St Petersburg Tram
Key System Truck Installation Hints
Because of the skirting on these models using the correct sideframe (CS261) will not work. The compromise is to use the
frame. Since the car is skirted the fact that this is not the original truck is hidden. What follows are the experiences of Dick Ford in his successful attempt to power this fine model.
You can refer to or download truck installation
drawing number one, and drawing number two for additional details of this installation.
Remove the brake springs, file the end beams to measure 0.295" top of beam to top of rail head, basically removing the mold marks.
Remove approx. 0.020" from underside of car skirts, immediately over truck end beams.
Using 28" wheels eliminates the need to do this.
Make sure that floor is level, and do not rely on truck mounting boss to be accurately centered.
The following is a photo sequence of how to mount a Q-Car trailer truck to the center skirted truck. For a larger picture you can click on each photo.
Dick Ford's Followup Note:
22 February 2001
I thought that you might be interested in the results of last night's shake down trip of the "Key System" bridge articulated car.
I took it to BSSME layout in Roslindale last night. The car ran great, no problems at all, even ran in correct direction.
The C50 Std side frames, with the brake springs removed work nicely under the car. My trucks work fine with the 30" wheels, but maybe smaller diameter [28"] would be better.
The minimum radius is controlled by car body contact at the articulation joint, not the wheel-base or truck swing. My geometry says a minimum radius for these cars is 11.5". BSSME's limiting radius is 15".
I was able to mount the power truck without removing the seats above it by carefully cutting the plastic/epoxy floor away from underneath the car after determining where to cut for clearances. What a help CAD programs are.
I mounted the power truck bolster length-wise in the car. The top of the bolster works out to be exactly the same level as the top of the original floor, therefore the only thing related to the power truck is the mounting 2-56 lock nut.
Please share this information with any of your customers if they are interested.
CS228 C50 Standard Trucks
Although mentioned in other parts of this web site, the following is repeated for anyone working on a St. Petersburg car.
When doing this work great care must be taken not to get plastic filings on the interior of the model. Brush any lose material from the floor before you do any test fitting. Static electricity will have that material sticking to the glazing, and you will not be happy trying to get it off. Vacuum the floor after each machining step.
One final caution, to reduce the chance of scratching the very fine paint work on these models we recommend you place the body on a clean soft rubber pad or clean linen cloth. We like working off a freshly laundered T Shirt.
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