The list of innovations that make the Comp Crawler an RC revolution is long, and it starts with a solid foundation. The Twin Vertical Plate (TVP) chassis with adjustable upper shock mounts offers unbeatable stability and rigidity in a durable, lightweight design. The result is confident handling over any terrain and outstanding suspension articulation. And Team Losi Racing has gone one step further, by offering this innovative crawling chassis pre-built and tuned right out of the box. All you have to do is add the electronics of your choice and paint the included Lexan Grappler Pro body.

Team Losi Racing’s Comp Crawler is the first rock crawling platform in the industry to offer a revolutionary front and rear “dig” transmission. The use of an optional third channel setup allows the front or rear drive axle to be disengaged, locking the wheels in place and acting as a steering brake for precise lateral movement on and over obstacles. The transmission case has been fitted with adjustable servo mounts that will allow for the use of most “mini” servos and includes an aluminum servo arm. The third channel on a 3-channel radio (such as the Spektrum DX3R) allows the full use of the DIG transmission, and also requires a micro servo installation for actuation. If you do not have a 3-channel radio system or extra servo, there is no need to worry – the Comp Crawler will function with full-time 4WD with our without a dig servo hooked up.

The solid axle setup on the Comp Crawler offers a significant reduction in flex for improved performance. Inside, the axles utilize a worm gear drive for outstanding precision in throttle control and maneuverability. Another benefit of the worm gear drivetrain design is the elimination of the “torque twist” commonly found in shaft driven rock crawlers. As a result, the Comp Crawler stays in contact with the ground for uninterrupted grip.

The Comp Crawler features a 4-link suspension layout that offers 70 degrees of suspension articulation. This specially designed 4-link suspension setup is used in combination with the Twin Vertical Plate chassis to reduce axle swing and eliminate side-to-side movement for increased steering and maneuvering precision. 7mm diameter aluminum suspension links are hard anodized and triangulated to the center of the chassis for better balance front to rear when the suspension starts to twist. 4-inch aluminum threaded shocks with titanium nitride (TiNi) shafts allow the suspension to articulate without any binds.

Just like full-size crawlers, the 1/10 Comp Crawler utilizes functional beadlock wheels with aluminum outer rings. The functioning beadlock allows for the tires to maintain more contact and traction, while the aluminum outer rings provide evenly distributed pressure for unbeatable tire mounting. Losi’s National Champion Rock Claws 2.2 Tires come mounted on the beadlock wheels, complete with foam inserts. The added ground clearance from the Rock Claws tires makes conquering any and all courses easier.

Features:

• COMPACT FRONT & REAR LOCKING (DIG) CENTER TRANSMISSION ALLOWS THE CRAWLER TO OVERTAKE OBSTACLES WITH EASE
• FRONT AND REAR SOLID AXLE WITH WORM GEAR DRIVE
• FRONT AND REAR LOCKED DIFFERENTIAL PROVIDES FULL TIME 4WD
• 4-LINK SUSPENSION MINIMIZES REAR AXLE SWING,ALLOWING FOR MORE PRECISE HANDLING
• 3-PIECE 2.2″ BEAD LOCK WHEELS WITH ALUMINUM OUTER RINGS
• 2.2 LOSI ROCK CLAWS TIRES WITH FOAM INSERTS
• 4″ ALUMINUM THREADED SHOCKS WITH TITANIUM NITRIDE (TiNi) SHAFTS ALLOW THE SUSPENSION TO ARTICULATE WITHOUT ANY BINDS
• DURABLE CV FRONT AXLE SHAFTS ALLOW FOR INCREASED STEERING RANGE
• TWIN VERTICAL PLATE CHASSIS WITH ADJUSTABLE SHOCK MOUNTS
• ZERO ACKERMAN STEERING PROVIDES CLASS LEADING PERFORMANCE WITH 45 DEGREES OF STEERING THROW
• ALUMINUM UPPER AND LOWER SUSPENSION LINKS FOR ADDED STRENGTH
• RACE ROLLER CHASSIS IS PREASSEMBLED; SIMPLY ADD ELECTRONICS, PAINT AND GO

Features
Give ‘Em The Shafts - Venom’s included VC drive system provide smooth operation throughout the suspension’s range of articulation and steering. The drive shafts are composed of steel shaft ends and ball joints while the main slider shaft is composed of the same glass filled nylon as the rest of the kit. These shafts are lightweight, helping keep the CG low, and are also durable for punishment on the rocks. Venom uses the same style joints in the axles to provide maximum steering angle, up to 40, while still maintaining smooth operation and durability.

Lock ‘Em Up - One of the coolest features on this rig is the lockable differentials. A sliding mechanism on the outside of the axle housing contains a shift fork on the inside that engages the red anodized locking ring. The red anodized ring slides back and forth to engage the three locking pins into the differential bevel gear and thus locks the differential for some serious crawling action. As an optional part, Venom offers a remote locking kit (VEN-8347) to allow you to lock and unlock the differential on the fly.

Continue Reading…

Continue Reading…

Trim the Foam

Soft compound tires require foam inserts to help them keep their shape. In some cases, the foam inserts make the tires too stiff for crawling and don’t allow the tire to conform to the rock’s surface. You want the tire to be flexible yet stiff enough support for the tire to prevent it from folding over. Some people cut their inserts in a star type pattern to make flexing a little easier. Making this modification is easy. Mark the foams with the desired pattern, and carefully cut the sections out using a sharp hobby knife. How much foam you remove will be based on the flexibility of your tires. Softer tires require more foam to be left for support.

A key to good traction is to have the tread of tire to be generally as flat as possible. A larger contact surface means more traction. An insert that is wider than the tire will distort the tread of the tire and potentially reduce the contact patch. You can eliminate this problem by cutting the foam insert so that it’s the same width as the tire.

Rims
A common practice in rock crawling is to narrow the rims. Doing this provides more clearance between the links and the tires when steering, and since the tire is pulled in, it will increase the tire’s “side bite” by bringing the tread down the side slightly. If cutting rims and gluing them back together isn’t your thing, you can pick up some rims that are already narrowed. are available from Axial, RC4WD and RPM. Axial also offers Maxx-size rims in a narrow form.

A flat tread works better on the rocks than a rounded tread. The more tire contact you have on the rocks, the better your truck will crawl.

Weight
The only thing you need to know is that generally you want more weight up front than in the rear of the truck. This helps the truck handle vertical climbs. Some guys like to add equal weight to both ends of the truck. Either way, you’ll want a lit- tle weight in all four tires. When considering the weight dis- tribution, also remember one of the best things you can do to improve your crawler is to lower the center of gravity. So, moving the battery from the top of the chassis over to the front axle or links accomplishes two things: it moves weight forward for a better balance and lowers the CG

PELLETS
A great way to add weight to your tires is to fill them with used in air powered pellet rifles. The pellets roll around and stay at the bottom of the tires at all times,and that keeps the truck’s center of gravity low and reduces rollovers. The pellets also replace the foam inserts. Filling the tires can be a bit tricky. Attach your tire to one side of the wheel and stick a small funnel into the open side of the tire and use it to direct the pellets into the tire. Fill the tire about halfway, and make sure that you have an equal amount in each tire. There is a downside to this setup; it doesn’t work well when side hilling when you drive your truck perpendicular to its incline.

STICK-ON WEIGHTS
You can also add weight to your tires by using stick-on lead weights on the rims. Start with 3 to 7 ounces of weight on each rim, and make sure you prep the surface of the rims by cleaning them with motor spray before you stick the weights to the rims.

When adding weight to your rims, you can add the same weight all around, or more weight up front than in the rear; 60/40 is the typical split.

Source
rc car action

1. Choosing a chassis – One of the first things you will want to do is choose a chassis with a low center of gravity. As obvious as this sounds it is sometimes over looked. You want to keep every ounce of weight as low to the ground as you can when climbing a steep incline. If your weight is not distributed correctly you run the risk of rolling your RC rock crawler over on it side.

2. Tires – For tires you’re going to want soft, large tires with a pronounced tread pattern for maximum ground clearance and grip. If you run the tires without foam inserts to allow them to flex but the tires don’t support your truck adequately, then look to soft inserts for support. The reason you want soft tires is that you want your tire to flatten out and give under the weight of the crawler. This is the same effect as deflating your tires in a full size crawler. This will give you maximum traction during the climb.

TIP: To soften hard tires try spraying a little WD-40 on them.

Cons: A little heavier, a little more expensive, some say to much effort to change tires.

4. Suspension – When it comes to RC rock crawling the suspension is the main ingredient, but not just any suspension will do. Articulation is the key here, but an independent A-arm type will not allow you to get the adequate articulation required. What you will need is a solid front and rear axle with a 4-link suspension. This will allow for maximum articulation and grip.

TIP: For maximum axle articulation keep your shock and spring combination soft.

5. Locked differentials – In most RC cars differentials are a must, but not when it comes to crawling. This is the most important modification you will need to do. If you don’t have locked differentials the power will be sent to the opposite wheel that isn’t under load. By having locked differentials the wheel maintains constant power when going over rocks. Locking out the differentials can be done a number of different ways: epoxy, JB Weld, or you can purchase lockers.

MORE HELPFUL TIPS: Four wheel steering, forward mounting your battery, mount your steering servos on top of each axle.

If you enjoyed this article please click on one of my sponsors, help me support this site. ]]> http://www.rcgawker.com/2009/07/how-to-build-your-own-rc-rock-crawler/feed/ 0