MTL Pass Trucks

[ljudice]

Are MTL 3 axle trucks swappable for 2 axle trucks in the paired window coach?

Thanks,

[bbussey]

The three-axle trucks with the semi-offset hole that were designed for the single-window coach may work.

[ljudice]

I wasn't clear - I want to turn a six axle to a four axle....

[bbussey]

Ah. I don’t think so, not without modifying the bolster locations.

[Lemosteam]

@bbussey , @Ed Kapuscinski and I did this on a MTL PC coach using my 2DP5 trucks. There is enough material in the shell casting (or underbody casting, I cannot recall) to move the pin location to where the end overhang is acceptable, proportionally. 

So I think any two axle passenger truck with a centered bolster hole will work.

[thomasjmdavis]

Here is the underside. Note that the center sill casting continues on past the bolster mounting.  The casting is solid and should support a bolster hole.  There is even a slight dimple there (at least on this particular one) to help center the drill- or not if it is not exactly centered. The one caveat would be that there is not quite as much bearing surface, compared to the intended location, but if that presents any issues, adding a bit of material to widen the casting would be easy enough.  Sorry for the crappy phone pics, but it's too early in the morning and I'm still on my first cup of coffee.



Here is a MTL 4 wheel truck under it at the revised location (this is not attached, so give or take 1/32 or so for my eyeball alignment):

[peteski]

The dimples are a result of not enough plastic being injected into the mold, and the area with the dimple also being relatively thick (requiring  more plastic).

Also, the actual bolster is part of the interior floor.  The underframe simply has a hole in it, and the bolster is just poking through it. You can see that the bolster has the same color as the car's interior (not the underframe).

If one wanted to duplicate that when moving the bolster then they would drill a hole through the underframe, then glue the "new" bolster onto the interior floor molding.

Easiest would be to just take a flush-cut razor saw and cut the original bolster off the floor casting.  Then drill the new hole in the underframe, and glue the cut off bolster back onto the floor casting, adding a plastic shim between the bolster and floor to compensate for the saw's kerf.

[Lemosteam]

The underframe works perfectly for a new bolster hole.  I have done it and if you center a 2mm drill in that square boss it positions the truck just right.  It has an added benefit, if you remove the underframe the trucks come along for the ride!

And actually the dimple is from material shrinkage because the material is too thick in that area.  It is not from no enough material being forced into the mold cavity.

[peteski]

And actually the dimple is from material shrinkage because the material is too thick in that area.  It is not from no enough material being forced into the mold cavity.

I guess we are basically saying the same thing: not enough material. But thanks for the clarification (I knew it had somethgin to do with the part's thickness in that area).  A sink mark.

But this whole thing makes me wonder why MTL decided to mold the bolster with the floor molding, not the underframe. It is a bit unusual.  If the wanted to relocate the bolster, they would have to modify 2 molds, not just one.  @MTLJoe : any secrets you can reveal here?

Still, cutting off the original bolster from the floor, drilling the hole in the underframe and gluing that bolster into it would be a quick and easy mod (rather than fabricating a new bolster from styrene).

[Lemosteam]

@thomasjmdavis 's method only requires drilling a 2mm hole.  The old boss does not need to be removed at all, if I remember correctly.

[peteski]

@thomasjmdavis 's method only requires drilling a 2mm hole.  The old boss does not need to be removed at all, if I remember correctly.

Good deal!

[ljudice]

Arrrrghhhhhh! Not what I wanted to hear  - my shaky hand isn't looking for a project....

Why is MTL using 3 axle trucks on PRR themed coaches?????

I could live with the MTL car as a P70 stand-in

[thomasjmdavis]

The dimples are a result of not enough plastic being injected into the mold, and the area with the dimple also being relatively thick (requiring  more plastic).

Also, the actual bolster is part of the interior floor.  The underframe simply has a hole in it, and the bolster is just poking through it. You can see that the bolster has the same color as the car's interior (not the underframe).

If one wanted to duplicate that when moving the bolster then they would drill a hole through the underframe, then glue the "new" bolster onto the interior floor molding.

Easiest would be to just take a flush-cut razor saw and cut the original bolster off the floor casting.  Then drill the new hole in the underframe, and glue the cut off bolster back onto the floor casting, adding a plastic shim between the bolster and floor to compensate for the saw's kerf.

To make that "easiest" you must have a very small razor saw.  No doubt somebody makes one....

The bottom edge of the car side is below the floor level.  To get a saw in flat to the floor would require a flexible blade saw along the lines of the Tamiya hobby pull saw, but with a blade width of less that the clearance between the bolster and the side, which is 0.216. My Tamiya is 0.40 wide, and so would need something 1/2 the width.

[peteski]

Oops!  It's been some time since I had a MTL heavyweight car apart.  I thought the bolster was part of the interior molding, bit it is molded in the floor, integral with the car body.  Of course in this case, finding a narrow razor saw would be quite difficult.  Never mind - looks like I had a "senior moment".

[ljudice]

Oops!  It's been some time since I had a MTL heavyweight car apart.  I thought the bolster was part of the interior molding, bit it is molded in the floor, integral with the car body.  Of course in this case, finding a narrow razor saw would be quite difficult.  Never mind - looks like I had a "senior moment".

so there are 2 paired window bodies???  Because some roads have 2 axle trucks....