HPI 6x6 Truck

[Steve118]

I'm currently building a full size 4x4 replica of a Willys MB, not an actual one but fibreglass copy.

Anyway in between and after seeing all the scale MAN military 6x6 and 8x8 decided to have a go myself!

First thing was a base model and decided on the Wheely King as one came along quite cheap.

Having bought up a load of spares I thought it was about time to get cracking.

So, after buying another second hand axle and a 4x4 conversion kit and some other bits and bobs I've ended up with this:

I used the standard chassis as a pattern and made two new motor mounts that I can also hang the front bones off:

Got some 6mm bar, some m4x20 grub screws and a bit of drilling and tapping later:

I used the standard crawler bones off the donor and constructed the new top bones to the right length.

Got hold of some U section ali for the chassis and after a bit of tweaking for the width bolted the motor mount on:

I had to move the chassis rails a bit closer together so the front shocks would sit nice:

Now with the long 66mm props I'm going to end up with a 18" wheelbase.

This would make the truck about 30" long. Thing is I would like to push the rear axle setup another couple inches back so is there anyway of extending the prop shaft?

As I came to this page the ad box top right had a picture of a double length like inner bit?

And for now, just for reference:

Thanks,
Steve

 

[Gula]

Take an extra male portion of the drive shaft glue about an inch into the female shaft, then get another female shaft and you're done, extended shaft!

 

[lonleycreeper]

Very nice start.
You will want to build a rear link mount on the chassis vs having the links attach to the middle axle. Otherwise the middle axle movement will screw up the rear axle.

 

[Steve118]

Ok, its been a while, cracking on slowly.

Decided to make a new chassis out of flat bar, the only ali thick enough was mega expensive and a bit too thick for my liking so decided on steel bar. This will make welding things on dead easy.

So, first thing was to sort out the extra length in the wheel base I wanted and came up with this:

A little block with a 6mm bearing in it that carry's an hpi drive shaft out of the bottom of the trans. Mounted it back so a long prop would sit in.

Back from there the middle axle is mounted again with the normal hpi bones and top A frame although I've mounted this with a custom set up.

You can see the setup I've gone for here but still need to fit a panhard rod to control the back axle.

Not happy with the shocks, they are far to soft, especially the front ones. Thinking on making some spacers to move them out from the chassis and going for some 90mm new ones mounted vertically.

So, there we are, just need to mount the steering servo, make all the bits I've got for the panhard rod fit and it should be on its wheels and drivable..

Stay tuned!

Steve

 

[Steve118]

Been a while, working 12 hour nights, 3 projects on the go.. wow!

Anyways, need some advice. The shocks are too soft, its like the thing wants to fall over and that before any radio gear, battery or any bodywork!

Q,s? Are the shock angles causing this, or, are the springs too soft? The front dives down on the shocks a lot as well...

Can I get stronger springs for the wheely king or am I better off mounting them upright?

 

[Tommy R]

Mounting them vertically will help, but probably not enough. Sorry, can't help with thoughts on what springs will fit your shocks, though.

 

[lonleycreeper]

Vertical mounting of the shocks will help, but you really need firmer springs. 90mm or so shocks can effectively raise the spring rate, lower your ride height and lower your CG. Stock 120's are to long for a scale multi axle IMO.

 

[Gula]

Your steel chassis rails and super tall aluminum trans "holder" are causing you to have a very high center of gravity. If you could create some sort of shock hoop, so that your shock tops are higher than the rails, that would help!