1/16 RC US 155mm Gun Motor Carriage M12 - Build

[lmcq11]

Thanks Barry,

In the following two posts, i am presenting the spade elevation mechanism.

The M12 rear spade is equipped with a winch on the right side that is operated with a manual crank from the fighting compartment. It controls a metal cable that goes through a set of pulleys at the rear attached to the hull and the spade.

1/16 RC US 155mm Gun Motor Carriage M12 - Build

As this is a detailed scale model in addition to being an RC model, I need all details to be authentic. I wanted to install inside the hull right side the small RC winch below with the cable that would run through the upper hull and through the manual winch, simulating the manual cranking as the spade goes up and down. However, i did not realize earlier that this little winch is so powerful. One imperfect use of the winch using the RC control or an issue somewhere in the end to end system and the whole elevation system could be destroyed. You will see down below.

1/16 RC US 155mm Gun Motor Carriage M12 - Build

First thing to do was to create a working manual winch, whether it is operated by the RC winch inside the hull or manually with the crank using fingers. Vandra provides 3D printed set of parts for a non functional winch, and which has limited resemblance to the real thing, as shown next to the 1/35 kit, which is also incomplete but at least resembling. I therefore had to create the winch from scratch.

1/16 RC US 155mm Gun Motor Carriage M12 - Build

This is the drum. I used a gear taken from an old turret pellet shooter i had in the scrapyard, with some metal tubing and plastic.

1/16 RC US 155mm Gun Motor Carriage M12 - Build

The created the working mechanism with a pinion gear attached to the crank. I reused a section of the Vandra part for the arm.

1/16 RC US 155mm Gun Motor Carriage M12 - Build

As shown below, the cable uses a string of pulleys at specific locations on the hull and spade, with the end point of the cable on the left side of the spade. The whole mechanism is therefore quite fragile for RC purposes.

1/16 RC US 155mm Gun Motor Carriage M12 - Build

View of the first pulley, its a double wheel pulley with the cable running through the middle. The cable goes up and down as the spade is raised or lowered.

1/16 RC US 155mm Gun Motor Carriage M12 - Build

Working pulleys are created using simple material, replacing the 3D printed static ones provided by Vandra.

1/16 RC US 155mm Gun Motor Carriage M12 - Build

1/16 RC US 155mm Gun Motor Carriage M12 - Build

And this is the spade elevation system.

1/16 RC US 155mm Gun Motor Carriage M12 - Build

Continuing on following post

[lmcq11]

View of the raised position. When raised, there are two locking bar with hooks that needs to be pulled up and attached to their anchor points on the hull. Notice position of the cable on the upper pulley.

1/16 RC US 155mm Gun Motor Carriage M12 - Build

Close up on the hull main pulleys, created with the proper shape and attachment points.

1/16 RC US 155mm Gun Motor Carriage M12 - Build

First pulley on the spade. You can see the attachment point for the right locking bar.

1/16 RC US 155mm Gun Motor Carriage M12 - Build

The spade is lowered or raised by manually turning the crank slowly on the winch, while carefully monitoring the cable on the spade pulleys at the rear. As the weight of the whole spade is no way near the real things, and as the little pulleys are light and not as precise as they should be, the cable gets easily pulled sideways and stuck, at different places every time. Operating the RC winch to the cable would certainly tear different parts of the spade elevation system at one time or another. I determined it was too risky to leave it on. So, i reluctantly decided to switch to the manual mode, like the real thing, and remove the RC winch from inside the hull.

1/16 RC US 155mm Gun Motor Carriage M12 - Build

Left side with pulley number 2 on the spade and number 3 on the hull, and the end point on the spade.

1/16 RC US 155mm Gun Motor Carriage M12 - Build

1/16 RC US 155mm Gun Motor Carriage M12 - Build

Overview of the pulleys and cable.

1/16 RC US 155mm Gun Motor Carriage M12 - Build

1/16 RC US 155mm Gun Motor Carriage M12 - Build

You can see the little hole through which the cable from the internal RC winch was coming out, doing a few loops around the drum and then going towards the back. As mentioned above, it did not work out for me due to the fragility of the pulley system of the M12 design. Maybe someone with better skills could make it work perfectly but i preferred to keep it manual to safeguard the model. The RC winch was too powerful to trust. There was also difficult to make it stop at the precise position needed. And the travel lock bars have to be manually positioned also.

1/16 RC US 155mm Gun Motor Carriage M12 - Build

And one last view for Herman who seems to like the Canadian landscape in winter.

1/16 RC US 155mm Gun Motor Carriage M12 - Build

Next step, rear mud guards and tail lights, then detail the top of the upper hull sides. Getting towards the finish line here.

Regards, Louis

[tankme]

That's quite the system there and you did it justice. I'm sure with way it is designed the real crews of the M12 clothes lined themselves on those cables on more than one occasion.

[HERMAN BIX]

Magnificent.............
That pulley arrangement is a work of art, and I can see why you would not want it to be powered.

Thanks for the landscape shot!...............its 31C outside here
I show the kids what Canada looks like in real life winter ! "dad, why dont you move there & build models"

[EAO]

Dear God!

Louis has now mastered rigging! What's next!?! Stunning work as always!

Cheers,
Eric.

[lmcq11]

Thank you Tankme, Herman and Eric for your encouragements. Yeah, not a fan of rigging on RC tanks, but looks good.

Continuing with the build, with a short Youtube video of the model in action at the end of the 3rd post.

The Vandra rear mud guards are too wide, too short and don't have the right shape.

1/16 RC US 155mm Gun Motor Carriage M12 - Build

New ones are done in plasticard. In order for them to keep their shape, i gave them an internal structure that does not show under an thin plasticard overlay.

1/16 RC US 155mm Gun Motor Carriage M12 - Build

They are mounted on the lower hull in order to keep the upper hull removable. Their shape sliding under the fender does not allow them to be installed on the upper hull. The support bracket was an issue though.

1/16 RC US 155mm Gun Motor Carriage M12 - Build

They are given the steps seen in references. To keep the hull removable, the tip of the bracket needs to remain unattached. Care is required when putting down the upper hull.

1/16 RC US 155mm Gun Motor Carriage M12 - Build

All the details on top of the hull needed to be redone for accuracy, including the cleaning rods that look much better in brass than the resin blob provided.

1/16 RC US 155mm Gun Motor Carriage M12 - Build

1/16 RC US 155mm Gun Motor Carriage M12 - Build

One of the rod is shorter on purpose, seen in reference.

1/16 RC US 155mm Gun Motor Carriage M12 - Build

What i think are fuel tank vents were also redone, replacing the 3D printed blobs.

1/16 RC US 155mm Gun Motor Carriage M12 - Build

The resin fuel caps were removed and replaced with Mato metal fuel caps, augmented with some brass rods for details and repositioned at the proper place on both sides.

1/16 RC US 155mm Gun Motor Carriage M12 - Build

The M12 now features a full load of ammo.

1/16 RC US 155mm Gun Motor Carriage M12 - Build

Continuing on following post.

[lmcq11]

Rear lights LEDs have been wired. Ammo are just temporarily installed with a small drop of superglue, until painting is finished.

1/16 RC US 155mm Gun Motor Carriage M12 - Build

Noticed the bracket to secure the ammo rounds in place.

1/16 RC US 155mm Gun Motor Carriage M12 - Build

1/16 RC US 155mm Gun Motor Carriage M12 - Build

I noticed later that the tip of one of the ammo round on the right was damaged and need repair. I need to remove them all anyway for the painting.

1/16 RC US 155mm Gun Motor Carriage M12 - Build

Overview of the fighting compartment.

1/16 RC US 155mm Gun Motor Carriage M12 - Build

The fire extinguisher stand on the right was fun to build. I do have an extinguisher that fits it but it seems to have been lost somewhere on the messy workbench, can't find it right now.

1/16 RC US 155mm Gun Motor Carriage M12 - Build

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1/16 RC US 155mm Gun Motor Carriage M12 - Build

Th rear is mostly finished.

1/16 RC US 155mm Gun Motor Carriage M12 - Build

The pin going down on both sides is called a sponson brace. There is another metal plate that need to be aligned with it and attached to the lower hull, not yet in place.

1/16 RC US 155mm Gun Motor Carriage M12 - Build

1/16 RC US 155mm Gun Motor Carriage M12 - Build

continuing on following post

[lmcq11]

1/16 RC US 155mm Gun Motor Carriage M12 - Build

Head light LEDs have been wired.

1/16 RC US 155mm Gun Motor Carriage M12 - Build

1/16 RC US 155mm Gun Motor Carriage M12 - Build

Final overview of the electronics under the hood. The Heng Long T90 short battery fits the small compartment above the recoil servo.

1/16 RC US 155mm Gun Motor Carriage M12 - Build

Overview of the model as it stands today.

1/16 RC US 155mm Gun Motor Carriage M12 - Build

1/16 RC US 155mm Gun Motor Carriage M12 - Build

View of the rear mug guards with the spade in raised position.

1/16 RC US 155mm Gun Motor Carriage M12 - Build

1/16 RC US 155mm Gun Motor Carriage M12 - Build

1/16 RC US 155mm Gun Motor Carriage M12 - Build

Short YouTube video of the mostly completed model in action. The spade would need to be firmly dug in in order to provide support for the hull, but you get the idea.

phpBB [video]

Next step, a final walk around to add the missing details, such are storage boxes on fenders, tools and tie downs,

Regards, Louis

[PainlessWolf]

Louis!
All of the Kudos from me for the day, Doc. Another rare piece of Armor brought to Life in a museum grade quality Build.
regards,
Painless

[lmcq11]

Louis!
All of the Kudos from me for the day, Doc. Another rare piece of Armor brought to Life in a museum grade quality Build.
regards,
Painless

Thank you Painless, as you can see, i am a big fan of American Armour.

The following 3 posts are to finalize the construction of the build, with the remaining accessories and tools.

Seen below are the Vandra provided boxes and tools, compared to their Academy 1/35 equivalents. There are major differences between all components and they all have issues.

1/16 RC US 155mm Gun Motor Carriage M12 - Build

Starting with the box for the grousers on the left side.

1/16 RC US 155mm Gun Motor Carriage M12 - Build

I used the Academy box for size and shapes extrapolation to 1/16. Sadly, I noticed later on that i should not have done that without checking against references. The box ended up to be on the short side by a few mm. Not dramatic, I decided to live with it. I also did not repro the grousers as this box in wartime reference pictures seems to have been mostly used for general storage instead.

1/16 RC US 155mm Gun Motor Carriage M12 - Build

1/16 RC US 155mm Gun Motor Carriage M12 - Build

The two boxes on the left fender also gave me issues. Reference pictures also show variations of these in terms of details and orientation.

1/16 RC US 155mm Gun Motor Carriage M12 - Build

I decided to reuse the small Vandra box, although i had to shorter it dramatically as it was way too high. The larger one should be more square and needed to be completely redone.

1/16 RC US 155mm Gun Motor Carriage M12 - Build

1/16 RC US 155mm Gun Motor Carriage M12 - Build

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These bizarre things seen deployed under both tracks at the front are called "Collapsible chocks" and used to stabilize the tank prior to firing.

1/16 RC US 155mm Gun Motor Carriage M12 - Build

These are stored on right front fender as shown here on the Aberdeen M12 prior to its restoration. They seem complicated at first but after some analysis of pictures and study of the 1/35 kit, they are simpler than they look.

1/16 RC US 155mm Gun Motor Carriage M12 - Build

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1/16 RC US 155mm Gun Motor Carriage M12 - Build

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continuing on following post.