On real tanks how exactly does the torsion suspension work? Is it a certain material for how much spring it has, how do they adjust it? So much tension and weight how do they secure it to the suspension arm? I'm having trouble on a new design im working on.

Torsion bars work by the arm twisting the spring steel torsion bar. When the wheel, arm and bar are installed, there are splines on the bars end that lock into the mounting anchor location on the opposit side of the tank.. The arm is installed with the arm pointing almost down. As the tank is lowered, the arm/wheels are forced up into thier proper alignment. The torsion bar provides the spring action as
the wheels and arms want to twist down. The driver bow gunner hatches on the M-26-45-46-47 also use a torsion bar to open. The photo shows an M-26 hatch.....the bar running along in the slot is the torsion bar and the anchor is at the rear of the hatch. When the hatch is installed, it is open, and the torsion bar and anchor are fitted and bolted in place. As the hatch is closed, the torsion bar is twisted and takes most of the weight off the hatch for opening. With a broken bar, one man cannot open the heavy hatch alone. Suspension bars work the same way.

Check here,
http://en.wikipedia.org/wiki/Torsion_bar

So what type of material can you use? I cant imagine stainless steel working well. I seen on the wiki its rated by the diameter, length and material. Anyone know of a chart to see what possible setup I could use? I have been looking around for a while and havent come up with anything.

This is the Asiatam version,perfect torsion bar suspension with splined attachment bracket for the spring bar.The early hulls like this one had to strong a spring rod,Asiatam marketed a softer spring.But as the wieght of my TIGER VI passed 20lbs. ths original spring rods were just right.

my pre turet turn, gun elevation, and gun fire tamya had strips of spring steel. if you know anyone with a pre-1975 mopar the front suspention is torsion bar. made for that great mopar ride!

Joe

Ask Perry S. He's the proud MOPAR owner right down to the pistol grip shifter.Boy am I envious Vanishing point alive and well. Sax

You'll have to check out different steel rods and select one that will give to 45-60 degree twists without breaking and return back to the original point. . Don't forget that end has to be solidly mounted in the opposit side of the tank. Not going to be an easy job. Do you really need the torsion bars? [:-]

Ha, I have a couple restored, sitting in my garage right now.

Perry

You could buy the torsion bar bag from a Tamiya kit for your project.

Hey Perry,Glad you got involved as soon as MOPAR was mentioned guess who came to mind.you told me about the challenger what else is in the garage? And I guess i should mention that the size and type of wire determines it spring tension strength,and the Asiatam spring tension rods are a very small gauge but seem to be very rigid,if I push a control arm to the stop it spring back perfect every time and they sell the rods seperately so maybe you could try the Asiatam torsion rods?

My Asiatam PzIII bars are perfect, but over time, they weaken. I now store the tank on blocks to take the weight off the bars and have noticed an improvement in performance. The KV-1 hull is a different story. Mine came to me with the rear swingarms fully compressed and they never really recovered. I switched the bars around until the front & rear were stiff and the middle were softer. With all the weight in the butt, I had to install a spring inside the rear stop to get it to sit level. This works great, but when the rear bottoms out, it'll bounce just a little.

I'm planning for my next build to be a M1A2 Abrams 1/6th scale so being that huge I'd like to have its real suspension. I might have to just use compression springs.

Torsion bars or 'torsion springs' are a pretty old concept. If yo have a TB suspension tank that starts to sink after use then the TB's are underdesigned and they are being being pushed beyond their design limit. Properly designed they should always return to their beginning point. That is unless the yield strength of the material is exceeded.

If your interested I could send yo the equations for their design.

Perry

My problem with the PzIII suspension was that it always sat with the battery in it and would sag to that side a bit. Since I now store it with the weight off the tracks, it no longer sags when I do run it. I figure letting the springs hang with the weight of the metal roadwheels allows the spring to maintain it's original shape.

The KV-1 rear springs were basically bent from being compressed when I received it, but even if they were not, they are still not strong enough to support that long arse with metal gears and motors mounted. The last spring is before the gearboxes, so that's a lot of added weight and leverage on those rear wheels.