Something Slightly Screwy Here...

[dto]

Here's a "head's up" for Bachmann and customers interested in the new lower freight car underframes. 

After considering the possible options for lowering my freight cars (Bachmann's low archbar trucks, sawing off the bolster nubs, etc.), I purchased two sets of the new underframes.  Installation couldn't be easier -- remove the two screws holding the trucks, and the original underframe falls out.  (Just remember the orientation of the vacuum brake components when dropping in the new frame.)  No instructions are needed -- even adding the bolster adapter brushings for those using the low archbar trucks seems self-explanatory.  Coupler boxes are also modified to remain at standard HO height, so you can hook up original and modified cars.

However, after installing the new frames I noticed my boxcars leaning at drunken angles.  Apparently there is too much "play" with the trucks.  The new bolsters are trimmed flush with the surface of the underframes, but the screws are the same length as the originals.  I had to recheck to see if I didn't accidentally use the original set, but all screws are the same length.

The screws pass through the trucks and the bolsters, into sockets in the car bottom.  Since this is a dead-end, you cannot sink the screws deeper to compensate for the shorter underframe bolsters. 

A simple "fix" for future Bachmann production runs would be to substitute shorter screws, with a notice to low archbar truck owners to use their original screws (I don't think shorter screws will reach through the bolster adapter brushings.)  Another possibility are washer inserts for the original trucks. 

(Again, I'm assuming that this glitch is common for the entire production run, but perhaps I just got a batch that escaped quality control.)

If other modelers have the same problem, drilling past the dead-end in the car bottom might work, though you'd probably go right through and ruin the flatcar and gondola decking.  (This shouldn't be a problem with boxcars.)  Finding shorter screws is of course the ideal option, but I don't know offhand if any suitable replacement is available if Bachmann doesn't have any in current inventory.  I'll probably scratchbuild sheet styrene washer inserts to go inside the trucks -- I don't think hardware stores will carry that particular size.

But whatever option you choose, DON'T try to cut the screws down to size!  These are hardened steel, so you'll probably won't be able to do so without ruining the screw thread (and whatever cutting tools you're abusing).  And then there's the danger of flying shrapnel... 

Granted, this is a minor issue, and I'll continue to convert my frieght cars with these sets.  But I thought this notice might be useful. 


DTO

[Tim]

DTO

check out this thread.

http://www.bachmanntrains.com/home-usa/board/index.php/topic,6766.0.html

Addendum to my original post.

The washers I refer to are #3 flat washer.

The screws can be shortened more than the 1/16" for open cars or add washers.

The truck bolster needs to be chamfered on the top to ride better on the post.

Clearing the hole in the truck bolster with a #20 drill also improves the truck operation.

CAUTION: Do not use a power drill to clear the bolster hole!  It will grab the plastic  and

you will ruin the truck bolster.

Have fun

Tim L. Anders
Souderton, PA

[dto]

Thanks, Tim!  I'm surprised I overlooked that discussion thread -- I wondered if anyone else noticed the screw issue before my post.  I'll start looking for #3 washers ASAP.

One question about chamfering the truck bolsters -- since this makes the now-tapered end of the underframe bolster post fit better inside the bevelled hole, won't this lower the cars even more?  I'm slightly concerned about maintaining coupler heights.

Thanks again!

DTO

[Tim]

DTO

Chamfering the bolster doesn't have a noticeable effect on car/coupler height.

It allows the bolster to seat properly on the bearing.

As for cutting the screws, I used a dremel cutoff wheel for the major cut

then used the face of the wheel to true the end of the screw.

Hope this helps

Tim L. Anders
Souderton, PA