R8 Collet Set or R8-ER32 Collet Set

[YYCHM]

I think a collet set is in my future. I've used both R8 and R8-ER32 style and both require unscrewing something in order to change tools. Both appear to boast the same accuracy. Is there any significant advantage to one over the other? Cost wise they appear to be on par with one another for the same size range. The ER32 style appears to require significantly less collets to cover the same size range.

 

[Johnwa]

Depends on what you’re using them for.
In a mill any extra chuck reduces your z travel. For holding endmills you only need 4 or 5 sizes. If you’re holding drill bits then you will need more.

on a lathe where you are holding stock then the ERs are better. The ERs hold at both ends of the collet so ”should” give less runout. If you have the right chuck the work can also extend through the collet.
You can get ER hex collets but square ones.

My SM lathe manual shows an adapter for a 5C collet. With a hollow drawbar work can extend through the spindle.

 

[DavidR8]

I have ER32 and MT3 collets. The ER32 collet chuck consumes 2.75" of Z axis so I use the MT3 collets when I need the extra space. But I prefer the ER32

 

[YYCHM]

@David_R8 Why do you prefer the ER32?

@Johnwa These will be for use on my mill with the main intent to eliminate using the drill chuck.

A set of 1/16"-3/4" by 32nds R8 collets (23pcs) costs the same as a 11pc ER32 set ranging from 1/8"-3/4" and I see the ER32 got some bad reviews v.s. the R8s which had great reviews.

 

[Johnwa]

Is the spindle a Morse taper?

 

[DavidR8]

@David_R8 Why do you prefer the ER32?

@Johnwa These will be for use on my mill with the main intent to eliminate using the drill chuck.

A set of 1/16"-3/4" by 32nds R8 collets (23pcs) costs the same as a 11pc ER32 set ranging from 1/8"-3/4" and I see the ER32 got some bad reviews v.s. the R8s which had great reviews.

Changing tooling with the MT3 collets requires loosening the drawbar whereas the ER32 is a simple wrench and the tooling drops out.

 

[Johnwa]

Ditto on what @David_R8 says. In addition MTs can grab pretty tight and sometimes it can take quite a rap to get them to release.

 

[YYCHM]

Is the spindle a Morse taper?

No, my spindle is R8 and I don't have any issues getting tools or the collets out. Loosen and tap the draw bar with the wrench.

Would a R8 collet sized to a 32nd be able to take a tool 1/64" larger?

 

[Johnwa]

I don’t think you can go larger but you can go smaller.
https://www.mcmaster.com/r8-collets/

 

[Johnwa]

You’re better off sticking with the R8s. The ER32 chuck extends quite bit reducing your z clearance and likely adds more leverage causing the head to deflect.

 

[YYCHM]

I don’t think you can go larger but you can go smaller.
https://www.mcmaster.com/r8-collets/

Not following what the chart is telling you. What I'm asking is, would a collet set in 32nds be able to accommodate a drill bit set in 64ths.

 

[Johnwa]

No it doesn’t look like it will.

 

[YYCHM]

No it doesn’t look like it will.

That's what I concluded to. Looks like +- 0.002 max.

KBC doesn't even sell single R8 collets in 64th inch increments. Hmm... neither does McMaster-Carr?

 

[PeterT]

These will be for use on my mill with the main intent to eliminate using the drill chuck.
Personally I would find this to be a PITA. Think of a very typical drilling operation - edge find from a side or part feature, then spot drill, then regular drill, then maybe counterbore/chamfer/tap/enlarged drill... That's many different collect changes because there is high probability each tool shank will be different diameter. I mean, that's why chucks were invented LOL. Another mini disadvantage to R8 for drilling is collet is very high up in the blunt end of the quill. On small/short drills this can actually impair your vision of the hole a bit.


Would a R8 collet sized to a 32nd be able to take a tool 1/64" larger?
Never exceed your collet nominal capacity & also don't grip something too far under size. That's a good way to distort them.

One benefit of ER is the wider capacity from the perspective you can grip all kinds of endmills, imperial or metric (among other things). The average price of NAm EM's is pretty high compared to a lot of Asian offerings if you look in the right place. Now there are also legitimate EM holders to match your shank which are typically also have a set screw for the flat on the shank. I typically dont see them slip up to 1/2" diameter but I'm not really doing serious hogging.

 

[DavidR8]

These will be for use on my mill with the main intent to eliminate using the drill chuck.
Personally I would find this to be a PITA. Think of a very typical drilling operation - edge find from a side or part feature, then spot drill, then regular drill, then maybe counterbore/chamfer/tap/enlarged drill... That's many different collect changes because there is high probability each tool shank will be different diameter. I mean, that's why chucks were invented LOL. Another mini disadvantage to R8 for drilling is collet is very high up in the blunt end of the quill. On small/short drills this can actually impair your vision of the hole a bit.


Would a R8 collet sized to a 32nd be able to take a tool 1/64" larger?
Never exceed your collet nominal capacity & also don't grip something too far under size. That's a good way to distort them.

One benefit of ER is the wider capacity from the perspective you can grip all kinds of endmills, imperial or metric (among other things). The average price of NAm EM's is pretty high compared to a lot of Asian offerings if you look in the right place. Now there are also legitimate EM holders to match your shank which are typically also have a set screw for the flat on the shank. I typically don't see them slip up to 1/2" diameter but I'm not really doing serious hogging.

I agree with Peter re drilling with a collet chuck. A good quality drill chuck is money well spent. I have both a keyless and keyed chuck. The keyless I use for drill diameters under 3/8" and I use the keyed for bits over 3/8".

 

[YotaBota]

I'm reading the McMaster chart as -.004 and +0 so you can be 4 thou under but nothing over.

I bought a 7 piece R8 set (1/8 to 7/8) from Accusize and they seem to be okay. I'm buying mostly 1/2 and 3/8 shank EMs and haven't had any problems. The only issue I've had is my with my center finder (Starrett), it is double ended and I need to wedge the collet open a bit for the finder to release without stretching the spring.
I think it would be easier to use a chuck and the stubby bits for drilling holes, just my 2 cents.

 

[YYCHM]

Well..... since R8 collets aren't offered in 64th inch increments it looks like they are a no-go as a do all collet system for me. If they were offered in 64ths I'd be going that way.

ER32 appears to be the way to go BUT they also appear to be more expensive in terms of obtaining the same quality as a regular R8. Makes sense as they are much more sophisticated.

I don't mind lots of collet changes to accomplish things, what I really want to do is eliminate having to use a drill chuck. Collets are more rigid, accurate and take up less head space.

Keep the comments coming please.

@David_R8 which ER32 set do you have?

 

[Tom O]

I'll get some er32 collets and holders for the Haas at some point for those tighter cuts.
I have 3 keyless drill chucks ( cat 40 ) for pilot, drill and countersink they say though not to push the drill all the way in when tightening because by design it will draw it in.

 

[Dabbler]

A precision drill chuck can do what you want with any drill, stubby, specialized or whatever.

For 40 years I have had a small number of R8 collets for mills, a great chuck, and a 3/4" Weldon holder for annular cutters. I have an r8-er40 adapter with collets covering 1/64-1" that I have never used.

 

[Tom O]

I'm thinking of the difference of circumference 40 vs 32 for those tighter cuts.