backlash on PDC 18/4 hexagon socket holder of the drill spindle

olocirb

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Apr 7, 2021
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Hello,
I've done a small video to show my wonder, it's on youtube :
There's a very noticable backlash on my drill's socket holder.
Is it the same with yours or should I contact support ?
Thanks for your feedbacks !
Mathias
 
Backlash? Is that the word we use for this? Maybe it is, but doesn’t compute for me lol. .

Anyway, don’t have that drill but my T18 & C18 are on the bench in front of me and both have wobble in the bit when inserted like you have in your video. Maybe not quite as much, but in the same ball park. It’s impressive how little wobble that other drill has (Milwaukee?)

Ultimately with such a short length I can’t see it being an issue in use, and using the bit like that is surely a “when required” option rather than the defacto use? But your opinion or preference maybe different.

I did own the PDC at one point and like the drills I have front of me I don’t remember it being any more snug of a fit.

 
olocirb said:
Hello,
I've done a small video to show my wonder, it's on youtube
There's a very noticable backlash on my drill's socket holder.
Is it the same with yours or should I contact support ?
Thanks for your feedbacks !
Mathias
You are sticking a HEX bit into a Centrotec socket. Apples with Oranges basically.

The direct insertion of a HEX bit there is an emergency use case when you absolutely need to reduce the depth of the driver.

HEX can be put there this way, but it is not the way the Centrotec socket is to be used in normal operation. It is a bit bigger and is not symmetrical to avoid inserting Centrotec bits into common HEX sockets by accident.

Normal use is a Centrotec bit in a Centrotec chuck, or HEX bit in a BHS adapter in Centrotec chuck.

EDIT:
I see you put another Video of the gearbox. That is an actual known limitation of the DRC/PDC line. The gearbox selector is sometimes hard to select - especially the 3rd speed. This is "normal" and is not indicative of a faulty tool.

It does not bother me as I usually run the drill at 1,2 or 4, but can be annoying at times.

They have actually re-designed the gear selector in the new TPC to address this.
 
Mino. What are you talking about? Centrotec bits fit into hex bit holders 100% (they might not lock in but they fit)

And the centrotec shaft is exactly hex. The PDC, like CXS has a magnet to keep them in (if I recall correctly) and the T18/C18 have a spring retention clip to keep them in. 100% designed for use like that. The centrotec bits, in the centrotec Chuck, have no need for these magnets or retention clips. They’re there for the use of standard hex bits.
 
mrB said:
Mino. What are you talking about? Centrotec bits fit into hex bit holders 100% (they might not lock in but they fit)

And the centrotec shaft is exactly hex. The PDC, like CXS has a magnet to keep them in (if I recall correctly) and the T18/C18 have a spring retention clip to keep them in. 100% designed for use like that. The centrotec bits, in the centrotec Chuck, have no need for these magnets or retention clips. They’re there for the use of standard hex bits.
I will have to cross check mine tomorrow then.

I remembered the Centrotec slot not being exact same as the HEX, and there being some compatibility limitations when was digging this time ago. Always considered the hex bits being a bit loose in the shaft hole as a "feature/characteristic" of Centrotec, not a form of bad milling.

I know HEX fits in both DRC and C drills, and use it too, albeit rarely as angle adapter is the tool to use when there is a lack of space. But never seen it as a "should be used like this normally" scenario so was not bothered by the slot being wobbly with HEX bits.
 
Hi !
The other drill is an AEG.

I used this word "backlash" because as you figured out, i'm not an english speaker, and this is the closest word I found to express that !https://en.wikipedia.org/wiki/Backlash_(engineering)

Yes I detected that centrotec doesn't seem to be exactly the same as hex. It's actually quite annoying when using the angle chunk as it takes loads of room with adapter.

i've seen in user manual that it was possible to directly use hex on drill as I've done in video, but it was only to show this "wobble"
(thanks for the word haha). In fact, I alway use centrotec chunk.

Do you have the same wobble ? somehow i feel that it could prevent me to screw perfectly straight.

I don't know ... I feel a bit disappointed this wobble and the gearbox.
But this torque bleeping is really great !

Thanks for your feedbacks !
 
1 - The wobble is normal with Hex bits and it is intended that way by the engineers. Nothing wrong here. You can still screw perfectly straight. MAke this connection too tight, and you'll get a lot of stuck bits.

2 - Centrotec has a slightly smaller diameter than Hex bits, that's why you can't inserts Hex bits in the standard Centrotec chuck. But just like Hex, they're perfectly, symmetrically 6-sided. Bit and axle must always be able to line up perfectly no matter the orientation.

3 - What OP calls backlash is generally called "runout" by the Americans. Nothing wrong in making mistakes when learning another language.
 
Olocirb:
Ha. I did not spot English was your second language at all.

Alex:
I disagree that centrotec is a different size to hex. It is the same size, but the corners are more rounded. That’s why hex bits won’t always through the centrotec Chuck.

That’s why centrotec drills will slot into any standard bit adapter nicely, and why you can make almost any hex bit (that’s long enough) into a centrotec bit with an angle grinder. Shave the corners and add a second retention groove (done many in my time, mostly spade bits)

Also I would say runout is more specific to alignment than fit. Slap a keyless Chuck on that drills shaft and there will be zero runout (practically speaking).
Splitting hairs here I know, and I’m not even saying I’m right, but in my mind you can’t call this runout.
 
What mrB said^
Even Centrotec bit holder, ie: BHS 60 wobbles.
There’s a bit more slack even when you stick Festool’s bit holder directly into the stubby shaft (w/o the Centrotec chuck) than with a standard bit and bit holder like your AEG. It is the Centrotec chuck that centers and tighten things up.
 
OK guys !
Thanks for your answers and clarification.
So i'll consider this loose socket as a normal component.
Cheers !
Mathias
 
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