Torque difference between C15 vs T15

[dbworkshop]

Shane

Is there really a difference in the torque produced between those two drills? Or typo?  I would have thought that they would use 95% of the same parts therefore the only difference would be in the handle configuration.

Any news on the centrotec sys yet…

Thanks
Dan

 

[Administrator_JSVN]

According to the information provided by Germany, there is a difference. We will check with Germany to verify and I'll get back to you when we get a response.

 

[AlexThePalex]

C15 - Torque wood/steel 25/40Nm
T15 - Torque wood/steel 27/40Nm

Wow, what a difference.  [unsure]

 

[Ken Nagrod]

Yea, it is a very small difference, but it would be interesting to know why.

 

[newbirdhunter]

Curious: Why produce two drills with only a minor difference between them? Are there separate intended audiences for each drill and if so who are those intended audiences? Would one assume that the C15 is geared more towards the "hobbyist" while the T15 is geared more towards the "day-in-day-out contractor" based on such a small difference in torque (and handle design)?

 

[tbellemare]

There's a big difference in handle/body design.

The "C" drills have grips that are designed more for one-handed handling. One can grip them in such a way as to push with the web between thumb and forefinger actually down the rotational axis of the bit.

Using a typical "T" drill, and Festool "T" drills conform, the user normally needs 2 hands to push down the axis of rotation of the bit. Shaq might not...

The Festool t-drills also allow for a shorter overall stack (tip of bit/driver-to-back of drill) because the handle is slightly forward of the c-drills.

It's been discussed many times here and continues to be a point of interest.

Tom

 

[AlexThePalex]

Curious: Why produce two drills with only a minor difference between them? Are there separate intended audiences for each drill and if so who are those intended audiences? Would one assume that the C15 is geared more towards the "hobbyist" while the T15 is geared more towards the "day-in-day-out contractor" based on such a small difference in torque (and handle design)?

It has little to do with audience. In fact, for years Festool only made C type drills, it was what they believed in. Their signature. In that same time, Festool was almost exclusively sold to professionals. Only later did they make T drills, probably because they realised there was a demand for it. Not everybody is crazy about the C drill handle.

 

[tjbnwi]

I wondering how the drill knows that it is drilling into wood or steel?

Torque is the amount of twist power, dosen't matter what product your drilling into.

If the rating are for high/low setting I get it. I also know steel should be drilled at a slower speed. I think there is a translation problem.

Tom

 

[AlexThePalex]

I wondering how the drill knows that it is drilling into wood or steel?

Torque is the amount of twist power, dosen't matter what product your drilling into.

Yes it does. Torque can only be measured if two objects make friction together. Steel against steel leads to higher friction than steel against wood because steel is much harder.

 

[skids]

Curious: Why produce two drills with only a minor difference between them? Are there separate intended audiences for each drill and if so who are those intended audiences? Would one assume that the C15 is geared more towards the "hobbyist" while the T15 is geared more towards the "day-in-day-out contractor" based on such a small difference in torque (and handle design)?

It has little to do with audience. In fact, for years Festool only made C type drills, it was what they believed in. Their signature. In that same time, Festool was almost exclusively sold to professionals. Only later did they make T drills, probably because they realised there was a demand for it. Not everybody is crazy about the C drill handle.

I prefer c handle quite honestly. Have had, and still have one T handle.  C handle is more comfortable and I like how you can effortlessly get behind the bit for more efficient and accurate drilling.

I agree that the torque differences are negligible between these two drills and. Its just not worth splitting hairs over.

 

[tjbnwi]

I wondering how the drill knows that it is drilling into wood or steel?

Torque is the amount of twist power, dosen't matter what product your drilling into.

Yes it does. Torque can only be measured if two objects make friction together. Steel against steel leads to higher friction than steel against wood because steel is much harder.

The material has no affect on a torque measurement. If you tighten a bolt to 20 Nm in a piece of wood or a piece of steel it is still 20 Nm. The twist applied to achieve the reading is the same.

Maximum torque is a function of the tool not the product being drilled. I agree that the torque (more importantly speed) necessary to drill one material over the other may be different. More torque is used to drive a screw into oak than pine, they're both wood. A screw into aluminum may take less torque than into the oak, metal/wood.

Torque is twist, friction only affects how soon you reach that torque.

There is a higher speed lower torque setting and a lower speed higher torque setting on both of my Festool drills. Slower speeds are required for harder materials, again I believe this is a translation issue. It should read high/low (speed or torque) not wood/steel.

Tom

 

[AlexThePalex]

It is not a translation issue. Over here the torque for a drill is always given for different materials.

My guess is you're thinking too absolute. The maximum torque a drill can create is one thing, and theorethically that's one single value, but you can't measure that theorethical value.

In order to be able to actually measure a torque value you have to hold two materials together. At that moment, the torque measured is always a variable that depends on both those materials. And since every material has a different friction coefficient you will measure different torques when you use different materials.

 

[tjbnwi]

Only absolute is the listed maximum torque. You're through its entire range can be measured. It's done everyday.

So you're telling me that drilling a 1/8" hole in 18 gauge sheet metal needs to be done in the steel setting and a 25 mm hole in 10" thick hard maple would be drilled on the wood setting?

The drill does not know what the material is, those decisions need to be made by the operator.

What do you do if you have a wood/steel sandwich and the materials have the same Rockwell?

Tom

 

[AlexThePalex]

Only absolute is the listed maximum torque. You're through its entire range can be measured. It's done everyday.

Listed for a certain material.

So you're telling me that drilling a 1/8" hole in 18 gauge sheet metal needs to be done in the steel setting and a 25 mm hole in 10" thick hard maple would be drilled on the wood setting?

??? There is no steel or wood setting on Festool drills. There is a 1st and 2nd gear selector. When you put it in 1st gear it works with low speed but high torque, and 2nd gear works with high speed but lower torque.

What a max torque value for a certain material means is that the drill can transfer that max torque to the material. The power a drill has remains the same, no matter what material you drill in, but how much of that power can be transfered to the material is what varies because of different material properties.

The drill does not know what the material is, those decisions need to be made by the operator.

Yep, that's correct.

What do you do if you have a wood/steel sandwich and the materials have the same Rockwell?

You drill it with the speed you prefer. You really don't need to make any setting on the drill to get a hole through and through.

 

[tjbnwi]

C15 - Torque wood/steel 25/40Nm
T15 - Torque wood/steel 27/40Nm

Wow, what a difference.  [unsure]

But yet you show where they list for steel and wood.

Material has nothing to do with maximum available torque. That is strictly the highest amount of twist that is applied to the output shaft of the drill. It is measured on a test bench then published in the specs.

Looking at the spec you listed, the drill knows to limit the torque applied to 27 NM because you're drilling wood? What happens when you need 27.1 Nm in wood, does the drill stop? Simple chip clearing will affect the torque need to drill a material. When it comes to wood, there is a Janka range of 400-3700. Listing the the for the material (as you posted) is foolish. If they listed speed for wood/steel that would be good.

Tom

 

[AlexThePalex]

Material has nothing to do with maximum available torque. That is strictly the highest amount of twist that is applied to the output shaft of the drill. It is measured on a test bench then published in the specs.

Tom, you're really not listening to a word I say. The torque listed is not about what the motor applies to the drill shaft, it's about what the drill shaft applies to the material.

I'm stopping this conversation. If you think you know it better than all the engineering guys, fine by me.

 

[newbirdhunter]

Thanks @Tom and @Alex for your informative and educational replies. Appreciate it.

Frank