# How do I isolate Rivarossi GG-1 motor



## musicwerks

Dear chaps,

I have done several hard wiring of decoders onto old hornby and bachmann, I just cant figure out Rivarossi GG-1 

I had been studying the frame and motor. There is a ring metal contact from the motor to the metal tracks and wheels. 

Most of the other locos I DCC, I just cut off the metal contact with a cutter (a piece of brass strip mostly).

Now for the Rviarossi GG-1 the contact is a brass cylinder from the motor stuck to the metal frame of the front trucks. It seems that I have no way to isolate the motor from the frame. Is the motor eletrcially connected to the front trucks...how can I find out?? I have been wrecking my brains, I still cant figure it out :smilie_daumenneg:

A merchant did DDC jobs for Rivarossi GG-1s, thats what it looks like

http://www.dccroundhouse.com/DCC Backshop Examples.htm


Can anyone help? How can I isolate the motor from the tracks of Rivarossi GG-1?

Anyone DDC old Rivarossi GG-1 before. Help...

Musicwerks


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## DonR

Really surprised that no one with experience converting
the GG-1 has responded. 

I googled Rivarossi GG-1 and got several links some of which
describe what you should do. One titled: Need Help - old 
blue Rivarossi GG-1 has several suggestions.

I have never seen inside one. But there are some 'rules'
that apply to just about every DC loco.

The way I understand old DC loco motors were often grounded to
the frame for one side power pickup from wheels. Could that
connection by the 'brass cylinder' you mention?

When you inspect the wheels, those on one side
will have wipers of some sort connected to a wire. The opposite wheels will
not, most likely these are powering the frame. You should
see a wire from the wipers going up into the loco. That
is the other side. That would be connected to power input
on the decoder. A wire from the frame would connect to
the other decoder input. The decoder motor control wires
would both go directly to the motor.

Others have pointed out you must isolate the motor from the
frame so that it gets power only from the decoder. Some have
used electrical tape between the motor and frame. The bolts
holding it on would also need to be so they don't feed power
from the frame.

The headlights would be connected to the decoder light
wires.

Now if this works for you it would be a miracle since I have
no idea that I am all that much correct.

Don


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## musicwerks

*Thanks*

Hi Don,

The cylinder doesn't seem to link to any part of the 2 motor contacts except to the shaft of the motor.

I may try to do a connectivity test using my multimeter on DC tracks to see if the cylinder carries current.

If I can DCC the Rivarossi GG-1 without frying my DH123D, I will put a picture up for all to see as a reference.

Cheers
Kiong


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## musicwerks

Dear all,

I tried to DCC the Rivarossi GG-1 with DH123D. Well I didnt fry any decoder but the connection can't work for DDC to happen.

I have difficulty trying to find the connection to the trucks. I have tried many possible connection points to the front and back truck. 

I just can't get the current connection to the trucks.

Its horrible...I can't DDC Rivarossi...I have given up.

Kiong


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## DonR

Kiong

I just don't understand why one of our members who have had
experience with the GG-1 hasn't come in with help.

I feel like I'm just stumbling around in the dark and going on
assumptions and hope.

But, since this is a DC locomotive it's gotta have power from
both rails and should be a simple circuit to the motor and lights.

Have you tried using a 9V battery to test the motor and drive
system? 

Is the motor screwed to a metal frame? 
Since this is not your first decoder installation you
know about isolating the motor from the frame.

You say there are the 2 tabs on the motor for power.
One must be connected to a wire that leads to wipers
on wheels of one side.

Is the other tab connected to a strip attached to the
frame or to that brass tube you mention?

(since the rotor of the motor runs on bearings in the
motor frame any metal contact with the rotor shaft
and the wheels could defeat any isolation but if the
tabs go only to the brushes it may not matter)

Can this brass tube be mechanically disconnected, 
temporarily, to check whether it is used as a
power conduit?

There may also be a secondary wire to goes to
the pantographs so they can be used for power.
That can be ignored for now.

Otherwise it should be straightforward to find the
wipers on one side with a wire to the motor and lights.

If the trucks are metal, as is the frame, that is the
other side of the circuit it would seem to me. Somehow
the frame is connected to the other motor tab.

Determine all of that before you connect the decoder input.

Can you post pics of the loco with the shell off showing the
motor tabs and the tube you describe? And perhaps a close up
of the underside maybe showing the wipers?

And stay with us...it's gonna run soon.

Don


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## mopac

I am with Don. There has to be a way. Is there just 1 wire to motor? If so
then you know it has to be isolated. I have some rivarossi E8s but they must
be different than your GG-1. My frames are plastic so no isolation problems.
Some pics might be helpful. There has to be a path for power to get to your 
motor.


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## mopac

This should encourage you. This shows that dcc can be added to rivarossi GG-1.
It just does not show you how to install.

http://www.youtube.com/watch?v=pNn-GZAhkp0


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## musicwerks

mopac said:


> I am with Don. There has to be a way. Is there just 1 wire to motor? If so
> then you know it has to be isolated. I have some rivarossi E8s but they must
> be different than your GG-1. My frames are plastic so no isolation problems.
> Some pics might be helpful. There has to be a path for power to get to your
> motor.


Thanks for the encouragement, I haven't given up totally. I am just not as optimistic as before.

Cheers


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## musicwerks

Hi Don,

really appreciate your patience and support

Kindly review my replies



DonR said:


> Kiong
> 
> 
> Have you tried using a 9V battery to test the motor and drive
> system?
> 
> (Yes I have tested the motor and it runs with a DC power pack)
> 
> Is the motor screwed to a metal frame?
> 
> (I am not sure if the motor is really screwed to the frame but I read that the motor can be removed from the truck frame- so there must be some contraption or screws that secures it)
> 
> Since this is not your first decoder installation you
> know about isolating the motor from the frame.
> (Actually, I am still kinda confused with isolating the motor. Am I right to say its the contact points rather the actual motor housing that needs isolation? I am not clear here.
> 
> 
> You say there are the 2 tabs on the motor for power.
> One must be connected to a wire that leads to wipers
> on wheels of one side.
> 
> I couldn't find any leads to the wipers except some brass contacts in the centre of the engine that looks suspiciously like wipers. I am not sure.
> 
> Is the other tab connected to a strip attached to the
> frame or to that brass tube you mention?
> 
> (That other tab is connected to some brass sandwiched (hiddern) between the lead weights and the plastic frame in the centre of the locomotive. I wonder if these are the wipers
> 
> 
> (since the rotor of the motor runs on bearings in the
> motor frame any metal contact with the rotor shaft
> and the wheels could defeat any isolation but if the
> tabs go only to the brushes it may not matter)
> 
> Can this brass tube be mechanically disconnected,
> temporarily, to check whether it is used as a
> power conduit?
> 
> (I can try...)
> 
> There may also be a secondary wire to goes to
> the pantographs so they can be used for power.
> That can be ignored for now.
> (I did think of the pantographs alternative, it seems alot clearer..but problem is I don't have any pantographs on my layout at all.
> 
> 
> Otherwise it should be straightforward to find the
> wipers on one side with a wire to the motor and lights.
> 
> (I cant find wipers in the truck. The entire truck assembly is made of metal with metal axels and wheels...so I figure that the metal truck assemble acted as the wipers and replaced the wipers)
> 
> If the trucks are metal, as is the frame, that is the
> other side of the circuit it would seem to me. Somehow
> the frame is connected to the other motor tab.
> (I am not sure either )
> 
> 
> Determine all of that before you connect the decoder input.
> 
> Can you post pics of the loco with the shell off showing the
> motor tabs and the tube you describe? And perhaps a close up
> of the underside maybe showing the wipers?
> 
> I have severed many wires along my DCC trials (I am not even as sure if the loco can be resoldered to run in pure DC now)...But I will try.
> 
> I am attaching a old rivarossi diagram
> 
> And stay with us...it's gonna run soon.
> 
> Don


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## musicwerks

Hi Don and friends,

I am attaching interior view of another similar Rivrossi GG-1 which I own in its original DC state. 

The unit I tried to DCC is FUBAR...

See that sliver looking cylinder between the motor and the frame...





















See that silver nipple-like thing below. I soldered my red and black wires of the decoder to the each of them front and back of the engine...thinking it might be the contacts to the truck...nope that didnt work either. 




























Cheers 

Kiong


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## DonR

The pictures will be a big help. Give us some time to
study them. 

Don


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## shaygetz

Because those two brushes are wired, it's likely already isolated. Take a multimeter set to ohms or a continuity tester and touch one brush and then each wheel down one side, then the other. Repeat for the other brush...if the tester doesn't light or the meter peg out, you're good.


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## musicwerks

Dear friends,

I have successfully DCC rivarossi GG-1!!�� and I am going to share my method on the forums.

The brass cylinder carries current from the metal trucks to the motor. The metal cylinder is the front part of motor casing and the entire metal casing of the motor acts as an electric contact to the left tab on the motor contacts. 

To dcc, we must cut the brass contact from the metal motor casing to the left tab on the motor. 

I will post the pictures up shortly!

Thanks to Don, Mopac and Shay who had been helping and encouraging me thus far!

Kiong
Misicwerks


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## mopac

Congrats. Glad you got it going. This stuff will frustrate you some times.
Part of the fun. LOL.


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## DonR

Where there's a will...there's a bunch of rich relatives...

Any way...glad you got 'er done.

As a traction fan, the GG-1 was one of my favorite
locomotives. Alas, my midwestern layout doesn't
have any electrified lines.

Don


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## golfermd

I similar issue with my Rivarossi E-8A. My underframe has a slightly different configuration in that there is no separate ground post. So, if I am reading the previous posts correctly, the motor is isolated from the frame and all I have to do is remove the positive and ground leads from the motor can and use those as my track input leads to the sound board. Or am I wrong?

Underframe:










Engine Can:










Light Post:


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## mopac

Your light will have to be disconnected and wired to your board.


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## musicwerks

Thanks Don for the detailed steps you PM me. 

Cheers


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## musicwerks

Hi Golfermd,

I see in your picture 2 that you have cut off metal contact from the motor casing to the tabs.

You need to solder the decoder motor contacts to the 2 Leds on the back of the motor. One truck input (to rail) to the metal contact you have by the side of the motor and the truck input contact to the light post which goes to the front truck

The bulb needs to be removed from the post and solder a light LED/ 12v bulb to the lights output or your old bulb with the resistor .

I just dcc the exactly same loco last night. It worked okay but the loco wasn't a good runner so I may convert back to dc


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## golfermd

musicwerks said:


> I see in your picture 2 that you have cut off metal contact from the motor casing to the tabs.


These pictures are exactly how I got the locomotive, so I haven't done anything to it yet (including cutting anything). The person who had it before ran DC. I've ran it in DC mode and it ran great so it should do well in DCC.


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## musicwerks

Maybe I haven't seen clearly. You will need to look at the motor and cut the metal contact from the metal motor casing to the power tab.

This is a segregate the motor leads from the truck contacts.

Rgds


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