T-34 76 Tank

[ridix]

Hi all, I am starting a project to keep myself busy. It’s Russian T34 tank. They approached military hardware design in different way from west. It is always interesting to learn what they did. Modeling them will make me study there design more.

So far I collected number of orthogonal view of the tank. And, of course none of the view really lines up! There were different models during the war as well. I am going to focus on earlier models with 76mm gun. Here are the starting drawings with some vehicle envelopes worked out. Turret is organic in shape, but my first cut modeling seems to be working ok:

http://i1135.photobucket.com/albums/m626/cabby24/Blender%20WIP%202011/T34_76_1.jpg

[cobra6]

That is looking like a nice start :) As for the drawings, I would seriously advice you to use them just to block out the basic measurements of the tank, turret, gun and wheels. The detailing is best done by photo reference since drawings are almost always off.

You can probably find things like wheel diameters online, and otherwise I might be able to help you.

Cobra 6

[ridix]

Flying through track wheel detail:

http://i1135.photobucket.com/albums/m626/cabby24/Blender%20WIP%202011/T34_76_2.jpg

I want to be more accurate but detail information is sketch and limited anyway. Actually I started to sketch out the Tracks then realized that track width dimension need to be very exact to fit 74 of them around the tank wheels. I needed wheel laid out first to get the dimension!

[ridix]

Some more layouts: I am proceeding on to T 34 Power train layout.

http://i1135.photobucket.com/albums/m626/cabby24/Blender%20WIP%202011/T34_76_3.jpg

So far so good. All comports, Engine, Centrifugal fan, Clutch, two Steering Clutches, and to final drives seems to line up ok. There is air cleaner sitting on top of engine. At some point it was moved back in to Transmission comportment. I don’t know when this happened. But many of T34-85 variants show this.

[ridix]

Bogie wheel suspension arm worked out:

http://i1135.photobucket.com/albums/m626/cabby24/Blender%20WIP%202011/T34_76_4.jpg

T 34 drawing shows suspension spindle housing running all the way across the bottom of tank connecting suspension arm from each side. At first I took it as toque tube stabilized system. But the photo of suspension arm doesn’t show torque tube. So I really wandered what those housing was about. When I drew out the suspension arm to drawing, it actually span almost halfway across the hull on each side!

[Wigen]

Very nice work! Keep going!

[cobra6]

You are actually going to model the inside as well? :)

Cobra 6

[ridix]

I really don’t have enough detail to model inside. But I do like to study how they came up with this design. I mean T-34 suspension design is really American Christie Suspension design you know. Why did US Army dump this design? Russians had best performing tank design based on Christie Suspension at the beginning of the WW2.

As I look into it this suspension system, it is apparent that it can take lot of deflection. I mean T-34 suspension spring goes all the way up to turret deck! If you want to go fast on rough terrain, suspension needs lots of strokes. Germens and Ally had tanks with this tiny little toy springs! If you go off road, T-34 will run circle around those tanks.

Down side to this design is access to suspension system component. There is no way you can fix it in the field. You practically need to take everything apart to get to anything. But then this is fine if you are fighting in Russian home territory. You just send it back to factory.

Any way, I was looking and looking for hull rear detail. Because the final sprocket drive that protrude from the back simply didn’t look right. I finally concluded that rear panel integrates Armor Cap over the drive as show here:

http://i1135.photobucket.com/albums/m626/cabby24/Blender%20WIP%202011/T34_76_5.jpg

[cobra6]

Why did US Army dump this design?

(...)

Down side to this design is access to suspension system component. There is no way you can fix it in the field. You practically need to take everything apart to get to anything.

You answered your own question there I think :)

Cobra 6

[ridix]

Some more detail work: The main thing here was the fuel tank location. It is shown in yellow. Man, some of the fuel tank is sitting right along the tank hall next to crew compartment. If a round of armor piercing shell effectively penetrate the hall near there, the whole thing is going go up like a roman candle! This can get ugly.

http://i1135.photobucket.com/albums/m626/cabby24/Blender%20WIP%202011/T34_76_6.jpg

[cobra6]

Though because of the sloped armour they generally had less chance of a penetration, especially in the early days :)

But yeah, I mean generally German tanks have their ammo on the sides as well, so that is basically the same thing.

Cobra 6

[ridix]

I kept messing around with the tracks, and more or less settled with this one. My layout should be quite accurate, with exactly 74 tracks. I was surprised to find that Guide Horn that meshes into Sprocket Wheel at the back probably engaged one horn at a time. The whole track system has lot of slap in it in its design. I mean five bogy wheels on each side that support the weight of the tank can slide in and out! Only thing that is holding its lateral position is the tracks and horns. It is true you know. Manufacturing and assembling all that peaces of wheels and tracks will not be easy. System needs lot of slap in it. Tank mechanic is not a rocket scientist. This is more like simple farm equipment.

http://i1135.photobucket.com/albums/m626/cabby24/Blender%20WIP%202011/T34_76_7.jpg

http://i1135.photobucket.com/albums/m626/cabby24/Blender%20WIP%202011/T34_76_8.jpg

[cobra6]

Nice job! It's always good to have tank tracks match up instantly, then you know you did a proper modelling job ;)

Cobra 6

[killakanz]

Mine usually line up quite nicely. I tend to follow the rules I outlined here (http://www.military-meshes.com/forums/showthread.php?t=4633) and it usually turns out close or spot on. Most of the time all I do is adjust the idler wheel a bit (that's it's main job afterall :p ).

[ridix]

I am using Blender to model. So far I found two ways to make the tracks; using Curve modifier with Duplifaces or Array modifier fit to Curve. I was contemplating doing it manually if those methods didn’t workout.

Array modifier along the curve will deform each track to fit the curve, no good.

Dupliface method will create ditto tracks and it will not deform it. It’s nice but to fit it exact number of tracks will takes fine manipulation of track size. I managed so that is the method I used.

Problem with T-34 is that when you lay it out drive sprocket really don’t fit too well to the horn given number of tracks. Tiger seems to fit quite snug. So I say at least 6 teeth will be engaged at all times. This can reduce the size of teeth. Each tooth does not need to carry as higher torque load. Design approach is totally different from T-34 here.

[ridix]

Quick update on the front end:

http://i1135.photobucket.com/albums/m626/cabby24/Blender%20WIP%202011/T34_76_9.jpg

I was fussing with the detail of diver hatch for some time. All I have on it are some fuzzy drawings / photos and lots of different configurations. This one I modeled had two-hinge; one for the hatch, and other for the driver view port cover. They were somewhat imbedded into each other which made modeling definition little difficult.