sometimes find out if stuff is in the truck before tearing it apart, but some truck designs you can't see or get at where fibers pile/wind up. These are cheap and sharp for this sort of poking.

 

http://www.ebay.com/itm/1pcs-Stainless-Steel-Clips-Tweezer-Blackhead-Acne-Comedone-Remover-Needle-Tool-/332176712014?hash=item4d5746614e:g:lBsAAOSwhQhY00YI

 

Problem with fibers is they don't clean out with ultrasonic bath or blowing out usually has to be picked out or disassembled to get it all. I was amazed at the amount I was able to pull out of a few trucks, usually cat was involved...

 

Did you try any lubing after cleaning?

 

Could be motor brushes going, but the slow down seems more like something binding than stuttering of contact issues in trucks or brushes. I've not yet lost a Japanese train to a bad motor or brushes.

 

Good luck,

 

Jeff

[nah00]

I did find a bit of fuzz in the trucks and did add a drop of light oil to the gears inside the trucks. It really does seem like something is potentially binding the motor, it did have a lot of grease on the transfers from the trucks to the motor shaft some which was sticking/hardening a bit. I wiped some off but left most on.

[cteno4]

hmm, so did you pull the trucks all apart? might be some gunked up stuff in the axles and around all the gears that are binding. universal gear as well sometimes gets gunked up as they tend to use a heavy grease in there that sometimes can harden some or suck in fuzz and make a mess. motor seating as well as sometimes if loose it can get in a position where the motor shaft or couplings rub.

 

may need a total break down and cleaning with detergent and then isopropanol and then reassemble and re lube. its suspicious there was hardened grease in the transfer gear there. maybe gunked in the worm gear and its shaft as well and/or w/in the trucks.

 

this is why these are the worst as it means progressively trying things or just stripping it all down and cleaning and relubing to try to nuke it, but tedious and fiddly...

 

btw a cheap $25 ultrasonic cleaner works great for this sort of stuff. not battery powered ones, but small like 30-50w ones. dont need heated really as you can just use hot water in it.

 

http://www.ebay.com/itm/30W-50W-Mini-Ultrasonic-Cleaner-for-Jewelry-Glasses-Circuit-Board-Watch-CD-Lens-/322441464305?hash=item4b130249f1:g:VMoAAOSwTuJYumCE

 

tea strainers work great to hold all the small parts

 

http://www.ebay.com/itm/1pc-Stainless-Steel-Useful-Tea-Ball-Spice-Strainer-Mesh-Infuser-Filter-Herbal-/371808122267?var=&hash=item56917db59b:m:mIHcGPO6Zcz3JOTCpwYU4vA

 

you can get cleaner solutions but ive found soap and water and then isopropanol usually do great.

 

speaking of this i have to do all this with my old 922 ma dr yellow as its got something binding in it badly and their trucks are a $#%& to get off and apart to clean!

 

jeff

[beakaboy]

Just a slight possibility which I had with an older model some years ago. It made a slight noise as well from the motor area, so possibly not related. The magnets on motor or more specifically one side had come adrift from housing and would move slightly to bind motor. I used super glue to hold and seems to be holding up alright. I don't tend to run this unit for long periods due to chance of motor heat ungluing things. Also sometimes have issues with gunk on brushes and brush area, etc. However its  easy to lose things when taking apart.

[E6系]

H h hello,

 

Ju, ju, just b b b be p p p p patient and g g give it ssssssssssome t t t t time.

[nah00]

I didn't pull the trucks all apart for fear of losing bits but I think that's my next course, along with taking some of the extra grease off of the worm gear (there really as a lot on it, so much that it's working it's way all over the transfer into the truck). 

 

It is frustrating because it's basically take apart the whole thing, clean it, put it back together, problem is still there, repeat x 10. I did take the motor out and everything seemed to be in place but I will take another look at it this weekend. And I won't be surprised if this weekend it decides to run perfectly fine despite the fact I've done nothing.

 

Also does it matter that I store my locomotives flat? By flat I mean just in their cases but on the back of the case. 

[cteno4]

Nah,

 

Lol that's Murphy's first law of fixing things and the corollary is if you have someone else look at it it will run flawlessly when they try it. I call it my "touch" when folks bring stuff to me... it's very frustrating.

 

Sounds like you cleaned out the drive train everywhere but the trucks. It can be frustrating finding the binding point. Also worry of breaking something pulling it apart a lot.

 

Jeff

[nah00]

Yeah I am a bit worried about wearing out the pieces taking them apart and reassembling them but I'm going to give the trucks another go this weekend. 

 

Also I know about the magic 'touch'...like when a loco mysteriously stops and I duck under to get to it and the second before I touch it it pulls away not to stop again for the rest of the time I'm running. 

[HantuBlauLOL]

probably the electrical contact between the springs and metal chassis is dirty.

[nah00]

After leaving this on the back-burner for a while (changing jobs took up a lot of my time) I finally set to diagnosing this problem this weekend, and strangely enough the solution came with the older EF-81 I was able to pick up at the train show last weekend. 

 

The older one needed cleaning and I disassembled it just to make sure there was no gunk in the worm gear. I noticed there was hardly (if any) grease on the worm gear but yet after reassembly and a quick wheel polish and some drops of light oil it was running better than my problem child EF-81. So I decided I'd try one last thing before giving and ordering a new motor: getting as much of the grease off of the worm gears and housing as possible. Little bit of work with a toothbrush and warm water to clean them off, used a toothpick cut at an angle to coax some of it out. Put the whole thing back together and added just a touch of light oil and it was like getting a whole new locomotive. 

 

I figure what was happening was that there was so much grease it was seizing the gears either by getting small particles stuck in it or just it's natural stickiness. Explains why the locomotive ran fine after about 5-10 minutes of running fast but but would start stuttering again after 20 minutes at normal speed. Was able to have it basically crawl for close to an hour this morning which it's never been able to do.

 

Now I just need to get some new springs for the trucks, managed to mangle one pretty badly while not paying close attention snapping a truck back on. 

[cteno4]

Yeah hard packed old grease with lots of smutz mixed in can be horrid. Spot on cleaning it all out and starting over! Most of the worm gears need only a tiny bit of grease on them, I usually just use a thicker oil.

 

Jeff

[kvp]

This can happen with old new stock too as the grease (and the old maerklin oil) can harden with time, sometimes to a solid mass, jamming the drivetrain. No dirt is required for it.

[nah00]

This one definitely had what looked like a pea-sized glob mashed into both sides which was probably solidifying into a semi-solid mass and jamming the works. I'm lucky I didn't fry the motor before I figured out the issue. Had a similar issue with an Atlas MP-15DC but was able to cure the problem by running it at high speed for an hour, now it really crawls with no problems except an occasional stutter on a turnout.

[beakaboy]

good to hear you got the loco sorted. I had an interesting problem with a very early Kato EF66 recently. Got it with some other old EMU sets many years ago and had managed to get all the chassis running quite well considering their age and mileage. The EF66 had always been a problem as it ran quite slow at full throttle. I had stripped it down and cleaned everything and lightly lubed, but it still persisted in running slow and the motor would get quite warm. I was ready to consign the loco  to the  parts bin , but finally I had an in depth look at motor and turning the shaft, I noticed it was stiffer than usual and felt a bit rough. took the brushes out and springs were shorter than usual ones I have seen . Luckily I had a couple of spare longer springs  that came with brushes from Kato USA. These did the trick and the chassis is working quite well now. I have also noticed recently on secondhand items I have collected over the years, at least 3 chassis with cracked plastic yokes??  on motor shaft where the driveshaft pushes into. It seems as though the units have been stressed by gunk or hair ,etc binding the bogie gears. Tiny amount of Superglue in cracks seems to fix the issue for the moment .Just have to make sure I don't push driveshaft into yoke before glue has dried.  

[cteno4]

Interesting with the springs, wonder if they compressed with time.

 

I've had hairs get sucked into all parts of drive chains and cause bindings and stared the grease, oil, smutz build up as well into quite some masses.

 

When I first tried fixing Aaron's de10 tomix with the spring worm drive it was socked full of cat hair from his cat. The spring worm drive shaft was perfect to keep on reeling in more and more and more of it!

 

Jeff

[beakaboy]

Interesting with the springs, wonder if they compressed with time.

 

 

Possibility Jeff. I suspect too that maybe someone lost springs when dismantling and replaced with what they had available. The brushes themselves were only slightly worn down.