Sherman's Granddad - US M2 Medium

A Scratchbuilt Project - Part 1

The M2 was constructed of butt-jointed armoured plates riveted to an underlying frame. I by and large followed this construction method, cutting and joining the plates to match the originals.

I did not try to replicate the scale thickness of every plate - rather I settled on using the 1” (25.4mm) plate thickness overall for the hull structure. This scales out to 30 thou (0.75mm) in 1:35 scale. Apart from the 1.25” plating under the transmission and driver’s position, this was the thickest plate used on the M2, and in 1:35 scale provided a good basis for construction, allowing minimal internal bracing with virtually no distortion.

Major elements of construction are as follows:

• Hull Construction: All hull plates were constructed from 0.75mm (30 thou) sheet styrene, with internal bracing for vertical sides provided by 90 degree styrene angle pieces.
  

  Initially, all structural information which could be gleaned was entered into a computer aided drawing (CAD) package to produce a clean set of 4-view base drawings showing the hull plates without being cluttered by suspension, track guards or on-board storage. This enables a simplified view of the hull showing all angles and individual plate sides otherwise hidden by suspension units etc.

  A similar set of drawings was produced for the turret.

  From these simplified drawings, template drawings of the true shape of each hull plate were produced. Placement of rivets and scoring for the edges of plates not being cut separately are marked on the templates. Also, markings for the positioning of components such as suspension bogies are also incorporated in the template drawings.

  On the template drawings, I marked in the allowances for the thickness of the plastic sheet being used. Naturally, to get this right requires a good understanding of the “geometry” of the vehicles (i.e. how the plates were put together), which came from close study of pictures of surviving machines etc.

  The parts were then assembled using the plastic right angle shapes cut to length for bracing, and cemented with thin liquid cement.


• Suspension: Bogies are heavily modified Tamiya units from their M3 Grant kit. Drive sprockets and rear idlers (including mounts) came from the Academy M12 kit, as did the transmission cover and drive mount. Road wheels were from the Tamiya Early M4 since they were made to fit the axles of the M3 suspension units without the need to precisely drill out the axle holes.


• Tracks: What can I say? Guilty as charged of masochism! Given that many of the suspension components would be resin casts of modified kit parts which would be super glued to the plastic hull, I didn’t like the idea of using rubber band style tracks tensioned correctly (i.e. to remove any sagging).

  Also there would the problem of cutting down any suitable M4 track set to the correct width. Cutting down the width was necessary since the M2’s tracks ran well within the line of the overhanging fighting compartment / rear fuel tanks. Full width M4 tracks would be unacceptably wide in this regard.

  Accordingly, I settled on using the AFV Club T51 individual link tack set, with a single track shoe cut down to the correct width, and copies cast. And cast, and cast. Seventy nine per side plus spares.

  As a rare concession to sanity, I used the injection moulded connectors from the AFV set.


• 37mm Gun and Mount: The M2 used the early M21 mount (with shoulder brace) and an earlier version of the standard 37mm tank gun mounted in the M2 / M3 series light tanks. This featured a longer recoil / recuperator assembly beneath the barrel.
  

  As a base, I used 37mm gun and mount from the AFV Club M3A3 kit. The gun was modified with the longer recoil / recuperator assembly, and the mount modified with the shoulder brace on the left hand side.

  To provide a good mount for the gun assembly inside the turret, I used the cast bulge from the front plate of the AFV M3A3 turret (which was close to the correct size and shape as the M2 equivalent), and after modification to shape mounted it in the front plate of the M2 turret.

  The outer mantelet from the M3A3 was cut down and shaped into an M2 version. This was basically the correct outer dimensions, needing modification where it fitted to the gun assembly, and some additional detailing.

  Instead of using the barrel from the M3A3 kit, I substituted a turned aluminium version from Jordi Rubio. The kit barrel looks OK - the JR version is a bit more refined in shape, and I figured it would be a bit more resilient over time.



• Rivet Detail: Rivet positions were marked out on the templates for each plate and each position was drilled out with a motor tool after “centre punching” with a needle held in a pin vise. The holes were then fitted with Grandt Line rivets of correct size and shape. (0.32” / 0.75mm round headed).

  Various bolt heads were shaved off the “spares” moulded onto the sprues of the AFV Club M3A3 and the Academy M3 kits. These spares were the source of rounded, slotted bolt heads used to secure the glacis plate, and of the flat hex shaped bolt heads used elsewhere. For flat hex and round shaped bolts of different sizes to these I used a punch and die set.

  Riveted angle iron was fitted along the top edge of the lower hull, and on top of the rear fuel tanks up against the sides of the engine compartment. This was fabricated using Evergreen angle strip, riveted with Grandt Line rivets. One strip was thus fabricated, with additional strips cast from this master, then cut and fitted as needed.

Finally, repeat after me, “rivets are my friends”. Keep this chant in mind. It will help. Really.

Peter Hartup

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