MODIFICATION OF THE BOWSER TRACTION TRAILING TRUCK August 16, 2007 Shortly after the Bowser 125100 series of HO scale traction drive mechanisms were introduced in 1999, members of the Southern California Traction Club (SCTC) found that they could be used to replace worn out mechanisms in Suydam models of the Pacific Electric 800, 950 and 1000 series cars. The wheelbase was so right for those cars. They also found that they could be used to replace some of the vertical motor drives in items such as the MEW Sacramento Northern Holman Wood Coaches of the 1003-1006 class and others similarly equipped. Other than getting the new drive to the correct height there were two problems. First, there was no good brass bolster available other than the narrow one made for the Bowser cars. Second, there were no sideframes for the P.E. cars that matched the wheelbase of the Bowser trucks, and then modelers had to cut out a significant kidney shaped hole in the floor for the trailing truck. In the case of the PE models, the sideframes were not the same wheelbase as the Bowser unit so the trailing truck needed to be used also. Bowser solved the first problem with the issuance of a wide brass bolster, part number #001335, available from Bowser and Custom Traxx. Also John Kennedy of KND Enterprises developed and produced part KND-00-001 Bowser Motor Full Swing Adapter that solved the bolster problem and also helped the units negotiate tighter radius curves. The second problem was solved jointly by Bowser and Custom Traxx when the St. Louis 61A, St. Louis 23B, 27-MCB-3X, and Baldwin 78-30 sideframes were released. They are still available from Custom Traxx. The final problem has been solved many ways by different modelers. All of them involved cutting the vertical tabs from the parts 1256 and connecting the 1256 s electrically with wires in alternate means. KND Enterprises has a method, which is documented on their web site. The SCTC experimented with many different means of this until George Huckaby developed the following method that is described in detail in this document. This method not only avoids cutting the floor but also avoids cutting another hole in the floor for an electrical lead. Note 1: This method grounds all four wheels of the trailing truck so this method cannot be used for two-rail applications. To do this, you need the following: 1.Two inches of.020 spring wire. * 2. #76 drills 3. #66 drills
4. Soldering iron capable of 600 degrees Fahrenheit. 5. Bowser 65007 2-56 shouldered screw* *Both shown in photo below Shown below is the disassembled Bowser trailing truck equipped with 30 wheels and a Bowser diagram of the trailing trucks with the parts identified. The 65007 shouldered screw is provided in the Bowser 125100, 125110 and 125120 traction mechanisms along with the 256031 screw shown in the drawing below: The first step is to remove the two 1256 parts, stack them on top of each other and, using a #75 drill, drill one hole through both parts, 1mm to the right of the center of the distance between the two side frame mounting holes and 2mm below the top edge of the 1256 part. The.020 spring wire should pass through both of them at this point. (See below left) Note 2: If the holes are drilled as directed, there will be no interference with any of the four Bowser sideframes (PCC, Brill, Commonwealth or Baldwin). There may be a small amount of interference with other sideframes that use a larger mount. A small amount of filing of the side frame mount will correct this problem.
Place each 1256 part back onto the assembled 1290 trailing truck frames and using the #75 drill, drill two holes in the 1290, through the holes in the parts 1256 previously drilled. Remove the 1256s and enlarge the holes in the parts 1290 using a #66 drill. Reassemble the truck and the steel wire should easily pass through the entire assembly. (See above right) After this point the original tabs for making electrical connections are no longer needed, so they can be cut off with rail nippers or any good set of steel wire cutters. Clean the spring wire very well and the are around both holes in the parts 1256 and using a very hot soldering iron, solder one of the ends of the spring wire to one 1256. Note 3: Soldering the 1256 parts while attached to the plastic 1290 parts must be done with a very hot iron. Use a goof flux applied to both the wire and the area of the 1256 near the hole. As soon as you see the solder flow, remove the iron. This avoids melting the 1290 housing. Note 4: Soldering both sides is preferable only if you ensure that both 1256s are secured tightly to the sides of the 1290, If not, you will be unable to properly replace the bottom plate, part 1292, to secure the wheel sets. When the 65007 shouldered screw is inserted through the trailing truck assembly, it will make firm contact with the spring wire and as such ground all four wheels of the trailing truck. Note the view of the underside of the assembled truck less wheels. The 65007 shouldered screw makes great contract with the spring wire, which will be electrically connected to all four wheels, when they are installed.
The completely assembled truck with a Bowser Baldwin side frame is shown in the next photo. We attached a 2-56 nut to the top to hold the shouldered screw for this photo. Custom Traxx used this method in the assembly and installation of the trailing truck during the assembly of the KND Enterprises Lehigh Valley Transit 812 klt. We even ran the car initially with only pick-up from the trailing truck just to test this method. We have noted no problems to date. The chassis of that car
is shown below before the power truck pick-ups were connected. The car will spend the first few weeks being operated with only the modified rear truck pickups. The three-pin female connector connects to the shell (trolley pole hooks, rear trolley pole and front trolley pole.) We invite any modelers who have ideas concerning the Bowser mechanism to share them with Custom Traxx, KND Enterprises or the Trolleyville Times. GLH 8-16-07