The M48 was the tank that went to Viet Nam and, in this author’s opinion, the most aesthetic tank design ever produced in the United States.  For all its’ service, the M48 has not been represented very well as a scale model kit.  At this time, there are two 1/35 scale injection molded M48 kits available.  Unfortunately, neither kit comes up to the standards of the current crop of kits that we are now enjoying.  The first kit was initially produced by Monogram and has now been reissued by Revell.  In my opinion, the Monogram/Revell kit is only interesting from the standpoint that it gives us a peek into the past.  While the Monogram/Revell kit does represent the general shape of the M48A2, the details are cast on and crude.

The Tamiya M48A3, kit #35120 is a much better kit, but it also has its’ fair share of problems.  The Tamiya kit was initially designed to be motorized which leaves a number of holes that need to be filled.  The real weak point of this kit is the suspension.  The suspension is poorly represented and if assembled straight from the box will result in the tank sitting too tall with a slight forward inclination.  Correction of the suspension details would require a wholesale replacement of the bumpers and snubber mounts which, while certainly possible, is something that I have chosen not to do.  However, correcting the height and attitude of the way the tank sits is relatively easy.  Some modelers have claimed that the turret is a bit squashed.  In my opinion, the kit turret height is spot-on, but I will show a simple method to increase the height.  Despite these issues, the level of detail in the majority of the kit is still adequate to yield a convincing likeness of an M48.  A brief photo comparison of the Monogram and Tamiya kits can be found here.

My goal in this article is to present my techniques for solving some of the basic structural issues which will provide a more accurate palette for adding whatever level of detail the reader may want to add.  I make no claim that I am solving all the accuracy issues.

The first step in the construction is per the instructions, Fig. 1.  The reason for cementing the rear grill piece first is because it provides the rear support for the upper hull half and is the key to fitting the two hull pieces together.  Since the kit was designed to be motorized, there are number of cutouts that need to be filled.  A pretty good chunk is missing around the rear portion of the lower hull, so this area gets more involved, Fig. 2.  There is a slot just behind the front idler mount that needs to be filled.

There are some voids in the underside of the upper hull half that need to be filled, Figure 4.  Also evident here is the addition of .020” styrene to the end of the rear deck to bring it out more flush with the grill doors.  Figure 5 shows how the rear portions of the hull halves go together after being filled.

Some filling needs to be done on the inside of the final drive housings, Fig. 6.  Finally, the holes in the bottom of the hull need to be filled, Fig. 7.

Before cementing the upper and lower hull halves together, thin out the fender supports by beveling back the outside surface.  Figure 8 is before and Figure 9 is after.  I address the inside seam later.

At this point I cemented the two hull halves together.  With the hull cemented together before leveling the tank, you avoid any issue of warpage later.  Once together, it becomes obvious how blunted Tamiya has shaped the front of the hull.  To fix this issue, I masked off the area with some tape and applied a layer of cyanoacrylate and dental resin powder, Fig. 10.  I use this mixture as my standard filler and you can find a better explanation here.  Because the material sets up fast and hard, I was able to rough out this shape in about 15 minutes, Fig.  11.

Figure 12 is the original shape while figure 13 is the final primed shape.  Note that the seam on the fender support has been cleaned up and thinned a little more.

It is now time to focus on solving some of the suspension issues.  The geometry and representation of the suspension components are the two major shortcomings of this kit.  Theories have been advanced as to why there are errors in the suspension.  Theories aside, the fact is, the kit was designed from the outset in an era when Tamiya had a passion for motorization and, for whatever reason, some of the details and intricacies of the suspension got left behind.  My initial plan for this kit was to avoid a lot scratchbuilding, so I have attempted to work with the kit parts.  But I have to say, replacing the kit bumpers would go a long way to improving this model.  The M48A3 suspension is diagramed and labeled in Figure 14.

I began lowering the model by tacking a .080” tall piece of styrene strip to each row of suspension tubes, Fig. 15.  A good guide is the mold line.  Once the strips were attached, I checked to see if the tank sat level.  Sure enough, there was a very slight rock.  I cemented a piece of .010” styrene to the rear of the left hand styrene strip, Fig. 16.  I filed this .010 shim down until the tank sat straight.  So ultimately, the shim thickness ended up about at .006”.

Each support arm is molded with the bumper spring attached, so it is necessary to cut each bumper spring free.  I suggest labeling each bumper spring because they are not all the same and they are directional.  Each support arm is glued to place with the hull resting on the styrene strips and a .060” thick spacer under each axle, Fig. 17.  In the photo, a straight edge is used to check alignment.  Next, the bumpers are shortened and glued to place.  The real bumper supports are much more substantial than Tamiya has represented them.  In addition, they should be radiused into the hull.  In reality, the bumper springs are not in constant contact with the support arms, but this is not very visible under normal viewing of the model.  Short of fabricating new supports, I elected to at least incorporate the fillet which I think gives the flavor of the prototype.  The bumper support was outlined with tape, Fig. 18.   A mixture of cyanoacrylate and dental resin was flowed in around the bumper support.  I was only able to do two at a time because the tape needs to be pulled quickly before the mixture starts to set, Fig. 19.  Finally, Mr Surfacer 500 was brushed over the fillet.  After the Mr Surfacer set for 8 hours, I used a Q-Tip moistened with 90% Isopropyl Alcohol to smooth and blend it into the surrounding hull surface, Fig. 20.

I shortened the snubbers by cutting off the piston rod and drilling out the end of the shock body.  I also drilled through the upper mount and cemented in a short length of .035” styrene rod, Fig. 21, 22.

The kit was originally designed to have a solid axle supporting the drive sprockets, Fig. 23.  The solid axle was insurance that the drive sprockets were aligned properly.  To replace the solid axle, Tamiya provided a stub axle that is cemented into the final drive housing.  The flaw in this method of assembly is that the surface of the hull onto which the final drive housing is cemented is slightly angled so that the drive sprocket will not be aligned properly.  This is critical because I will be using a set of AFV Club individual link tracks.  My solution was to first cement the stub axle into the final drive housing.  The front portion of the stub axle was removed, Fig. 24.

The remaining portion of the axle was drilled to 3/32” from the inside, Fig. 25.  Brass rod is slipped through the holes and used to align the two final drive housings and also serve as the axle for the drive sprocket, Fig. 26.

The actual drive sprockets had three slots.  I used a vertical mill to cut the slots, Fig. 27.  In order to keep the rear drive sprocket properly aligned, I wanted to eliminate the slop that is induced by using the kit-supplied polycaps.  I drilled out a short length of acrylic rod and cemented it into the outside half of the drive sprocket, Fig. 28.  This replaces the polycap and maintains a correct alignment.  You could also use short lengths of the next larger sizes of telescoping tubing.

The two halves of the drive sprocket are cemented together.  I always like to do this on a flat surface using the guide teeth to help me insure that the sprocket is properly aligned, Fig. 29.  I never trust the keyways.  Figure 30 illustrates the possible misalignment that can happen with a stock assembly, while figure 31 shows a much better alignment that will not change when the tracks are mounted.

The tracks on the M48 are live and do not exhibit any sag.  Since I am using individual link tracks, there needs to be a way to adjust for the slack.  The best way is to do this is the same way it is done on the real tank.  A hole is drilled into the compensating idler support arm.  Center the hole to the raised circle on the inside of the arm, Fig. 32.  I used an 0-80 machine screw, but any small screw will do.  The only purpose of the screw is to keep the arm in place while taking the slack out of the tracks, Fig. 33.  Once the position is determined, the arm can be cemented in place.