Collet Chuck

[woodpig]

My new ER32 collet chuck arrived a couple of days ago so just gave it a quick outing. I wanted something a little safer than my other woodturning chucks for turning small stuff.

Only about £15 posted on eBay. I already have a full set of metric collets.

 

[katellwood]

Am assuming its a morse taper, does your headstock have a bore right through it and are you holding the chuck in place with a length of threaded bar or are you depending on the friction of the morse

My reason for asking in my old dominion and wadkin patternmakers lathes do not bore through the whole length of the headstock and I am not too confident in relying purely on the morse friction fit

 

[woodpig]

Yes it's an MT2 and the headstock on my lathe is hollow. The chuck is threaded M10 so it's held in place by a draw bar.

 

[selectortone]

That looks like a useful bit of gear Vic - looking forward to seeing it in the flesh.

 

[lurker]

Can you post a link to the seller please

 

[woodpig]

Can you post a link to the seller please

http://www.ebay.co.uk/itm/201614157661? ... EBIDX%3AIT

The price has gone down a bit since I bought it, only £14.69 now! Don't forget you'll need at least one collet for it. A 20mm will do for most jobs.

This is a posed shot and I'm not suggesting you do it but it shows how close to the work you can get if needed.

 

[Robbo3]

Threaded collet chucks are available from various suppliers including Axminster (a lot more expensive than Woodpigs).
- http://www.axminster.co.uk/axminster-ju ... ck-ax22446
or
- http://www.axminster.co.uk/axminster-en ... der-505124

or collet holders
- http://www.axminster.co.uk/accessories/ ... et-holders

Straight shank collet holders make a good changeable tool handle when covered with shrink tube. Different size collets enable various diameters of round bar to be chucked so that you can buy unhandled tools or grind your own.

The ER range of collets come in different sets numbered from ER8 to ER50 (that I know of). The larger the number the larger the collet & its holder - that's the physical size of the collet, not its bore.
Thus
ER20 collets range from 1 - 13mm capacity
ER25 collets range from 1 - 16mm capacity
ER32 collets range from 1 - 21mm capacity
etc.
Each collet can be compressed by 1mm thus each collet will hold anything up to 1mm less than its maximum capacity. Most are marked as such, eg, 5-4mm 4-3mm.
Imperial sizes are also available.

Other suppliers are :

Chronos (Dunstable)
- http://www.chronos.ltd.uk/acatalog/collets.html

Arc Euro Trade (Syston, Leicester)
- http://www.arceurotrade.co.uk/Catalogue/Collets

 

[woodpig]

Yes, I've made a couple of tool handles using C16 collet chucks. One ER16 and another in ER20.

 

[Random Orbital Bob]

This is all new to me because I'm guessing this design of chuck originates in milling metal?

So picking up from the context, can you correct my assumptions please:

Does the little chuck hold a range of collets which are removable and allow the gripping of varying diameters of stock (all thin presumably)?
The chuck is threaded onto a drawbar which in turn has a 2MT taper which seats in the lathe?
Following the Axy one from Robbo's link, their version is directly threaded and therefore just screws onto the spindle nose?

My interest is in turning typically 11mm square stock of ebony for various components but usually for apple stems. It's 11mm because it's harvested from reject guitar fingerboards into sticks which are a pain to turn in a normal sized chuck. Particularly knuckle pain!!

Looks like it would handle that beautifully.

last question: How much travel range does a typical collet have, is it 3-4 mm so in other words if my stock was typically 11mm, would there be a collet that does from circa 9-13mm or similar? Or are the ranges tighter ie 1-2mm?

Also any comments about the threaded design versus the morse taper design?

Many thanks

 

[CHJ]

Rob, Standard collets are designed for 1mm size variation of grip or similar imperial and have six leaves.

I.E. a 12mm will close down to 11mm.

For your square stock you will need to accommodate your square blanks across the diagonal and how true they will run will depend on if one corner slips into a gap between leaves.

How accurate is your 11mm stock dimension?

 

[Random Orbital Bob]

Ah....got you.....of course...they're expecting dowel stock aren't they (or in fact metal rod originally).

My 11mm stock is rough as old boots...the reject fingerboards are bandsawn on some kind of animal given the teeth marks. I then saw them into square pegs. They're only 11mm because that's the typical thickness of the fingerboards. I generally mount them into either a Jacobs chuck morse taper'd into the headstock or if I can be bothered a spare chuck with pin jaws. Both have their problems: The Jacobs chuck has the perennial risk of wobbling loose and the pin jaws are of course in a monster chuck that my knuckles are too close to for my taste........hence the interest in the collet chucks.
It's becoming clear to me they're expecting tightly controlled dimensions going in and as I now realise, round stock too.

 

[J-G]

This is all new to me because I'm guessing this design of chuck originates in milling metal?

Correct - I made my own collet chuck to screw directly on the nose of my Myford Super 7 - using standard ER32 collets and a the standard closing nut (it has an eccentric locator which I didn't bother to try to replicate!)

So picking up from the context, can you correct my assumptions please:

Does the little chuck hold a range of collets which are removable and allow the gripping of varying diameters of stock (all thin presumably)?
The chuck is threaded onto a drawbar which in turn has a 2MT taper which seats in the lathe?
Following the Axy one from Robbo's link, their version is directly threaded and therefore just screws onto the spindle nose?

Correct assumption - how the chuck actually connects to the lathe is a bit immaterial - ie. MT2 or direct thread

My interest is in turning typically 11mm square stock of ebony for various components but usually for apple stems. It's 11mm because it's harvested from reject guitar fingerboards into sticks which are a pain to turn in a normal sized chuck. Particularly knuckle pain!!

For that you would use a 16mm collet - the across corners would be 15.556mm and I would 'rub' the 4 corners off on my linisher so that it would go into the 15mm collet - better than squeezing the collet down half its travel. You only need to take off 0.3mm

Looks like it would handle that beautifully.

It certainly would.

last question: How much travel range does a typical collet have, is it 3-4 mm so in other words if my stock was typically 11mm, would there be a collet that does from circa 9-13mm or similar? Or are the ranges tighter ie 1-2mm?

The travel on most collets is 1mm - ie. a 20mm collet will still grip a 19mm dia bar but there are 2 'intermediate' sizes available 3½ and 2½, the 4mm and 3½mm still have 1mm travel but below that it's ½mm. I have a full set of 21 and use them on my milling machine and lathes. Most have 8 segments so can grip square material on the 'face' of each segment though smaller ones have only 6 so there is sometimes a compromise with two corners in the gaps - it's of little import though. You might actually squeeze the 11mm sq stock into a 15mm collet by aligning the corners with the gaps between the segments.

Also any comments about the threaded design versus the morse taper design?

Many thanks

For a lathe, I have a preference for the nose thread type - MT is good but putting side stress on it, a draw-bar would be de rigueur - My milling machine has to be MT - it doesn't have a nose thread!

 

[Random Orbital Bob]

Interesting....thanks for that. Having never milled metal before, this is opening a whole new perspective on engineering tolerances.

Combined with Chas, I now understand. Thanks Chaps.

 

[J-G]

Ah....got you.....of course...they're expecting dowel stock aren't they (or in fact metal rod originally).

My 11mm stock is rough as old boots...the reject fingerboards are bandsawn on some kind of animal given the teeth marks. I then saw them into square pegs. They're only 11mm because that's the typical thickness of the fingerboards. I generally mount them into either a Jacobs chuck morse taper'd into the headstock or if I can be bothered a spare chuck with pin jaws. Both have their problems: The Jacobs chuck has the perennial risk of wobbling loose and the pin jaws are of course in a monster chuck that my knuckles are too close to for my taste........hence the interest in the collet chucks.
It's becoming clear to me they're expecting tightly controlled dimensions going in and as I now realise, round stock too.

Two cross post whilst I was typing my epistle

Close tolerance not at all necessary.

I often use 'square' ie. rough sawn and questionable - stock and there is seldom an issue. 'Twisted' stock can be a problem and tail-stock support in the initial stages can be beneficial.

Once you have the square stock mounted you can very easily turn 10mm of the outlying end to round, remove the piece, change the collet and mount gripping on the freshly turned - now round - section - it takes all of 20 seconds

 

[woodpig]

Just to clarify one point Bob. I have seen the directly threaded chucks but they all came with a set of collets which I already have. Buying a MT2 chuck was a much cheaper option for me. I can also use this chuck in the tailstock of both my MW and WT lathes if the need ever arises.

 

[Random Orbital Bob]

Ah....got you.....of course...they're expecting dowel stock aren't they (or in fact metal rod originally).

My 11mm stock is rough as old boots...the reject fingerboards are bandsawn on some kind of animal given the teeth marks. I then saw them into square pegs. They're only 11mm because that's the typical thickness of the fingerboards. I generally mount them into either a Jacobs chuck morse taper'd into the headstock or if I can be bothered a spare chuck with pin jaws. Both have their problems: The Jacobs chuck has the perennial risk of wobbling loose and the pin jaws are of course in a monster chuck that my knuckles are too close to for my taste........hence the interest in the collet chucks.
It's becoming clear to me they're expecting tightly controlled dimensions going in and as I now realise, round stock too.

Two cross post whilst I was typing my epistle

Close tolerance not at all necessary.

I often use 'square' ie. rough sawn and questionable - stock and there is seldom an issue. 'Twisted' stock can be a problem and tail-stock support in the initial stages can be beneficial.

Once you have the square stock mounted you can very easily turn 10mm of the outlying end to round, remove the piece, change the collet and mount gripping on the freshly turned - now round - section - it takes all of 20 seconds

OK thanks for clarifying. That makes perfect sense and I appreciate the correction because I had pretty much gone away with the idea that if your stock wasn't more or less cylindrical then it could end up being mounted so skewwhiff that you might waste half it's diameter getting it true. By your description I'm guessing that swapping the collets is a very simple operation? Does one simply undo the outer gnurled chuck until the collet is sufficiently loose to pop out or is there a grub screw or other holding method?

 

[Random Orbital Bob]

Just to clarify one point Bob. I have seen the directly threaded chucks but they all came with a set of collets which I already have. Buying a MT2 chuck was a much cheaper option for me. I can also use this chuck in the tailstock of both my MW and WT lathes if the need ever arises.

Yes I appreciate that too....I know from previous posts that your engineering skills with metal are very advanced so I had guessed you might have some appropriate existing tools. Understandable choice for you. It's just the Wood lathe for me so I'd need everything and for that reason the Axy setup with it's bundled supply of collets has a certain amount of appeal. I don't think a choice between morse taper and threaded is a biggy for me based on explanations given in this thread. I must say I am tempted to get one though after this exchange. They are clearly a simple and efficient way to secure little jobs without a whacking great lump of metal spinning perilously close to your left hand. I also rather like the idea that your stock could be a longer rod with the majority "inside" the headstock hidden from view (my headstock is hollow). You turn your apple stem and part...then just loosen the collet and feed enough more to do the next one....very nice when you're doing batches for a bowl of fruit.

 

[TFrench]

By your description I'm guessing that swapping the collets is a very simple operation? Does one simply undo the outer gnurled chuck until the collet is sufficiently loose to pop out or is there a grub screw or other holding method?

Thats about it - the big knurled nut comes right off to allow the insert to come out. I fitted one to my morticer to make it reasier to swap bits.

 

[J-G]

By your description I'm guessing that swapping the collets is a very simple operation? Does one simply undo the outer gnurled chuck until the collet is sufficiently loose to pop out or is there a grub screw or other holding method?

Thats about it - the big knurled nut comes right off to allow the insert to come out. I fitted one to my morticer to make it reasier to swap bits.

That is not quite correct - with ER Collets - The collet needs to be inserted into the 'Nut' first and that assembly is then screwed onto the chuck body. In my ER32 set up the nut isn't knurled, it has 6 detents for tightening/loosening with a 'C' spanner as shown in the image posted by Woodpig. Some smaller sizes (ER11, 16, 20) have hexagon nuts which are tightened with a normal spanner.

Essentially the nut needs to be removed fully - rather than just 'loosened' and the collet swopped.

You may be wondering why '32' when the largest collet is 20mm. The 32 refers to the datum diameter of the collet (in mm) this is where engineering tolerances are key. This 32mm datum is the diameter at a very specific point on the taper.

If you want to see the technical details use this URL http://www.arceurotrade.co.uk/Catalogue ... ER-Collets - Incidentally you may find that spare collets are cheaper from ArcEuro as well.

 

[Random Orbital Bob]

Marvellous...thanks again for all the specifics.