I've been going round on circles on this one myself! I start with 5C because it's primarily intended to hold work whereas ER is primarily intended hold tools. But either will do the other. ER has the advantage of a wider gripping range per collet than 5C so you need fewer of them. But ER chucks have greater overhang which reduces accuracy. Pluses and minuses for both. Perhaps in practice they're so similar it doesn't matter?

I'm inclined to go 5C simply because it's the most common solution on a lathe. But I still haven't made my mind up…

Dave

ER collets can be used as milling cutter holders in both lathe and mill as well as for holding stock. Collets are available new for about the price of a used 5C.

5C is going out of favour and probably considered 'limited' and 'old fashioned' by some. Imported collet sets are available but as with drills in the end you only actually use a few sizes. The main advantage would be that an insert can be made for the 5MT spindle and with a drawbar keeps the job right up close tot he bearings. Max size is just over an inch but really most of the time for larger sizes of stock a regular chuck is adequate anyway.
Think about use on milling machine too. Standard spindex takes 5C but an ER32 modified spindex is available too (Arc) though not and ER40.

I think ER32 would end up cheaper than 5C if you don't need ER40 to get collet precision in larger sizes.

The good thing with 5C is that you can have a back-stop screwed into the collet for repetition work, they can hold short pieces of work, emergency collets can be machined to a special size and lastly square and hex collets

I have the 1224 Warco and after asking on here I took on Jasons advice and went for the 5C range and haven't look back

I was lucky in that I purchased a full set from Warco including the collet chuck already mounted for a good price and haven' t had anything yet that I couldn't hold

The bonus is having the square and hex holders as well

cheers

And talking about ER chuck overhang, 5C is just as bad:

**LINK**

I've got an ER40 on my Chester Crusader. Collets go up to 30mm, (32mm is also available). I made er ring to fit the nut, allows for quick opening of collet.

Main advantage of 5C is that hex and square collets are available. I'm very happer with ER!

Jim

I initialed shared the ER40 set up used for my milling by adding the D1-4 mount chuck on my Harrison M300. It is now just used on the VMC.

I got a great Ebay deal that came up using BIN as it just appeared, on the Pratt D1-4 collet setup which goes up to 38mm. Much better quality than the ER40 system but slower to load and unload. They are great chucks and very positive but they are difficult to get hold of and can command prices up to £500.

I have both, the collet chuck of choice for me is the 5C l like being able to tighten and loosen with a chuck key I also like the ability of the 5c collet to hold short lengths of material. It can be done with ER collets but it's a faf.

Hi,

I expect you will never get any consensus because the ER and 5C work holding approaches for the lathe have different positives and negatives and it would come down to what you want and can afford.

I get the best of both worlds.. I have a range of 5c mostly purchased second hand. I try and buy quality Crawford or Hardinge round (all second hand good condition and there are some real bargains out there for ex industry 5C) collets but for hex and square Chinese. I also have a 5C to ER40 collet for intermediate sized round bar.

What max size bar are you going to be working with? a D1-4 spindle has a nice spindle bore and it would be a shame to limit yourself if you intend to do larger work.

If your lathe is also sold in the USA there might be an option available for a collet closer as although 5C collets are a 100+ year old design they are very popular in the USA. It is a very nice arrangement.

Steve

Edited By SteveI on 02/11/2017 19:51:23

5C collets also fit spin-indexers , indexing fixtures, and other gadgets. To the best of my knowledge none of these things are made for ER.

Knowledge improvement time!

I believe you will find, if you look hard enough, an ER spin indexer available from ArcEuro. Named after the late John Stevenson?

It will accept both 5C and ER32 collets. Look it up, along with the square and hex indexers.