Author Topic: Er 32 or ER25  (Read 12081 times)

Baldrocker

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Er 32 or ER25
« on: January 09, 2009, 06:54:20 PM »
Hi Guys.
Need some advice from the ML7 devotees.
What would suit a Myford ML7 best. Metric ER32 collets
and chuck with 2MT tail or ER25 collets with same
chuck. Some ER32 collets on Ebay are stamped with
metric sizes and imperial equivalants (or Vice Versa)
would ER25 metric take imperial eqiuvalnts
Thanks Fellas

bogstandard

  • Guest
Re: Er 32 or ER25
« Reply #1 on: January 09, 2009, 10:44:02 PM »
Unlike normal types, say 5C collets, ER collets are a 'one size fits all' because of the compression range of each collet. Each one has a full compression range from one collet to the next, so are able to accomodate both metric and imperial. A metric set will have a metric hole size for a start (say 16mm), the imperial set (never seen one in the UK) will have the same sort of thing, but both standards will accomodate each other.

I personally would go for the largest size that will fit your machine. In your case I would suggest ER32.

http://rdgtools.co.uk/acatalog/CHRISTMAS_SPECIAL_S.html

The 10 pounds difference between these two is a no brainer really, the 32 set will hold much larger pieces.

John

Baldrocker

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Re: Er 32 or ER25
« Reply #2 on: January 10, 2009, 02:13:49 AM »
Thank you John
BR

bogstandard

  • Guest
Re: Er 32 or ER25
« Reply #3 on: January 10, 2009, 04:57:06 AM »
BR,

I should have asked why you wanted to go for the MT fitting. For tailstock or headstock fitting.

The reason being, if you were fitting to the headstock, if fitted to an MT taper, I suspect you would be limited by the length of material you could hold, whereas with the set I showed, the material would have unlimited access to the spindle hole. Also if you went for one of those two, you can just buy the collet holder for fitting the tailstock as well.

Maybe a bit too much info, but it is there if you need it.

John

Baldrocker

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Re: Er 32 or ER25
« Reply #4 on: January 10, 2009, 06:29:42 PM »
Never too much info John your input is valued and may stop me making a decision I regret later on.
My reasons are sad to say purely $$$$$,over AU$300 for the Myford thread v $180 for 2MT.
I have to say I like your reasoning. Would there be any advantage gripping wise between the two?
Regards
Paul aka BR

Baldrocker

  • Guest
Re: Er 32 or ER25
« Reply #5 on: January 10, 2009, 06:33:55 PM »
PS
Headstock.
I have to admit the idea of fitting to the tailstock
just didnt occur to me. At this stage the ts is just something stuck
on the other end most of the time.
Just goes to show my newbie-ness
BR

bogstandard

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Re: Er 32 or ER25
« Reply #6 on: January 11, 2009, 02:56:15 AM »
BR,

I fully understand your problems with the cashflow, I had to do everything over a long period of time when I first started machining at home, and it took many years to obtain the machines and tooling I wanted. So you must go with your heart and wallet with that decision, and don't be forced into making the decision, you are the only one who knows what you can afford to buy without stretching yourself. We are here to show you what is available.

The tailstock bit was only a suggestion, but as you expand your machining facilities, you would just buy the holder to fit your new machinery, and use your already purchased collets. That might be a long way down the line yet, but a little planning now can save a lot of pennies in the long run. There are lots of new ways being thought up how to use these collets, and they mostly seem to be based around the 32 size, which looks like it is going to become the accepted standard size for general machining.

There is no difference in the grip, as the pressure is applied by the nut, and that is a standard throughout the range of holders. The only difference is the type of nut, I use a ballraced one, and that imparts a lot more pressure because it overcomes the friction between the nut and collet.

John

Baldrocker

  • Guest
Re: Er 32 or ER25
« Reply #7 on: January 11, 2009, 06:22:40 AM »
John
Much food for thought, I'll keep you posted.
BR

Offline kellswaterri

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Re: Er 32 or ER25
« Reply #8 on: January 11, 2009, 07:14:59 AM »



,





There is no difference in the grip, as the pressure is applied by the nut, and that is a standard throughout the range of holders. The only difference is the type of nut, I use a ballraced one, and that imparts a lot more pressure because it overcomes the friction between the nut and collet.

John
[/quote]

Hi Bogs, can I ask you where is the above ''ballraced'' nut obtainable as I have not seen one? I currently use one set of ER25 colletts with two sets of nuts and holders , one for mill and one for lathe...a very useful piece of kit indeed.
All the best for now,
                           John.

Offline Darren

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Re: Er 32 or ER25
« Reply #9 on: January 11, 2009, 07:25:59 AM »
Yep, John advised me to get an ER set,

Very good advice indeed, really nice to use and so versatile across machines to boot.

The ball race nuts are avail on Ebay, I was just looking myself 
http://cgi.ebay.co.uk/ER32-collet-chuck-Ball-Bearing-Clamping-Nut-Quality-NEW_W0QQitemZ220338335932QQcmdZViewItemQQptZLH_DefaultDomain_3?hash=item220338335932&_trksid=p3286.c0.m14&_trkparms=66%3A3|65%3A10|39%3A1|240%3A1318
You will find it a distinct help… if you know and look as if you know what you are doing. (IRS training manual)

bogstandard

  • Guest
Re: Er 32 or ER25
« Reply #10 on: January 11, 2009, 07:49:18 AM »
John,

Darren is correct, they are good. Especially if you are fitting an imperial cutter that won't automatically hold in the collet while trying to tighten up (usually a three handed job). You can screw them up enough by hand to hold the cutter, then bring the spanner in. Not normally possible with a standard nut, and worth every penny for that alone, the other things are bonuses.

Just two problems, you have to get them while available as he doesn't have them all the time, and they are also a bit tight initially getting the collets into the nose of the nut, but that soon disappears when you get the hang of it.

This is one for your size.

http://cgi.ebay.co.uk/ER25-collet-chuck-Ball-Bearing-Clamping-Nut-Quality-NEW_W0QQitemZ220338807673QQihZ012QQcategoryZ12584QQcmdZViewItemQQ_trksidZp1713.m153.l1262

BTW, I use that seller for a few bits of my tooling, always good quality and reasonable in price.

Bogs

Offline kellswaterri

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Re: Er 32 or ER25
« Reply #11 on: January 11, 2009, 08:25:40 AM »
Hi Bogs & Darren, thank you for the replies... Have now sent the vendor a P/M.
All the best for now,
                          John.