I've been a framer most of my adult life. With the help of some top-flight carpenters I've taken my Albuquerque-based company, Framing Square, from a two-man operation to a major framing company with multistate operations. I employ between 50 and 100 carpenters, depending on the time of the year and the projects on my plate. And every step of the way I've had a wormdrive saw in my hand.
So, when the folks at Hanley-Wood's Tools of the Trade asked me if I'd test the latest batch of wormdrive saws, I jumped at the chance. I approached the task thinking that I was a wormdrive expert. However, I was surprised to find just how much there is to know about these tools.
Seventy-six years after Edmund Michel created the original wormdrive, he and his partner Joseph W. Sullivan went on to found Skil Corp. Skil improved and refined the tool into the sleek, efficient saw we know as the Skil 77. Other manufacturers developed their own saws to vie for a share of the wormdrive market that Skil dominated for so long. Today, there are a host of outstanding wormdrive saws to choose from.
We tested four traditional wormdrives--the Skil HD77M, Skil HD5860, Milwaukee 6377-6, and Milwaukee 6378--driven by traditional wormgear systems. Each of these saws has a forward-facing motor that drives a system of gears known as wormgears. The gears channel the motor's power to a shaft that exits the tool housing's left side.
We also tested two hypoid saws--Makita's 5277B and the DeWalt DW378G. Hypoids' geared drives resemble worm- gears, but are touted as an improvement. Proponents of the hypoid design claim that its finer-toothed gear system allows for closer gear meshing and greater surface-area contact. Manufac-turers say these factors result in smoother power transmission and cooler operation than that of conventional wormgear-driven saws.
A hypoid saw has a sealed gear system. A wormdrive saw requires a user to check the oil level and add lubricant when needed. Granted, the hypoid gear system is convenient, but how long will its sealed lubricant last? Both types of gears are hard-working, high-temperature systems. The ability to replenish the oil reservoir is probably a big plus for a wormdrive saw's longevity.
Skil wormdrives have been documented with some impressively long lives, and the folks at DeWalt told me their DW378G withstands over 700 hours of continuous operation (that's more than 10 years of hard field use). The hypoid saw is a relative newcomer, so it's hard to gauge its longevity against a worm-drive saw.
Personally, I've never owned a saw for more than a couple of years. Mine either get run over by a forklift or dropped from a building. If a saw is designed for 10 years of heavy use, I'll definitely destroy it before I burn it out.
Operation and handling. A tool can have a million nice features, but if you don't like the way it feels in your hands, you're not going to be happy with it. Before this test, I never gave much thought to a tool's balance. The first time a manufacturer rep mentioned his saw's balance, I laughed and told him that a wormdrive has no balance. It's a slave to gravity. The handle is on one end, and the weight is on the other.
In truth, that isn't all bad. A wormdrive's weight and balance, or lack thereof, help push it through cutting material. When you stand a 2x12 on edge and cut down through it, the saw does all the work. The opposite is true if you have to cut rafter tails from below. In this case, you're not only pushing the tool through the material, you're also supporting the saw's weight. (Did I mention the face full of sawdust that comes with this maneuver?)
When you pick up a well-balanced tool, the shoe plate naturally swings into a level position. You shouldn't have to use your wrist to level the saw. During cuts, the tool should set solidly on the shoe plate, not tend to tip over.
Weight. It's interesting how different manufacturers address this issue. The 71/4-inch saws we tested range from just 13 pounds for the DeWalt DW378G to a hefty 16.8 pounds for the Milwaukee 6377-6. DeWalt's housing is made of the same high-tech plastic used for NFL helmets. The company matched this to a lightweight cast-aluminum shoe. Our crews found the Makita 5277B light and easy to handle. It has a composite nylon housing and a steel shoe.
Skil really took the weight issue to heart. It designed its HD77M with an all-magnesium body and an aluminum plate shoe. The combination makes for a very lightweight package, but durability is a big trade-off. Our field guys complained that the aluminum shoe wasn't strong enough. Skil's literature says the tool's aluminum shoe can easily be straightened on the job site. To me, that sounds like the shoe can be easily bent as well.
Milwaukee uses all-steel shoe plates and a glass-reinforced nylon housing that's designed to withstand repeated falls from a height of six feet. Even the Milwaukee tools' power cords are impressive. They're 9 feet long, 3/4-inch thick, and made of 14-gauge, three-wire copper cable with an S-type, full-rubber insulation. The saws are heavy, but the folks at Milwaukee make no apologies. They call the 6377-6 a heavy-duty wormdrive, and they mean it.
We tested two 81/4-inch saws--the Milwaukee 6378 and Skil HD5860--which weigh 17.3 and 18.5 pounds, respectively. The Milwaukee 6378 appears to be a larger version of the company's 71/4-inch model. The two saws have identical specs, except the larger saw weighs 1/2 pound more. We liked the 6378. Surprisingly, it's 1.5 pounds lighter than Skil's 81/4-inch model. The Skil HD5860 has a die-cast aluminum housing and a durable steel shoe plate. It's a handful at 18.5 pounds.
Using the highly scientific "I can raise this thing with one hand and point it where I want to go" method, we choose the DW378G for best overall balance. DeWalt shortened its saw and gave it a better feel by setting the motor at an angle to the cutting table. The trigger and handle assembly are located behind and below the motor.
Torque. When you start any wormdrive's motor, you feel a twisting motion in the tool. Some framers call this "saw buck." It's inherent to the forward-facing motor. Some saws are engineered in such a way that torque is hardly noticeable. It's more pronounced in others.
A saw's power-to-weight ratio affects its torque. Theoretically, a light saw with a powerful motor should twist harder than a heavier tool with the same motor rating. Our carpenters complained that the DeWalt DW378G and Makita 5277B saws twisted severely when their motors started. This may be a product of their high-power-to-low-weight ratios, or it could result from their hypoid gear system signatures. However, our carpenters lodged the same complaint against the Milwaukee 6377-6, a traditional wormdrive and the heaviest of our 71/4-inch saws. So much for power-to-weight ratios and hypoid-versus-wormdrive theories.
The amount of buck in a saw may be a problem for one user and not for another. I recommend plugging the tool into a power outlet and trying it a few times before making your buying decision.
Power. The Skil HD77M has a 13-amp motor. The Makita has a 14-amp motor, and the DeWalt and Milwaukee saws rely on 15-amp units. A highly efficient 13-amp motor may deliver more cutting power than a less-efficient 15-amp motor. I crunched numbers to determine which of the saws we tested was the most powerful. After talking to various manufacturer reps, I found you simply can't go by the numbers to compare power.
In the end, we concluded that all the saws we tested had adequate power. There are no wimpy saws in the wormdrive category. However, if I had to pick one tool line as being more powerful than the others, I'd go with the Milwaukee tools. Their big motors feel more powerful than the other tools' motors.
Noise. I tried to get standard decibel ratings for the tools we tested. Makita was more than happy to provide its rating. It has the quietest saw in this class, and is proud of it. Noise-level information wasn't available for most of the other tools, so we created our own high-tech sound lab by closing the shop's overhead doors and telling everyone to shut up.
We then fired up the tools in groups of two. Is that one louder than the other one? Do you wanna hear 'em again? This process went on for a while, and we reached several conclusions. The hypoids, Makita's 5277B and DeWalt's DW378G, were the quietest of this noisy group. Of the traditional wormdrives, we felt the Skil saws were a little quieter than the Milwaukee tools.
In the end, we realized we were just splitting hairs. These are all noisy tools. I don't think I would choose one saw over another other based on noise level. However if operating noise is a major concern for you, the Makita or DeWalt models are your best bet.
All the saws in our test come with standard blades except for the DeWalt DW378G, which includes a high-quality 24-tooth carbide blade. We give DeWalt credit for added value.
The DW378G also boosts an improved blade guard design that eases severe angle cuts, the company says. I used four-foot-long Doug fir 2x6s to test this. I marked a 45-degree cut 1 inch from the end, then moved down the boards marking sharper angles until I got to 70 degrees. The saws handled differently on the cuts. The Skil HD77M's guard tended to push the saw out of line as I pushed its blade into the cut. I found that the DeWalt blade guard does indeed cut sharp angles more easily than the other saws do. And, since framers might be less inclined to cheat the DW378G guard up on angle cuts, they might be a little safer on the job with this tool. More value-added credit points for the DW378G.
Skil's HD5860 features an innovation called the 60º Pro Bevel. The tool's improved shoe plate design allows the big saw to cut 11/2-inch-deep, 60-degree bevel cuts. This is an invaluable feature if you cut-in a lot of roofs. For my money, this makes the Skil HD5860 the clear choice in the 81/4-inch category.
For as long as I can remember, framers have attached jerry-rigged sky hooks to wormdrives so they can hang the saws from rafters. This saves lots of aggravation and broken casings from saws being dropped off roofs. Third-party manufacturers recently started marketing professional-looking sky hooks that bolt to most wormdrive tools. These add-on hooks run about $12.
The guys at DeWalt have been paying attention to the people that use their tools. They noted that professional framers add sky hooks to their saws, so DeWalt designed the DW378G with a factory-built sky hook. We gave them more value-added points for this innovation.
If you've read this far, you've probably already guessed that my all-around favorite saw is De-Walt's DW378G. The runner-up is the Skil HD77M. In the 81/4- inch category, my pick is the Skil HD5860.
I feel we owe a debt of gratitude to Skil. It is, after all, the company that refined the earliest wormdrive saw. Skil set the industry standard, and set it high. The quality of tools in this category is a tribute to that benchmark.
Michael Davis owns Framing Square, a large framing company in Albuquerque, N.M. He is a contributing editor to Hanley-Wood's Tools of the Trade.