ER32/ER40 or 5C? Whats your choice and why?

[GrifterGuru]

When you are just using the chuck, slide the tail stock off if you want more clearance.
At least give the 5C a try. Holding small, very short work is something an ER system can't do.

@Larry$

Wrong, ER32 can hold short work. You simply use a section the same diameter stock behind it so you do not distort the collet, there are also other ways to hold short work with ER32 if you use your head to work out the solution.

As for sliding the tailstock off, I generally do not do that for a vast number of reasons including the fact that the space the lathe is in, it is a pain in the a$$.

It seems the obvious solution is to buy a bigger lathe - to fit the chuck.

@Chipper5783

Talk about an inappropriate comment.

I then got an ER32 set which totally overlaps stock size so I can accurately grip anything from 1/16 to 13/16.

@epanzella

That is why I went ER32 from the very beginning with the "option" of adding ER50 later if I could justify the need for it.

I have ER32 collets from 0.5mm to 26mm with 0.5 increments in some places across the metric set as well as a set of imperial collets, so I have every combination I need for now. I also find the 0.5mm (197 thou') clamping range of ER collets more useful than the 3-5 thou' (approx 0.1mm) of the 5C system.

 

[projectnut]

@Larry$

Wrong, ER32 can hold short work. You simply use a section the same diameter stock behind it so you do not distort the collet, there are also other ways to hold short work with ER32 if you use your head to work out the solution.

As for sliding the tailstock off, I generally do not do that for a vast number of reasons including the fact that the space the lathe is in, it is a pain in the a$$.



@Chipper5783

Talk about an inappropriate comment.



@epanzella

That is why I went ER32 from the very beginning with the "option" of adding ER50 later if I could justify the need for it.

I have ER32 collets from 0.5mm to 26mm with 0.5 increments in some places across the metric set as well as a set of imperial collets, so I have every combination I need for now. I also find the 0.5mm (197 thou') clamping range of ER collets more useful than the 3-5 thou' (approx 0.1mm) of the 5C system.

The clamping range of a quality 5C collet should be +/-.010". I have a full set of Hardinge 5C collets. They accept stock in the range previously mentioned. I also have a few lower end 5C collets that have a clamping range of -.010" to less than + .005"

 

[Larry$]

OK, your choice, stick to one size fits all.
Just seems like given the opportunity to expand your system .............

 

[GrifterGuru]

OK, your choice, stick to one size fits all.
Just seems like given the opportunity to expand your system .............

@Larry$

Oh, trust me, I have looked at it from every possible angle and considered all the pros and cons that go with that. At the end of the day I just have no space to store the collets and I really do not want to give up the bedway space it requires in use.

I will at least try it on the lathe and see how it goes. I have a few grub screws to shorten, so will give that job a try with the 5C given I have the collet stop and a torque wrench to ensure consistent force is used to tighten the collets into the chuck, which **should** help with consistency.

The clamping range of a quality 5C collet should be +/-.010". I have a full set of Hardinge 5C collets. They accept stock in the range previously mentioned. I also have a few lower end 5C collets that have a clamping range of -.010" to less than + .005"

@projectnut

I was taught that 3-5 thou' range is the limit of sensibility with 5C. I am not going to go against that as it came from a source with multi-decade experience.

 

[Larry$]

GrifterGuru, I've neve used a torque wrench on any of my 5C stuff But it was standard practice on my business CNC router. Tooling was pre set to height before being loaded in to the tool changer. ER32 system. But it was a 12hp spindle, 18,000rpm. Twice we had tooling come out, both times operator had decided he could get more length by not using the full depth of the collet.

 

[GrifterGuru]

GrifterGuru, I've neve used a torque wrench on any of my 5C stuff But it was standard practice on my business CNC router. Tooling was pre set to height before being loaded in to the tool changer. ER32 system. But it was a 12hp spindle, 18,000rpm. Twice we had tooling come out, both times operator had decided he could get more length by not using the full depth of the collet.

Problem with 5C with a chuck key, or for that matter ER collets actually, is inconsistency in clamping. A Torque wrench avoids that to a certain extent.

Not like I could or would fit a collet locker with an over-centre mech through the spindle.

 

[projectnut]

@Larry$

Oh, trust me, I have looked at it from every possible angle and considered all the pros and cons that go with that. At the end of the day I just have no space to store the collets and I really do not want to give up the bedway space it requires in use.

I will at least try it on the lathe and see how it goes. I have a few grub screws to shorten, so will give that job a try with the 5C given I have the collet stop and a torque wrench to ensure consistent force is used to tighten the collets into the chuck, which **should** help with consistency.




@projectnut

I was taught that 3-5 thou' range is the limit of sensibility with 5C. I am not going to go against that as it came from a source with multi-decade experience.

That doesn't sound practical. Imperial 5C collets come in .015" or 1/64" increments. If a 1/4" collet can only close to .245" and a 15/64" collet can only open to .235", how do you grip anything between .236" and .244".

 

[GrifterGuru]

+/- 3-5 thou' either way of nominal was what I was taught, I do not really want to go against that advice given it was earnt by somebody who knew what they were talking about, though I do not mind experimenting.

.236" is 6mm. .244" is 6.2mm. A 0.2mm spread. I would go with a 6mm ER collet given the better spread either side of nominal size.

 

[SouthernChap]

It seems the obvious solution is to buy a bigger lathe - to fit the chuck.

Only obvious if you ignore the concept that not everyone (and especially those in the UK) has space in their workshop for a larger lathe.

I have a 7x14 myself and I'm lucky that in the space I have for a lathe, I could (and will, when funds allow, fingers crossed this year, but maybe next) squeeze in a Boxford, Colchester Bantam or Harrison M250/300. All of those are around the 9x20 or 10x25 size. I'd love a Harrison L5/140 or a Colchester Student/Master but they just won't fit.

@GrifterGuru IIRC, is even more space constrained than I am and I'm pretty sure what he has, is what will fit.

 

[epanzella]

That doesn't sound practical. Imperial 5C collets come in .015" or 1/64" increments. If a 1/4" collet can only close to .245" and a 15/64" collet can only open to .235", how do you grip anything between .236" and .244".

You do it with an ER collet. 5C collets are only slotted on one end so they only collapse on one end. The more you have to squeeze down the collet the more tapered the bore of the collet gets. ER collets are slotted from both ends so that both ends collapse equally to grip a part without the bore getting tapered. This gives each collet more range in the parts it can hold.