Scratchbuilt Churchill Mk.IV AVRE SBG

[MonsieurTox]

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I hope you like, thanks for watching !

[Raminator]

Terrific work so far Mssr. Tox, a really beautiful model of an underappreciated tank! The combination of CNC milled styrene and resin 3D printing leaves a really great finish, much more pleasant to deal with than something printed from filament. What resin are you using? It'll be interesting to see how the running gear holds up to the metal tracks.

[MonsieurTox]

Thank you Raminator!

Yeah it's very good, CNC milled parts are great to get good accuracy and was a great help to make the suspension frame. Designing the parts in 3D then in 2D is very time consuming though. The good thing is that I have a great 3D model of the Churchill
I'm working on the track guards at the moment, this is probably the parts I've spent the most time to model in 3D. I thought that would be the easy part of the build, this is actually the most difficult part of it so far, so many angles, very thin panels, lots of sandwich of steel plate/frame/brackets to attach to the hull. Fortunately, thanks to the photogrammetry, I have been able to sort of a lot of the issues I had. The original tank I used for photogrammetry did not have it's track guards but still had the mounting brackets! And I have measurements of original track guards taken by great guys that are restoring a Mk IV in Belgium, look for them on Facebook, search for "Churchill Minotaur restoration". I've used their pics a lot to get the most details I could reproduce on my model.

3d resin parts are great too but they have their drawback. Lot of cleaning after having removed the supports, parts can distord after curing...

I'm using the standard Anycubic gray resin, I have tried several ABS like resin but wasn't very happy with them. I would like to try some Siraya at some points.

Anyway, the resin running gear are handling the metal track very well even if some parts are very thin (the side of wheel are 0.5mm thick).
I've runned it for about one hour so far and no sign of any problem, the resin is like glass so the metal tracks cant "grind" the parts easily, but they are brittle, I'm more concerned about gravels that could break the parts.
The only part I broke was one of the front suspension arm but it was all my fault, I tried to put the same spring than I used on the other bogies, and when I tried to insert it, I released it by mistake and with the strength of the spring it broke the part. I shortened the spring after that because that bogey suspension was not soft enough.
But in regular use, there's no constraint on the arm itself, all the load is on the spring and on the wheel axle, the suspension arm is just there to give a pivot point and to keep the wheel aligned, it's a bit like the compass (not sure of the word) on a aircraft landing gear, it' s just there to keep the wheels in line.

[Raminator]

I've tried a bunch of different resins and now exclusively use Siraya Tech stuff. I've had good results with their Blu V2; it's very strong and durable, but can be a pain in the arse to print with because of its high viscosity and light bleed. The parts are way stronger than so called "ABS-like" resins, the strength is more in-line with injection moulded plastic.

I've moved to a mixture of Build and Blu because it's easier to print while still being really tough, and actually printed some functional parts like replacement handles for pelican-style equipment cases at work.

[tankme]

When I get my resin printer up and running, I'm going to use some Siraya Build mixed with Tenacious (50/50). A modeler did extensive testing with it and it was the best blend of strength and temperature resistance for his model jets. Since it gets hot here in Texas I figured it would also work for tank parts. Of course I'll use some cheap stuff to learn with as Siraya isn't cheap.

[MonsieurTox]

I've tried a bunch of different resins and now exclusively use Siraya Tech stuff. I've had good results with their Blu V2; it's very strong and durable, but can be a pain in the arse to print with because of its high viscosity and light bleed. The parts are way stronger than so called "ABS-like" resins, the strength is more in-line with injection moulded plastic.

I've moved to a mixture of Build and Blu because it's easier to print while still being really tough, and actually printed some functional parts like replacement handles for pelican-style equipment cases at work.

When I get my resin printer up and running, I'm going to use some Siraya Build mixed with Tenacious (50/50). A modeler did extensive testing with it and it was the best blend of strength and temperature resistance for his model jets. Since it gets hot here in Texas I figured it would also work for tank parts. Of course I'll use some cheap stuff to learn with as Siraya isn't cheap.

Thank you guys, I really have to try the Siraya resins and experiment with some mixes... I would likfe to be able to print tracks for a 1/10 FT-17, I won't battling with it so I won't push it to the limits but I want something really strong but with good definition to be able to get thin tile with cast numbers on the inner face.

Well back to the Churchill,

I've built the lateral air filter boxes :

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I've been lazy and I printed the extra armor plate, did not want to take the time to build a jig and make the chamfers on the mill...

Today I've built the stowage box from styrene. The original is made of overlaping thin steel, so I had to recreat that adding strips of 0.3mm styrene on the required edges and sanded them down to 0.1mm (the cast shadows make them look thicker than they are in real life).

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I've made the pistol port hatch doors and textured them with Tamiya putty and acetone.

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I have primed the turret to see any imperfection and what that needs to be corrected. Still have some details to add to the turret.

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Stowage box is not glued, just pinned for now and the pistol port doors are just pressed in place but this is a tight fit so I dont think I will glued them.

Next major update will be the track guards !

Thanks for watching

[lmcq11]

Hi,

Excellent job, it will definitely be a superb Churchill. It brings back good memories of when i built my Mk III a couple of years ago, and also when i visited Normandy in 2011 with my father. It's holy ground.

Louis

Churchill Avre

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Vimoutier Tiger

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[MonsieurTox]

Hi,

Excellent job, it will definitely be a superb Churchill. It brings back good memories of when i built my Mk III a couple of years ago, and also when i visited Normandy in 2011 with my father. It's holy ground.

Louis

Churchill Avre.jpg

Normandy.jpg

Thank you Louis, your build has been of a great help for me. Your Dieppe Churchill is incredible !

You and your father were lucky to have full access to the Vimoutiers Tiger I, it's now enclosed by fences.
I've been able to make a good walkaround of it though !

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Great pics, One Charlie is why I wanted to make a AVRE, when I saw for the first his big spigot mortar, I knew I had to recreate one. And I love the spare suspension units on the rear track guards. I was thinking recreating One Charlie, but I have the same problem as you got, we both use the same (and only available) metal track of the late type. Fortunatly the AVRE were fitted with both early and late track style so I'll find another one. But I havent found pics of a very interesting one as of yet (most have no name, no spare suspension units etc...).
Maybe this one : "Leviathan", however I can't find any info or other pics of it.

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CAD work of the track guard is mostly done, thanks to the Churchill Minotaur restoration guys who provided me with a lot of measurements and to the photogrammetry of the Churchill wreck I made (it has no longer its track guard but it still has its support brackets which gave me the correct angle of the front and rear section, which is the same angle btw), I have been able to recreate them as close as possible. Probably not perfect, but I'm very happy with them.

Once thing AFV Club got mostly right on their kits is the rib spacing on the track guards. Spacing between ribs is uneven, I thought they were wrong but they are in fact right. The ribs are not evenly spaced (except one or two), that's weird, but there's a reason I haven't found yet !

Some views of the 3D model :

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[lmcq11]

Hi,

Having been buried during the fighting, 1Charlie is definitely authentic in all aspects. I also saw this Avre below at Lion-sur-mer but the track covers and the side exhaust stacks are obviously not original. The presence of some square platform on the front deck just in front of the howitzer is bizarre.

Avre Lion sur mer

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Sad to see the Vimoutier tiger fenced. The ability to have a "Wittmann pose" photo was highly valuable. I was able to take a lot of pictures of details people usually cannot see unless you are able to climb on a tiger, which is extremely rare. I was also able to take some interior shots of the Vimoutier tiger through an open slot under the fenders caused by the internal explosion.

Vimoutier tiger

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Vimoutier tiger

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Vimoutier tiger

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Vimoutier tiger

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Vimoutier tiger

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Regards, Louis

[MonsieurTox]

Hi,

Having been buried during the fighting, 1Charlie is definitely authentic in all aspects. I also saw this Avre below at Lion-sur-mer but the track covers and the side exhaust stacks are obviously not original. The presence of some square platform on the front deck just in front of the howitzer is bizarre.

avre 2.jpg

Yeah One Charlie is the best preserved AVRE I think, it may have the front section of the track guard partially restored though, they dont look original and in the pic of the recovery you can see they are clearly in a bad shape (of course, they pour some concrete over it !).

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The one of Lion-sur-Mer is nice but you're right the track guards are badly restored and I'm also wondering what is that square frame. I think I saw similar fittings on some MK VII AVRE but I could be wrong and I can find the pic I'm thinking of.

Sad to see the Vimoutier tiger fenced. The ability to have a "Wittmann pose" photo was highly valuable. I was able to take a lot of pictures of details people usually cannot see unless you are able to climb on a tiger, which is extremely rare. I was also able to take some interior shots of the Vimoutier tiger through an open slot under the fenders caused by the internal explosion.

vimoutier 3.jpg

vimoutier 5.jpg

Vimoutier 1.jpg

vimoutier 2.jpg

vimoutier 8.jpg

Regards, Louis

Yeah it's sad but people were stripping off what they could, probably to resell them.
Those are great pics, thanks for sharing them, it's unbelievable how it split in 2 parts...
While probably not accurate at all, I do like the camo which makes great pics !

The Churchill wreck I visited was not fenced but it was written it was forbidden to touch the tank.
Well, with a lot of care I climbed on it to take some pics of the top of the turret to get some good details...

Here are some examples out of the 450 pics I took of it :

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Anyway guys if you have any help regarding markings of a Churchill AVRE with late tracks, I would appreciate it !