1/6 scale RC Marder II Panzerjager with 7.5cm PaK40/2

[lmcq11]

Hi Everyone,

This is the planning phase of the build of an RC 1/6 scale Marder II based on the Dragon 1/6 Panzer II chassis.

The Marder II is a complex undertaking. I am currently accumulating knowledge of the tank, material and various parts, which take some time. I will start the actual construction after the summer. In the meantime, i will post a few updates once in a while on the status and also to provide an idea of the plan.

Objectives in general:
1- An 1/6 scale RC tank with motorized tracks, gun rotation and elevation, lights and sound. Recoil is still TBD.
2- Budget of less than US $1K, and have fun solving needs at the cheapest cost possible. I am an amateur...
3- Detailed crew compartment interior, including driver and transmission area at the front.
4- Be the most historically accurate as possible.
5- Buy some parts on the market, when available and affordable.

First, references such as the Achtung Panzer Vol 7 and Nuts and Bolts Volume 31 are essential.

Achtung Panzer Vol 7

This is the model that will be built. It is based on the Panzer II, not the 38(t).

Achtung Panzer Vol 7

Detailed view of the driver area from the fighting compartment. Some parts will come from Armorpax.

Achtung Panzer Vol 7

View of the radio and rear. The Fu5 radio is on order from Field of Armor. The rack will be quite something to build.

Achtung Panzer Vol 7

This is the Dragon kit, no 75045. It is a Panzer II C. The Marder II was built on the Panzer II F, so some area of the chassis will need rework, such are the front armor, driver periscope, idler wheels and exhaust. I purchased the kit a few years ago and was on sale for about $220 at that time. Now, I can see it is difficult to get and quite expensive.

Dragon 75045 1/6 Panzer II C

As a 1/6 scale model, it is large without being too big to handle, or to store. The turret won't be wasted, I am planning to use it later for a bunker model. That should be fun too at that scale.

Dragon 75045 1/6 Panzer II C

Next, I will post information on the gun.

Regards, Louis

[lmcq11]

Hi,

This is the gun that will be used. It is a 1/6 scale Ultimate Soldier Pak 40. It's big. I bought it "used" on eBay for $98. It is in good order. It will need rebuilding and the carriage won't be used. After examination, the level of detail is less than I expected. Although I still think it is a good base (better than nothing at the least), it will need a lot of corrections, detailing and enhancement to make it look good and accurate. Some parts will be replaced for sure, such as the hand wheels. At first sight, the dimensions and proportions seems ok. I'll find out later. It can manually recoil, so I will need help in figuring out how to make it recoil using some gizmo, but without losing the accuracy, at least visibly.

1/6 scale Ultimate Soldier Pak 40

1/6 scale Ultimate Soldier Pak 40

1/6 scale Ultimate Soldier Pak 40

1/6 scale Ultimate Soldier Pak 40

1/6 scale Ultimate Soldier Pak 40

4 ammo rounds and a box were coming with it but they are not good looking, unlikely to be used.

1/6 scale Ultimate Soldier Pak 40 ammo and box

Next, I will discuss the planned motorization.

Regards, Louis

[lmcq11]

Hi,

Now, for the motorization, I understand someone can sink a fortune on a 1/6 scale tank. But this is a plastic kit, not a metal kit, so I think the tank will be light enough to still be driven by 7.2 volts engines. A Marder II is not a leopard II, so as long as I can drive it around slowly, I will be happy. The sprockets and tracks of the kit are in plastic so I cannot put anything too strong on these either.

Because I do not want the engine and gears to be exposed in the driver area, I needed to find a way to put the motorization totally at the tip of the tank. I thought of a power tool motor with its inline gears.

I selected and purchased a 8 volt power tool at Walmart for $20 with the plan to disassemble it and use the motor and gears. Below is the model purchased.

Black and Decker power tool

Below is the engine and gears after stripping the power tool. The motor is a Leshi 7.2 Volt motor. The rotating gears are quite powerful and of good quality. I kept the metal shaft of the keyless knuckle. I will eventually cut it at the right location. There is a strong screw that goes inside and start to screw into the metal shaft about mid way inside. It's perfect. There is enough material here to build a strong base for the sprocket and a screw to keep it there. TBD how later.

Black and Decker power tool

This is how I am planning to install the motors, one of each side. it fits. I will have to install them on some frame, and also make them coexist with the front of the planned Armorpax Panzer II transmission that will likely have to be modified. Cables will run through the transmissions all the way to the controls at the rear of the tank where the Panzer II engine is located. The motors will be visible but that area at the front should be dark enough so that it will not be obvious. I did a trial by plugging the engine against a HL control and it works well. Motorizing a 1/6 scale tank for $40... well, that's the plan. Hope it works.

Planned arrangement of motor

Regards, Louis

[lmcq11]

Hi,

As you can see, a 1/6 scale Panzer II is not that much bigger than a 1/16 Leopard II. The Panzer II is of a manageable size for a 1/6 scale tank and the plastic is light, making it more easy to deal with than other large models, like the Dragon Sherman or full metal kits.

Panzer II / Leopard II comparison

Large plastic parts of that size have some warping in them, likely a molding limitation. Not exactly sure if the microwave is good to heat plastic and resolve such issues like it is for resin. I will have to make some tests. At least, there is no air bubbles... Dragon has molded reinforcement shapes on the inside of the hull parts. These will need to be sanded and replaced by a sheet of plasticard, likely with some metal parts as well that will replicate the bottom support struts for the suspension.

Panzer II parts

The kit comes with a nice and beautiful metal cover for the rear exhaust. Although the Panzer II C muffler is not the same shape as the Panzer II F used on the Marder II, I think this part can be reused with some basic reshaping. All the hinges will need to be made to work, some requiring replacement.

Panzer II muffler grill

I was advised by Sassgrunt that the panzer II tracks are nice and that simple and inexpensive 2 inch nails can be used as track pins. It's true, it fits perfectly. The track pin holes do not even have to be drilled. This will certainly save a lot of time and effort. The tracks are light, well done and quite solid. Just need to cut the tip of the nail, file the head to make it rougher and drive it inside the plastic track to make it stay there, similar to 1/16 track pins. Conversion to working tracks will be real easy.

Panzer II tracks

Panzer II tracks

Next, I have to inspect the road wheels and sprocket, and see what is the situation. That is likely where the main issue reside with the conversion. Based on the Sherman, road wheels shaping and usability is not a Dragon strength at that scale.

Regards, Louis

[HERMAN BIX]

I'm all eyes for this one mate..................very smart use of alternative hardware.

I think it should be in larger scale builds section though, but it can stay in here for a day or so.
Any issues with the shift to the other section ?

[lmcq11]

Thank you Herman, I did not realize it. Please shift to other section at your convenience.
regards, Louis

[HERMAN BIX]

Sweet as- no biggy mate................as long as youre ok, I will move it to where the big stuff lurks !

That PaK 40 sure looks good from here as it is.....

[lmcq11]

Hi,

Now for the suspension and wheels, it is better than anticipated.

The suspension arms are empty, but it creates a nice tub into which epoxy can be poured to increase robustness and also prevent dirt from entering the cavity when operating the vehicle. No, I will not make a working suspension by replacing this plastic components with metal ones.

Pz II Suspension

These are the main parts for the road wheels. You can notice a spelling mistake on the "Continental" markings. I never heard of Continentau. I think this can be easily fixed by changing the U to look like an L. You can also notice the plastic bearings that can be easily replaced by real ball bearings of 10x19x5mm diameters in order to get the road wheel to roll smoothly.

Pz II road wheel

Probably designed to be glued, some simple device using a screw will need to be used to keep the road wheel attached to the suspension arm.

Pz II road wheel

The return rollers are designed to be glued. I will need to replace the 10mm shaft by a 5mm one, and install one or two standard 5x10x4 ball bearings, with a plastic ring glued at the tip to keep everything in place. The rollers can be also filled with epoxy. Notice the spelling mistake on Continental also on the rollers.

Pz II return rollers

This is the whole arrangement. It is of good quality and will look good.

Pz II Suspension

This is the idler wheel parts. The Panzer IIC molded idler wheel patterns will need to be removed and reconfigured as per IIF version, reusing the same parts, no big deal.

Pz II idler

The plastic bearings will need to be replaced by a real ball bearings of 12x18x4mm, likely 2 per wheel, with a ring glued at the tip as a retention device.

Pz II idler

For the sprocket, the plastic shaft needs to be removed and a whole created in the transmission cover for the motorized shaft to connect with the sprocket. The plastic bearing won't be used of course.

Pz II sprocket

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Looking at the drill shaft, it will likely need to be cut around the marked location.

drill shaft

There are 3 grooves for the drill claws that I am planning to reuse to create a good strong anchor for the sprocket rotation. Not sure yet how I will finalize this critical arrangement (hub cap, sprocket, screw, shaft). The drill knuckle shaft itself can be unscrewed from the motor shaft and it is the screw inside that keeps it tight. I am planning to reuse this concept to allow the sprocket to be removed at any given time. So, the knuckle will likely be permanently fixed to the sprocket, but the center screw will be accessible through a removable hub cap. I have to think this over and ponder all the other options. The plastic sprocket itself needs to be reinforced as well on the inside around the joint with the knuckle, likely with epoxy or otherwise. How the motor and gearbox will be fixed to the chassis is another story.

drill shaft

Regards, Louis