Sunday, 23 November 2014
Universal Carrier Mk II or "the Bren Gun Carrier".
Picture Courtesy of Australian War Memorial
My next project will be the Universal Carrier Mk II, or as many people know it, the Bren Gun Carrier.
I have decided to make 12 of these versatile and widely used machines. Mine will be the Australian version, but the differences between the English built and Australian built versions are minor.
Construction started on the road wheels and drive sprockets. The drive sprockets were built up from .60 thou sheet and the method of cutting a raised circle for the face of the sprocket is illustrated below. A suitable sized hole is first drilled in the plastic sheet, the required diameter marked out and then the waste is gradually removed from around the circumference. A file is used to finish off any rough spots.
The rings were then laminated to .60 thou circles of plastic sheet and the drive sprockets were made up as per this post: Making Drive Sprockets
The road wheels were made up from 16 mm aluminium tube with a .20 thou plastic inner rim. This protruded from the aluminium tubing by .5 mm to give the impression of a rubber tyred wheel. 5/32nd tubing was used as an axle tube and six spokes per wheel were inserted. As I mentioned earlier, I am making the Australian version and one of the differences is flanged spokes as opposed to the plain spokes of the English version. The flanges were made up from C channel Plastruct (the old type, before they went to polystyrene). All of the above were used as masters to create silicon moulds so the road wheels and sprockets could be cast. This also gives me the option for the Vickers Light Tanks if I ever decide to go down that path. A jig was made up with the intention of casting road wheels, sprockets, suspension units and tracks as one casting, but on reflection I felt this would have been a nightmare to de-mould, the road wheels alone take a bit of effort!
The lower hull sides were marked out on .30 thou sheet and then cut, care being taken to ensure uniformity. The NWSL Chopper was used extensively in this process. The holes for the axle tubes were also drilled out using a simple drilling jig and a drill stand.
Noting that the three bottom road wheel's centrelines bisect the floor, I scribed a cut line through this point so that after drilling the holes, the waste could then then be snapped off.
The side and end plates of the lower hulls were cut from .30 thou sheet, with the width again being cut with chopper to achieve uniformity. Offcuts were used to brace the sides and ends.
After the axle tubes had been secured to the hull sides, the floor plates were added, these being cut from .40 thou sheet. These plates were also braced with offcuts of plastic strip.
The above photo shows a completed lower hull with road wheels, drive sprocket and suspension units attached. I am aware that the road wheels, etc, should be thinner but I have modelled them this way, a sort of bas relief, as I believe it makes for a stronger model. I don't think it will distract overly from the completed model and it is easier to do!