Interesting observation on Leo2A4 drive sprocket

[[]_--__[]KITT]

I own a Minichamps Greece Leo2A4 and I've noticed that the left and right drive sprockets are not exactly symmetrical.

The left drive sprocket has much less distance to its front wheel while the right drive sprocket has more distance to its front wheel.

And all this time I thought it was a Minichamps mold fault or inaccuracy but I've just noticed exactly the same observation on SB Pro PE Leo2A4:eek2:.

Why is the drive sprocket not symmetrical with the left drive sprocket being closer to the next front wheel? Thx

[GaryOwen]

The difference in the distance between the sprockets and the first road wheel is most likely due to offset from the torsion bars.

[[]_--__[]KITT]

Of course but why they need to be offset? the drive sprockets in M1 for example are perfectly symmetrical?

And furthermore due to this offsetting of the drive sprocket....one side of the track would appear to be loosen while the other one being a little tighter. Am I correct? I suspected this to enable the tank to drive forward in a straight line without being swirled off to the right or left from full stop position. But I don't remember why I suspected this though:biggrin:

Or was it to enable the tank to swirl(rotate) 360 degree without moving an inch(rotating in its axis)....?? I'm losing my memory LOL

[oscar19681]

Hey kitt sometimes i think your post are just about.. Uhm.. Well nothing at all? Seems like you post for every little thing that comes up in your mind or are you just posting to post or something?

[dejawolf]

from what i see, the leopard 2a4 drivesprockets are perfectly symmetrical as well, its only the roadwheels that are assymetrical.

[RogueSnake79]

The M1 abrams road wheels are not symmetrical. Someone told be why and I forgot. 1 Track has more links in it than the other. Perhaps its the same with the leopard.

Probably the torsion bar deal Gary speaks of.

[GaryOwen]

The torsion bars run inside the bottom of the hull from the arm on one side to the other side of the hull. There is one bar per arm, each taking the entire width of the hull. Thus the bar for the first arm on one side must be placed aft of the bar for the first arm on the other side. This is what I meant by offset. Look closely at any AFV with a torsion bar suspension and you'll see it.

[[]_--__[]KITT]

Hey kitt sometimes i think your post are just about.. Uhm.. Well nothing at all? Seems like you post for every little thing that comes up in your mind or are you just posting to post or something?

I was just simply curious...really... not to simply bloat my post count:)

The torsion bars run inside the bottom of the hull from the arm on one side to the other side of the hull. There is one bar per arm, each taking the entire width of the hull. Thus the bar for the first arm on one side must be placed aft of the bar for the first arm on the other side. This is what I meant by offset. Look closely at any AFV with a torsion bar suspension and you'll see it.

Ahh I see. Thx Gary. I can't seem to find this information in any tank book I own.

@Deja perhaps you were right that the drive sprockets are indeed symmetrical but the wheels are not.

@RogueSnake, yea I've also read that even the Russian tanks' tracks are not of the same length for each side with one side being longer than the other. Don't know the reason. Are you sure the wheels on M1 are not symmetrical?

After seeing the M1 Minichamps model(assuming it's an accurate representation) I really can't see that the wheels and drive sprocket are offset from each other on the other side, they look symmetrical to me....(anyone is not obliged to answer this if you think this is nothing of course:)). I just want to know the detail of one of my favorite machines. They are not of torsion bar? All my books don't seem to mention the suspension type of each tank. Let alone explain each type.

I always presumed that the wheels on each side would be aesthetically symmetrical as what I've seen in cars, buses and trucks:biggrin:

[dejawolf]

here's a pic of torsion bars being fitted on WW2 tanks:

http://www.alanhamby.com/suspension.html

the torsion bars are difficult to see from the interior, as they're all covered by casings.

but you can see the torsion bars (barely) in this picture:

its those white tubes you see running along the bottom of the engine bay.

if you want an accurate abrams kit, this is what you should get:

http://www.armorama.com/modules.php?op=modload&name=Reviews&file=index&req=showcontent&id=1911

[[]_--__[]KITT]

Ohh I see that's how they make the wheels to appear symmetrical....

I've stopped building model kit for some time been thinking to build a titanic model but...now collecting Minichamps tank diecasts instead for the love of a working suspension.....

[Homer]

Here ya go...

[congo]

@RogueSnake, yea I've also read that even the Russian tanks' tracks are not of the same length for each side with one side being longer than the other. Don't know the reason. Are you sure the wheels on M1 are not symmetrical?

This doesnt make sense to me, If the distance from the drive sprocket to the front idler is the same the slight offset in the road wheels shouldn't affect the track length. If the drive sprockets are offset well thats another story.

[Homer]

I believe most if not all tracked vehicles with torsion bar suspension have asymmetric wheels and tracks... here's a pic that illustrates why:

[Hedgehog]

Where?

[Homer]

Think backwards... The picture implies from the idler to first road wheel on each side has the same number of links and the same deal from last road wheel to the sprocket on each side... don't you think that is impossible? There must be a difference somewhere

[12Alfa]

I belive the M113 family has more track pads per side than the other, M548 for sure, broke many of them tracks. LOL

[GaryOwen]

I belive the M113 family has more track pads per side than the other, M548 for sure, broke many of them tracks. LOL

I can certainly vouch for the M113 having different numbers of track pads on each side. I was told that the reason for this was because the linkage from the differential to the final drives was of different length on either side and that the different number of pads was to compensate for the difference in torque.

(Caveat: I dropped out of engineering school and eventually got my undergraduate degree in philosophy -- something about the mathematical limit of an applied sciences degree as the GPA approaches zero being a bachelor of arts degree --, so I'd be willing to buy any plausible explanation involving mechanical forces that I don't understand.)

[[]_--__[]KITT]

Here ya go...

Damn it the pics won't show

The torsion bar looks rather small in diameter....by the looks of it they seem to be vulnerable to break off:)

[Homer]

I belive the M113 family has more track pads per side than the other, M548 for sure, broke many of them tracks. LOL

63 links on the left and 64 links on the right.

_--__[]KITT;148691']Damn it the pics won't show

The torsion bar looks rather small in diameter....by the looks of it they seem to be vulnerable to break off:)

PM me your email address and I'll send them over.

Torsion bar suspension is an ingenious design (Porsche IIRC). Extremely strong and compact... perfect for AFVs.

[[]_--__[]KITT]

@Homer: PM sent

Besides torsion bar we know that the British use the hydro pneumatic suspension which judging by the way Challenger moves in videos, is more advanced than the torsion bar type.

Does anybody have a clue how hydro-pneumatic suspension work? Any pictures would be welcome too. I may be wrong but I think isn't hydro-pneumatic suspension has also been used in automobiles as well where you can set the suspension either to normal, soft or racing(hard)?

[dejawolf]

http://en.wikipedia.org/wiki/Hydropneumatic_suspension

[[]_--__[]KITT]

Hey why didn't I think of Wikipedia:redface:?

thx

[Hedgehog]

T-95 (yank prototype) and S tanks are prime examples using hydropneumatic suspension