Nikki & Frank S, loco to tender interconnect..

PhilP

PhilP

G Scale, 7/8th's, Electronics
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Would anyone have the original uses noted for the four-wire connection between the Nikki & Frank S loco and tender please?
Listed top to bottom (or bottom to top!)
 
Assuming my old sketch is correct, marked 20261 tender
Top Motor Green via DIP sw
2 Common, to PU Brown
3 PU & rear plug White
Bottom DIP sw to rear light
 
dutchelm said:
Assuming my old sketch is correct, marked 20261 tender
Top Motor Green via DIP sw
2 Common, to PU Brown
3 PU & rear plug White
Bottom DIP sw to rear light
Click to expand...

Thanks Mike, I'll use that as a start..

I have an early RC conversion here.. Rx in the cab, 3-wire (servo lead) to MAC5 in the tender, then it all turns into a bit of a 'rats-nest'! - Hopefully, the original wiring has not been mucked about between the loco and tender, and I can get it running.. .. Then fit new batteries and a Revolution set.
 
Phil, I would most certainly suggest testing out the connections with a Meter as well. Just in case!
 
dunnyrail said:
Phil, I would most certainly suggest testing out the connections with a Meter as well. Just in case!
Click to expand...

Oh yes!

But it gives me a start, as I am trying to avoid having the loco apart if possible..

In theory, I should be able to do all I need by attacking the tender behind! :giggle::giggle::giggle:
 
Had my one of these to bits, loco and tender. A weird system where the tender picks up power, sends it to a circuit board in the loco which sends it back to the motor in the tender along with the loco pickup and motor.
I have a bald patch just because of this loco :banghead:
 
pugwash said:
Had my one of these to bits, loco and tender. A weird system where the tender picks up power, sends it to a circuit board in the loco which sends it back to the motor in the tender along with the loco pickup and motor.
I have a bald patch just because of this loco :banghead:
Click to expand...

If you think of it as the older clam-shell 3-wire block, plus a feed for the rear-light...

Does that help? :think:
 
Not too sure Phil, however I did replace both motors. The original problem was that the loco and tender tried to run at different speeds, it turned out that one wire of the connector ribbon between the loco and tender was broken just at the connector to the tender (too much flexing, or I suspect the previous owner of pulling the connector out by tugging the cable) so I cut the ribbon back a bit and snapped on a new connector.
I also had a local carpenter make up a box with 45mm grooves so the loco/tender didn't have to be taken apart.
 
pugwash said:
Had my one of these to bits, loco and tender. A weird system where the tender picks up power, sends it to a circuit board in the loco which sends it back to the motor in the tender along with the loco pickup and motor.
I have a bald patch just because of this loco :banghead:
Click to expand...
Yes, I had the same perplexation with the Frank S version. I assumed the tender was broken because it wouldn't run independently. Spent a long time trying to troubleshoot it before figuring out the weird interaction with the loco. I was intending to put decoders in them anyway which I eventually did. 55021s in both. Pretty easy and now both can run independently as expected.
 
Didn't the original analogue Frank S/Nikki&Frank S models have some circuitry in them which reduced the tender's speed slightly to compensate for its tendency to try to push the loco along? I assume that is the reason for the "odd" wiring between the two....?

At some point I will need to look at chipping the NOS green one I managed to find a couple of years back - I haven't had one apart before, since my blue N&F came to me with two Massoth decoders installed by a previous owner, and my black one has LGB factory-installed DCC and sound.

Jon.
 
Zerogee said:
Didn't the original analogue Frank S/Nikki&Frank S models have some circuitry in them which reduced the tender's speed slightly to compensate for its tendency to try to push the loco along? I assume that is the reason for the "odd" wiring between the two....?

At some point I will need to look at chipping the NOS green one I managed to find a couple of years back - I haven't had one apart before, since my blue N&F came to me with two Massoth decoders installed by a previous owner, and my black one has LGB factory-installed DCC and sound.

Jon.
Click to expand...

They should be fairly close, speed-wise??
Not sure if LGB were that clever-thinking then?

With this one, the plot has thickened slightly..
It had an obscure RC receiver 'velcro'd' in the cab, and a servo connection into the tender to an early Brian Jones Mac 3(?).. It then had three packs of Strikalite 'C' cells (4.8V each pack) in series..

I lifted the (analaogue) LGB board in the loco, and it appears the wiring has been altered (green wire moved, and a short length of tinned copper wire bridged along a number of contacts..

All the bullets, extra busbars etc. in the 'blocks have been removed, and so power is fed-forward from the tender to the loco.. It appears the directional lighting is still controlled by the diodes on the original LGB board.

All this was proved by powering the loco by feeding a bench PSU into (what would have been) the output-leads from the Mac 3.

Interesting how technology has moved on.. The 'C' cell packs (NiCd) are rated at 1800mA, the replacement (NiMH) packs will be 'AA' and rated at 2300mA.
 
Yes, it turns out that speed matching was the reason for the strange wiring. With the 55021 decoders installed both my loco and tender run at the exact same speed, even without tweaking the decoders. I guess the back emf works well for that. I also have an early digital version of Niki Frank S that originally had the 55020 decoders. The loco and tender did not run terribly well together. Not very smooth. Replacing the decoders with 55021s solved that one too.
 
Sorry to dredge an old thread but it was relevant.

I've been running mine today (the Marklin mfx version) and it's a really poor runner. It constantly feels like the tender and body are fighting - domonatrated with periodic grunts. I have a single pair of crossover R1s to switch between parallel lines on my layout and even at slow speeds I can't get it to navigate them. It's a stunning loco and I want to run it more but whenever the inspiration hits me I don't feel I can put it through more than 1 loop...

I've got the LGB 24266 version - has anyone got any tips for getting this loco to the point I want to run it?
 
If you don't need the power you could just take the motor out of the tender leaving all the wiring in place for pickups etc. Bit drastic but it would resolve the conflict between the motors, if that is the problem, and if it doesn't it tells you the problem is elsewhere.
 
Hadn’t thought about that. You’re right, drastic but so is having a loco that I don’t want to run so I see where you’re coming from with the idea. The trains I pull aren’t that long so don’t think I need the full strength.

@Greg Elmassian , I’m running DCC. This came factory fitted with an mfx decoder.
 
Is there not a decoder in the tender, as well as the loco?

Tender is easy to open up and see..

I would check continuity along each side of each unit.

PhilP
 
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