E-100 super heavy tank

Specifications:

Scale: 1/22

Drivetrain: 2 L motors

Turret traverse: M motor

Gun elevation: M Motor

Power supply: Rechargeable LiPO battery

Suspension: Torsion bars

History

Super heavy and prototype vehicles have always been interesting subjects for me, as I find they push the limitations of engineering. As usually each vehicle focuses on a large caliber armament mounted on a heavily armored hull, and to lower the ground pressure for these vehicles, a wide track is usually required as well. For the design of the E-100, a late war German prototype vehicle from the Entwicklung series

, a means of standardization of components for vehicle production. The E-series was divided into 5 classes to replace the current range of armored vehicles used by the Wehrmacht , E-10 (a small armored vehicle of the 10-15 ton class), E-25 (an armored vheicle of the 25-30 ton class), E-50 (a medium armored vehicle of the 50 ton class to replace the Panther), E-75 (a heavy armored vehicle of the 75-80 ton class to replace the Tiger), and the E-100 (an overly heavy armored vehicle of the 130-140 ton class). Out of all of these vehicles the E-100 had the most developmental progress, and was being assembled in Haustenbeck, where it was later captured by the allies. Most components of the hull were complete, though at the time of capture, the E-100 was missing the coil springs needed to complete the suspension, as the coil springs had been delivered to the wrong location by rail. Some progress was continued following, the capture, as the vehicle had the coil springs installed, and the remaining suspension components were installed. The vehicle was then relocated outside, and it was later shipped to United Kingdom after the war where it was studied, and later scrapped. The vehicle featured the Maybach HL230p30 V12 700HP engine, which was already strained in the application of the 70 ton Tiger II. Though planned upgrades for a Maybach 1200HP engine was considered as a future option to propel the 123 ton vehicle to 40 kph.

A color photograph of the E-100 Chassis after capture

The armament and turret configurations vary, as on the factory assembly drawings the vehicle is fitted with the Maus Turret, with an up armed 15cm cannon. Information about these design choices can be clarified from Hilary Doyle's Panzer Trackts 6-3. Documentation from 17 may 1944 reports that Krupp had designed a new turret for the E-100 that weighed only 35 tons, and was based on the same configuration of the Maus II turret (drawing Bz 3269) with the 12.8 cm gun, and a thinner armor thickness layout. On the 8th of april 1944 Krupp was assigned to create a 1:5 scale wooden model with a 12.8cm armament. Krupp was latter assigned on 15th of may 1944 to create a 1:10 scale model of the Maus II turret with a rangefinder. Following 10th of july 1944, development of all armored vehicle with heavy guns was halted by Reichminister Speer, due to the current situation in the war. 

E-100 hull with planned Maus II turret.

My model

The main focus with designing this model was to replicate the external appearance at the smallest scale that I could motorize fully with the current range of Lego treads. Having previously built an E-100 four years ago, I wanted to reattempt that design, however see if it was possible to do almost all of the same functionality at a smaller scale, as If I planned to do the model at 1/18th scale, this would require brick built treads, something I am looking into for future models, though the cost for the treads would be somewhat expensive, as it would require around 1000 parts per tread, and with college, I had little time to spend building, as all of the design and building was accomplished during short breaks from college. 

My old disproportionate E-100 from 2014, my 3rd major tank model, 

as you can see we all have to start somewhere.

The biggest challenge with the design of my new model was the spacial constraints for the motors and power supply. I utilized torsion bar suspension, as this is one of the more compact forms for suspension that is possible with the Lego system. This meant that everything else would need to be mounted above this, thus my largest constraint being the battery box, this required me to make the hull slightly taller, even with the battery box being mounted directly above the torsion bars on its side. I originally intended to fit an engine into the engine bay, however I still needed to mount an Sbrick for controlling the model. After several attempts, I decided to not include the engine bay, as this made it difficult to charge and toggle the power switch for the LiPo battery. The final result of the hull being a robust and simple drivetrain, and a compact traverse mechanism all mounted in the hull, eliminating any needed wires to be routed into the turret. Another feature I wanted to replicate was the ability to remove the armored side skirts, this was intended in the real vehicle for rail transport. As the skirts and the outer road wheels would be removed, and a smaller transport track would be used, so the vehicle could fit onto railcars.

Internals of the model

The turret was another challenge for the design of the model, it is rather straightforward in shape, though making these angles structurally strong was an interesting challenge, as there are a couple parts that have some minor flex in them, though this makes the turret completely rigid. Another challenge for the turret design was the mantlet, as with its form, and the positions of the trunnion inside of the turret required me to make the front armored plate spring loaded, thus eliminating most of the play in the trunnion, as this applies a constant force to the back of the mantlet, and it allows the mantlet to move upwards, this will angle the front plate backwards slightly. 

A still from one of the renders, you can see the shape of the turret support structure

Overall I am very pleased with the results of this design, it is about 90% accurate, with some features needing to be slightly altered due to the limitations with Lego. Though this may be one of my better scale accurate models, though I am striving with future models to get even closer, though that's just one of the challenges with working with Lego.

And since I did a large portion of the design for this model digitally, instructions are available for it.

Orthographic views of my model

a comparison with blueprints from Hilary Doyle's Panzer Tracts 6-3

Video

More photos