Large Scale Central

What's wrong with this ?

Electronics Power and Sound
#1

I have a monster little boxcab, made mostly of steel and therefore weighing a ton. I completely rewired it as performance was somewhat flaky but it made very little difference - every time it hit a bump (e.g. not perfect rail joint) it would stop and I’ve have to jiggle something to get it working again.

I finally figured out what the problem was. Can you guess from this photo?

(Oh, and don’t tell me it’s because the battery is disconnected at the plug on the right. I took the photo after unplugging it.)

#2

Oh, and this is what it looks like when it isn’t stopping:

#3

Pete Thornton said:

I have a monster little boxcab, made mostly of steel and therefore weighing a ton. I completely rewired it as performance was somewhat flaky but it made very little difference - every time it hit a bump (e.g. not perfect rail joint) it would stop and I’ve have to jiggle something to get it working again.

I finally figured out what the problem was. Can you guess from this photo?

(Oh, and don’t tell me it’s because the battery is disconnected at the plug on the right. I took the photo after unplugging it.)

Not real sure what the electirical problem is, but it does look like your engineer is refusing to go - maybe you just need to pay him more, or at least change management style. (https://www.largescalecentral.com/externals/tinymce/plugins/emoticons/img/smiley-foot-in-mouth.gif)

#4

Those slide switches aren’t real reliable. I’d check that first

#5

I’ll bite. Does it have something to do with the way the batteries are wired? From what I can see all batteries aren’t used. Not seeing hidden connections for battery pod.

#6

Pete Thornton said:

I finally figured out what the problem was. Can you guess from this photo?

I’m wondering if batteries are getting bounced out of holder; two on our right look to be displaced toward us from the contact points on holder.

And, yeah, at least get the driver an on-board coffee pot or something.

#7

Hit a bump and bump the switch to an intermediate position, then have to jiggle it back into position.

#8

Not being able to fully trace the wires, I cant say for sure. But if a colour code was properly followed, then why is a red and back wire, wire nutted together?

#9

David Maynard said:

Not being able to fully trace the wires, I cant say for sure. But if a colour code was properly followed, then why is a red and back wire, wire nutted together?

I believe that is the disconnected battery connector, not wire nuts…

#10

Pete,

What is going on with the three RED wires at right center above a black doodad opposite side of grab irons? What are the red wires connected to? Looks like they need to be all connected together?

I note the battery negative feeds into a terminal strip of sorts, with jumpers interconnecting all black wires. Something loose therein?

Michael

#11

I agree, it’s the battery on the far right that is almost out of contact.

Greg

#12

Pete,

I just noticed it looks like the battery holder appears to be damaged from heat above the top of the cell on the right side? Perhaps high resistance presented itself at the intersection of the cells negative pole and spring tab creating enough heat to disfigure the plastic and reduce conductivity of same…

Michael

#13

John Caughey said:

Those slide switches aren’t real reliable. I’d check that first

My guess as well.

#14

Battery holder, second from the left upper contact appears to be missing, at least it’s not through the end and flared over like the others

#15

Since there is a new battery holder outside the engine, it could be because the batteries are standing up vs. lying down in the holder.

I doubt there are any missing contacts as the symptom is interrupted service, not a lack of.

#16

Well, John nailed the issue, and lots of you got close, but not how/why the actual problem is caused. Here’s the solution I came up with - now what was wrong with the old set up? Hint: maybe you guys aren’t too familiar with the physical characteristics of LiIon 18650 batteries?

P.S. I haven’t actually tested this to prove it solves the problem! But I am pretty confident it will.

#17

Pete Thornton said:

Hint: maybe you guys aren’t too familiar with the physical characteristics of LiIon 18650 batteries?

Correct deduction; I have never used them and it has been about a decade since I’ve done anything with rechargeable batteries, or radio control.

#18

well don’t hold us in suspense, which guess was it and did it fix the problem!!

#19

The batteries are dense and a sharp bounce could depress a weak spring allowing a battery to break contact. Horizontally there is no such condition.

What did I win?

#20

Not real sure what the electirical problem is, but it does look like your engineer is refusing to go - maybe you just need to pay him more, or at least change management style. (https://www.largescalecentral.com/externals/tinymce/plugins/emoticons/img/smiley-foot-in-mouth.gif)

Almost missed that one, Bruce. He’s actually sitting back as the boxcab has the latest “Automatic Train Control”. It even beeps if the engine tries to veer out of its tracks.