LGB's American Standard Gauge 1/29 Scale Trucks & Mods for Car Lowering

LGB's American Standard Gauge 1/29 Scale Trucks & Mods for Car Lowering
Ted Doskaris
Rev. GE-A
February 15, 2017

The LGB Freight Truck - as factory equipped meant for American Standard Gauge Cars

Contents:

Preface
Modification Overview
Equalization
Truck Modification
Truck Disassembly
Fabricated Bolster Components
Sideframe Modifications
Truck Assembled with Replacement Bolster

Preface

The German company, Lehmann Gross Bahn, (LGB) trucks to be described and illustrated are used on LGB's American standard gauge 1/29 scale cars.  A typical example truck is shown below.

Trucks can be of different colors and have plastic or metal clad wheels

LGB's truck has molded-in emulated roller bearings and spring packs and as such do not mechanically function.

The LGB truck's appearance resembles a prototype ASF / Bettendorf friction bearing type but for its molded-in emulated roller bearings.

The closet resemblance of the LGB truck to a prototype that I found thus far is to a Barber-Bettendorf caboose truck, except for spring pack & longer scaled up wheel base.  So it seems the LGB truck is at best modeled on an obscure combination of prototype components.

Modification Overview

The LGB truck with some work and time can be modified to lower an LGB car for a more prototypical height from the railhead, particularly desirable since this facilitates installing Kadee body mount centerset type couplers.  The lowered truck as modified could, also, be used on other brand 1/29 scale cars when using body mount couplers.  Accordingly, comparisons are mostly made with an Aristo-Craft Barber roller bearing truck that serves as a "bench mark".

The essence of the modification is to lower the LGB truck's bolster (by replacing it) with respect to the side frames to be similar to that of the Aristo truck and many other brand trucks.

For example, by replacing the LGB truck's bolster it can be more like an Aristo-Craft truck.
Shown below is a measured comparison with respect to Aristo's Barber truck.

Shown below is a measured comparison with respect to Aristo's Bettendorf friction bearing type truck.

Equalization

The LGB truck affords a limited amount of equalization by allowing one of its sideframes to vertically pivot with respect to the truck bolster so that a car can traverse less than ideal track work.

For cars equipped with modified trucks, the trade-off is lost equalization should a car be operated on poor track work.  By design, equalization is afforded in the factory LGB truck with one of its side frames having a crowned pocket that allows it to pivot with respect to the attached bolster, providing the bolster attaching screw is not too tight.  Some out-of-the-box LGB cars made in China exhibited this.

For example comparisons, other brands like Aristo-Craft & some USA trains trucks mimic prototypes by using miniature coil springs that when not too stiff afford equalization, whereas, some other USA Trains & AML trucks with molded-in springs virtually have no equalization.

Truck Modification

Only the truck's sideframes will be retained.  Wheels will be replaced with smaller diameter and heavier Aristo-Craft metal wheels or other brand metal wheels that contribute to lowering a car.  Aristo metal wheels (ART/CRE-29111 types) are heavier than either LGB's plastic or metal clad wheels, and as such benefit the car's operational stability in a train traversing tighter diameter track curves.

Using Aristo's smaller diameter metal wheels contributes to lowering a car by about 0.025 inch, which is discernable with respect to aligning Kadee body mount couplers with a Kadee 980 gauge.  For exact wheel measurements, see Greg's  "Wheels & Trucks" page (Scroll to table for dimensions of Rolling Stock wheels).

Truck Disassembly

The truck is to be disassembled in preparation for later installation of replacement bolster components.

Fabricated Bolster Components

Illustrated below are dimensions of the replacement bolster that includes a metal bracket and plastic "H" spacer.  The bracket material is steel and the "H" spacer material is ABS plastic obtained from TAP Plastics.

Sideframe Modifications - if needed

When using modified LGB trucks, some car applications require additional side frame rib trimming so mounted trucks can freely pivot with respect to underframe obstructions.
 
LGB American standard gauge cars using modified trucks not requiring trimmed-off ribs include the Modern Tank Car and Center Flow Hopper Car.  These cars are described with body mounting Kadee couplers in respective "vignettes".

LGB  cars requiring trimmed-off ribs include the 40 foot Boxcar, External post Modern 50 foot Boxcar and 50 foot Flatcar.  In this case, sideframe ribs are to be trimmed as illustrated below.  These cars are, also, described with body mounting Kadee couplers in respective "vignettes".

The illustration below includes perspectives of rib trimming and then assembled truck components.

Truck Assembled with Replacement Bolster

The truck is assembled with its bolster replacement components as illustrated below.
Note: Shorter 7/16 inch long screws are to be used in place of 1/2 inch screws depicted for side frames that must have trimmed-off ribs for car applications previously described.

The completed truck is now ready for installation on an LGB (or possibly different brand) American standard gauge type freight car.

NOTE: Should the circumstance arise, the modified LGB truck is restorable to its original factory bolster in unblemished condition - except for those that required additional sideframe rib trimming.

End,
-Ted