Bully Build - Take Two

[xirtic]

Parts: (Total Weight: 8.25 pounds)
· Reign J2-TT Narrow Chassis (Modified Upper Link Locations)
· Bully Axles
· JP Customs Warrior II 45T Motor (x2)
· Castle Sidewinder ESC
· Castle BEC
· PunkRC Dig Switch
· Losi 4” Crawler Shocks (Droop with 80wt Oil & limited with hollowed Delrin spacers)
· Hitec 5955 Steering Servo
· MSD Top Gun 2.2 Beadlocks (2 – 1/8” breather holes)
· Panther Tires
· Kreepy Red Memory Foams (Front) with a ¼” ring of firm foam on the outside
· Aces Doughnuts 5.5” Memory Foam (Rear)
· Firestone Stick-On Wheel Weights (9oz front, 4.5oz rear)
· Zippy-H 1450mah 30c-40c 3 cell LiPo
· Spektrum AR6000 RX
· Spektrum DX6 TX (Modified for throttle return, upgraded voltage regulator, internal antenna)
· Links – All are custom ¼” Delrin Tube filled with M4 Threaded Rod and Revo Ends. (Bent Lowers)
· Custom ¼” Delrin Chassis Braces
· Custom Aluminum Steering Servo Mount
· Custom Lexan Battery Tray on rear axle
· Custom Lexan upper link RX tray
· Body Mounts (Modified Axial)
· Associated Chassis Protector on all lower axle parts
· Deans Connectors on power leads, 4mm Gold Bullets on Motor & ESC leads & Deans 12ga wire

After learning that a Torsion Chassis was not my thing, I went back to the bench and started rebuilding the truck. I figured that I could take the rig that I did well with last year (Shafty) and steal some of the working ideas from it and move them with some changes to the MOA platform.

To start, I took last year’s comp chassis and added upper link mount points farther into the chassis. Reign left some nice metal that was perfectly placed to allow for longer upper links.

Next, I dropped the axles into my jig, and placed the chassis dead center…..and started building links. This was an opportunity to try something different. People have been using threaded rod sleeved in brake line, and this is strong, but it is not slick. So I decided to take ¼” Delrin Tube and hollow it out to 5/32” this is perfect to just slide M4 threaded rod thru (barely makes it). Then cap that off with Revo ends. These are VERY strong, VERY slick, and nice and thin to clear the shocks, motor, and gearbox.

After attaching the shocks & wheels, and setting the ride height, we had a roller. I then installed the steering servo bracket, electronics, and built steering links (same process as the upper/lower links). Wiring in this configuration was MUCH easier than the previous truck (Dual ESC, Dual Dig w/2 micro servos & 2 switches) The chassis is actually spacious now instead of being over-filled with electronics. This definitely is helping the droop handle climbs. The less in the chassis the better.

Thru testing, this is performing better for my style of driving. I can go slow and get the articulation that I desire, and if needed, I can punch it, and have some NICE wheel speed. The PunkRC Dig Unit is SWEET. It is so fast and never seems to skip a beat. I have it on the UP/DOWN of the right stick that I use for steering….it is just so intuitive and easy…no more flipping a toggle on the radio for dig. I also liked the control of the 2 ESCs…I do not know yet if I am going to miss it, but the feel of the rig with one ESC is not bad…just something that I will need to adjust to.

[xirtic]

.....and here are some articulation shots (Body ON & OFF).

[Ripperfi]

Thank you for the idea on the links. Looks like a winning truck. whats your thoughts on the bully axle vs the berg axle?

[xirtic]

I do not have any experiance with the Berg axles to form an informed opinion. That being said, now that RC4wd has sorted out the issues with the Bully CVDs, and they are now making a cast version that costs $90 less than this version, the Bully is rock solid. I have been beating on these axles since February, and I really like them. When I build another rig, I will buy another set of Bully Axles.

[Ripperfi]

Originally Posted by xirtic

When I build another rig, I will buy another set of Bully Axles.

Will they be bully or bully 2's?

[xirtic]

The original "Bully" is no longer going to be production. So my next set will be "Bully 2" axles. The Bully 2 is heavier, so may require less wheel weight.

[Stormin2u]

That worked out so well nice work.

[Racer4Life]

That looks really good. Nice write up as well.

[jetboat]

droop will you never learn???

[xirtic]

Originally Posted by jetboat

droop will you never learn???

LOL....last year the DROOP beat you. I can remember the chants "Droop is Poop" and "Break....Break....Break". Yet the droop never failed me, and MY rig did not break in a comp. Hmmmmmmm. "GO DROOP!! GO DROOP!!" will be this year's chant.

[Ripperfi]

Progressive droop, theres a concept.

[hitman46mod]

Great build. Run what works.

[jetboat]

I would just like to point out.... Droop does = poop as you still finished behind me

Seriously, Im not sure how you are liking it but, what I was seeing wasnt good. when you tried to climb the front end seemed to unload bad and it was looking like the weight was all transferring to the rear. Judging gives you a different view (as you are fully aware) so you can see things you cant see driving.

[xirtic]

I think that I am running tooooo much weight in the wheels. I still have the weight in there from the Zero-T Chassis build...I am going to try and drop that by 1/2 and see what I get. (9 ounces added up front and 4.5 in the back needs to be reduced.) I think that dropping that weight will help. I really do not want to go back to a SPRUNG design. I have the parts to switch it, I just am fighting it.

[mini max]

does it take sidehills good or is it alittle top heavy..nice looking rig

[xirtic]

Originally Posted by mini max

does it take sidehills good or is it alittle top heavy..nice looking rig

Sidehills were fine, but going up on ledges caused problems. I was running FAR too much weight in the wheels to support the droop effectively. When I ran droop as a shafty rig (axial), the axles held very little weight...and I added about 3oz of weight to make the droop slow and effective. In the Bully Build, I failed to take into account the axle weight, added to the motor weight at the axle, added to the extra wheel weight that I had added to the wheels when I tried the Zero-T chassis. This added A LOT of weight to the droop....tooo much weight. The suspension would just unload like crazy.

NOW the rig has gone thru some changes.

1. Reign J2-TT chassis is replaced with a Reign Widemouth chassis.
2. The rig is now sprung.
3. I dropped the extra weight from the wheels. Now running 3oz up front and no extra weight out back.
4. New links to support this change. (Lengths changed, but same construction.)

In testing this is working MUCH better. I am no longer unloading the suspension in a negative fashion, and the rig is very predictable. Articulation is also increased by about 15%-20%.

I did not want to go sprung as I prefer the feel of a droop setup, but I think that the weight of this MOA setup made running a pure droop suspension a poor choice. JEFF (JetBoat)...I hate to say that you were right, but in this case I really have no choice. Droop on a Bully MOA = POOP.

[xirtic]

Some steering changes have come to pass in the past week. After 2 weeks in a row of destroying servo horns (Due to the horn pointing up above the servo). When I would try an flip myself back over, or on the initial flip itself, I would bend the horn...this was risky in terms of a touch/repair penalty.

Montrucks latest steering/servo mount was my motivation for the solution that I crafted for myself. Thanks for the inspiration. It is not traditional in terms of the drag link/tie rod locations.....but I think that it will work. I could move the drag link below the hub mounting points....but I do not want to scarifice the ground clearance...so I am going to give this a try. Please pardon my not so great Blackberry Camera.

[53 willys]

NICE I like it....I have been playing with steering on my rig aswell....I thought something like this would be nice just like you after seeing SAVER's post.

please let us know how it goes....

[xirtic]

Originally Posted by 53 willys

NICE I like it....I have been playing with steering on my rig aswell....I thought something like this would be nice just like you after seeing SAVER's post.

please let us know how it goes....

Was in a local comp over the weekend and put this part thru it's paces. NO DAMAGE. It took some tumbles as well as front end binding on rocks...but nothing flexes or breaks. My servo arm also survived the day with barely a scratch. At this point, I am calling this part a success. Now to work on putting the prototype into CAD and making some more with tighter tolerences. (This is not a hot project...but something that I am thinking of doing)

[53 willys]

Originally Posted by xirtic

Was in a local comp over the weekend and put this part thru it's paces. NO DAMAGE. It took some tumbles as well as front end binding on rocks...but nothing flexes or breaks. My servo arm also survived the day with barely a scratch. At this point, I am calling this part a success. Now to work on putting the prototype into CAD and making some more with tighter tolerences. (This is not a hot project...but something that I am thinking of doing)

cool!! burn one out for me while your at it?!?!? I would like to try that servo bracket out forsure.