In order to modify the mounting area for trucks and couplers
as little as possible I used the following approach to convert the frame.
- Remove the cast on coupler boxes and other detail on the underside of the frame.
The details I'm talking about are marked black on the picture. I did so by
first cutting them off and then sanding everything smooth.
- The little recess in the truck mounting area has to be filled with some scrap styrene.
Sand smooth after the glue has dried.
- The photo below shows the underside of the frame after the modifications are
completed. Now it's time to narrow it to fit under the modified hopper.
- Now cut off the outer side beams first. This can
easily be done without a table saw. Cut as close to the sidebeams as possible.
- If you plan to use a table saw, the small mounting details for the brake parts
might make it difficult to use the fence of your saw properly. I solved that situation by
laying a steel ruler between the fence and the underframe.
- Now narrow down the underframe to the required width by filing off material from the
center parts of the frame. Some care has to be taken here to make sure that you
remove same amount from both sides of the triangular sections and from both end parts.
- After these operations done, you should have four parts as on the photo to the right.
Make sure that everything fits nicely between the sides of your hopper.
- This is probably the most difficult step of the whole modification. The frame
parts have to be glued together again and everything has to be square.
- While I didn't do so, you can make that step easier by removing all the NBWs
and other detail from the upside of the frame parts as this would give you a level area
to align everything.
- Glue one triangular part to the sidebeam, making sure that the ends are properly aligned
and the crossbeam on which the hopper sits is on a right angle to the side. Repeat for
other two parts.
- After glue has set, glue the two halves together again checking for alignment at the ends.
Voila, your new frame is completed.