- 100-grit sandpaper or nail file (sanding stick).
- Reamers/round files for deburring/enlarging holes: 1/16” to 7/64”.
- Sharp tweezers and small pliers.
(Images to come)
- Glue the base and the base tails together. The ends of the base may require some trimming for an exact fit. It may be best to glue them while upside down on a flat surface,, to ensure a flat top for rails.
- Glue two “D” (four wheelsets) bogies centered on each base leg. Make sure they are aligned precisely so the base can travel on standard Z gauge track. You may fit the wheel sets now or at a later time. Snap each wheel set into its sockets by holding them diagonally in the bogie and twisting them into place.
- Glue sidewalks and enclosure at the bottom edge of the main beams. These are “handed”—the one with the enclosure goes on the left or port side.
- Trim the transfer bin tracks (.80” square plastic rod 100 mm long) centered in the height of the main beams. The back ends are flush with the first horizontal brace.
- Trim the width of the transfer bin rail riders so the bin moves freely. Usually a bit of sanding with 100 grit sandpaper or nail file will do.
- Glue the Larry car track supports to the bottoms of the main beams. The rectangular pieces are glued to the crossbeam of the tails so they protrude slightly toward the inside. The triangular pieces are similarly mounted slightly protruding inward. The tallest triangles are mounted where the curve of the front base legs meet the bottom of the main beam. The least tall triangles are mounted where the curve of the back leg meets the bottom of the main beam. The middle-high triangles are glue in the center between the other triangles.
- Glue a length of brass rail to the bottom tips of the supports on each inner side. The base of the rails is oriented toward the supports.
- The tower. Glue the “C” (3-wheelsets) and “A” (one wheelset) bogies to the extreme edges. The C bogies align with the front of the tower; the A bogies align with the rear. Place the wheel sets in the bogies.
- Place the tower centered on the base. Mark where the outer wheels of the bogies meet the base.
- Temporarily tack glue rails parallel to the edges of the base at bother outer marks. Check that the outer wheels ride properly on the outer tracks, adjust as necessary, and glue the tracks.
- Using a Z-track gauge, temporarily tack the inner tracks 6.5 mm inside the outer tracks. Check for correct gauge, adjust as necessary and glue.
- Assemble the bin and the base of the Larry car. Note the rails are at an angle, and the bin should be oriented on the base so the top of the bin is level with the main structure. Trim the rail riders so the Larry car can move smoothly.
- Assemble the nine pieces of the walking beam. Glue the four pieces of the front: the top and bottom clip the sides—the beams are in between the top and bottom. Note that the bearing hole is slightly toward the bottom, not the top. Glue the four pieces of the back, noting that the curve at the rear is toward the bottom. Glue the machinery house flush with the back.
- Assemble the five pieces of the support beam. Again, the top and bottom clip the sides and the solid end bearing block. Note: you may want to expand the rear bearing hole into a slot extending backwards (toward the rear) for adjusting the positioning of the vertical beam later.
- Assemble the vertical beam. The chain guards are level with the top of the four square holes with the tails pointing down and flush with the front edges. Save mounting the chain for later. The ring slides down the top and can be glued.
- Ream the 8 pieces of 3/32” x 8 mm bearings to remove burrs, rough edges, and other debris. Try fitting them in four holes in the tower, two at the end of the walking beam and two at the end of the support beam. These holes may have to be reamed to fit the bearings. The tower bearings should be flush with the inner edges. The bearings may be a little long for the ends of the beams but can protrude a bit inwards, as long as the vertical beam will fit. The bearings will later be trimmed on the outside.
- Ream and debar the 1/16” axles. Make sure the 1/16 axles fit through the holes in the center and far end of the walking beam, and both ends of the support beam. Ream the holes if needed. If the rear hole in the support beam has been elongated, make sure the 1/16 axle can slide, ideally with a bit of friction.
- Position the walking beam in the tower at the top. Starting at one edge, slide the 1/16 axle through the bearing, through the beam, and into the other side bearing. The axle should protrude a bit on either side.
- Use the same procedure to mount the support beam to the lower holes in the tower.
- Use the same procedure to mount the top of the vertical beam to the end of the walking beam, and the middle hole of the vertical beam. You now have a working mechanism.
- Mount the bucket on the end of the vertical beam. The tail points inward tower the base. Cut and glue the chains between the guard and the bucket.
- Position the base at the edge of a table so that the bucket can reach beyond the “floor.” Mount the tower on the rails on the base and move it to the front end. Observe if the vertical beam is 90 degrees vertical when the walking beam is at its highest position. It may point a bit inward. If so then pull gently on the support beam to move its rear axle backwards in its slot (or find some other method to move the axle). Holding the tower steady, gently push down the end of the walking beam. It should remain vertical. If it kicks past vertical (it points out), then push gently on the support to move the axle forward a bit. It is OK for the vertical beam to point gently inward at the top and outward at the bottom.
- You may have to weight the rear of the walking beam. I glue bb’s in the machinery house. A lead weight attached to the bottom of the machinery room also works. Or weights mount to the bottom of the platform between the A bogies. Otherwise the entire moving assembly tend to tip forward.
Known inaccuracies: there are actually three rings on the vertical beam. Two of them are at the pivot points at the top with the walking beam and in the middle with the support beam. The middle ring is larger in diameter and has a walkway around it. The two rings allow the bucket to pivot 360 degrees. Modeling that in N or S scale would prove immensely challenging as the clearances required were too tiny to be robust and the rings interfered with the up and down motion. Getting the geometry of the four pivot points correct was challenging enough without adding another degree of freedom of movement. But I am working on a compromise solution.
There are other walkways, machinery mounting points and other details that I believed to be too small or insignificant to incorporate. Those are additions and tasks for the very expert modelers. I am always working to incorporate these details in the 3D printing process.
- Working z track gauge has been developed and will be included in future kits. 10-15-2020.