TDK 12 CE and 15.6 CE Drills

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Hello Everyone,
Below is a review I wrote of the two Festool TDK drills.  This was originally written in October 2004, and the details are still accurate.  Please feel free to post follow-up questions or comments about the review.

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A Review of the Festool TDK 12-volt and 15.6-volt Cordless Drills
By Matthew Schenker

Introduction
I recently received the Festool TDK 12 CE and the Festool TDK 15.6 CE cordless drills from Festool for review purposes.  Over the past couple of weeks, I put them to work.  With the TDKs, I tested four different Festool chucks, including the basic chuck, two special chucks designed to drill and drive in challenging situations, and Festool’s new Centrotec chuck.  In all my tests, I was impressed with the power and handling of the Festool TDK drills.  Impressed because of the size and weight of these drills, but not surprised, since I already own and use several Festool tools and have become accustomed to this company’s outstanding engineering and design accomplishments.

In the past, I often considered adding a Festool cordless drill to my tool collection.  But I hesitated because the stated voltage ratings of the Festool drills is lower than others on the market.  For example, Festool markets their CDD and TDD drills at 12 volts.  With the new TDK drills, Festool is marketing them as 12-volt and 15.6-volt machines.  At first, this may seem to put them below the level of so many other drills available at 14.4, 18, and 24 volts.  However, after having an opportunity to use the TDK drills, I can attest that there is something about their design that gives them much more power than what you normally associate with a 12-volt or 15.6-volt cordless drill.

In the tests described in this review, I compared the Festool TDK drills head-to-head with a Makita 14.4-volt drill (item no. 6336DWDE) and a DeWalt “Compact” 18-volt drill (item no. DC759KA).

First Impressions
Balance
Holding each of the four drills in my hands, I immediately noticed that the Festool TDKs simply feel better and seem to settle in my hands more naturally.  The Festool TDK drills have a slightly rubberized grip.  The DeWalt also has a rubberized grip.  The Makita has an all-plastic handle.  The two Festool TDKs have a different center of gravity than the other drills I tested.  With the Makita and DeWalt, the center of gravity is near the base, where the battery is located.  This is most noticeable when you are holding the DeWalt or Makita horizontally, as the rear end of these drill feels as though it is pulling downward like the heavier side of a scale.  With the Festool TDKs, the center of gravity is balanced somehow.  Holding the TDK drills either vertically or horizontally, they have equilibrium, and the weight is distributed evenly from top to bottom.  This simple factor can reduce fatigue caused by the weight of the tool, especially during long projects that involve having to drill in uncomfortable positions.

Size and Weight
When I opened their Systainers, my first impression was that the TDKs are even smaller than expected.  Comparing the two TDKs with the DeWalt and the Makita, the biggest size difference is in the length of the “nose” -- the total length of the horizontal part from the rear to the tip of the chuck.  The two TDKs have identical nose lengths.  In fact, the entire body of the 12-volt and 15.6-volt TDKs are the same size and height.  The only size difference between the two TDKs is their batteries, with the 15.6-volt battery being a little fatter.  The TDK noses are about 1.25” shorter than the DeWalt, and about 1.75” shorter than the Makita.  Measuring the height of the drills from base to top, batteries installed, the TDKs are about 1/2” shorter than the DeWalt and about 1” shorter than the Makita at their highest point.

With the batteries installed in all the drills, the TDKs feel lighter than the Makita or DeWalt.  Due to their better balance, the TDKs appear to be even lighter than their stated weights.  Here is the weight of each of the four drills I tested, with batteries, from heaviest to lightest:
> 18-volt DeWalt: 5.2 lbs.
> 14.4-volt Makita: 5.1 lbs.
> 15.6-volt TDK: 5 lbs.
> 12-volt TDK: 4.4 lbs.

Stability
Although they are smaller than the Makita or the DeWalt, both of the Festool TDK drills are very stable.  I had no problem placing them down securely on a surface.

Shape
The TDK drills have a straight design, with the chucks aiming at a right angle with the handle, as opposed to the Makita, and most other cordless drills, which aim at a slight angle up from the handle.  The DeWalt drill also has a more right-angle direction.

The TDK Package
Festool includes the following items in the package with both the 12-volt and the 15.6-volt TDK drills:
> The drill
> Two NiCD batteries (item no. 492 268 or item no. 492 279)
> One LC 45 battery charger (item no. 492 138)
> One Fastfix keyless chuck (item no. 490 698)
> One Centrotec chuck (item no. 492 135)
> One 4mm Centrotec-style drill bit (item no. 492 513)
> One Centrotec screwdriver holder (item no. 492 539)
> A “Sys 1” Systainer (item no. 445 433)

The Festool Chuck System
Festool’s “Fastfix” Chucks
For some time, Festool has been offering a unique chuck system, called Fastfix, on their drills.  Until I got my hands on one, I did not realize how versatile the Fastfix system is.  With most drills, the chuck is firmly mounted to the drill stem, and can only be added or removed by using a hammer and a piece of wood to bang it on or off.  It is not something you want to do very often.  By contrast, the Fastfix chucks slip on and off Festool drills easily, a simple idea that allows for quick exchanges of different chucks for drilling and/or screwdriving.  You pull back on a sleeve and slip the chuck onto the drill.  Then you let go of the sleeve, and the chuck is secured.  To remove the chuck, you simply pull back on the sleeve again and pull the chuck away from the drill stem.  No turning or cranking or banging.  The Right-Angle and Eccentric chucks (described later in this review) both use the Fastfix system.  With Fastfix, if you have a couple of chucks, you can load a drill bit in one and a screwdriver in another, or a countersink in one and a drill bit in another, or any other combination, then swap the chucks as needed.  It actually takes less time to change Fastfix chucks on Festool drills than it takes to just install a bit on other drills.  In addition, all Fastfix chucks are keyless.

The Centrotec Concept
Centrotec is Festool’s latest drill-chuck innovation.  At first glance, the Centrotec does not even look like a drill chuck, but rather like two cylindrical plastic pieces joined together.  It appears simple, but it does something that no other drill chuck I know of can do.  Both ends of the Centrotec chuck have a Fastfix collar.  This means that you can slip it on and off the drill stem easily.  Then, with the Centrotec attached to the drill, you can insert any hex-head drill or screwdriver very easily.  Just pull back on a spring-loaded sleeve, slip a bit in, and let go.  Centrotec takes the concept of a keyless chuck to the next logical level.  In under 10 seconds, I was able to remove one chuck from the Festool TDK, slip on the Centrotec chuck, and install a drill bit or screwdriver.  The Centrotec is much more compact and narrow than any other drill chucks, allowing you to get into tight places.  There is just one catch: you have to use hex-head drill bits and screwdrivers with the Centrotec chuck.

Torque and Speed Settings
The moment you look at the TDK drills, you notice that Festool engineers were going for more precision with torque settings.  The Festool TDKs use a dial-like switch to set the torque, and it clicks precisely into place.  With the 14.4-volt Makita, and the 18-volt DeWalt, you turn the entire head to set the torque.

It is standard for cordless drills to allow a user to change speeds by applying more or less pressure on the trigger.  The triggers on the Festool TDK drills are very sensitive to finger pressure, and allow the user to smoothly step up or down in speed.  I found that with the TDK drills each step of speed control is very distinct.  Both the Makita and the DeWalt also have distinct speed controls.  With the Festool TDKs, I found it easier to hold the trigger steady at a particular speed setting as compared with the Makita or the DeWalt.
Bench Tests: Drilling and Screwdriving with the TDK Drills
For the first test, I used each of the four drills to bore several holes of different sizes in a piece of red oak.  For the second test, I drove several 2.5” screws into a length of 2x4.  All four drills started the tests with a fully charged battery.  Throughout the test, the Centrotec chucks on the two TDKs held onto their bits tightly, with no slipping.

Using Novadrive Bits to Drill Holes in Red Oak
For my drilling tests, I used a set of seven Festool Novadrive bits (item no. 492 519), with bits ranging from 3mm to 10mm.  The bits have hex-head shafts, which work in the Centrotec chuck as well as the Makita and DeWalt chucks.  In my tests, the Novadrive bits cut effortlessly and cleanly through the wood in all four drills.  But keep in mind that Novadrive bits are metric, which could be an issue if you want to use them to bore pilot holes for standard screws.

One bit at a time, I bore holes at different torque settings with each bit in each of the four drills.  I compared the ease and speed of drilling.  With my 14.4-volt Makita, I detected noticeable increase in speed and ease of drilling as I moved up the torque settings.  At the higher torque settings, the Makita went through the wood very easily.  With the DeWalt 18-volt, I noticed the same increase in speed and ease of drilling as I moved up the torque settings.  With the TDK 12-volt drill in its lower torque setting, the same Novadrive bit went through the red oak a little more easily than the Makita 14.4.  The TDK 12-volt drill was equal to the DeWalt 18-volt at lower torque settings.  At the higher torque settings, both TDKs exhibited more ease and speed than either the Makita or the DeWalt.

With smaller drill bits, the difference between the four machines was not so great.  However, with the larger (10mm) drill bit, at the higher torque settings, the 12-volt TDK and the 15.6-volt TDK drilled through the oak faster, and more easily, than the 14.4-volt Makita or the 18-volt DeWalt.  It was particularly surprising to see the 12-volt TDK drill the 10mm bit more quickly and easily than the 18-volt DeWalt.  The 12-volt TDK went through the oak so fast that I hardly had to apply any pressure.  With the 15.6-volt TDK at the higher torque settings, the drill sank into the wood with slightly more ease and speed than the 12-volt TDK at the same setting, but the difference was slight.  Both of the TDKs drilled incredibly fast at the higher torque settings, using any of the seven drill bits.  The interesting thing here is that the 12-volt TDK outperformed the 18-volt DeWalt.

Using the Centrotec chuck, snapping the drill bits in and out of the TDKs was much more pleasant than twisting the chuck to loosen and tighten bits in the Makita and DeWalt.  I felt no fatigue when changing bits on the Centrotec chucks in the TDKs.

Screwdriving in 2x4s
For the screwdriving test, I used the Centrotec chuck along with Festool’s hex-head screwdriver (item no. 492 531).  To test the power of the four different drills, I did not make any pilot holes, and I drove 10 2.5” drywall screws into a 2x4.  I then reversed the screws out of their holes.  I used a different torque setting for each screw.  All four of the drills do have more than 10 torque settings -- the TDK drills have 42 settings, the DeWalt has 34 settings, and the Makita has 30 settings.  I drove five screws in each gear (all three drills have two gears).  In this test, I was measuring two main factors: (1) how deeply the drill can drive the screw before its gears lock up, and (2) how much effort it takes to get the screw in.  These two measures are important in real-life work, when you need your drill to have good power, and you need it to drive all the screws in with less effort, preventing fatigue.

At the lowest torque setting in gear 1, neither the 14.4-volt Makita nor the 18-volt DeWalt were able to drive the screw more than about 1/2” before their gears locked up.  At the lowest torque setting, the 12-volt TDK drove the 2.5” screw all the way in, until it was about level with the wood surface.  Strangely, the 12-volt TDK did better than the 15.6-volt TDK at the lowest torque setting.  The 15.6-volt TDK could only drive the screw about 1.25” at the lowest torque setting (better than the Makita or DeWalt but not as good as the 12-volt TDK).

Stepping up to the mid-range torque setting of gear 1, the 12-volt TDK still slightly outperforming the 15.6-volt model in speed, ease, and depth of drive.  Both TDK models were able to get the screw all the way into the 2x4.  With both the DeWalt and the Makita, in the mid-range torque setting of gear 1, I had to use more force to drive the screws, and neither of these drills could get the screw all the way in.

At the highest torque setting in gear 1, both the 12-volt and the 15.6-volt TDKs sank the screws deep into the 2x4.  The gears of the TDKs did not give in, and would have pulled the screw right through the 2x4 if I let them.  The TDKs did this with hardly any pushing from me.  With the DeWalt 18-volt, the screw sank into the 2x4, but needed considerably more pushing from me to get it all the way in.  With the Makita 14.4, at the highest torque setting in gear 1, the gears locked up as the screw sank slightly below the surface of the 2x4.  The Makita needed considerable pushing to get the screw in.

A Project-Based Test
I had to install a large picture window in my house.  This involved the installation of several support columns, sills, and other components on both sides and on the top and bottom of the interior and exterior of the window.  Counting all parts of this project, I had to drive about 85 screws.  It was a good way to test the TDK drills in real life, and see how they compare to my 14.4-volt Makita and 18-volt DeWalt.

Countersinking
I had to install support columns all around the interior and exterior of the window, each being 2.5” wide and requiring several countersunk screws, followed by driving 1.5” wood screws into the studs.  I pre-countersunk the holes in my woodshop.  Along with the TDK drills, I received a Festool countersink attachment (item no. 492 523) designed for use in the Centrotec chuck.  Unfortunately, the Festool countersink also drills a 3.5mm pilot hole, which is too large for the #8 screws I was using.  However, I could not resist testing it out.  Later in this review, I give an assessment of the Festool countersink.

For my window project, I decided to use my set of Weldon countersinks.  I installed the one I needed in each of the four drills, then cut the countersinks using a high torque setting.  Both the TDK 12-volt and the TDK 15.6-volt drove the countersink into the wood extremely quickly and with almost no effort.  The 18-volt DeWalt also drove the countersink easily, but still with more effort than the two TDKs.  The 14.4-volt Makita  required more force than any of the other drills to achieve the desired countersink depth.

Drilling and Screwdriving
With all the countersinks done, my task now was to drill pilot holes and drive the screws through the support columns of my window and into the studs.  Using the Makita or the DeWalt, I found I had my usual problem of not being able to avoid hitting the surface of an adjoining wall, or in this case the window.  This is due to the width of the chuck.  Since the window was finished with polyurethane, I was concerned about damaging it with a spinning drill chuck. 

Switching to the Festool TDK made a big difference.  The Centrotec bit is very narrow and allowed me to drive the screws in without rubbing against the window.  I also used the Eccentric Chuck for some of the drilling and driving here (I describe the Eccentric Chuck later in this review).  The TDK drills made the pilot holes and drove in the screws quickly.  Since I have two Centrotec chucks, I loaded my drill bit in one and a screwdriver in the other, and easily switched between the two as needed. 

The power, speed, and lighter weight of the TDK drills was especially appreciated when I got to the upper supports and had to work with my arms extended and my head tilted way back.  Comparing the 12-volt TDK with the 15.6-volt TDK during this particular job, the difference in power was not that significant.  However, I could feel the eight-ounce weight difference between the 12-volt and the 15.6-volt TDK.  I soon found myself reaching for the 12-volt TDK more often.

One important note about the TDKs: when I used the higher torque settings of gear 1, the screws easily bore straight through the countersink.  Before I even realized the screw had hit the bottom of the countersink, it was already pulled into the wood.  Therefore, it is safe to say that the TDK drills are so powerful that you need to make sure to find the torque setting that is appropriate for the job.  With the precise torque dials on the TDKs, it was easy for me to pinpoint the best setting.  For the job at hand, a torque setting about 1/3 of the way up the scale in gear 1 was powerful enough to drive the screws and have the gears lock when it hit the bottom of the countersink.

The Power Source: Batteries and Chargers
The TDK drills come with two NiCD batteries and a charger (you also have the option of purchasing NiMH batteries as an accessory).  When my drills arrived, the batteries needed to be charged.  According to Festool’s marketing brochure, the NiCd batteries should reach a full charge in 50 minutes.  They actually charged in a little less time than that, but figure one hour just to be sure.

The charger itself is sleek, styled just like other Festool tools.  Rather than plugging the battery into the charger, as with the DeWalt and Makita models, Festool batteries slide onto their charger.  The battery and the charger have interlocking hooks that make positive contact.  The same slide mechanism is employed when you install the battery onto the TDK drill.  According to Festool’s marketing brochure, this sliding mechanism cleans the electrical contacts.  Mechanically, the sliding system works fine.  The batteries slide on and off easily.  There is an indicator light on the TDK charger that lets you know what stage the battery charge is at.

I used one battery in each of the TDK drills for all parts of the tests and the window project.  They showed no sign of reaching the end of their strength.  The DeWalt 18-volt battery was also still going strong at the end of all the work.  However, the Makita needed a recharge.  After completing the test and the window project described in this review, I went on to do a number of other small tasks with the 12-volt TDK.  As of this writing, I still have not needed to recharge its battery.

Unique Chucks and Bits
There are two special-use chucks available for Festool cordless drills: the Right-Angle Chuck (item no. 490 293) and the Eccentric Chuck (item no. 490 294).  For a long time, I saw pictures of these chucks, but this was my chance to see how well they perform.  Both of these chucks use the Festool Fastfix system, making them easy to slip on and off.

Right-Angle Chuck
To test the Right-Angle Chuck, I installed a molding on the top of a cabinet I was building.  Since the cabinet was in my shop, I did not necessarily have to use the Right-Angle Chuck, but this operation imitated what I would have to do if the cabinet had already been installed.  With the cabinet on the workbench, I kneeled and used my fingers to simulate reaching for the top of the cabinet in a situation where I could not see it.  I guided the Right-Angle Chuck onto the screw, and at a slow speed drove the bit in.  It worked wonderfully.  With the Right-Angle Chuck, in either of the TDK drills, my recommendation is to use the lowest possible torque setting, especially if you are driving smaller screws.  At the higher torque settings, it was more difficult to keep the chuck on the bit.  Also, since you cannot see the screw in a lot of right-angle operations, you want to make sure you do not drive too far into the wood.  The 12-volt and 15.6-volt TDKs both have so much power, you actually need to tap less of their potential in some circumstances, and this is one of them.  The Right-Angle Chuck would be especially useful in situations when you have to drill on the inside of a small cabinet, a drawer, or a box, and cannot fit the entire drill in that space.  Since it has a circular base, the Right-Angle Chuck can be installed on the drill stem aiming in lots of different directions.

Eccentric Chuck
Festool’s Eccentric Chuck allows you to achieve two major tasks: (1) drill or drive in a tight corner, and (2) drill or drive almost to the edge of a panel without hitting the adjoining panel.  With the Eccentric Chuck and a Festool screwdriver bit, I was able to go right into the corner of a test project without touching the sides at all. 

I also used the Eccentric Chuck in my picture-window project, where I wanted to drive screws close to the edge of the vertical and horizontal support columns.  Before using the Festool drills, in a situation like this I always had to put screws further away from the edge just to make sure my drill could access them.  I was very happy when the Eccentric Chuck allowed me to drive a screw about 1” from the edges (if it had been necessary, the Eccentric Chuck could have gotten me even closer).  I drove eight screws on the inside and eight on the outside with the Eccentric Chuck.  It held all the screws securely.  But again, watch the torque, as the TDK drills have the power to pull screws right through drywall or wood.

Countersink Bit
In my test of the Festool countersink bit (item no. 492 523), I was very impressed with how cleanly and accurately it cuts.  I was also very impressed with its simple depth-stop mechanism, which really works: using a hex key, you loosen the shaft to slide the countersink up and down, then lock it.  At first glance, the Festool countersink appears to be similar to other countersink/drill-bit combinations, but it works much better than others I have used.  In my tool test, I chucked the Festool countersink in all four drills and made a series of holes at identical depths.  The model I tested had a metric drill bit (3.5mm), so it is not practical for #8 screws.  Festool also makes two countersinks without a drill bit (item no. 492 520 and item no. 492 521), which would probably be more useful to American woodworkers not using the metric system.  Based on the quality of the cut I got from the countersink/drill-bit combination, I am looking forward to testing the countersink-only model in a later review.

Price
Commenting on price gets us into subjective territory, since I must give my opinion about whether or not it is worth the extra money to have Festool’s design and engineering features in your shop.  The Festool TDK drills have more power, are better-balanced, and are more comfortable to use than other cordless drills.  Answering for myself, based on how frequently I use a cordless drill in my projects, the price of the Festool drills is justified.  For the reader, all I can do is provide as much information about these drills as possible, so that you can decide if it is also worth it to you.

For comparison purposes, here are the prices of the four drills I reviewed:
> The 14.4-volt Makita: currently $220
> The 18-volt DeWalt: currently $200
> The 12-volt Festool TDK: $325
> The 15.6-volt Festool TDK: $375

Conclusion
The Festool TDK 12-volt and 15.6-volt TDK cordless drills are impressive little machines.  The new Centrotec chuck takes Festool’s Fastfix system to new heights.  The Fastfix and Centrotec systems allow quick changes between drilling and screwdriving by swapping out both the chuck and the bit in less than 10 seconds.  The Festool TDKs offer lots of ways to drive at different angles and get at difficult-to-reach spots.

Even though the TDKs are rated at 12 volts and 15.6 volts, both outperform drills rated at 14.4 volts and 18 volts.  Even the 12-volt model was more powerful in my tests than the 18-volt DeWalt.  Comparing the power of the 12-volt TDK to the 15.6-volt TDK, I did not see a big difference between them.  The 15.6 TDK did drive screws in a little faster, but not much.  Both drills have enough power that you sometimes have to keep them under control in the higher torque settings.

During the drilling and screwdriving tests, and the window project, I constantly switched back and forth from the Makita or the DeWalt to the Festool TDKs.  This gave me a good feel for size and balance differences.  Switching back to the DeWalt and the Makita, they always felt clunky and awkward after using the Festool drills.

If the bulk of your work is heavy carpentry or construction work, the 15.6-volt TDK may be a better choice.  But if you are a fine woodworker who wants a drill for both cabinetry as well as carpentry and construction projects, my conclusion is that the 12-volt TDK is perfect.

The TDK drills fit nicely into Festool’s line of impressive machines.  They are a joy to hold and to use.
 
Matthew Schenker said:
Hello Everyone,
Below is a review I wrote of the two Festool TDK drills.  This was originally written in October 2004, and the details are still accurate.  Please feel free to post follow-up questions or comments about the review.
Thanks,
Matthew Schenker

* * * *
Screwdriving in 2x4s
For the screwdriving test, I used the Centrotec chuck along with Festool’s hex-head screwdriver (item no. 492 531).  To test the power of the four different drills, I did not make any pilot holes, and I drove 10 2.5” drywall screws into a 2x4.  I then reversed the screws out of their holes.  I used a different torque setting for each screw.  All four of the drills do have more than 10 torque settings -- the TDK drills have 42 settings, the DeWalt has 34 settings, and the Makita has 30 settings.  I drove five screws in each gear (all three drills have two gears).  In this test, I was measuring two main factors: (1) how deeply the drill can drive the screw before its gears lock up, and (2) how much effort it takes to get the screw in.  These two measures are important in real-life work, when you need your drill to have good power, and you need it to drive all the screws in with less effort, preventing fatigue.

At the lowest torque setting in gear 1, neither the 14.4-volt Makita nor the 18-volt DeWalt were able to drive the screw more than about 1/2” before their gears locked up.  At the lowest torque setting, the 12-volt TDK drove the 2.5” screw all the way in, until it was about level with the wood surface.  Strangely, the 12-volt TDK did better than the 15.6-volt TDK at the lowest torque setting.  The 15.6-volt TDK could only drive the screw about 1.25” at the lowest torque setting (better than the Makita or DeWalt but not as good as the 12-volt TDK).

Stepping up to the mid-range torque setting of gear 1, the 12-volt TDK still slightly outperforming the 15.6-volt model in speed, ease, and depth of drive.  Both TDK models were able to get the screw all the way into the 2x4.  With both the DeWalt and the Makita, in the mid-range torque setting of gear 1, I had to use more force to drive the screws, and neither of these drills could get the screw all the way in.

At the highest torque setting in gear 1, both the 12-volt and the 15.6-volt TDKs sank the screws deep into the 2x4.  The gears of the TDKs did not give in, and would have pulled the screw right through the 2x4 if I let them.  The TDKs did this with hardly any pushing from me.  With the DeWalt 18-volt, the screw sank into the 2x4, but needed considerably more pushing from me to get it all the way in.  With the Makita 14.4, at the highest torque setting in gear 1, the gears locked up as the screw sank slightly below the surface of the 2x4.  The Makita needed considerable pushing to get the screw in.

drills fit nicely into Festool’s line of impressive machines.  They are a joy to hold and to use.

Matthew,

Please clarify some of the observations that you made regarding the torque output of the drills that you compared.  My presently understanding is that when their controls are set at the lower end of their range, the torque output of Festool drills was [considerably] higher than that of the DeWalt and Makita units used in your comparison.  To me, that is not necessarily a good characteristic, since the purpose of choosing a lower torque setting is to prevent driving a screw too deep or shearing off its head.  For example, when installing drawer slide screws or hinges on decorative boxes, reliable low torque settings that truly limit torque to relatively low levels would seem to be desirable. 
 
David,
It's been a while since I did this test, but what I found was that, at the lowest torque levels, the drills did not drive the screws into the wood.

The real surprise for me was that the 12-volt model drove the screws deeper than the 15.6-volt model at the lowest torque levels.  I'm no expert on cordless drills, so maybe this is not as surprising as I thought.

But neither TDK model drove the screws in deeply, nor would they shear off the heads of the screws.  They definitely drove deeper than the DeWalt or Makita, but very controllably.

Matthew Schenker
 
Matthew Schenker said:
David,
It's been a while since I did this test, but what I found was that, at the lowest torque levels, the drills did not drive the screws into the wood.

The real surprise for me was that the 12-volt model drove the screws deeper than the 15.6-volt model at the lowest torque levels.  I'm no expert on cordless drills, so maybe this is not as surprising as I thought.

But neither TDK model drove the screws in deeply, nor would they shear off the heads of the screws.  They definitely drove deeper than the DeWalt or Makita, but very controllably.

Matthew Schenker

Matt, Maybe i'm missing something but I don't believe you WANT the screws driven in at the lower torque. I would think you would want room to sneak up on the right setting for any given set of circumstances.
 
Greg,
Yes, I know.  I was just reporting the difference between the various drills.  I didn't mean it as a positive or negative thing.  The 15.6-volt did not drive the screw in on the low-torque setting.  The 12-volt drove it in level with the wood surface.  Neither one drove the screws deeply into the wood at the low torque setting.  I've used both TDKs successfully at various torque settings.

But I did find it interesting to note the differences in the drills.

Matthew
 
Matthew Schenker said:
The 15.6-volt did not drive the screw in on the low-torque setting.  The 12-volt drove it in level with the wood surface.  Neither one drove the screws deeply into the wood at the low torque setting.

Just to clarify: I believe that by "torque setting" you mean the clutch release, rather than the "1" or "2" speed setting on the TDK 12, right? I can totally believe that clutches aren't calibrated the same between different designs of drill, in fact I wouldn't be all that surprised to find out that they're different between drills. Clutches are a matter of "when will this mechanical connection fail", and that sort of thing can be sensitive to things like humidity. Not that that's going to be a huge factor, but making something that slips reliably at the same torque ain't trivial.

On the whole "more power from higher voltage" thing, people seem to forget that the electric motor that starts their car is a 12v motor, and that sucker generates a heck of a lot of torque. "Bigger numbers means more torque" is a marketing thing, not an engineering thing.

(Well, okay, there are issues of battery heat and "internal resistance" that might limit what you can do with a given form factor, but there are way too many other variables to take "115 volts is more powerful than 12 volts" at face value.)

 
I chose the terms "torque setting" and "torque output" because I was thinking that the Festool drills had electronic torque output controls.  Is that feature only on the current C12 model?

If I now understand Matthew's test and results correctly, it means that at a given "torque output" setting at or near the low end of the available range of set points, the Festool drills produce a higher "torque output" when the trigger is fully depressed.
 
Dave Ronyak said:
I chose the terms "torque setting" and "torque output" because I was thinking that the Festool drills had electronic torque output controls.  Is that feature only on the current C12 model?

The box identifies mine as the "C12 CE-NC-C45-Plus USA". When I set the torque adjustment low enough and drive a screw, the drill makes a sound like a mechanical clutch slipping, and then stops.

That seems to be at the same place no matter how far back I have the trigger pulled (ie: speed), but it may be different as to whether or not the speed selection switch is set to "1" or "2", I haven't tested that too thoroughly (don't drive many screws at speed "2".

So it seems to me that the speed output (and, since this is a brushless motor with all sorts of electronics controlling that, the trigger position really is speed) is electronic, but the torque setting is mechanical with some sort of electronic shut-off.

And that's one of the things I have to get used to versus my old corded DeWalt: At low trigger/speed settings, that one would bog down as the head of the screw pulled into the wood because the trigger controlled voltage which gave the motor the ability to draw different amounts of current, not speed. The brushless motor and assorted electronics on the C12 means it'll quite happily keep going as long as it can turn the motor, and if it can do that, it'll probably be able to keep up the speed you asked for.

Motor control is hard, and as humans in the loop we're used to dealing with derivatives of what we actually want to control, controlling voltage which controls current flow which controls torque which controls speed, but available torque is a function of current speed... (and the hoops we jump through to control the speed of automobiles make that function even more amazing).

The brushless motor changes a lot of that, and that's hard to adapt to.
 
Dan,
Just to clarify: I believe that by "torque setting" you mean the clutch release, rather than the "1" or "2" speed setting on the TDK 12, right?

My reviews of tools are admittedly from the perspective of an intermediate woodworker!  But in some ways, I like to think that is a useful perspective.  I'll let other people come in with the expert's view.

But if my reviews are unclear in any way, I like people to jump in and ask me to clarify.  So, yes, I was referring to the clutch release!

Matthew Schenker
 
Matthew Schenker said:
My reviews of tools are admittedly from the perspective of an intermediate woodworker!

I'm probably several steps behind you in that front, so I appreciate that perspective! I'm just a computer geek who over-reaches in wood occasionally.

And I wasn't trying to be pedantic for its own sake, just trying to make sure I understood ya!

Thanks!
 
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