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Exploring the Festool Drill Chuck Line
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Figure 1: Festool C12 cordless drill, shown with the Centrotec chuck mounted.
—Photo courtesy of Festool.
 
Figure 2: Festool C12 cordless drill, shown with optional chuck set. From top to bottom: the keyless, offset, and right-angle chucks. The Centrotec chuck is mounted on the drill body.
—Photo courtesy of Festool.
 
After months of lusting after Festool’s C12 cordless drill, I finally justified the expense of adding one to my workshop. On the face of it, they’re not cheap, but they allow you to do things that other individual drills do not, so if your choice is one Festool or a collection of several other specialized drills, then you come out far ahead – functionally and monetarily – with Festool.

Because the various entries in the Festool product line are designed to work together to make the whole greater than the sum of the parts, I opted to get the C12 with the expansion chuck set. While the base drill comes standard with the keyless and Centrotec chucks, the set includes the right-angle and offset chucks which make your drill ultimately flexible. The way in which all these chucks are used and combined is somewhat cryptic and unexplored in the product literature, so it is the intention of this article to try and clarify some of the potential mystery.

The Chucks:

Festool drill chucks are interchangeable amongst all their drills featuring “FastFix” quick-connect capability. It’s also possible to seat a standard .25" hex-shank directly into the drill motor without using a chuck at all. This allows you to squeeze an already compact drill into even tighter spaces.

Figure 3: Half-inch keyless drill chuck.
—Photo courtesy of Festool.
 
Figure 4: Centrotec chuck.
—Photo courtesy of Festool.
 
Figure 5: Offset chuck.
—Photo courtesy of Festool.
 
Figure 6: Right-angle chuck.
—Photo courtesy of Festool.
 
Figure 7: Depth-stop chuck. (Not included in set.)
—Photo courtesy of Festool.
 

NOTE: The sequence of the following descriptions corresponds to the order of the accompanying sidebar photos:

All of the chucks can be purchased individually, or for maximum savings, Festool offers a set which packages the offset and right-angle chucks along with the standard keyless and Centrotec offerings. (The cost savings in the price of the set is significant enough that you buy one chuck and basically get the other for $27.) While the depth-stop chuck must be purchased separately, it does store in the Systainer with all the other chucks.

Chuck mounting:

There are two different types of FastFix chucks: those which mount by locking onto the output shaft of the drill (via a spring-loaded, retractable ring), and those which mount to the face of the drill by means of a collar equipped with locking lugs. All of the chucks are interchangeable across the drills, themselves, but only certain of the chucks can be chained together.

There is no “positioning” to the keyless chuck or for the Centrotec adapter. These mount by means of the retractable spring collar, and can be fitted to the bare drill motor, as well as to the right-angle and offset chucks.

Fast Fact:
 
A positioning stop every 22.5° gives you 16 positions of adjustment.

The right-angle and offset chucks may be positioned at 22.5° increments around the 360° face of the drill. These mount by placing the chuck at the desired angle on the face of the drill and tightening the collar. Lugged-collar chucks can only be mounted to the drill, and not to each other.

There is no “positioning” to the depth-stop chuck, but it secures to the drill with a lugged collar.

The range of motion, from locked to unlocked or vice versa, for the lugged-collar on any chuck is a quarter of a rotation.

Methods of Work:
 
The C12 is equipped with a brushless DC motor that is functionally, a 3-phase AC power plant. The unique thing about 3-phase motors is that they inherently produce full torque at any speed, even at the lowest of RPM’s. This has a direct application in the driving of screws, since it means that you don’t have to pulse the motor speed way up to get that last little bit of oomph required to seat a stubborn screw.

As a word of warning, the “full torque at minimal RPM” feature can be rather painful if you’re used to loosening your keyless chuck by grabbing it with your hand and pulsing the trigger in reverse. I tried that once and the chuck turned out to be tighter than I expected. It spun happily around in my grip – just like it’s supposed to – and I wound up being the proud recipient of a lovely set of blisters. Oops! That’ll teach me to ignore the built-in shaft-lock, but old habits die hard...

Chuck capacities:

Centrotec:

Geometry for Dummies:
 
A hexagon is a 6-sided figure with pointy bits where the faces meet. The Centrotec profile flattens off these pointy bits to make 6 additional small faces, making the shape now 12-sided. If you measure a diagonal through the small faces that were formerly pointy bits, you have a slightly smaller diameter than a normal hex-shanked bit.

Festool has created a proprietary shank for their Centrotec quick-change adapter. At first glance, Centrotec bits are .25" hex shanks, but this isn’t quite the case. A hexagon is a six-sided figure. On closer inspection, the Centrotec shanks have slightly beveled vertices (the points where the sides meet). While maintaining the general look of a hex shank, in actuality, this subtle change makes the shank an irregular dodecagon – a twelve-sided figure where all the faces are not the same length – and therefore, slightly smaller in diameter when measuring diagonally. This insures that Centrotec shanks will work in standard .25" drivers, but the tiny increase in the width of a .25" hex shank will prevent it from being mounted in the Centrotec chuck.

Lest this be confused with an annoying marketing ploy to lock customers into buying proprietary consumable parts, the Centrotec product line has a number of unique features which differentiate it from the generic .25" hex consumables. The shank portion of a Centrotec bit is twice the length of the corresponding area on a standard .25" bit. This results in a much greater surface area supported by the Centrotec adapter, as well as having an integral groove for the quick-release feature (reminiscent of the QD fittings used on air tools). It is impossible to over-seat a Centrotec bit (should you want to try) because of the small O-ring recessed into the shank.

Working Chuck Sizes:

Since one of the great advantages (and marketing points) of the Festool drill line is that the various chucks can be used to work in tight places, it’s important to take a look at just how tight those places can be.

The offset chuck is used for “straight-in” applications, i.e. parallel to the drill, and allows you to work flush against adjacent surfaces. For situations where you have to work perpendicularly to the drill body, you use the right-angle chuck, either alone or in combination with the Centrotec or keyless chucks.

Clearances Summary:
 
• Right-angle chuck: 2.3"
• Right-angle with Centrotec: 3.74"
• Right-angle with keyless: 4.14"

Empty, the right-angle chuck measures 2.3" from the mouth of the drive shaft to the back of the chuck body. The drive shaft, itself, measures .6". This is important to know if you need to add another chuck since the length of the drive shaft will need to be subtracted from the overall dimension. The internal depth stop in the drive shaft socket is .4" (aka 10mm, aka 1 centimeter). When loaded with a typical .25" Phillips bit (measuring .98" overall), the working clearance for the right-angle chuck is 2.9" plus the length of the desired screw.

The Centrotec chuck measures 1.44" from tip to tip, empty.

With the jaws completely retracted, the keyless chuck measures 2.44" from tip to tip.

For obvious reasons, the summary dimensions do not include the length of the necessary drill bit, or driver-tip and screw. These should be easy to calculate in the field.

Figure 8: Right-angle chuck adaptor for generic drill.
—Photo courtesy of woodcraft.com.
 

By way of comparison, this Heavy Duty 90° Drill Attachment available at Woodcraft (also a stocking Festool dealer) measures 5" from the tip of the chuck to the back of the drill body. This is almost seven-eighths of an inch longer than the Festool right-angle/keyless chuck combination which would be used for drilling. If the job is driving screws, then the 2.77" difference in length is more than double the size of the Festool right-angle chuck which can be used to drive screws without the need of an additional chuck.

When dealing with close spaces, every fraction of an inch counts. We recently installed an eighteen foot header flush against the rafters in a remodeled house. The engineering plans required several straps and brackets to secure it to the existing perpendicular wall. There were some options in the planning stage, but none of them – like tearing off part of the roofing and lagging things in from above – were very attractive (or feasible). Having the C12 and its suite of chucks in our bag of tricks meant the difference between getting the job done right and having a seriously disgruntled client.


Festool: 888 337 8600

C12 Drill & Chuck set
P/N: PC1213S (1.3 Ah batteries)
Price: $460.00

Depth-stop chuck
P/N: 493539
Price: $88.00