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

[HERMAN BIX]

Mate, you are like "The Terminator of 1/16th Scale Modeling".................
Relentless, unstoppable, and without pity(for us normal folks) .........

The problem solving on the fly(well thats how easy it looks) is astonishing, again !!
You'll need a 'Long Tom' as a partner wont you ?

[tankme]

I applaud the dedication to getting the projects done in a timely manor... Well and all the detail work. Louis isn't afraid to completely rework....well anything.

[lmcq11]

Mate, you are like "The Terminator of 1/16th Scale Modeling".................
Relentless, unstoppable, and without pity(for us normal folks)

Looks who is taking... Well, thanks. Following retirement last year and with limited travelling and socializing, i have plenty of free time. But I try to limit the modelling to about 4 hours per day though, leaving plenty of time for reading, tea time, eating and exercising...

Louis isn't afraid to completely rework....well anything.

This is where the fun is. I get bored if i just build a kit as is. Also trying to show interesting stuff people have not seen before.

Continuing with the build.

I am starting to put together the howitzer. Because of the scratch building of components, i have to tackle individual items in parallel to make sure that they integrate well at the end, modular approach.

Here is a good picture of the breech. It is also showing the brackets that secure the ammo in place on the sides. I will repro that at the end of the build. Also shown are the two large canisters on the floor rack seen previously. I assume they hold the cartridges.

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

Good view with the breechblock open and being loaded, showing the complex mechanism.

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

Close up of the breech on the surviving M12.

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

Because of the high deck floor, the Vandra gun mount will not be used as it is too short. I also found its resin components to be too weak for recoil. I am starting a new one. Until i can figure the exact height of the mount, i only created the basic form at this time.

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

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

The Vandra cradle is not bad but the details were removed, including the anchor to the mount because these were not located at the right place. Its core is heavy but it makes a stable base. I will be reusing it. A new sliding base plate is made in 1.5mm glossy plasticard. It would have been better to have black colored plasticard for this because painting it will be an issue for sure for the mechanism.

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

New mounting elements are being designed, further forward and on the outer rim.

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

The Vandra breech was just a flat wall with a resin breechblock part glued on it. I have decided that the howitzer should have a opening breechblock to make it more interesting. I created a hollow breech and added carbon tubing inside.

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

The breechblock dimensions were taken from the 1/35 kit but i found it to be too small somehow. I therefore expanded it so that there is more material around the central core.

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

There is no way i would take the time to create a working complex mechanism as show in the picture at the start of the post, but i was able to make it open and close with the main hinge alone. All the finer detailing will be added later as it would otherwise be damaged during heavy construction.

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

continuing on following post

[lmcq11]

The howitzer barrel is given its base for mounting on the cradle.

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

Open breechblock mechanism is completed with the Vandra resin cylinder above it and re-integrated at both ends with stronger material.

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

The core components for the howitzer barrel and its sliding breech mechanism have been built. Secondary cosmetic elements will be added later. At this time, i just want the core components designed so that i can plan and create the prized RC sliding breech recoil, push rod and servo mechanism. A lot of things depends on it.

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

The barrel slides smoothly and freely on the cradle rails. The carbon barrel is extremely light and strong, which will help with the recoil servo. The two holes at the back of the cradle will be handling the piston rods in and out in free flow.

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

The RC recoil system will be designed with the goal of maximizing the length of the recoil.

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

Before cutting the mount, finalizing its shapes or making any holes for the pivot, i have to study and determine the right height for the howitzer on the chassis.

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

The 1/35 kit is helpful for the study as the height is otherwise difficult to determine with pictures.

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

I compared the following two pictures, making sure everything compares well and is where it should be. The gun mount position is looking good (height, position, various surrounding elements). It seems the Vandra fuel cap on top of the hull is not... the only molded on detail i had not removed...

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

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

I have determined that the height is good. Next step is to finalize the mount and gun pivot system.

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

Regards, Louis

[lmcq11]

Hi,

The gun cradle is installed on the mount.

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

At least five finetuning adjustments were required on the connections at the top to make the cradle strait. Its easy to make mistakes on a scratch built howitzer mount like this. Half a millimeter too much left, right, up or down on any of the four holes involved and the gun is not strait. Looking good now.

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

For gun elevation, i was initially planning to install the servo under the deck. However, with the larger base, i noticed it is just wide enough to fit a striped out micro servo inside the mount, allowing me to keep the limited space under the hull for something else. It remains to be seen if this small servo is enough to kept the howitzer steady when the barrel will recoil.

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

The pins of the cradle and mount connections are kept easily removable at this time. The tip of the elevation rod can be manually pushed into or pulled out of the resin cradle hole made on the side.

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

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

The servo wiring goes through the mount and is hidden.

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

The remaining details of the howitzer will be done after the recoil system has been built and fully tested. Until then, they would just be in the way.

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

Showing howitzer at maximum elevation. I could make it go higher but it is pointless as it would bend the recoil push rod too much and create too much resistance. To be confirmed soon enough. Its always time to make the elevation rod longer.

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

The model as it stands today.

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

Time to relax with Platon. Next step; the sliding breech recoil.

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

Regards, Louis

[Ecam]

Keep it up! Hard to wait for progress. Great work!

[HERMAN BIX]

Almost looks like 'Hagenau' outside your window

[Ecam]

Had to re-read this whole thread over! What a job! Love those graphite tubes, I would never have thought they could be cut that cleanly with a hand saw and sanded. I would have figured they would fray.

[BarryC]

Almost looks like 'Hagenau' outside your window

It does for sure.

Barry

[tankme]

Had to re-read this whole thread over! What a job! Love those graphite tubes, I would never have thought they could be cut that cleanly with a hand saw and sanded. I would have figured they would fray.

I have one carbon fiber tube I've cut and if your tools are sharp then there are no issues with fraying. The black dust created is very nasty though. It is a very fine powder and like graphite it sticks to everything.