Tatra model

[cranetruck]

Is there a good plastic model of this vehicle, which will accurately show details of suspension etc? (I haven't looked around yet)
TIA

 

[DDoyle]

Which Tatra?

 

[cranetruck]

Any one with the "tubular" suspension system. An animated display of its operation would be useful too.

 

[jodka]

An animated display of its operation would be useful too.

Bjorn,

I did see one of those on youtube. It was a cgi animation demonstrating half axles flexing and comparing early and later model tatra tubular suspensions.

I would search for that link for you but I am at work now where streaming video is verboten. If someone else here has not uncovered it by this evening when I get home then I would be glad to look it up then.

- Allen

 

[jodka]

Bjorn,

Here is the link to the youtube video.

Is that helpful?

- Allen

 

[cranetruck]

Thanks Allen, much appreciated, guess it's up to the offroaders to decide if it's worth the complexity.

The objection may be that an independent suspension doesn't lift the vehicle over an obstacle, although it provides for a "nicer" ride.

 

[jodka]

Bjorn,

Well I think you have hit on a fascinating question here, about how this tatra half-axel design performs compared to the conventional design.

I don't have have an answer, but here are some random comments on the subject:

- Somewhere, among the many youtube disco remix videos of tatra 8x8s offroading, is mention that the design increases tire surface area contact offroad. That statement does not explain. But it might be a clue to discovering what motivates the design.

- It would be interesting to compare the posture of a half-axle 8x8 on various surface countours to that of a conventional 8x8 on those same countours. (Probably why you want the model.)

- About lifting over obstacles, of course it depends on how much above horizontal the half axels flex. Can someone with a tatra comment on that?

- Allen

 

[tatra813]

Bjorn,

Well I think you have hit on a fascinating question here, about how this tatra half-axel design performs compared to the conventional design.

I don't have have an answer, but here are some random comments on the subject:

- Somewhere, among the many youtube disco remix videos of tatra 8x8s offroading, is mention that the design increases tire surface area contact offroad. That statement does not explain. But it might be a clue to discovering what motivates the design.

- It would be interesting to compare the posture of a half-axle 8x8 on various surface countours to that of a conventional 8x8 on those same countours. (Probably why you want the model.)


- About lifting over obstacles, of course it depends on how much above horizontal the half axels flex. Can someone with a tatra comment on that?


Tatra 813 wrote.

With all the axles so close together you dont need it to lift you over things. with more tires on the ground you also maintain more control if you watch the youtube vids the wheels often still come off the ground.
All I can say is I have owned MANY large trucks, mainly for fun and the independant suspention is night and day compared to the solid axle! it also has better ground clearance. The thing I like about the Tatra is it does what all the other trucks I have owned over the years could not do in respect to offroad ability. The drivelines and half axles are not really that complex, they are just different also you can drag the whole bottom of the vehicle over bumps rocks etc, nothing to damage, the center tube is very thick for this reason, no drivelines to worry about. In addition if you get a flat you just air it up and keep air going in it while you drive back home. or you can totally remove the complete wheel up to 2 wheels can be removed and still drive it as long as they are on different sides of the truck, there is a yoke you hook the half axle to the frame which holds it up while you drive. Im not saying any of this to dismise the abilitys of anyone elses truck, its just my opinion from all the trucks I have had mainly large trucks and how nice it is in comparison like I said mainly in offroad ability.

The only downside is the rig is so heavy that I worry about getting it stuck and even with the 50,000 winch not getting unstuck. Maybe no tree to winch off of etc.

I did love my duece I used to own, if you put on Detroit lockers it does pretty well also you definitily get thrown around alot more, and if you dont watch out that steering wheel will rip your arm off if not paying attention and you hit a rock etc!! been there done that one. the other problem with the Tatra offroad is with its size there arnt alot of trails that you can fit on offroad, so you end up making your own, luckily the tires pretty much hit most of the brush etc.

I use my 1st tatra for offroading and I baby my other one. They are definitily tough.
If you look at the Europe truck trials video for the Tatra big truck class they dominate the class, in fact no other brand even has a chance!! the six wheel drive trucks with sold axles cant compete with them period. I think most of that is its a 8x8.
The other thing that is a problem it the front end that sticks out past the tires and on extreme angles you can hit the ground with the bumper. Luckily with a 3/8 thick VERY solid bumper you can just plow through it.

I know Man makes a nice 8x8 also but the reviews I have read is the Tatra dominates over it also. I did a lot of research before falling in love with the Tatras.

Ive seen some nice Mercedes 8x8s that seem to do very well offroad also.

I would like to see some pics or comments from other guys with big trucks doing extreme offroad stuff, I like seeing any big truck offroad in action.

The only other thing I dont like with any of the big trucks is with the diesels you cant do quick shifts and hop over obsticles etc like you would a jeep, you have to offroad with a totally different mentality, you just pick a gear and go and plow through anything in your way.

The funnest thing for me offroad is watching this huge truck slide down hills and spin all tires etc, its just amazing to me the truck can still be thrown around etc like a smaller truck would. OK Im babbling on Ill stop I wish more big trucks were around where I live to go wheeling with.

The other problem with the duece is the big gap between the front axle and first rear axle, it really limits you. relocating the fuel tank on the bed helps with this a lot.

 

[cranetruck]

Appreciate your comments Tatra813, you refer to the deuce a number of times, there is no comparison to the 8x8 m656/xm757. The m656 beats the 2-1/2 and 5 ton 6x6s hands down in all tests shown in Aberdeen Proving Grounds vintage videos...
The idea is to stick to 8x8 type suspensions, the dual bogie vs the Tatra tube type. Also size matters where big enough wheels alone on an articulated 4x4 (the Goer) can outperform most smaller vehicles, so to keep from comparing "oranges and apples" let's keep the 6x6s out of this discussion, thanks.

Tatra813: "The only other thing I dont like with any of the big trucks is with the diesels you cant do quick shifts and hop over obsticles etc like you would a jeep, you have to offroad with a totally different mentality, you just pick a gear and go and plow through anything in your way."

Funny, , then again m656/xm757 got a small increment 6-speed auto trans for this exact reason, to be able to accelerate off road without loosing momentum.

When I'm good and ready, I'll take my 757 off road too (I live "off road"), but one thing I won't do is "plow through" or "hop over" anything, my pockets aren't deep enough....come to think of it, my son probably would..... if he got the chance..

 

[tatra813]

The auto tranny would definitily be an advantage in that respect!!

Ill leave the dueces out of it, I dont know of any official facts about actuall offroad differences as far as which is better etc. Ive never driven a different 8x8 so the duece is my best comparison. but I get your point.

My guess is there are different pro's and con's between out 8x8's I dont know if either one is necesseraly better, maybe better for different applications, etc

 

[Jones]

FWIW; A lot of the later MVs are going independant. Even the A3 HEMTTs with the Pro-Pulse have an experimental independant front suspension set-up. Field trials conducted by actual troops usually highlight the bad ideas pretty fast.
Murphy's Law for Mechanics; the more pieces and parts in anything-- the more there is to break or wear out.

 

[TnD]

Thought I'd chime in on this topic.

There's two sides to this. Solid axles are preferable from the standpoint of keeping maximum clearance under the chassis as the suspension flexes, and simplicity.

As for independent; If you have the additional static ground clearance offered by the independent suspension coupled with multiple contact patches of an 8x8, AND an incredibly rigid backbone/chassis, plus the ability of the suspension {being independent}to more closely follow the terrain. This all adds up to the ideal vehicle for transporting loads especially sensitive ones , i.e. ICBMs, over rough terrain.

Everyone(including Tatra) refers to the Tatra design as a backbone chassis, however, if you look at the section view of the chassis with the two 'I'-beams mounted on the supports, what you have is a triangular truss just like is used for almost every heavy lift crane. This all serves to protect the load by eliminating twisting forces being transfered to it which can happen in a ladder frame.

My. $.02
Dave

 

[rmgill]

Did you guys see the 1:10 scale model someone's building? Looks like he replicated the tube frame, the differentials, the transmission and the other details. Pretty cool.

 

[tatra813]

There are lots of models for sale on e-bay

type in tatra 813. be sure to click worldwide search