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Ball Bearing Collet Nuts
- Thread starter JustaDB
- Start date
This is one I was looking at:
VicHobbyGuy
Ultra Member
I bought one of the bearing nuts - "just to see if I could tell the difference". I couldn't, really. That said, most of my ER32 stuff in question came straight from AliExpress. One R8 ER32 "CanCNC"came from BB, and was likely from China or India with a bit better finish. It all works well enough for me, but perhaps paying a few hundred per holder, from a 'western' manufacturer would make a difference. I'll never know.
ER 32 Ball Bearing Collet Nut
www.shars.com
So do i need one of these for my ER32s or is it something that would be nice to have?
I haven't tried them yet & haven't felt the strong need, but did a bit of reading a while back. I cant recall if they apply the same clamping force to tool with less input tightening torque, or can achieve higher levels of clamping force than regular. I guess it would be a nice to have on most HSS or carbide tooling which can take the load. Some guys use ER for work holding too so I could see being more cautious on distorting thin wall stock for example, but likely something you can feel. I seem to recall the wrench spline dimensions might be different on bearing style vs regular ER nuts, but maybe that was brand specific. Some are offered in hex too, some are size dependent.
Former Member
Guest
Using them on my CNC I can tell you that unless you're a gorillia regular nuts do not tighten enough when you do something stupid and your endmill will slip. The Ball nuts well easy to tighten and loosen, no slip.
IMHO it is worth to have at least one as there is a difference in how they increase the grip strength and ease of use they offer.
Just remember its a rabbit hole.....
IMHO it is worth to have at least one as there is a difference in how they increase the grip strength and ease of use they offer.
Just remember its a rabbit hole.....
Former Member
Guest
As a note I got mine from the UK, if I remember correctly at about CDN$35.00 each shipping included.
When do you find this starts to happen? High chip load, RPM, interrupted cutting...? The bearing style doesn't seem expensive & its not like they require dedicated holders so seems like good insurance.
Former Member
Guest
Rapid feed with an unintentional cut.....don't ask.
I have 3 ER40 collet chucks. Last year I wanted to test the run-out due to the collet nuts. I have ETM, Techniks, and KBC Chinese. The ETM has the bearings, the other two do not. I completely cleaned all parts, I used the same collet chuck (ETM), and the same collet (Lyndex), used a 0.500" pin gauge, and torqued as equally as I could without a torque wrench.
I wrote down the results, but of course, I can't remember where I put them. But I do remember that the ETM had the least runout, followed closely by the Techniks, and then the chinese (which was consderably worse than the other two).
I wrote down the results, but of course, I can't remember where I put them. But I do remember that the ETM had the least runout, followed closely by the Techniks, and then the chinese (which was consderably worse than the other two).
At one point I will purchase a ball bearing nut for my er32 Ali Express collet set.
I use this collet set on the mill and my endmill grinding set-up. That's were I run into a problem. When I try to accurately set the endmill cutting edge in my collet holder and I go to tighten the collet nut the endmill or collar rotates and I lose my setting.
Maybe the bearing nut will prevent this rotation. ER collet are not keyed , like 5C, R8......
I use this collet set on the mill and my endmill grinding set-up. That's were I run into a problem. When I try to accurately set the endmill cutting edge in my collet holder and I go to tighten the collet nut the endmill or collar rotates and I lose my setting.
Maybe the bearing nut will prevent this rotation. ER collet are not keyed , like 5C, R8......
VicHobbyGuy
Ultra Member
Don't your ER collet holders have flats so you can put a wrench/spanner on the holder while you tighten the collet nut? Is your mill spindle R8 or Morse taper?
Yes my holder has flat.
Its the collet itself rotating in the holder which also rotated the endmill I am trying to sharpen, Not by much but enough to shift the cutting edge that I am trying to sharpen with the grinder. If the ER collet was keyed it would not rotate in the holder. Hopefully the ball bearing nut will reduce the friction between the collet and the nut to prevent it from rotating in the holder
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VicHobbyGuy
Ultra Member
Ah, I understand now. I never paid any attention to whether the collet was rotating, Other 'one piece' collet types (like R8) that just 'pull straight in' wouldn't produce the same problem. And if you are trying to hold the end mill for sharpening, rotation matters.
Chipper5783
Super User
Yes on the ball bearing collet nuts. The TG100s that came with the machine (about 10) all have the bearing nut (3 styles of holders), I’ve since purchased some ER (to get in closer). I’m using the std nut in ER20 (pretty small) but the ball bearing nut in the ER25 and ER32 - my main reason is that they are not all that expensive and it makes me feel good. If the EM pulls out, it can sure spoil your day.
I’ve had my share of bad days, but only had an EM pull out one time - a really trashed tool in a collet directly in the #40 taper (called SK40). It was totally my bad, but any insurance that is cheap/easy to reduce mistakes - well, I’ll take it.
I’ve had my share of bad days, but only had an EM pull out one time - a really trashed tool in a collet directly in the #40 taper (called SK40). It was totally my bad, but any insurance that is cheap/easy to reduce mistakes - well, I’ll take it.
I confess that this is sooooo hard for me to accept. The ratio between tightening the nut and gripping friction of both surfaces of the collet is enormous. The force exerted on the endmill flutes when you sharpen them cannot be very much at all.
Have you cleaned all the oil out? Everything should be dry.
Are the tapers all clean or is there some dirt in there?
Is something else moving?
Am I missing something?
Regofix (the inventor of ER collets) has a chart of recommended torque and holding force here:
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I think what @fixerup means is that the endmill flute has to sit on the tooth rest of the grinder so that the grinding wheel is properly positioned, but when you go to tighten the collet nut, it squirms slightly out of position.
Former Member
Guest
Doesn't your sharpener allow alignment after installing cutter? This is when the miss-alignment occurs in all circumstances.
Thanks for that link. Interesting, their torque spec for ER40 is 128 NM which is 94 LB FT. Lots of other sources specify 130-140 LB FT for ER40. I guess I've been over tightening!
darrin1200
Darrin
I found this one on Amazon.
Bearing Collet Nut - Amazon.ca
I may try this. One issue I have that it might help with, is remounting mandrels I use to hold my work.
When I tighten the mandrel in the collet, it is just slightly off. If I loosen it up, just enough to allow the mandrel to be turned in the collet, and retighten it, it’s perfect.
Sorry guys, I am not explaining the issue very well.
The collet rotation occurs at the beginning when I am inserting the endmill in the ER collet holder and then I align the endmill cutting edges parallel to grinding table before tightening the collet nut. Then I tighten the collet nut, which unfortunately rotate the collet in the holder and my endmill cutting edge are no longer parallel with my grinding table..
I hope the new collet bearing nut will reduce the initial tightening friction between the two and prevent the collet to rotate