Festool C12 EC-TEC manual Conclusion

Another feature of the C12 gearbox is the integral shaft-lock to assist in bit changing. The motor can rotate the drill chuck, but the drill chuck cannot

rotate the motor. With the shaft-lock, you can tighten the chuck as hard as you want, and the gearbox will hold fast.

Conclusion

I'm not big on drawing conclusions for others to follow. I am more comfortable writing fact-based information. So instead, I will use this space to provide some of the opinion-based information I came across during my examination. It might be

ahodge-podge of ideas, but I guess that's what opinions are supposed to be.

I first saw a cutaway model of the C12 at the AWFS trade show in Las Vegas this summer (see the cutaway picture on page 2). I was so fascinated with the idea that a 3-phase motor was being used in a battery operated tool that I volunteered to write this technical review and give it to Festool without taking a fee for my work.

With technology this cutting-edge, I knew there would be a lot of people that were not yet familiar with it (including myself). Besides, I was dying for a chance to tear this drill apart to see how it worked (I am a card-carrying member of tool-junkies anonymous).

While it wasn't very scientific, one of the first things I did when the drill arrived was to try to drive a 4-inch screw into a block of wood; except I wanted to see what would happen at ultra- ultra-low speed—about 1 revolution per second. I carefully held the trigger in a fixed position so the bit was spinning at a constant speed, and then started the screw into the wood. I can't even begin to tell you just how blown away I was when the drill kept plodding along until the entire 4-inch screw was sunk into the wood. I tried the same thing with one of my other drills, and it stalled after just 1 inch.

Oh by the way, I wasn’t doing this in low-gear like you would expect. The drill was in high- gear! The motor appears to deliver a constant torque at any speed or load. However, without seeing the schematic of the motor's electronic

controller I cannot state this as fact, so I am leaving it as just my opinion.

My excitement just kept escalating from there on. So the next thing I did was build a dynamometer so I could compare the power of this 12-volt drill against several 14 and 18-volt drills I bought at my local home center.

Unfortunately, when the three most popular drills on the market (names withheld) started smoking under my dynamometer's load, I decided it would not be wise to publish this data, lest I wanted a lawsuit. However, I found it very curious that the only drills with torque curves higher than the C12 were also the ones that allowed their motors to self-destruct.

I could have legitimately published the rest of the data, and throw out outlying data because the drills destroyed themselves to achieve their results. Instead, I decided to throw out the entire test, because trying to explain the outliers might have sounded like I was playing games with the data; and I refuse to publish anything that sounds misleading.

Finally, there are a lot of intangibles about this drill that don’t fit neatly into a technical review. Here are some other quick observations:

►The motor is extremely smooth and quiet; noticeably so over other cordless drills.

►The drill is perfectly balanced, with the center of balance right over the trigger—you can balance the drill on your index finger.

►Even with the largest optional batteries, the drill is still very light.

►Changing batteries is very easy because the batteries slide in from the front, and the latches don't need to support the weight of the battery like most other drills.

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