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Ian Wigglesworth
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750 Posts
Discussion Starter · #1 ·
Hi guys,

Just trying to fit a decoder into a N-gauge split chassis loco.

Virtually finsihed, the only problem is connecting the red and black wires to each half of the chassis.

There is no room for wires, although I could file a groove into the block, but where to attach them is a mjor problem.
I've read that someone who converted a split chassis managed to clean the black powder coating off and solder direct to the chassis!!

I find this hard to believe, the solder just wouldn't stick, I think you would need to braze the wires to it!!

Any suggestions, is it possible to solder to a chassis?

Cheers
 

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Just another modeller
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9,983 Posts
QUOTE (wiggy25 @ 29 Mar 2008, 19:29) <{POST_SNAPBACK}>Hi guys,

Just trying to fit a decoder into a N-gauge split chassis loco.

Virtually finsihed, the only problem is connecting the red and black wires to each half of the chassis.

There is no room for wires, although I could file a groove into the block, but where to attach them is a mjor problem.
I've read that someone who converted a split chassis managed to clean the black powder coating off and solder direct to the chassis!!

I find this hard to believe, the solder just wouldn't stick, I think you would need to braze the wires to it!!

Any suggestions, is it possible to solder to a chassis?

Cheers

***Hi Ian

You are right - the chassis block will not easily take solder directly...

(1) drill a small hole in each half wherever you want to attach the wires. If its in N and you had to groove the chassis for wire, make it at the end of the groove/within the groove.
(2) Slightly countersink the small hole with a larger drill bit.
(3) Drive a "pin" made of a brass pin, solid copper wire or even a steel panel pin into the hole so its a very tight fit.
(4) cut off flush with the chassis leaving just the bit thats in the cuntersink proud of the metal chassis
(5) Solder the wire to the "Pin". The countersinkk will let the solder sit below chassis level so it won't affect body placement etc...

Richard
DCCconcepts
 

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QUOTE (wiggy25 @ 29 Mar 2008, 10:29) <{POST_SNAPBACK}>Any suggestions, is it possible to solder to a chassis?

Cheers

On the Class 40, at least:

Just trap the wires under the screws (one each side) when you re-assemble the two halves of the chassis. There's no need to file grooves for the wires. On one side you have square recesses where there's a nut and there's plenty of room to get the wire under the nut. On the other side the screw head is in a circular recess but the body still goos back on whith the decoder wire in place. Decoder (MX620) sits on a piece of plasticard (for insulation) on the top of the chassis block.

Andrew Crosland
 

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Ian Wigglesworth
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750 Posts
Discussion Starter · #6 ·
Well, I've done it!

One of them anyway!
Not pretty, but it's hidden under the body and it all works.

Trying to do another split chassis, got the meter out, no shorts anywhere put it on the track and hey presto a puff of smoke!
Two decoders fried, thank you TCS for me being a Goof, decoders on there way back.
This loco is just about to hit the wall, I just can't find where the bloody short circuit is thats causing the decoders to durn out.
At this rate TCS will be out of decoders and I will single handedly have stopped them from ever doing a Goof-Proof warranty again!

It's days like this that makes you want to slap manufacturers for making it so bloody hard to fit decoders!

So I have one more decoder left....3rd time lucky????
 

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Administrator
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QUOTE So I have one more decoder left....3rd time lucky????

You /know/ the answer to this one, but I'm going to tell you anyway. Don't do it until you've stripped the litter beggar right down to its constituent parts and given it a good talking to. It's just the way these things go.

David
 

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Just another modeller
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9,983 Posts
QUOTE (wiggy25 @ 1 Apr 2008, 05:39) <{POST_SNAPBACK}>Well, I've done it!

One of them anyway!
Not pretty, but it's hidden under the body and it all works.

Trying to do another split chassis, got the meter out, no shorts anywhere put it on the track and hey presto a puff of smoke!
Two decoders fried, thank you TCS for me being a Goof, decoders on there way back.
This loco is just about to hit the wall, I just can't find where the bloody short circuit is thats causing the decoders to durn out.
At this rate TCS will be out of decoders and I will single handedly have stopped them from ever doing a Goof-Proof warranty again!

It's days like this that makes you want to slap manufacturers for making it so bloody hard to fit decoders!

So I have one more decoder left....3rd time lucky????

***it'll be a fine bit of metal like wire offccuts or a shaving from your drilling, a screw that goes in a smidgeon too far between the halves touching the other side, a wire attached to the motor thats stripped a bit too far and touches the chassis when the bodys on or a contact strip thats not properly insulated from the body.... either way it'll be there if you look hard enough.

change your meter range to a higher impedance and see if it registers then (instead of ohms, to K or meg ohms). Take care, Fairness has a part to play here and Goof proof has to have its its limits (If I have a customer who has multiple failures under goof proof, I insist on seeing the loco itsself and if necessary doing the install at the owners cost)

Richard
DCCconcepts
 

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Ian Wigglesworth
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750 Posts
Discussion Starter · #9 ·
Well,

took it apart a few more times and could find nothing wrong.

As a check connected the motor terminals to the DC controller, nothing!!
Put a meter across it, dead short..bloody motor, although it could have been me though if I had the soldering iron on it for too long.

Hey ho, check everything at least twice!!
I've done two others and they are running fine, just have to wait for a new motor and replacement decoders now.
 

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Paul Hamilton aka &quot;Lancashire Fusilier&quot;
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844 Posts
Thanks for sharing this with us Ian as this is the sort of personal experience we will all find of value as we also move down the path. Congrats on having the guts to give it a go.
 

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QUOTE (wiggy25 @ 2 Apr 2008, 20:11) <{POST_SNAPBACK}>Well,

took it apart a few more times and could find nothing wrong.

As a check connected the motor terminals to the DC controller, nothing!!
Put a meter across it, dead short..bloody motor, although it could have been me though if I had the soldering iron on it for too long.

What loco was it?

I've had two Farish 66s where the motor went low resistance after some time in service, frying at least one of the decoders in the process. There is a posting somewhere on here about it from a few months back.
 

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Ian Wigglesworth
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750 Posts
Discussion Starter · #12 ·
Edwin,

It was a Tomix 'James' N-gauge loco from the Thomas the tank engine range.
It did work fine, it may have been me holding the soldering iron on the motor terminals for too long.

LF,

No problem, hope it helps others out.
One thing though and I hope others will back me up on this, if you are going to try and fit decoders yourself then I would recommend the following:-

The controller you get must be able to read and write CV's and have a program track.
In my haste to see the locos running I just put them on my layout and ran them with the EZ command..very foolish!
I did test my installation but somethings get missed, as I've proven with two dead decoders!
If I had not rushed to run them and gone up stairs, I could have checked them properly with my PowerCab (this is how I tested the other two locos)
The PowerCab has a program track option which means only limited power goes to the track, not enough to drive the loco, which means hopefully not enough power to fry the decoder.
Using this I can write and read back CV settings which should give an indication if the decoder install is correct, the loco will give a jerk and I can read back settings I've just written to the decoder, if all is not what it seems the loco comes apart again!!
As a double check I then turn on the track current monitoring available in the PowerCab and increase the speed step by 1.
If it starts to go up too quickly and above 0.2amps the loco is off the track very quick, this normally saves the decoder from frying.

None of my N-gauge locos draw more than 0.15 amps even with lighting switched on or hitting a dirty bit of track, they all normally run about 0.04 to a max of 0.11amp when hitting a crappy bit of track work.

If you buy DCC on board or pay to have decoders fitted then not too much of a problem and the EZ command is fine, but if you do want to have a go yourself I can only give my advice as above.

Cheers
 
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