The Hulett Unloader has three major subassemblies: the base platform, the moving platform and the walking beam. Use these three photos as an overall reference to the build.
I built the first model from the top down, figuring that tolerances would flow from the inside out. That is, the outside dimension of the walking beam would determine the inside dimension of the moving platform, which would in turn determine the dimensions of the main base. These directions build in the opposite order.
This is a challenging kit. Builders will have to determine their own preferences for tolerances, bearings, wheels, axles, movements and other things pertaining to movements. The kit is as accurate as I can make it for N scale, but modeling tolerances are huge compared to prototypical tolerances. I will give suggestions on how to hinge the assemblies, but the materials are the buyer’s responsibility.
It seems a modeler could substitute N or Z scale trucks for the rolling platform and perhaps even for the main base platform. The main beams are just wide enough for standard gauge Z scale. The towers on the base platform are narrower than standard Z, but the trucks could be narrowed. In N scale, 36″ Z scale wheels are just slightly smaller than prototype. There is not much room for wheels for the larry.
The Cutting Layout
The cutting layouts are important to identify parts–especially in this kit. Somehow I am having trouble handling pdf files, so these are jpgs for now. They will help you locate where the parts are, and perhaps how they go together.
The cutting layouts shown above have changed many times, and may be slightly different than the kit you receive. The reason is the dynamics of my cutters with styrene. Sometimes the most obvious layouts, such as grouping all parts in subassemblies together, cannot be reliably cut. So I have to move parts around until most everything cuts reliably. I strive to make cuts that are just about all the way through, but that is often an unrealistic goal, as styrene sheet is not uniform in thickness and hardness of the surfaces. Some kits will arrive with a baggie of parts that were cut all the way through and thus fell off the sheets; other kits will arrive with separate sheets to account for any parts that were miscut. Also, there may be extra parts, or parts for which I’ve simply forgotten their purpose, especially strips cut for reinforcements that might not be needed.
Base Platform
The base platform consists of two long box beams supported on two towers. There are many square chads that can be used to reinforce/align the building of these structures.
Towers
Build four base extensions. Glue the inner pieces to one side, than glue on the other side.
Built one tower by gluing four vertical supports to the face plate, then gluing the other plate. Repeat for the other tower. Notice that one tower has a Y reinforcing web, while the other has a half Y. Glue the Y to each outside edge, and four partial webs to the inside edges. Glue the half Y to each outside edge, and two partial webs to the inside.
Glue the base extensions to the towers.
Glue a bottom reinforcing strip into position.
Using a toothpick, curl about .4″ of each top reinforcing strip. Coax it into position and glue, again holding until the glue holds.
Note that the rear base has reinforcement on both sides, while the front has reinforcements only on one side.
Main Beams
You need to build a left hand and a right hand beam! Always keep the handedness in mind while gluing, and also which side is up. Remember that everything aligns from the rear, tapered end.
For each beam, start by laminating an inner face from two solid parts.
Laminate an outer face from two latticed parts. The diagonal lattice goes to the inside of the beam.
Laminate the two parts of the top of the beam.
Notice there is a jut for a long landing, and the orientation of the jut..
Start gluing the outer (latticed) beam at the end, again with the top clipping the side. At the jut, the top will protrude over the side. Use the other end of the top to make sure the side is aligned (i.e., flush with the top at both ends, but the top overhangs in the middle).
Glue the inner (solid) beam to the top. The top clips the side.
Glue the bottom to the sides. Let it dry a bit before bending the bottom around the curve and gluing it. This will add rigidity and “plumbness” to the beam.
Make the second beam a mirror image of the first.
Glue the front tower to the beams, with the reinforcements facing toward the rear. Align the non-reinforced side with the start of the curve in the bottom of the beam.
Glue the rear tower to the beams, with the rear of the reinforcements aligned with the start of the lattice. (Different model used for photo: it shows the alignment and also the inner tracks you will add later.)
[This section superceded, see later in directions: The kit includes parts to build eight four axle dummy bogies. Laminate the two rectangles, then glue a dummy bogies on each side. The ovals go on the outside of each bogie. The base tracks are up to the builder. For easily movable towers, consider N or NN3 trucks from railroad cars, and appropriate track. (Not shown yet: to be added later.) I recommend you install these bogies later, as you will be handling the base platform quite a lot.]
Laminate the rear cross beam: the “X’s” are on the inside. Laminate the top cross lattice (two pieces for strength. Glue the top cross lattice in place, then glue three less deep cross braces (one at each end of the top brace, and one in the middle). You can see the transfer loader at mid right, above the knife, colored red.
The inside of the base contains two tracks. The topmost, at the front of the unloader, is for the transfer loader. These rails extend from the front to where the top brace starts. It is a simple strip glued to the inner sides. It may require an additional strip or two to be added, or even that the strip be thinned for clearance. (The transfer loader has two compartments, each with a circular diaphragm at the bottom. I presume each half held one load. Directions to build these are later.) Also shown here is what I presume is a weather shelter, built from a 6mm strip on the top and a rectangular side piece. The railing and stairway are added later.
The bottom track is for the transfer lorry, which is loaded by the transfer loader above, and shuttles back and forth the entire length of the main beams. This is the lorry that actual dumps loads into cars.
[This section superceded: These tracks. made from a 2 mm strip, hang rather precariously from the beams, and rise from the front to the rear. I did not had clear images of what the supports looked like, so I fabricated the triangular supports by trial and error. We will build the transfer lorry later. At the far left, you can see a walkway added to the top of the bottom beam, made from a 4 mm strip. You may find it better to use a Plastruct or Evergreen shape, or 0.40 (code 40) rail, for these tracks.
I also added tracks to the top of the main beams. I used strips of plastic (not included); you may wish to use Plastruct or Evergreen shapes or code 40 rail.]
Walking Beam
Start with the upper walking beam. Laminate two of each side. The rounded corner is the bottom rear. Laminate the ribbing on the sides, making sure to make a left side and a right side.
Laminate the inner reinforcements to the top and bottom of the front of the beam. You may have to cut the loop at the front off at a later time.
Laminate the inner reinforcements to the top and bottom of the rear of the beam. (I forgot this step in the build I photographed. The beam turned out just as good)
Glue the rear top onto the rear of the beam, with the rears aligned. The rear top goes on top of the beams, not inside them.
Glue the rear bottom to the rear of the beam, noting that it extends slightly past the rounded corner. Let dry for strength, as you will be bending the sides of the beam in the next step.
Glue the front top to the beam, bending it. Use masking tape to hold. The rear of the front butts against the front of the rear.
Glue the bottom front to the beam.
Laminate the two bottoms of the mechanical house, and glue at the top, at the rear, of the beam. Assemble the four sides around the bottoms. The sides of the house extend past the front and rear. The front has two windows.
Glue the third “bottom” to the slightly larger top, centering it all around. Glue the top over the walls, with the smaller piece down, on the inside.
Assemble the hoist guide with two inner solid pieces and two outer ribbed pieces. Glue to the center front top of the beam, with the rounded edge of the guide aligned with the first straight cross-piece of the beam.
From the 4 mm strips, cut two walkways to length and install. Railings should be installed later.
Drill 1/16″ (1.5 mm) holes at the front of the beam and the center. The center hole should be slightly below the vertical center.
Guide Beam Assembly
Laminate the solid and ribbed pieces, making sure to make a left and right side. (One ribbed piece is missing.)
Beginning at the rear (wide), glue the top to the beams. You should be able to coax the top around the corner. You may have to glue the back half before attempting to bend the front half around the curve.
I had to slice across the bottom piece at the curve to make it fit correctly, and trim it slightly.
You will have to drill 1/16″ holes at both ends. I would leave this to later, when you are assembling the entire platform, as alignment can vary, and slight differences in assembly can cause great variations in the geometry.
Vertical Beam
The vertical beam is four long pieces. Glue the sides to the almost straight back, with the back inside the sides, then bend and glue the front. There are three “washers” that fit at various places along the top part of the beam. I would leave installation of these until final assembly.
The Bucket
Have fun! There are only 18 pieces to an inoperable bucket, but they are fiddly.
I’d start with the bucket, as it will help you understand the geometry required for the mechanism. Make a right and left bucket. The bottoms glue flush inside the sides. Ream out the marked holes as needed to fit plastic rod. There are two rods for each side of the bucket. Use them to square up the assembly.
The mount consists of two horizontal rectangles which are glued inside the vertical pieces, in line with the square rear end. Glue two narrow strips across the outside of these vertical pieces, then glue the two other vertical pieces to them. The mount just glues up to the bottom of the vertical beam, and the bucket should slide up into the gaps between the vertical pieces. Whew!
The Rolling Platform
Laminate the two largest base pieces. The Front is where the protruding notches are.
Laminate the two smaller base pieces (rectangles). The top has cut-outs at the front.
Glue the smaller base to the larger base, centered from side to side, with the fronts align so that the protruding notches still protrude–i.e., align them on the inner front edge.
Laminate two solid curved risers with ribbed risers, making one left and one right side.
Using a 5.862 mm strip, cut some interior reinforcements. The layout is not critical as long as these ribs do not interfere with any openings. You need just enough to keep things square. I used a strip along the bottom and just a few risers. (I missed this step during this build.)
Assemble the outer ribbed (laminated) pieces with the inner solid pieces. Glue the H-shaped piece to one of the risers, then to the other. The H is identical top and bottom.
Cut and glue the 6.975 mm strip to the top, along the curve.
Glue the “inside” of the H into place (two thicknesses are provided), then glue the top and bottom pieces of the H’s crossbar.
Using excess 6.975 strip, cut top caps (nearly square) and glue. (Not shown)
Assemble the non-working wheels. There are spacers at the top, then small wheels, then a group of three larger wheels. The smaller wheels are glued equidistant around the bottom edge to form a rudimentary flange. There are three-wheel trucks at the front and single wheels at the rear. You may wish to substitute these non-working wheels with actual N or Z scale wheels.
You may want to wait until the base platform is assembled before installing the wheels.
Assemble the rear wheel guides and glue into place.
Railings and stairways should be installed later.
Transfer Bin and Ore Larry
I believe the transfer bin served as a funnel and a buffer for loads. It had two bins, each bin with a diaphragm style shutter. I have not modeled this yet. Here are the parts for the bin. The two sides (curved ends) have already been laminated.
Glue the interior partitions in place centered as shown. The partitions are shorter in width and must be centered. I forgot to curl the two ends of the bottom beforehand. Use a thin paintbrush and curl just the 1/4″ or so.
Glue the sides to the bottom and the partitions.
Using tape, curl up and glue the bottom to the ends, and also two more partitions to the top, to enclose the ends. These last pieces slant a bit from the ends to the middle.
When dry, position strips along the long sides, to slide along the strips previously glued to the inner main beams. The strips–I used .020 x .040 but suggest .040 x .040 might be better, are about half down the depth of the bin, but it is best to check this alignment before finally gluing. The bin should be just below the top of the beams.
By this time, the ore larry might seem pretty simple. There are two tops, two bottoms, two side pieces, some strips, and some scrap to fit. Punch out the inner rectangles from the top and bottom and save them. Using the strips, build boxes around the openings. The long sides should be flush with the edges of the rectancles. They are building the U-channel on which the larry slides.
Glue the tops and bottoms together, forming the channels.Glue the sides of the bucket to the top (larger rectangle). There should be space to slide one of the saved rectangles into place and glue. When dry, trim and repeat on the other side (not shown).
Trim the second sloping piece, then slide the bottom into place and glue. Fini! except that I did not build the bucket at the bottom. As with the transfer bin, I am looking at that–the pieces will be small!
Bogies and tracks
As originally built, and included in the standard kit, the wheels, bogies and track were all styrene, allowing parts to be repositioned. After discussion with a few modelers, I decided to add code 40 nickel-silver tracks on the base and for the ore larry, and metal Z scale 36″ wheelsets. The transfer loader is still styrene–the transfer loader moves only 1/2 of its length back and forth (if ever). so some friction was acceptable. The ore lorry has a built in horizontal U channel. which supports it top and bottom. I could not find a way to squeeze in wheelsets or ball bearings for the ore larry, but feel the friction is acceptable.
Construction of the standard kit follows most of the steps of the deluxe kit. The exception is that styrene wheels without axles are glued to the side frames of the bogies, instead of wheelsets being inserted.
Install the tracks on the top of the base platform. It is just wide enough to accept standard Z gauge. Use a track gauge, or continually test with wheelsets. If using plastic, a rail height of at least .040″ is recommended. I used .020″x .040″ strips, but these may be too thin for easy and accurate installation. I would build a 4-wheel bogie (below) to determine gauge, which will be larger than standard Z gauge (unless you narrow the bogies).
Installation of the ore larry tracks. While precarious looking, this installation is actually quite sturdy, and uses the geometry of the main beams very cleverly (that’s Hulett, not me, being clever). First install five supports along the sloped bottom, with the edges flush to the outside. These determine the slope of the track.
Next, using a tacky glue, align the rail, its top inward, along the strip. I use strips of masking tape to hold it into position while the glue dries.
Next, there are three triangular braces, of the same width but diminishing height, that attach, roughly, the rear of the front tower support curve (tallest), the front of the rear tower support curve (shortest), and in the middle of the two. The supports again align at the outside edge. Using tape, glue into place at the bottoms.
Installation of the tracks on which the whole machine moves (so that it can align with the holds) is up to the modeler. Standard Z gauge track should work well, ties included.
Each bogie consists of 9 pieces: two inner bases, four side frames, two end pieces, and a top plate. There are four 4-wheel bogies, two 3-wheel bogies, and two 1-wheel bogies. They are identical in width. Laminate the inner bases together, and then the two side frames. The holes in the side frame can be poked out with a small diameter drill. Glue the side frames to the inner bases–the frames are outside of the bases. Once dry, insert the wheelsets, then cut a strip approximately to length and glue across the ends, as shown at top left, below. The end strips prevent the side frames from splaying outward.
Here’s a view of a 3- and a 4-wheel bogie, with the parts for a 3-wheel bogie.
I lined up the bogies on the base platform and the moving platform by eye. You may want to align one side and glue the bogies, before proceeding to the other side and checking that the distances between the bogies matches the distances between the tracks.
Here we are upright, and ready to start the hinging process.
Hinging The Beast
I used 1/16″ tubing inside of 3/32″ tubing for the main hinge points on the tower. I drilled straight through both towers, making sure the drill bit was properly aligned. I put the 1/16″ tubing in place to make sure the bearings were aligned. The bearing stick out on the outside; that will be trimmed later. You want minimal overhang on the inside, as tolerances are pretty tight. I used a fancy white glue to cement the bearings in place.
I drilled 1/16″ holes in the center of the walking beam–centered on the mid support beam, but about 1/16″ down from the vertical center. The holes in the supporting beam need to be close to the first crossbeams, as shown. I am not using bearings here, as the 1/16″ tubing will be glued to the walking beam and supporting beam. Gluing is probably not necessary.
I drilled very small pinholes at the front of the beams. These may have to be moved once the final assembly begins. I just glue a scrap of styrene over any place that needs a new hole. You may also have to shave the contour of the supporting beam so that the vertical beam fits.
First trial fit of the two beams. You can see that the lower supporting beam is a bit off. Rather than remove the bearing, I just covered the holes in the supporting beam with scraps, and redrilled a bit forward of the old position.
I used thin piano wire to hinge the vertical beam to the walking beam (top) and the supporting beam (bottom). You want the beam to remain vertical in two directions as it goes up and down. It’s easiest to adjust the top locations.
On overall view. I built the machinery house–two floors, four walls and an inner and outer (larger) roof and glued it to the end of the walking beam.
There are also dummy guides for the rear of the moving platform. Pre-curling the styrene covers makes assembly easy.