Heljan Bo-Bo Locos: Pivot Frames

This section describes the assembly of one of the two pivot frames. In practice you would probably build the two frames together.

If you are a novice at soldering, the frames make good practice pieces: with this in mind, some guidance is given for the soldering operations.

Pivot Frame etch and insulator Remove one of the Pivot Frames (6) from the fret and tidy up tags.

Test the nylon insulator for a free fit through the central hole, opening out with a round file or broach if necessary.

Check that the slots in the outer flanges of the etch are clear to the material thickness.

Pivot Frame folds Make the four folds in the Pivot Frame etch.

Pivot flanges Remove two of the Pivot Flanges (5) from the fret and tidy up tags.

Fit the flanges into place on the pivot frame, ensuring that the tabs on their lower ends are fitted into the slots in the lower flanges of the frame.

Frame and Ribs clamped up Apply some liquid flux along the joints between the flanges and the top face of the frame. Clean and flux the soldering iron bit, load it with solder, use a tool or clamp to hold the flanges firmly in place…

Top joints of frame soldered …and let some solder run along those top joints.

Pivot Ribs Remove two of the Pivot Ribs (7) from the fret, clean up tags and slot them into position at the sides of the assembly.

Soldering to side of frame Apply liquid flux to all joints and along the folds on one side of the assembly. Clean and load the iron as before, and apply it to the joints toward the top of the sides. Note how, if you keep the iron in place for long enough, the solder flows through all the joints and folds, following the flux. Reload the iron and repeat until all joints and folds are reinforced by solder. Avoid applying the iron inside the rectangular space formed by the rib and the lower flange of the frame, so that solder doesn't flow on to the inside faces of that space.

Repeat for the joints and folds on the other side of the pivot frame.

Completed Pivot Frames Wash the frame assembly to remove and neutralize any remaining flux. Clean away excess solder with scrapers or a fibreglass burnishing tool.