changing the new Lionel GG1 to run on smaller radii THAN 072

[AlanRail]

THEORY!!

In reviewing the way the GG1 takes in a radius curve it struck me that the engine trucks had a lot more give that it was giving; meaning that although the front trucks jumped the track on entering a slightler smaller radius than 072 the allowable angle of movement on the trucks seems capable of smaller radii turns.

So I asked myself; "Self, ( I do talk to myself on occasion; you need to be concerned when you start answering yourself as well); if I can loosen the front truck assembly where it connects to the articulated set of wheels , I can "maybe" give it a little more play."

The inner set of articulated trucks are connected to the front trucks with a secondary assembly; this secondary assembly allows the coupler to move somewhat independently of the front trucks; but not completely.

In effect the articulated set of wheels controls the front trucks unlike the new MTH & earlier LIONEL GG1s where the front trucks are completely dis-associated from the inner articulated sets.

I THINK, the point is to disconnect the secondary assembly from the articulated set of trucks so that the front trucks can move freely.

I need to investigate further the linkage assembly between the two sets trucks.

Alan

[spankybird]

Alan,
talking to yourself isn't bad, even answering yourself is bad.

Having an agurment with your self and LOSING is BAD.

[lionelsoni]

The postwar GG1's unpowered outer trucks are pivoted from the powered inner trucks. There is a hook on each truck running in a slot in the floor whose only function seems to be to keep the truck from dangling too far from the body when the locomotive is lifted off the track.

[AlanRail]

Bob

on the new GG1 there is another connection between the inner set of articulated wheels that connects the coupler with the outer trucks; ( the coupler is separate from the outer trucks) this piece seems to limit the movement or rotation of the outer trucks so that on curves slightly less than 072 this piece will not permit rotation of the outer trucks beyond 072 with the inner articulated wheel set.

The proposition is to somehow free the outer trucks to rotate greater and allow a slightly tighter that 072" diameter before derailing occurs..

This secondary linkage is sprung loaded twice; once at the truck and once more at the coupler. Also it seems that the direction is key too. only the front truck in the direction of motion derails.. could be the weight is too great and with the forward motion it doesn't allow the front truck to rotate as much.

Alan

[lionelsoni]

I meant only to point out that the traditional GG1s are articulated much as you described the new one.

One important detail about that articulation is that it is not a simple pivot, but uses a slotted hole so that the unpowered truck can move sideways to some extent. This is essential for handling a transition in radius and could explain why the leading truck is the one that derails for you, if the slot is too short or absent on the new GG1.

[Anonymous]

Alan,

Does it derail when turning to the left and turning to the right? The one I tested only derailed when turning to the right. I did not have a chance to examine it well, but there was a rod running from the left front of the pilot, back to left front side of the power trunk. There was another rod on the right rear (if there is a front and rear on a GG1). This rod seemed to tie the pilot to the power truck and restrict movement of the pilot truck. Is this correct? This rod does not appear on any prototype photos that I have seen.

Again, I did not pick the model up, I only ran it.

By the way, the previous MTH Premier GG1 will not negotiate 054 curves (at least my old one will not). The new one will handle the 054 with ease. I do not know if this is an anomoly with my old GG1 or if this is normal.

[Anonymous]

I have the Lionel GG1 and while I love the train, I can't run it on our club's layout. The curves are 072, however the tracks are not perfect. My train derails, front trucks only, just as described in this thread. I was wondering if anyone was able to figure out how to modify the design to allow for slightly smaller radii, thus perhaps making up for the trackwork. Note, the trackwork is good enough to run everything else that club members bring down, it's just this GG1 that is picky.