Thread: FP2/12mm T-nut dimensions

Originally Posted by DennisCA

Soooo I am doing it wrong when I am tightening the collets in place (on an SK40 ER-32 collet holder)? I usually put the machine in lowest gear and tighten it in place so I dont have to remove the collet holder from the machine.

ER32 need, I think, around 100 Nm torque. If you can apply this using the low gear then you're ok...
Doesn't your holder have flats for a second wrench? So that torque is between the two wrenches and you can really tighten it!

Different strokes....two worlds here.
Dave (rimcanyon) is talking about the CNC spindle setup. There the gripper is used to hold the tool holder/collet in the spindle.....Tools are held via a set screw, of retaining nut or collet closer
cap nut....
There its not recommend to tighten the tool holding while mounted in the spindle (on the machine) and hence the need for a tool tightening fixture that lives in most cases on the bench...

The manual FP's use the direct pull from tightening the draw bar to clamp the tools in the case of direct mounted collets etc.
The use of mounted collet chucks changes this, as the tool holding is supplied as with the NC's using a collet closing nut,etc.....there the size of the collet and tool dictate whether one should be
tightening on or off the machine.....
Personally have had good results using the direct mounted #40 collets (genuine Deckel in good condition) No problems with tool slippage or pull out.
When using a collet chuck (as discussed in post 11 above) i pretty much always install and tighten the tool off the machine...maybe just a habit from my NC's....

Cheers Ross

Originally Posted by thanvg

ER32 need, I think, around 100 Nm torque. If you can apply this using the low gear then you're ok...
Doesn't your holder have flats for a second wrench? So that torque is between the two wrenches and you can really tighten it!

Nope there are no flats on the holder, but I've had this tool slip in the collet when cutting steel:


I think a collet might not the best way to hold this tool. Maybe I made some kind off the machine holder so I could really torque it down it might work. I've come to distrust the collet for saw arbors though.

I have considered alternatives, such as an SK40 to MT2 adapter and turning the cylindrical shaft to an MT2 taper instead, then using the drawbar to hold it directly, I think a morse taper should have more hold than a collet.

Or simpler, using an end mill holder and milling a flat on the shaft to prevent turning.

Hey Dennis,

I would bet that, if you are just using low gear to tighten the ER chuck, you're not tightening it enough.

Since there are no flats on your holder, make a bench mounted 'socket' for the iso 40 taper that will allow for proper tightening of the ER chucks (and shell mills and, probably, more). Something like this: Google Image Result

BR,
Thanos

Originally Posted by sigurasg

Thanks. That seller doesn't offer shipping to Canada by default, and NA-based sellers with similar T-nuts seem to want a kings ransom for them. I've sent the seller an inquiry about shipping to this here frozen Tundra.

So after a bit of back and forth on eBay messages, we finally worked this out through email and PayPal. If you're outside his listed postal areas, he'll probably still ship to you. Feel free to hit me up for his email.

Originally Posted by thanvg

Hey Dennis,

I would bet that, if you are just using low gear to tighten the ER chuck, you're not tightening it enough.

Since there are no flats on your holder, make a bench mounted 'socket' for the iso 40 taper that will allow for proper tightening of the ER chucks (and shell mills and, probably, more). Something like this: Google Image Result

BR,
Thanos

I made a holder for my ER-32 collet last weekend, haven't yet tried it with the slitting saw though.

Originally Posted by sigurasg

Interesting, looks like there are different series of these too. On FS' site they list
OZ415 (aka OZ16),
OZ462 (aka OZ25) and
OZ467 (aka OZ32).
Looks like they go to 16, 25, 32 mm respectively. Other than some incidental information, I can't seem to find a spec for those collets. Pretty shallow taper though, and looks like they have a 0.5mm clamping range.

So out of curiosity I sent a query to a local industrial supplier, who will sell me KAR-brand OZ25 collets at a fairly reasonable price - CAD27 each. I think this'd be a reasonable way for me to hold my "larger" endmills.

Originally Posted by sigurasg

So out of curiosity I sent a query to a local industrial supplier, who will sell me KAR-brand OZ25 collets at a fairly reasonable price - CAD27 each. I think this'd be a reasonable way for me to hold my "larger" endmills.

I've been looking at the OZ25 collet adapters listed on the FS site, and there are a couple of variants there. I believe some of these are commonly known as BT40 (with drive notches) and SK40 (with an extra V-notch for orientation). Some of those clearly have a separate pull stud with the S20x2 thread.
A couple, like this one have the drive keys, look nice and short and seem to have an integral S20x2 thread:

There's no vertical wasted for automatic tool changer features on these.

Is there a good unique name (read: search term for Google) for this style of taper adapter? At least one of those listed on the FS is Kelch-branded, but I can't find anyone selling this style of adapter. I'd buy one of those sets, except I don't foresee that the metric collets would be of any use to me as all my tooling is imperial.

Hmm - there are BT40, CAT40, DIN2080 and SK40S20x2.....

And I have never seen a tool changer with a threaded draw bar (your comment: There's no wasted...).

If you want max. headroom, just go with direct collets. By having the tool inside the spindle itself.

I would think you could get Inch size collets? Spannzange 462E OZ25 DIN ISO 10897 B ehem. DIN 6388

A Weldon holder will never slip. Just make a flat (for the screw) on the saw holder and you're on.

They are even cheap. At least my Kelch holders were (by w-tool.de in Germany).

I bought from 6mm to 20mm - and later found 25mm and 32mm also.

Cheers
Erik

Originally Posted by Erik

And I have never seen a tool changer with a threaded draw bar (your comment: There's no wasted...).

I'm referring to features below the spindle nose, where a tool changer would "grab" the holder. The "old-style" Kolch and Deckel collet adapters have no such features.

Originally Posted by Erik

If you want max. headroom, just go with direct collets. By having the tool inside the spindle itself.

I would think you could get Inch size collets? Spannzange 462E OZ25 DIN ISO 10897 B ehem. DIN 6388

Yeah, I have a couple of those. I only bought 3/4" and 1" though, thinking that I was covered up to the max range of the E355 collets (5/8").