ER Sets

[Alan]

Good Morning Gentlemen

I have just discovered how inaccurate a three jaw is when trying to turn down very small diameters. I think I need to purchase an ER set of collets. However there seems to be ER25 & ER32 sets available. Apart from the number if collets supplied in a set and the price! What is the differences? should I go 25 or 32 ?

Alan

[russell]

It depends on the size range you need. The 25 and 32 refer to the nominal diameter of the large end of the collet so the ER32 collets can be obtained for larger sizes than the ER25.
Bear in mind that if you buy a standard collet holder on a taper shank you can't pass bar stock through it so for use on your lathe it is better to buy a holder designed to fit a backplate or better still make one to screw directly onto the lathe mandrel. This can be machined in situ thus ensuring accurate alignment.

Russell.

[Alan]

Thanks for that Russel

It sounds that the 32 series would be more versitile ? can you advise on quality? I see RDG sell at a reasonable cost but Chronos sell what i think is called te Vertex range which according to them is higher quality!!

Alan

[davediy]

Hi I purchased a set from chronos because of their claim of better quality and I'm quite pleased with them so far. I chose the ER32 set as it covered a larger range of sizes at the time.
Unfortunately I don't own any other Collet's to compare them with so my experience may be some what limited
but I would easily consider buying more of the same as and when needed.
It helps to get a set you can use on as much equipment as possible your lathe, mill, drill etc. if not make sure you can get holders for your type of equipment
My set will fit on both lathe, mill and pedestal drill if needed.
Hope this helps
Dave

[Staffordshirechina]

Hi Alan,
I went for ER32. That lets you go up to 20mm diameter which covers most useful stuff. The next size up ER40 gets a bit expensive and there are not so many chuck options for model engineers. ER25 is just a bit too small for some things eg. 3/4 endmills.
Like Dave, my set came from Chronos and are well finished. I have other Vertex stuff and it does appear better finished and accurate than some of the RDG mega-cheap stuff.
I find these collets very versatile. I have the 3MT holder supplied with my set, a 40INT holder for the milling machines, a home-made Myford nose fitting that uses the bezel from either of the others and likewise special fittings I made for my T & C grinder for drill sharpening or endmills.
The design of the collet holder is very easy to copy by model engineers.
One use I had not thought of until I had some is for centring my rotary table. My table has a 20mm hole in the centre. So a piece of 20mm ground bar in an ER collet in the spindle locates the table whilst it is bolted down, zero the DRO and you are bang on very quickly.

Most Useful items!

Les

[Alan]

Once again Chaps, thanks, very interesting

Alan

[ajsbsa]

Hi
I have been very impressed with an Ebay seller from Hong Kong ctctoolseller very good quality and very good pricing. I have bought several items from him including ER collet sets, they do 20mm shank which suits my Downham jig borer as well as small ER sets for my Cowells.
Steve

[SteveW]

Gentlemen,

I have an R8 drill/mill so bought an R8/ER32 set, a ER32 collect holder and a Myford back plate.

The R8/ER32 set was at the time the cheapest way of getting a set from around 2mm right up to 20mm. Fitting the back plate was reasonably easy and had been very useful.

[Deleted]

The ER-25s I bought from Rotagrip at Ally Pally appear, at first sight, to be very good. They fit straight into an adapter nose obtained from Myfords and result in minimum overhang. All the 2MT chucks I have tried are far too long and leave the workpiece or cutter waving about in the breeze. I was given (as an awful warning) a 2MT milling chuck which had bent at the unsupported large end of the taper when trying to take only a modest cut.

[rodwilson]

Anybody knows who produces a backplate type chuck for ER11's?

[44767]

rodwilson, I doubt you'd find one that small. Is your lathe so small that you only need up to 6mm collets? Have you considered a larger collet chuck and holding in that a straight shank ER 11 chuck?

[ajsbsa]

Hi
I just reread the start of this thread and maybe an easier solution is to make your three jaw accurate to about half a thou with an adjustable backplate.
Much quicker to set up than four jaw although it will not have the repeatability of a collet for one off stuff its fine. Here are some pictures of mine not a kit I made it up as I went along but I believe you can get a kit from Hemmingway.









Just an Idea
Steve

[simonwass]

I've come to find runout is easily caused by swarf in the jaw teeth, if I find I have a problem usually a dismantle and careful clean cures it.

[rodwilson]

Thanks for the reply. It's just that I came by a set of ER11s and recently purchased a Cowell's ME90. I have a Myford for the bigger stuff. Arc Euro do a ER16 chuck with a backplate so I may have to go down that route and/or make the adjustable backplate for the three jaw.