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

[SoCalBobS]

Chiming in re Vandra kits. My building focus is for functioning models to be used in IR battles, not for finescale detail. I find them a fun challenge. They're certainly not "shake the box and it's done" products.

[tankme]

I'm sure if anyone can fix the M12, lmcq11 can... My Vandra SU-122 has been shelved for a while so I can forget how frustrating fixing the gun elevation is.

[EAO]

Louis,

Now this will be fun...again!

Can you imagine being around one of these when it sent a round downrange?!? That blast must have been brutal!

As the late Col. Jeff Cooper once said, "If I had known that I'd live through all these battles, I might have worried about hearing protection"!

Cheers,
Eric.

[lmcq11]

Thank you guys for your encouragements, i think this is becoming a difficult build.

This post is for the suspension bogies.

To make the build more interesting, i decided to introduce a component i never used before, the Sherman Mato metal bogies that comes with the all metal Sherman and M10. The original M4A1 plastic bogies were way oversized, positioned too far away from the hull and not enough space was left between bogies for the suspension to fully operate. Comparing them with the metal replacement, it is an improvement but we can see how oversized the plastic bogies where, and probably how undersized the metal replacements are.

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

The suspension on these is fabulous. It operates like the real thing. No more simple swivel and no compromises.

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

The suspension arms elevates independently and they slides under the arm above, linked to a pivot central part with two real compression springs which swivel inside the suspension hub, and sliding up and down along rails as well.

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

It is the first time i investigate these bogies, a nice touch over the use of plastic Mato or Heng Long bogies.

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

They need some clean up, a bit of polishing and filing of the rubber band to make them look worn without the molding edges. Comparing before and after.

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

For some reason that eludes me, Mato wants its suspension to be 3mm away from the hull than it should. I see no reason for that. The spacers that were doing that were removed with the Dremel and a sanding disk. Not easy as it is quite hard.

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

The metal bogies are ready to be mounted on the hull.

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

They were attached using epoxy glue as the metal attachment that locked the bogies inside the hull were not usable anymore due to the removal of the spacers on the front plate.

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

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

The interior of the hull was cleaned up of all features, and made ready for the next steps. This is where the bad surprised started.

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

Continuing on following post

[lmcq11]

The 1/35 scale Academy kit will get partially assembled as i advance with the 1/16 model, and will be kept at my side at all times.

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

Bad surprise, by dry fitting the deck over the lower hull, we can see that the Vandra M12 designer did not represent the upper hull correctly. The deck is not lowered inside the hull as it should be. And that also means that a lot of other things will also not be right.

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

Double checking with reference book also show the deck is about 1 feet lower than the Vandra kit.

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

Ok... no trouble, i hated the double diamond tread plates anyway. Cracking the hull open on a Vandra kit is unavoidable when looking for an accurate model. But i was not planning having to do this, there is nothing easy with these kits. I really want an M12 that is accurate, not something that looks like an M12 twelve feet away. These kits are not for everyone, and it might be easier to just scratch build one...

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

Ah, another bad surprise. Despite my calculations and the shaving of some of the metal from the Sherman gearbox, i am missing about 2mm for the upper hull to fit over the motor at the top. Need to find a solution.

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

Time for a break and some re-planning.

Regards, Louis

[BarryC]

Louis,

Looks like the Vandra kit is made to only "appear" to be an M12.

Barry

[tankme]

Louis,

Looks like the Vandra kit is made to only "appear" to be an M12.

Barry

That's an understatement...

[lmcq11]

Looks like the Vandra kit is made to only "appear" to be an M12

Yeah, Checking dimensions against references like a good 1/35 kit would not take the designer much effort. It would actually be simpler as it would ensure the parts come together at the end, and the accuracy would be ensured.

Continuing with the build.

Looking at the upper hull in preparation for the next step, i saw there is a strip along the hull that need to be reduced from 6mm to 4.5. Its going way too low and it shows when sitting on the lower hull.

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

Searching through the junkyard, i found an old Heng Long Panzer III/IV gearbox with metal gears, good enough for an M12. Likely some leftover from another conversion years ago. I did a limited refurbishment of the gearbox by replacing the old motors by less older ones, replaced the old torn wires, replaced the tiny type 104 capacitors by new ones, added a third capacitor between the + and - poles. Tests show it is working well, a lot more responsive at low speed. I had to remove 3mm from the main shaft to align the sprockets with the roadwheels, a 1 minute cut with a metal saw and some filing.

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

Gearbox installed on a 3mm plasticard support base glued earlier to the bottom of the hull. Reinforcement added to the front, providing support for that gearbox screw and also support for the long side covers. The fit of the Heng Long gearbox inside the Mato M4A1 hull is extremely tight. I had to do some surgery by removing anything that was in the way.

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

The three piece transmission cover provided by Vandra is installed, one of the thing they do well. I know its shape was adapted to fit the Heng Long gearbox and the RC Sherman lower hull. It is out of scope of this project to do anything about it that would make this part more accurate.

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

The spacing between the sprocket and the hull cover plate is realistic.

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

No more space issue with the fitting of the upper hull over the gearbox motors.

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

The fenders at the front need to be flat.

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

The M3 Lee fenders that Vandra provided for the M12 need to be discarded. References show no embossed stiffeners on them, and the ugly squared holes meant to go around screws for the transmission cover don't fit my project. These fender parts will be replaced by a flat plasticard section of a thickness to be determined.

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

Looking at the lower rear plate and its angle. The rear of the M12 is totally different that what is normally seen on any Sherman.

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

The whole Sherman M4A1 rear armored plate with the engine hatches has therefore been removed for a complete redesign, including the idler adjusters. The engine on the M12 is located in the middle of the vehicle, which explains the difference.

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

Continuing on following post.

[lmcq11]

Before doing anything at the rear, the upper hull at the front need to be integrated with the transmission cover. Some adjustment is required to get the best fit possible there, which will then determine by default the situation at the rear. The integration at the front looks simpler to do than it actually is... How it ends up depends on the skill of the builder. The fenders that will hide the joint line will be added later.

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

This is the situation at the rear, looking ok. The upper hull is probably 1 or 2 mm too long. I already pushed the upper hull as forward as possible.

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

Dry fitting the new lower base for the howitzer and doing some calculations and planning for next steps. The rear is vertical down to the base, and then angled towards the inside. The 1/35 kit will provide the specs because there is very limited info on the rear of the M12, the rear blade is pretty much hiding the bottom of the hull in that area, its not showing on any picture.

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

The new base will have sides that will connect to the upper hull so that when the upper hull is raised to access the electronics, the whole base with the howitzer will slide and come out as well, along with all the servos attached to it.

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

The M12 as it stands today.

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

Regards, Louis

[lmcq11]

Hi,

Building the 1/35 kit in parallel with the 1/16 model allows me to learn about the M12, of which i really did not know anything. I am discovering it as i go. Comparing the two, we can see the differences with the Vandra kit, including the deck floor previously discarded. Most structural details are simplified, or purely invented to patch an area that the designer did not want to focus on.

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

Sometimes, i do not bother building the 1/35 kit, i would just analyse the individual parts and instructions, and do something similar. But the level of work required for this build prompts me to completely build the 1/35. This reminds me of my 1/35 days and why i switched to 1/16 kitbashing... I would finish the 1/35 in a couple of days... Following instructions, taking care of ejection pins or using a bit of putty here and there really does not bring any challenge. But its really good to get an accurate model. I would not be able to do this 1/16 model just by looking at some pictures. I need the three dimensional view.

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

The left side crew seating area is hollow, with storage under the seats. The seats level are lower than the top plate. There are also triangular plates that protrude inside. The floor is lower. The ammo rounds are places on top of the deck floor, and not inside it. There are ammo stands on the sides. Engine air filters at the front. The floor thread plate is partial and of a single diamond pattern.

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

The right side has a hollow storage compartment. Check out the modified Sherman idler adjusters.

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

A new rear plate is done in 3mm plasticard, and reinforced inside. The dimensions and angle of the new rear plate are taken from the 1/35 kit.

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

The Mato metal Sherman Idler adjusters need modifications. The first step is the remove the rear panels for the bolts with a metal saw, and do some filing.

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

The mounts for the rear blade is right on top of the idler adjusters, and there is a notch inside them where the brackets for the blade go into.

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

These are the finished mounting for the idler adjusters. The ears that are bolted on the sides are not exactly as they should be but since these are mostly hidden behind the idler wheels and tracks, i did not bother modifying them.

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

The rear of the vehicle is cut. I removed about 4mm in length from the Vandra upper hull at the back. This makes it more in line with measurements of the 1/35 kit and aligns with the fighting compartment deck. The bottom rear plate is prepared to have the idler adjusters installed.

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

As most of the rear plates with bolts had to be removed, the idler adjusters are glued with epoxy, and also bolted on the sides.

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

continuing on following post