Tank wagon - Need design tips to carry heavy fuel tanks

[Cairol]

I'm currently building a tank wagon to fuel my rocket on the launch pad.

Problem is: Even the biggest rover wheels get destroyed easily while driving the truck from the SPH to the launch pad.

I've currently 2x 5 of the biggest wheels installed and it's still not sufficient to carry the 4 Kerbodyne S3-14400 fuel tanks.

The slightest uneven part of ground, or braking the thing will make the tires flat.

How do you build your fuel trucks? Do I have to make it smaller and use multiple of them instead?

[Snark]

Goodness, that's quite a beast!

A possibly silly question, but is there a reason to need to do this, or is it just for fun? (I can see needing a fuel truck for bases on other planets, but Kerbin can provide all the needed fuel at launch...)

I seem to recall reading on the forums somewhere that airplane landing gear has an improbably high weight tolerance (though I've never tested it myself)... maybe worth an experiment to rest most of the vehicle's weight on some landing gear?

[Signo]

If you are not against modding, Kerbal Foundries add quite a few wheels and crawlers apart from the antigrav repulsors.

With that you will have plenty of new ways to solve your wheels issues.

[Cairol]

It's just for fun.

I downloaded KAS and now wanted to fuel my rockets on the ground and do some other cool stuff with it. Just because I can.

I totally love KIS and KAS. Should have recognized those mods earlier...

Will try landing gears then. But they are not controllable like rovr wheels. Not so good for a fueling truck.

If the fuel tanks are much smaller, they can't refuel a common rocket in one go. So I was looking for an appropriate fuel wagon.

That's why it's pretty big atm.

EDIT:

Haha. XXXXXD

I put some landing gears on and some turbo jet engines. Two for forward movement and one for breaking / reverse movement.

This thing is so ugly. But shockingly enough, it kind of works.

To get in and out, I can lower the landing gears, so the retractable ladder can reach the ground. It's like getting on and off of a camel. XD

However, it does not steer at all and even then, the speed control is a joke for a fuel truck.

I call it "a creative fail".

Guess I will build a smaller, more vehicle-like verhicle with rover wheels then.

Edited July 12, 2015 by Cairol

[Mic_n]

If you have landing gear PLUS the rover wheels (aligned to sit very slightly higher), the landing gear can "take the weight" and when the suspension compresses, the powered wheels come into contact with the ground to provide drive, while being saved from bearing too much weight?

Does that work?

If you've then drained the tanks and it's light enough to uncompress the suspension and lift those power wheels back off the ground, then maybe it's light enough to drive on them by itself - you could raise the gear to let the rover wheels back down when there's only a light weight there..

[Cairol]

I did something like this now. I reduced the tanks to 2 and put four landing gears to support the rear half and two rover wheels for propulsion and steering in the front.

It's slow as hell. About 9 m/s max. And the rover wheels get a puncture as soon as I drive it on deep grass.

It works. But there is still a ton of potential to improve it.

Anyway. I know know how to go with this.

[Claw]

Yes, the landing gear is much more rugged than the rover wheels (unfortunately). The wheels are receiving a revamp in the next update, so hopefully they will manage this sort of thing.

In the mean time, I'm not sure if there is any stock way to directly reinforce the rover wheels. You could tweak the .cfg files, or try the other methods above. Setting up multiple types of wheels (landing gear with rover wheels) can be a bit of a challenge because the rover wheels might lose contact with the ground from time to time. I would place them slightly lower so that their suspension compresses slightly before the landing gear take the load. This may not completely fix your problem though.

You may even want to fiddle with the order in which you attach the wheels (if using mixed wheel types). Since physics and part modules are processed in a serial fashion, it could have an effect on how things get distributed. I can't say it will for certain, but based on my experience I'd say it's highly likely.

And congrats on at least partial success.

Cheers,

~Claw