Arnold BR 42 Thread

[mike_lawyer]

I decided to split off the discussion of a potential 2-10-x chassis from Randy's Trix 2-10-0 build.  I have one on order that I should receive next week.  I will post measurements of the drivers and spacing so that we can discuss whether this will be a good, modern chassis for 2-10-x builds.

[wm3798]

The followers of the Fireball will be watching with interest.

Lee

[mike_lawyer]

I found a video in German of a guy who super detailed one of these locos.  When he disassembled the loco, you can see that it comes with a coreless motor with a flywheel.  The motor sits inside.the boiler.

One of the difficulties I see is that the boiler for the BR 42 sits up higher than a North American loco.  That may pose some problems if I have to "lower" the motor to fit under a GHQ or Minitrix shell for an I1 conversion.

I am supposed to receive the loco on Monday, so I will see how it is assembled.

[peteski]

One of the difficulties I see is that the boiler for the BR 42 sits up higher than a North American loco.  That may pose some problems if I have to "lower" the motor to fit under a GHQ or Minitrix shell for an I1 conversion.

Is it possible that the boiler diameter of the American loco is larger than the German one?  If that is the case, and you make a new boiler, being larger diameter, it could appear to sit lower in the chassis.

[mike_lawyer]

So I received the Arnold BR 42 in the mail today and had a brief opportunity to run it on my Atlas C55 layout.  There are some good and some problems for using this mechanism for a 2-10-0 conversion:

1.  The engine is very smooth and quiet running.  The mechanism is very solid as a base mechanism.  I have not opened it up, but the motor is virtually silent.  Very impressive.
2.  Three of the drivers are driven by gearing, while two are driven solely by the siderods.  The 3-5 drivers are driven by the gears, while the 1-2 drivers appear to be sidebar driven.
3.  Driver 3 is a traction tire driver.  I expect that pulling power will be fairly strong given that the traction tire is on a gear driven driver, although I have not tested it.
4.  The fine details on the valve gear are very nice and much improved over the old Trix decapod mechanism.  It ranks up there with the quality of the BLI Mikados and the Bachmann 2-8-0.
5.  The driver size is only very slightly smaller than the drivers on a Kato Mikado.  Not enough to really notice side-by-side.  The drivers might be 1 mm or less smaller diameter.  Spacing between drivers appears good.
6.  The downside - The pilot truck, and it appears two of the drivers (1 and 5) are not Atlas Code 55 compatible.  Neither are the tender trucks, although for a conversion, I would use a Bachmann Spectrum tender, so that's not a real issue.  I suppose I can just grind down the flanges on the two drivers and replace the pilot wheel for a 2-10-0 conversion.

The bottom line is that this engine is a great chassis, but it is not Atlas C55 compatible right out of the box.  I also have not disassembled the locomotive to determine if there are any frame modifications that will need to be made for a conversion, such as possibly the need to lower the motor housing to allow a North American boiler to fit on top.

[peteski]

Sounds good Mike.  Considering what other modifications would have to be made to it, high flanges on the leading and trailing truck wheels (but not on the drivers) seems like very minor inconvenience.

As for comparing its valve gear to BLI and Bachmann locos, while they have similar level of detail/complexity, I think that Minitrix uses etched metal parts, while BLI and Bachmann uses stamped metal which is not as fine looking.

[mike_lawyer]

Sounds good Mike.  Considering what other modifications would have to be made to it, high flanges on the leading and trailing truck wheels (but not on the drivers) seems like very minor inconvenience.

As for comparing its valve gear to BLI and Bachmann locos, while they have similar level of detail/complexity, I think that Minitrix uses etched metal parts, while BLI and Bachmann uses stamped metal which is not as fine looking.

Pete, I will have to grind down the flanges on drivers 1 and 5, as they are also too large.  So that will take a little work.  But that should not be too much of a problem.  I will need to tear apart the boiler to see if any additional modifications are needed.  But overall, this is a great mechanism that I would recommend as a solid basis as a chassis.

[peteski]

Pete, I will have to grind down the flanges on drivers 1 and 5, as they are also too large.  So that will take a little work.  But that should not be too much of a problem.  I will need to tear apart the boiler to see if any additional modifications are needed.  But overall, this is a great mechanism that I would recommend as a solid basis as a chassis.

I didn't read carefully enough.    Hopefully it will work out.  That would make it a nice running and looking loco.