Beetlejuice v3 Bully

[Tomy]

EDIT July 29th 2010: This build started off as a Bully ARTR in May 2009. A few days ago I switched over to the BJV3 chassis.

I just got the Bully ARTR.

It turned out it isn't exactly an ARTR as it needs some modifications. But I believe there's a lot of potential in this rig.

Right out of the box ground clearance was over 4in and the wheelbase was around 11in.

I tried to lower and lenghten the rig by movin the shocks inwards. It helped, but wasn't enough. Luckily I found that the Axial bent links are just about the right lenght, and I happened to have enough of them. By using the shortest traxxas rod ends, the wheelbase is spot on. Switching lowers of course led to the need of longer uppers as well. I made them out of a Delrin rod.





Eventually, I'll use button head screws to mount the skid and lower links to the chassis. This will make for a smooth enough transition between the chassis plates and mounting screws and prevent the rig from getting hung up there.

After these modifications, the rig was still a bit to high for my liking so I shortened the shocks with fuel tubing. These shocks are really thin and so is the piston inside. I tried 20wt oil at first, but that was too stiff for these shocks. Now I've got 7,5wt oil, which I normally use in the fork of my MTB. The shocks feel better now. But I think I'll eventually end up switching the shocks for some Losi or Traxxas shocks. But I'll give these a go first - maybe they surprise me.




The wheelbase is now fine and the rig has a ground clearance of 8,5cm. I'm planning to use HB Rovers, which will lower the rig some and it will probably end up around 7,5cm.



The rear gearbox was hanging really low so I clocked it by using longer uppers in the rear. In the front I have to keep proper steering geometry, so it hangs down lower there, but I think it won't be a problem up front.



The Bully chassis was designed with a Mamba Max in mind. A MM would fit perfectly in the belly of the chassis. I'm using a Sidewinder and will mount it vertical on one of the side plates. I think there is still enough room for a RX and a CC Bec. The dig plate will have to go to either end of the chassis closer to the shock mounts. But I'm hoping nothing except the body will be mounted above the chassis plates.



This is as far as I've come. More to come later.

[Harley]

Good looking start

It's funny that the wheel base wasn't dead on 12.5" from the box You would think if they were trying to make a comp crawler they would get that right.

I still have to grab a set of these axles.

[roborg5000]

Originally Posted by Harley0706

Good looking start

It's funny that the wheel base wasn't dead on 12.5" from the box You would think if they were trying to make a comp crawler they would get that right.

I still have to grab a set of these axles.

It will be fixed with the B2 version ARTR

[jason]

Originally Posted by Tomy

Right out of the box ground clearance was over 4in and the wheelbase was around 11in.

Damn crazy that it would have an 11" wheelbase.

Originally Posted by RC4wd website

The Bully is the most advanced MOA (Motor on Axle) competition crawler on the market.

[roborg5000]

Originally Posted by jason

Damn crazy that it would have an 11" wheelbase.

Trust me !

It wasnt measured out that way

Something happened along the way through emails and measurements got changed.

Lower links were place on the outside of the chassis as well.

Im trying to fix the problem .

[papabash]

When will the B2 ARTR be available?

[EXW]

Will those of us that ordered the B1 ARTR be sent the correct links to fix this?

Thanks

[Tomy]

Made the dig swith today.

I started off with a piece of aluminun L-profile. The switch mount is cut to shape and holes drilled:




Here's the servo and switch mounted on the mount:




And this is how I installed it on the chassis:




I'm going to start off with front dig only. So I'm only using one switch. I decided to use bullet connectors. This is my first MOA and I'm not too sure about the wiring. The bullet connectors, however, will give me the possibility to easily switch wires to the motors if they run the wrong way. The Lipo will have a deans, though.

[Racer4Life]

Originally Posted by EXW

Will those of us that ordered the B1 ARTR be sent the correct links to fix this?

Thanks

Send an e-mail to RC4WD.

Tomy...nice work on the rig. Thanks for taking the time to post up.

[EXW]

[quote=Racer4Life;1803163]Send an e-mail to RC4WD.

Thanks Racer, I sent an e-mail to Mike. He said they will send the new links out in two weeks.

[Tomy]

Got the button head screws yesterday. It's just a small detail, but I think it can make a difference in tight places.

[Tomy]

Did my first test run today! The rig does everything my Axial SWX does - some things better, some worse. I expected a MOA to benefit more from a lower center of gravity, but it turned out the difference is not that significant. I can run the Bully with about 10mm more ground clearance than on the SWX, without sacrificing sidehilling performance. Of course axle clearance is much better than on the SWX.

Having no previous experience with the Bully axles, I was worried about wheelspeed. But the Bullys have enough of that. The rig runs slightly faster than an Axial with a 3S Lipo and a 14t pinion.

I'm only using one ESC, so there is clod stall. However, I found that clod stall is really helpful in most situations. The benefits clearly outweigh the drawbacks. But there were situations where I wished the rear wheels would run evenly with the front, making it more difficult to run certain lines compared to the SWX.

So far the shocks are a dissapointment. As I wrote in a previous post, I'm running 7,5wt oil but the shocks are still too stiff and sticky. I'll run them for a few weeks still and see if they get better with some break in. If not, I'll try to increase oil flow by modifying the pistons. And if that doesn't help I'll get Losi or Traxxas shocks.

The stock X-lock tires felt really hard and stiff, so I switched for some Chisels I've run on the SWX. They never really impressed me on the Axial, but now they really came alive and performed great on the Bully. Maybe they needed the extra weight of the Bully axles. I'll try the X-locks once I get some softer foams for them.

I wanted to fit all the electronics in the belly of the chassis. And there they are:





Only the dig switch rises above the chassis plates:





Up front I'm using a Savox 20kg servo. It has all the torque I need:





I made a battery plate on the rear axle for a 3S 1500mAh Lipo:





For now I'm running an Axial ARTR body. I'll post some body pistures once I get a new body painted.

And here's the current spec:

Bully axles
Bully chassis
Custom links
Sidewinder ESC
CC BEC
Savox 20kg servo
3S 1500mAh Lipo
Pro-Line Chisel tires on heavily reinforced RC4WD Rock Ripper wheels

[Soup Man]

Any reason you didn't go to a punk dig switch?

[Tomy]

Originally Posted by Soup Man

Any reason you didn't go to a punk dig switch?

I read about the punk dig switch, but figured this would do for me as I only wanted front dig. Besides, the punk dig is around $50 and this dig cost me $15. And it works really well! I hope I won't burn the switch as I've read others have done. But so far no troubles .

[Xtant3150c]

Rig is coming along nicely!

I agree on your dig switch being cheaper and I think it should work o.k. just depends on how you use it I guess? I would think the switches would last longer if you not flipping it on and off every 5 seconds? If you don't burn up switches then there probably isn't a real need for a Punk R/C dig switch.

You can run front dig only with the Punk R/C dig switch. I bought one for my Bully/KK4.0 rig more to simplify the electronics layout/setup. The added reliability it seems to have over the dig servo/switch setup is a plus.

[Tomy]

Originally Posted by Xtant3150c

Rig is coming along nicely!
If you don't burn up switches then there probably isn't a real need for a Punk R/C dig switch.

The micro servo/switch dig works well so far.

Here's a video of one the first test runs. Haven't had the time to paint a new body, so I'm running the Axial ARTR body waiting for time and motivation. The truck is doing quite well. The biggest issue is the shocks, which are too stiff. In the rear they've loosened up a bit, but up front they are too stiff. The steering servo is really noisy, but has great torque.

http://www.youtube.com/watch?v=JYUYdtjZ6zQ

[Tomy]

I was planning to run the stock shocks for a few weeks to see if they would improve with a bit of wear. But I had to give up on them today. They were only getting worse over the past few days turning so stiff that the springs would hardly return the shocks to their full lenght. And this with 7,5wt oil in them.

I borrowed Losi crawler shocks from my SWX just to see if they would fit without any binding issues. There is rubbing between the spring and gearbox at maximum flex, but nothing too serious I believe.



The Losis really are a huge improvement over the stock shocks performance vise. For example, I'm able to do the first climb in the video in the previous post at almost every attempt now having shocks with proper damping. And now the rig flexes smoothly allowing it to conform to the terrain much better. The stock shocks are simply not anywhere near comp level shocks.

[T-buck]

What weight oil you running in the Losi shocks??

[Tomy]

Originally Posted by T-buck

What weight oil you running in the Losi shocks??

Right now I'm still running the shocks as they were on my Axial SWX. I've got Losi red springs with 35wt oil in three shocks and a silver spring with 50wt oil in the rear left (seen from behind). But this is the setup I use on the Axial to eliminate torque twist. As soon as I get a new set of Losi shocks I'm going to put these ones back on the SWX. I'll proably run the shocks on the Bully with red springs, or the next stiffer spring rate with 35wt oil in all corners.

[Tomy]

It's done (for now)!

Here's the spec:

Bully axles, obviously
Bully chassis
Losi crawler shocks, red springs with 35wt oil (not in the pics yet)
Axial body
Wheels cnc-machined by a local guy
HB Rover tires, Pro-Line oversized foam up front and stock foams in the rear
Motors brushed 55t
CC Sidewinder ESC
Savox 20kg servo
CC Bec
Dig switch from 7kg micro servo and 5A switch
3S 1500mAh Lipo