Why would you choose either ER32 or ER40 collet for PM-1022V?

[cneuor]

The only ER collet chuck that Precision Matthews offers for PM-1022V lathe, at least at this time, is the ER40. They say, if you want ER32, you can custom-fit the back plate and people have done it. Before I knew this, I thought I wanted the ER32. But now I am wondering if I should get myself the available ER40 and be done with it. So, I would like to ask this question: why ER32 and not ER40 or vice versa? Other than the set of ER40 collets will cost not really a significant amount more over ER32, is there anything else?

As a separate subject - I could not find any info about the "V-Flange Collet Chuck". What is that, how to use it, and why to have it if there is the ERxx chuck?

 

[ChazzC]

I already have ER32 collets (1mm - 25mm) so I would start with them with a custom collet chuck; however, when/if I buy a PM 1022 I would probably include the ER40 chuck allong with a couple of extra back plates for other chucking tooling (my Accusize 5” 3-jaw, Eccentric Engineering Flexi-Chuck and ?

 

[davidpbest]

I have both. The choice between the two for me boils down to the size of what I want to hold and whether I'm trying to hold a tool or material being cut by a tool. For instance, I prefer the ER32 for holding tools (drill bits, end mills, etc.) in the tailstock of a lathe. I also prefer it for holding the same kinds of tools in the mill spindle. But for holding materials that are being machined, the ER40 will handle larger diameter materials in the lathe spindle, or in a hex-block. This all gets more complicated when you also consider 5C collets/chucks. You might find this paper,which I posted here earlier, helpful in understanding the tradeoffs.

 

[Advil]

The document above is the full answer. To add to that:

This page from LittleMachineShop pretty much sums up the sizes of collet commonly available for ER32 and ER40:

ER Collet Sizes

This page shows the size and clamping range of the various size ER collets that we carry.

littlemachineshop.com

Note the minimums and maximums.

 

[m1kemex]

I already have ER32 collets (1mm - 25mm)

Didn't ER32 end at 20mm?