Adapting the centrotec chuck to take normal bits

[tazprime38]

I was about to adapt a wera bit holder so it would fit the centrotec chuck. I have converted one before to work perfectly with the centrotec chuck.

This got me thinking.  I examined the centrotec chuck carefully and thought what if it could be converted to take normal bits. The size of the hole in the top section would need to be enlarged slightly. This would then allow normal bits to be inserted.  You would only need to file a notch in the bits so they would lock in the ball dent.

I thought about removing the wire retaining ring at the top of the chuck so I could dismantle it ready for drilling but was worried about getting the ball and springs back in when putting it back together.  I only have one of these so haven't done it yet.

The other way I have thought it could be done is by pulling back the green sleeve which releases the balls inside the collar and then drill the hole out with a slightly larger drill. The drill bit will automatically push the balls back into there recess so they should not get damaged. The main problem I see is this may cause the ball retaining holes to be enlarged too much and allow the balls to drop out. Personally I believe it should not as not enough material will be removed.

I would be doing this free hand so may not be the best way to go about this.

What are your thoughts and feasibility of doing this?

 

[greg mann]

The metal body is probably too hard to be machined. A drill will not work, you need a reamer and it would most likely only work if it was carbide tipped, sized correctly within one or two thou and done in affixed position; like in a lathe or drill press. You also run the risk of removing the material that retains the balls.

'Normal' bits are not as consistently manufactured as Centrotec bits. Even if you succeed you may find some that work well and others that work poorly. My advice is to embrace the Centrotec system. It is more closely controlled and the performance is more consistent. Festool make a nice adapter for one inch bits and they are ubiquitous. Their collection of more specialized bits is pricey but of high quality.

 

[Holmz]

I had picked up a centrotec systainer as I was leaning towards the FT drill/driver which seems to be 6-mm ( which is smaller than 1/4").
While I like the idea of the centrotec being locked into requiring 6-mm means I could not use the more common 1/4 gear.

Then I picked up an A10M, but the Metabo is pretty much the same.
It takes 1/4" bits as well as the 6-mm, so most all the centrotec gears fits fine-n-dandy. And when I need to get the 1/4" bits locally they also fit.

 

[tazprime38]

I agree with the points raised about the way it should be drilled. Will be investigating this further and may see if an engineering workshop could do this.

Regarding the centrotec bits being superior etc, I am sure they are but the bits that are available in normal 1/4 shank I have been using for years without issue and don't want to be forced by a company to exclusively use there bits.  I don't like being limited into what I can use and be forced to pay extra for a particular type of bit in this case.

Has anyone ever taken a centrotek chuck apart and rebuilt it? Taking it apart may be a better option to do the improvement.

I have also noticed that there are two types of centrotec chucks available,  the standard and a heavy duty verson. Has anyone used the heavy duty one and what is its main purpose?

 

[AlexThePalex]

I don't like being limited into what I can use and be forced to pay extra for a particular type of bit in this case.

You are not. You can use any bit you like. Why'd you think that?

Adapting the centrotec chuck is a waste of your time, it's not going to work.

Using the centrotec bit adapter is a far more elegant solution, and the same as you have with any other drill of any other brand.

 

[jbasen]

I modified a Milwaukee bit holder to fit the centrotec chuck.  The Milwaukee bit holder can hold either a standard bit or a centrotec bit so you don't have to switch back and forth between bit holders; you just grab whatever bit you need.

Here is the link to that thread

http://festoolownersgroup.com/festool-jigs-tool-enhancements/universal-centrotec-standard-bit-holder-that-fits-a-centrotec-chuck/msg309890/#msg309890

 

[elfick]

[member=5519]tazprime38[/member] I think the problem you'd hit with this idea is that most standard ball detent bits don't have enough shaft below the detent to fully engage into the drive. That's why the centrotec detent is so much higher on the shaft.

 

[fshanno]

Using the centrotec bit adapter is a far more elegant solution, and the same as you have with any other drill of any other brand.

I don't think it's elegant.  I think it's goofy.  Why not just make a Fastfix chuck that accepts standard 1/4" ball detent bits?  It could be stubby, shorter than the Centrotec chuck.  And it could pop the bit out and lock open for one handed bit insertion.  It would be great.

Festool could charge a small fortune for it and still we would all buy it.

I don't understand why Snappy doesn't offer one.

 

[tazprime38]

Using the centrotec bit adapter is a far more elegant solution, and the same as you have with any other drill of any other brand.

I don't think it's elegant.  I think it's goofy.  Why not just make a Fastfix chuck that accepts standard 1/4" ball detent bits?  It could be stubby, shorter than the Centrotec chuck.  And it could pop the bit out and lock open for one handed bit insertion.  It would be great.

Festool could charge a small fortune for it and still we would all buy it.

I don't understand why Snappy doesn't offer one.

Completely agree with you. I am surprised no third party company has made a Centrotec type chuck that would accept normal bits.

 

[greg mann]

Using the centrotec bit adapter is a far more elegant solution, and the same as you have with any other drill of any other brand.

I don't think it's elegant.  I think it's goofy.  Why not just make a Fastfix chuck that accepts standard 1/4" ball detent bits?  It could be stubby, shorter than the Centrotec chuck.  And it could pop the bit out and lock open for one handed bit insertion.  It would be great.

Festool could charge a small fortune for it and still we would all buy it.

I don't understand why Snappy doesn't offer one.

If you think it through the groove in a standard bit is too close to the end of the shank for retention. It would be buried inside the spindle of the drill. You would need a second groove further up the shank to accomplish retention, which would make it essentially a Centrotec shank with the original groove still intact and doing nothing. And of course it would not be a standard shank any longer. Festool drives the bit with the hex internal to the spindle. That necessitated moving the groove further up the shank to facilitate retention. A standard shank works in an impact driver because there is no need to provide an interface for mounting a chuck. Festool could have made their drills like impact drivers but we would all be complaining about the inability to mount a chuck.

What Festool essential did was redesign the shank to improve versatility of the mother tool. This is similar in concept to Canon redesigning their lens mount when they went to autofocus capability. They decided the older mount would not allow the forward development they envisioned. Nikon did not and they managed much better backward compatibility at some expense to going forward. Who seems to be winning at the high end of the market these days?

Disclaimer: For all of you photography junkies on this forum I may not have all the details exactly right but I believe I am pretty close, so please cut me a little slack if you think I missed something.  [unsure]  I think the analogy is appropriate enough.

 

[fshanno]

If you think it through the groove in a standard bit is too close to the end of the shank for retention. It would be buried inside the spindle of the drill.

I don't think so.  I think it would work and it would be an easy adaptation.

[attachimg=1]

All that has to happen is for this hole to be hex shaped instead of round.  Everything else can stay exactly the same.  It will work.
I have some standard hex bits that are a tad undersized.  They fit in the round hole without modification.  And they will engage and stay in place because the balls and the detents are close enough.  But because they are a hex peg in a round hole they spin freely.

Just make the hole hexagonal and a bit larger and we're done.  It's that simple.

It's just cheesy to see a bit holder holding a bit holder holding a bit.  Especially a long bit like those for pocket hole screws.

 

[Cheese]

Just make the hole hexagonal and a bit larger and we're done.  It's that simple.

I wish it were, but unfortunately that's not the case. I took an Apex bit (probably the most durable U.S. bit made), chucked it in the lathe and turned it down to the same diameter and length as a Festool BH 60.

[attachthumb=1]
The first thing you notice is how much shorter the driven hex end is on the Apex bit, around .400" shorter.

[attachthumb=2]
Also notice the difference in widths of the detent grooves. Festool is around .150", while the Apex (a standard) is almost .240". This causes a problem that we'll look at later on.

[attachthumb=3]
Apex mounted in Centrotec chuck

[attachthumb=4]
BH 60 mounted in Centrotec

[attachthumb=5]
Apex from the rear, notice how little of the hex protrudes into the cavity.

[attachthumb=6]
BH 60 from the rear.

[attachthumb=7]
Apex bit inserted fully into the chuck

[attachthumb=8]
Apex bit pulled forward while chuck is still in the "locking" mode. That wider detent groove width causes a lot of extra forwards/rearwards slop when using the bit.

Finally, I mounted the Centrotec with the Apex bit into my C 15...it resulted in the bit not being driven by the drill because there wasn't any engagement between the external hex of the bit and the internal hex of the drill. If I pushed on the Apex bit with a lot of forward thrust, I could get the bit to want to rotate just slightly, but there wasn't any real engagement. It's about .400" too short.

As [member=22]greg mann[/member] suggested, the location of the groove has to be moved to provide the additional external/internal engagement needed for the drill and also the width of that groove needs to be maintained to the Festool spec to prevent any excessive driver bit movement.

 

[greg mann]

Festool controls runout by locating on the ground OD of their bits with the Centrotec chuck and uses the flats driven by the internal hex of the spindle, decoupling these two requirements to not allow poorly made flats cause wobble, which would be a major complaint if they put the hex in the chuck, and sometimes happens inspite of their best efforts. They would need even more clearance in the two hexed components to assure easy alignment and insertion, regardless of the relative lack of consistency in the ubiquitous array of bits available in the market. No one would be happy if their bit, whatever its overall quality was or country of origin, did not fit easily and did not run true. Festoons solution, which can be perceived any way one wishes, allows them to control wobble and still have pretty easy change-outs. IMO, they identified weaknesses in the standard bit and improved it in ways the legacy design would not allow. That made it proprietary but is not inconsistent with the way they do things. For example, their random orbit sanders to work properly they need a hole in the middle. Proprietary, but I don't hear a lot of complaining about that.

Edit: I think Cheese's excellent post above dovetails well with mine. The lack of a full length match of the drive flats would cause accelerated wear issues over time. Also, many (most) hex drives on the market will not insert far enough into the Centrotec chuck, causing the lack of drive issue Cheese pointed out. If the Centrotec is shortened to accommodate this lack of length then there is even less room for retention balls, no matching groove anyway and less opportunity to mitigate wobble. Shortening the spindle to gain room to use the existing groove would eliminate the ability to mount a chuck and would compromise the use of 1 inch length bits directly in the spindle, a very nice application tool that seems to be continuously overlooked.

 

[Cheese]

Festool controls runout by locating on the ground OD of their bits with the Centrotec chuck and uses the flats driven by the internal hex of the spindle, decoupling these two requirements to not allow poorly made flats cause wobble, which would be a major complaint if they put the hex in the chuck, and sometimes happens inspite of their best efforts....

This is the first time I've ever used a Centrotec chuck, prior to this discussion I've put various bits in the end of the C 15/CXS and lived with the wobble or just used the 3-jaw chuck instead. However, stepping through this evaluation opened my eyes as to how elegant the Festool solution really is. Using the flats to drive and the OD to align is simple but ingenious. The example that springs to mind is like using a steady rest on a lathe.

 

[fshanno]

Just make the hole hexagonal and a bit larger and we're done.  It's that simple.

I wish it were, but unfortunately that's not the case.......

Okay!  Now I see why you aren't following me.  Your picture clued me and it's my fault.  I completely failed to reference an important part of the concept.  But it's still very simple, very easy. 

The chuck itself will contain a hex nib that is fixed to the body of the chuck.  That nib will engage in the hex hole in the Fastfix receiver in the drill. 

Your picture shows what the chuck would look like.  Imagine that the black hex nib is not part of the bit at all.  It's part of the chuck!  Again, that nib will enter the Fastfix receiver.  It is part of the body of the chuck.  So when the receiver spins the chuck must also spin.  It's as if the tail end of a Centrotec bit were glued into the Centrotec chuck.

[attachthumb=1]

I believe that's how the the Metabo adapter chuck works.  But Matabo made theirs about 20mm longer than it needed in my opinion

[attachthumb=2]

I think a Fastfix chuck for standard ball detent bits could be designed that is only a few millimeters longer than the Fastfix Centrotec chuck that we all know.

 

[Cheese]

This is similar in concept to Canon redesigning their lens mount when they went to autofocus capability. They decided the older mount would not allow the forward development they envisioned. Nikon did not and they managed much better backward compatibility at some expense to going forward. Who seems to be winning at the high end of the market these days?

[member=22]greg mann[/member]
I almost forgot...being a Nikon guy for the last 35+ years, your analogy works for me, however "winning at the high end", we shall see what pans out when Nikon releases the rumored D400 and D5 this year. [big grin]

 

[greg mann]

This is similar in concept to Canon redesigning their lens mount when they went to autofocus capability. They decided the older mount would not allow the forward development they envisioned. Nikon did not and they managed much better backward compatibility at some expense to going forward. Who seems to be winning at the high end of the market these days?

[member=22]greg mann[/member]
I almost forgot...being a Nikon guy for the last 35+ years, your analogy works for me, however "winning at the high end", we shall see what pans out when Nikon releases the rumored D400 and D5 this year. [big grin]

Yea, I'm a 35 year Nikon guy myself. That said, Canon wasn't even close back then. Their penetration into the high end market cannot be ignored.

 

[greg mann]

Metabo made theirs about 20mm longer because theyneeded to. If you integrate the hex drive into the Centrotec chuck, which appears to be what Metabo did, then the standard ball detention has to be out front by necessity. You have an internal component with a male hex to go into the spindle, a female hex to receive the tool and a transition web to hold them together. They have essentially made an impact driver chuck with its own hex shank. It has two quick release functions, one to install and remove the whole thing from the drill and one to remove the various tools from the adapter itself.

 

[GhostFist]

I have the new metabo drill and the quick chuck. Works like a charm. New metabo drills also fit the centrotec chuck so you get the best of everything without modifications.
I also own a cxs and a t15

 

[fshanno]

Metabo made theirs about 20mm longer because theyneeded to. If you integrate the hex drive into the Centrotec chuck, which appears to be what Metabo did, then the standard ball detention has to be out front by necessity. You have an internal component with a male hex to go into the spindle, a female hex to receive the tool and a transition web to hold them together. They have essentially made an impact driver chuck with its own hex shank. It has two quick release functions, one to install and remove the whole thing from the drill and one to remove the various tools from the adapter itself.

There are 20mm already available on the Festool Centrotec chuck.  The smaller diameter hole, the one in front, is 20mm deep.  That should be enough for a standard bit.  Bits insert 19mm in my Makita 12v.