A common mistake with the ER type chuck is not to insert the collet into the nut before screwing onto the nose, if you have fallen into this trap the runout will be excessive. The collet should be inserted into the nose with a tipping and pushing motion, the collet should then be retained in the nut and spin easily. The cutter must not be inserted until the collett is in the nut.

Mike

Edited By Michael Poole on 27/12/2015 12:01:59

It would be worth checking if it is the chuck or the collet at fault. I put a clock on the inside surface of my ER20 chuck and found it to run perfectly true. I came to the conclusion that the cheap collets were at fault.

I have also read that the collets need to be tightened quite hard

I tend to favour older Jacob's 1/2" chucks. There are usually a number of them about on ebay etc but often they are 2 morse. 3 morse should be around as well.

Some years ago Rotagrip had a lot of used ones about and may still have them. No facilities for a draw bar though.

I have also used one of the heavy duty ones on this page but infrequently. Seems ok and well made to me.

**LINK**

Arbour from the same source.

John

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What sort of run out are you looking for, quality chucks can be had with a quoted runout if you look on the right websites. Unmounted ones from 0.04mm or ones with integral shanks a little better at 0.03mm but like most things you gets what you pay for the 0.04mm start around £100 and upto £500 for the 0.03mm integral ones.

Look for makes liek Rohm, Accupro, albrecht.

J

Over the last two or three years I have slowly gone round and replaced all the drill chucks with keyless ones.

Not a small task as each machine has 2 to 4 chucks to speed operations up. It has been a worthwhile task though and I reckon at least 2 months of the year have been saved not having to look for a damn chuck key.

Each machine also has a strap wrench hanging on the tool board for that machine and it's only a 2 second job to give the chuck a quick tighten to stop the tool spinning.

I found that even with so called class chucks like Jacobs [ although I still feel they should have stuck to making Cream Crackers ] the keyed chucks, no matter how much you tightened them, they still spun the drills.

One thing I did find though that was when I bought my new TOS lathe it came fully tooled up and I had a real good deal off the importer. It came with four 1/2 capacity Jacob keyless chucks on MT4 tapers to for the tailstock.

None of these chucks survived the first year. They all self tightened as they do but then tightened to a point where they exploded internally. The only one I did manage to undo, everything fell out as shrapnel. I'm certain that the parts were over hardened.

These have now all been replaced with decent quality Chinese imports from a well know distributor in Leicester who shall remain nameless with not breakages in the last ? got to be 10 years.

Edited By John Stevenson on 27/12/2015 16:04:42

I've never ever had any problem at all with my older Jacob's 1/2" keyed chuck John S even with 1" blacksmith drills in them – in fact it's drills like that which cause me to use it rather than a industrial Rohm keyless. The Jacob's probably came with the lathes I have owned so circa 30 years old or so apart from a used one which I bought from Rotagrip for a Raglan I had bought of a dealer. All no draw bar. Then there was all of the Jacob's of all sorts of sizes during training. They would be old now too.

The stupid 5/8 2 morse on on my bench drill part gave up the ghost the 1st time I drilled some 3/8 holes in stainless. It's ok 1/4 dia and up but smaller stuff wobbles all over the place of late.

I do have a spare Jacob's of the right age.

John

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Edited By John W1 on 27/12/2015 16:42:07

Hi Sarah, sent you a message re your chuck. Mick