Oberon's Berg Stick

[oberon crawler]

I've been trawling these threads for weeks so I thought it's about time I shared a little about my build too.

Berg axles
Custom homebrew stick chassis
4WS with twin 5645MG's
integy V11 45t lathes
Dual FX-R's (No switch dig on this baby!!!)
AR 6100e rx
Dx7
Battery Elite 1500 8 cell
Wheels Mayhem 7's

This rig is for the Australian TRAIL class which is basically 12.5" superclass with 2.2" wheels, so i've gone independant rear steer to keep up with everyone else.

Also I've gone twin ESC's which will also be independant/mixed bias so I will have front dig, rear dig, any proportion of either, plus front axle fwd - rear axle rev (i think it's called reverse burn although i'm not sure).
It all depends on how i program my mixes.
Either way I'll be using all four stick axis at the same time (you have to do that to fly a heli anyway so it won't be totally new).

Suggestions are very welcome as this is my first build other than an axial.

[sportpak]

I like the mount for the backbone. I had trouble finding a combination that I liked. Someday I'll post pictures of mine.

Keep it going man. Stick chassis' are the coolest.

Ben

[jeeper_05]

are those baja 5b ball joints?

[Stormin2u]

I really like the stick chassis for these clod style axles it looks like you've got a great build going here keep us up to speed with your progress.

[deuce_crawler]

Where'd you get those mounts for the backbone?

[oberon crawler]

Originally Posted by sportpak

I like the mount for the backbone. I had trouble finding a combination that I liked. Someday I'll post pictures of mine.

Keep it going man. Stick chassis' are the coolest.

Ben

Thanks Ben, I was going to just make mounts kinda like the stock ones but with a hole in the centre for the ball joint but then i decided I could make it a little longer and make it a mount for one end of the servo too.

Originally Posted by jeeper_05

are those baja 5b ball joints?

Yep they are, I'd never seen one in the flesh before, I didn't even know how big they were i just ordered them over the phone, when they turned up i was a little disapointed with the slop in them, there are some really nice billet ones with a nylon liner that are a 5b hop up that would be better but i couldn't get hold of any...

Originally Posted by Stormin2u

I really like the stick chassis for these clod style axles it looks like you've got a great build going here keep us up to speed with your progress.

Thanks, will do. Next is links and shocks then just electrics and programing, I've got about 6 weeks to go.

Originally Posted by deuce_crawler

Where'd you get those mounts for the backbone?

It's just 1" x 1" x 1/8" alu angle and the plugs in the end of the Backbone tube were just machined from 3/4" solid alu rod with a hole tapped in the end.

[Stick King]

Nice build oberon! Keep us posted!!

[Markil]

Looks like you've done your research, I think you'll do well in trail

Makes me want to get a set of bergs and build another rig. I could always adapt my current trail to fit into our new 2.2 class coming in for next year. I guess I know what I'll be asking for christmas now

[oberon crawler]

Originally Posted by Markil

Looks like you've done your research, I think you'll do well in trail

Makes me want to get a set of bergs and build another rig. I could always adapt my current trail to fit into our new 2.2 class coming in for next year. I guess I know what I'll be asking for christmas now

If your current trail machine is shaft driven you won't need to do much to make it fit Aus2.2! maybe lock out the rear axle and that's it.

I'll definately be doing that to my axial as there's no way it'll keep up in trail class anymore!!

I imagine everyone in Oz who has a shafted trail rig will go Aus2.2 and Trail will be just like the real US2.2 class except we have rear steer.

[oberon crawler]

A few progess pics,

This build is an experiment and the chassis is a bit different.
there are NO SPRINGS so far anyway, just heavy oil.
The links are 3/16" Carbon Fibre solid rod into revo ends (slippery, strong and light)
I still have the option of going dual shock with springs if i want to but I'm just not experienced enough yet to know what's best so i'm doing a trial and error thing.
The front ball joint is LOCKED in an attempt to really eliminate any front axle steer without putting the BB end of the links on the lower side of the BB thus losing CG and creating catch points.
I should have it rolling (with the stock wheels - waiting on my mahems) this comming week so we'll see how it goes.

Well she's a roller, all that's left to do now is paint the body, fit my mayhems (when they arrive) and spend 5 weeks practicing

The batteries i've tried and fit are a 2s 1900, a 3s 1200 and a 8cell elite 1500 pack.

The only thing mounted on the BB is the reciever (AR6100e), everything else is on the axles except lipo's which fit under the BB on the front links.

No bec, no dig switches, no esc switches, no springs, no front axle steer, no worries

[Markil]

Originally Posted by oberon crawler

If your current trail machine is shaft driven you won't need to do much to make it fit Aus2.2! maybe lock out the rear axle and that's it.

I'll definately be doing that to my axial as there's no way it'll keep up in trail class anymore!!

I imagine everyone in Oz who has a shafted trail rig will go Aus2.2 and Trail will be just like the real US2.2 class except we have rear steer.

I'll need to totall rebuild for 2.2, I got the custom tuber frame

But mate, I'm looking forward to seeing this in action Keep up the good work

[BitHed]

...aw DOOD!! Thats cool! I really like that...Looking forward to its evolution

[BitHed]

...looking at it closer i realise that those are the rodends from the Baja 5B? Been looking at those for a while...

[oberon crawler]

Originally Posted by Markil

I'll need to totall rebuild for 2.2, I got the custom tuber frame

But mate, I'm looking forward to seeing this in action Keep up the good work

Ah, you're going a tuber, nice. That was going to be my next move with my axial.

Originally Posted by BitHed

...aw DOOD!! Thats cool! I really like that...Looking forward to its evolution

Thanks alot mate, once I get the body painted and my mayhems on it will be nice, I was playing last night with driving the front axle fwd and the rear axle rev, it will spin on the spot like a bobcat I think that's called reverse burn and counts as a rev so i'll have to limit that. However i can make the rig move sideways by using front dig then rear dig etc all in forward drive, that's cool.

Originally Posted by BitHed

...looking at it closer i realise that those are the rodends from the Baja 5B? Been looking at those for a while...

Yep, 5B ball joints, if i was going again i'd use smaller ones or the machined alloy hop up 5b joints. They look 'the ducks guts' and would have less slop

[LincolnBlack]

Nice work Obe, I love the purity of it. Makes mine look like its been hit with the ugly stick.

I've been thinking about going back to a torsion chassis as I'm not real happy with the link setup on mine even though it does give me the 105mm GC I like. I'm temped to change it, but 4 weeks out from the Nats is probably not a good idea.

To help axle steer, could you not turn the rod end upside down so that the back bone is just above the front motor?

[genki]

Great work, the stick looks the goods and very clean! Did you decide on which beadlocks yet?

[oberon crawler]

Originally Posted by LincolnBlack

Nice work Obe, I love the purity of it. Makes mine look like its been hit with the ugly stick.

I've been thinking about going back to a torsion chassis as I'm not real happy with the link setup on mine even though it does give me the 105mm GC I like. I'm temped to change it, but 4 weeks out from the Nats is probably not a good idea.

To help axle steer, could you not turn the rod end upside down so that the back bone is just above the front motor?

Thanks for the thumbs up Linc, it means alot comming from an experienced crawler such as yourself, I'm sure you'll do just fine with your rig as it is coupled with your driving ability ;)
I on the other hand am trying to make up for the serious lack in years of driving and competing that everyone else has. Corey will set a mean nats course i'm sure but i'm hoping us cloders can show those sponsored shafties how it's done...

About the back bone, if you mean effectively move the pivot point down below the centre of the back bone? then yes i could. I thought about that, you'd end up with a total back bone structure that was bent in the middle like a bridge.

I ended up cutting about 3/8" off the bottom of the rod ends to lower the backbone, (this was recomended by a guy on rcc to help reduce the amount that the axle would swing out to the side when the rig articulates). After driving it this week and considering the other measures i've taken to clean up axle steer i don't think it was neccesary and although i still have almost 4" GC I would like more.

If i moved the pivot lower than the bb (remember my rig only has ONE PIVOT POINT) it would introduce extra axle steer compared to a conventional setup.
overall i'm very happy with it's performance, particularly in the side hill and breakover department. I think i have the cg as low as any berg so far and it's going even lower in the next week or so. Also I'm going to swap the carbon links out for integy bent links (when i scavenge another $60) as i don't think the carbon will hold up to the wear of the rocks and apart from that it's just practice and fine tune the programming.

The dual FX-r's are a treat and i'm using a front dig operated from a tx switch + a switchable proportional drive biasing mix using the other vertical axis on my dx7. So as i slide the spare stick forward i go proportionally from reverse burn to front dig to 4wd to rear dig, all without touching a switch. If I put the spare stick in to the centre I just have 4wd with the main stick only.
The steering is independent and run from the two horizontals, It's a load of fun but driving it makes you feel alot more retarded than using a wheel radio :P

Originally Posted by genki

Great work, the stick looks the goods and very clean! Did you decide on which beadlocks yet?

Yep i have paid for some 7's like yours and some panthers hopefully they'll be here soon, all that's left then is paint that body.

[LincolnBlack]

I find 105-110mm ground clearance to be the magic number on a rig with a 320mm wheelbase. With that you will be able to climb a square edged rock (like a step) with very little bellying out.

Looking through the pics and processing the 'suspension' in my head, I reckon this thing has serious potential.

[oberon crawler]

Originally Posted by LincolnBlack

I find 105-110mm ground clearance to be the magic number on a rig with a 320mm wheelbase. With that you will be able to climb a square edged rock (like a step) with very little bellying out.

Looking through the pics and processing the 'suspension' in my head, I reckon this thing has serious potential.

105-110, I had that spot on before i cut the ball joints and I still had a rigid, no slop, no axle steer front end the same as I have now but just 10mm higher. I could go back there easily as i have a spare set of joints etc.
Btw, with the shock mounted to the BB with such a short arm I had to run 80wt oil and zap up the holes in the damper to get a nice slow damped articulation. it's not sloppy at all like i feared it would be with no springs.

[oberon crawler]

Some pics of finished product except for the mayhems,