Departure from the Norm
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February 10, 2006 • Skyjack, Inc.,
Image 1. Skyjack's all new 6826RT compact rough-terrain scissor lift.
Differential drive is a proven product, and Skyjack has produced tens of thousands of machines featuring these virtually indestructible systems. But as solid as they are, it's no big secret that differential drive limits the turning angle of the tire and how low the chassis can be positioned. These specifications ultimately dictate the success of compact rough-terrain scissor lifts, compelling Skyjack to make this change in its long-standing design philosophy to fully participate in one of the fastest growing segments of the scissor lift market.
The designation “compact rough-terrain scissor lift” describes exactly why this product is so popular. Its rough-terrain capabilities sufficiently work in the most challenging jobsites. Couple this with a compact height and width and a tight turning radius to make the machine more flexible, the compact RT scissor lift allows for application flexibility that is matched by few products of any size or model, indoors or out. It is also a reality that rental rates for larger platform-sized 26- to 32-foot scissor lifts have lagged behind the rest of the market. Rental operators need a product that will allow them to gain more acceptable levels of return.
As Skyjack stood by and watched Genie, JLG, and Haulotte deliver thousands of its compact RT machines to the global marketplace, Skyjack recognized and accepted the fact that its current differential drive system placed too many limitations on its ability to deliver a product that could meet all the market demands. Even if Skyjack could overcome these limitations with its differential drive, it would simply be too costly to allow for the kind of price point the market mandates. Changing its traditional design would be Skyjack's only resolution to enter this product segment
Two products make up this new family of compacts: The 6826RT, with a 68-inch wide platform and 26-foot platform height, and the 6832RT, which is the same product with an extra set of scissors and added ballast. Skyjack was accommodating enough to arrange for me to see one of the first test mules of the 6826RT just prior to it going into the field. Ahern Equipment Rentals is one of Skyjack's biggest and most loyal customers, and I had the chance to scope out this new compact entry at its headquarters in Las Vegas, Nev. (Thanks to the folks at Ahern for allowing us run of the place). Aside from designing a unit that conformed to the market demands, Skyjack went into this project with a clear objective: Carry over as much of its signature design features as possible. As Chris Dossin, director of marketing, explained, “We wanted to Skyjack it.” No compromises were made to the company's reputation for reliability and serviceability, he said.
I have been around Skyjack products for 20 years, and I can say that beyond the familiar orange-and-gray paint scheme, there is so much about the 6826RT that screams Skyjack • those characteristics will become apparent as we work our way through the equipment review.
Design departures
Skyjack uses what it calls a crossover symmetrical hydraulic drive system, and simply stated, it is a system that utilizes a flow divider that splits the hydraulic flow from front left wheel to rear right and vice versa for the other two. For these new compact units, Skyjack has opted to utilize a Barnes Haldex mechanical gear flow divider, which the company believes performs better in low-flow demands than traditional cartridge valves. I had the opportunity to give this new drive system a go and found the power to be impressive. Skyjack will publish the gradeability to be an eye-popping 50 percent. Top speed is a brisk 4 mph, and of course, the 5-foot inside turning radius afforded by the new drive system is a great improvement.
With that said, the only concern I had was the way power was transferred to the drive wheels. On a couple of occasions, I noted the system was not able to utilize all the power it had at hand (Image 2). Although I really didn't have a problem getting to where I wanted to go, I don't believe the flow dividers were performing at optimum levels. The system also made the drive feel a little jerky. Every time I lost traction, a muted squeal from the valves hinted that the flow dividers were not properly adjusted. But remember, this is a field test unit, and its sole purpose is to work out these kinds of glitches.
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Image 2. Although it didn't feel like the drive system was performing at its optimum level, I didn't have any trouble going where I wanted.
When you start looking at the 6826RT's overall construction, many unmistakable Skyjack features shine through. Starting with the construction of the scissor stack, the stack on the 6826RT is slightly narrower than other Skyjack RT scissor lifts to accommodate the need to position the stack lower and, at the same time, hold the overall 68-inch width. As with every Skyjack product, cast ears are utilized, and these are welded to 3/16” thick wall steel box tubes. The 26-foot unit is equipped with dual lift cylinders, and coupled with generous cross bracing, it adds up to impressive rigidity. As the platform rises, the scissors travel on UHMW slide pads at the top and steel rollers (Image 3) with needle bearings at the bottom.
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Image 3. Steel rollers at the bottom allow for smooth scissor-stack elevation. Also note the 800-watt inverter.
Dual grab bars on either side of the entry make it very easy to access the 12-gauge diamond plate steel work platform. Fold-down guardrails are standard and can be knocked down in a matter of minutes. As I mentioned earlier, I have been around Skyjack scissors for 20 years, and for each and every one of those years, I have beaten up Skyjack over the design of the deck extension system (Image 4) • well, not anymore!
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Image 4. Hallelujah! I am pleased to try out the redesigned deck extension system.
I am very pleased to say that the new system designed for this series is wonderful. Dual push bars allow you to easily roll the spacious 60-inch long deck out and lock it down in nearly two dozen positions. It is also important to note that you can drive either compact RT model at full height when the deck is fully deployed.
Another signature Skyjack feature is its very robust and easy-to-use all aluminum control box. In this application, it can be located on both the main deck and, for improved visibility, at the leading edge of the extension.
Next issue, I will continue my discussion of Skyjack's new design as we take a look at its serviceability and I delivery my final verdict on the machines.
