Mark IV British WWI tank
The Mark IV British WWI tank is on top of my (too much) long “to do” list since when I got the Ehmar Mark IV Male.
Ehmar Mark IV Male 1/35
I was immediately impressed from this strange shaped tank, and decided to build the model with the full interior, so started to collect as many infos as possible. Certainly it helps, to live in the Internet era, however the turning point was to get the Owner’s Workshop Manual on the Mark IV.
The Great War Centenary in 2014 was the occasion to finally start working on the Mark IV.
Since this building will be a long and tricky one, I’ll post more different articles, each of them concerning a limited section of the model, as “autonomous” posts.
At least, that’s my goal at the moment..
Well, the introduction is done. Let’s start with the first post.
Mark IV British WWI tank – The differential
Proceeding from the back of the tank to the front the main elements are the radiator, the differential, the gearbox, the engine and the driving compartment.
These elements are resting on a subframe.
I found many photos and also some useful drawings of the interior, thanks to Internet and to the mates of Landships II. Then, the Owner’s Workshop Manual was of great help, too, and finally I myself made some rough drawings to try to forget nothing during the building.
Two sections of aluminium tube and a plasticard disk were used to build the basic structure of the differential.
The structure once assembled. The pencil lines on the tubes show the limits of the tapered sections of the axles, to be reproduced from the center towards the ends.
The main body and the axles are shaped with Milliput. This kind of work would be easier having a lathe.. The tapered shape of the axles was pretty tricky to get.
The junction between the upper and lower halves of the case of the differential are made with plasticard. The pieces are yet quite roughly shaped..
Once assembled the plasticard pieces, the junction area of the upper half of the case was reproduced with Milliput. Then I drilled holes (black arrow) to insert plastic rod sections, reproducing the holders for the bolts actually joining the two halves. The heads of the bolts are plastic rivets (red arrow). Note the metal strips, used to reproduce the ends of the tapered sections of the axles.
The supports of the differential are made with plasticard. As usually, to make scratchbuilding easier, the piece that you want to reproduce must be discomposed down to its basic components..
Without any doubt, not the best photo..The support assembled (red arrows). Their inner walls still missing.
Front right view. More details added to the main body.
Front left view. To be honest, I cannot describe what every part was for.
Hexagonal bolts added. I used both resin bolts by Verlinden and copies of them made pressing heated sprue into a Milliput mold. However, the resin ones looks far better, so I placed them on the fore part of the differential.
Again, I’m not able to describe the function of the details inside the yellow circles. The ends of the differential are only roughly shaped since they will be covered in the finished model. They are..telescopic at the moment, to allow a proper fitting of the differential to the side walls of the vehicle.
This little stuff on the bottom of the differential case is not yet completed. I’ll add the missing bits just before placing definitively the differential. The carpet monsters here are fat enough..
The back of the differential. My goal is to allow to have a look as complete as possible at the interior of the model when it will be finished. This area will be visible through the door of the rear plate.
Some sanding still needed, and probably I’ll be aware of some still missing detail in the next days.
However, at the moment I call the differential case done.
Of course the shaft joining the differential to the engine will be built after the engine itself.
Next post on the radiator.