Thread: Fitting collet chuck to lathe for Dummies

Hi Grahame
You usually just machine up a washer with a step in it to fit the end of the spindle and use some thread rod, but nothing stopping you making a custom draw bar to suit which would be better I think. You can also just use a washer, but a stepped one will keep in centered better.

H&F have the MT3 to ER32 and so does CTC. H&F charge around $150 where CTC is around $60-70 posted.

If you want something to have a bar going through, you can buy a ER collet chuck that is back plate mounted, these can be bought from a few places around the world like CDCO. You will then need to buy a back plate to mount it onto that suits your lathe.

Dave

G'Day,
Photo of backplate mount ER 32 collet chuck attached,
Regards,
Martin

Originally Posted by Grahame Collins

I seem to remember being told that ER 32 is the size to go for.

Yes, if 20mm is big enough. ER40 will get you 25mm capacity but you will spend more on collets.

Please correct me if I am wrong but I take it that a morse taper fits in the middle of chuck mount (D1.4 - 3 pins ) and is seated by a draw bar.

Yes, but do check the spec on your spindle taper. Some are oddballs.

There are 3 mounting options: 1) Camlock mount, 2) taper mount with drawbar, 3) taper mount with draw tube.

1 has the advantage of a through bore but is harder to make. Commercial camlock collet chucks exist but reports suggest accuracy is patchy.
2 is simplest - just buy a chuck on a MT arbour and make up a drawbar.
3 has through access but requires you to turn up a taper to suit your spindle and the taper for the collets and thread for the nut.

I have tried option 2 and it's ok, but not rigid enough because it's only a MT2. If going this way use the biggest taper possible. I will try and get some pics later. Option 3 is on my project list. This and a home-made camlock both have the considerable advantage of having the critical bits machined in situ, so concentricity is guaranteed. Also you are making the chuck so you just have to buy collets, a nut and a spanner.

Big Shed shows how he did his one here.

I made one for my my lathe with a drawbar . The lathe came with MT 5 to MT 3 adaptor and I machined up an extra MT 5 to NT 30 adaptor. That way I can use my milling stuff in my lathe spindle also.
The trick is when you make a stepped collar to put in the geared end of the spindle , cut a sideways slot in it so it can be dropped in from the side after the drawbar is started in the chuck taper threads. This way it is far easier and quicker to line it up from feel and start the thread first . Also you can fit the drawbar and headstock adaptor onto the chuck first then insert it through the headstock first then just drop the stepped insert on at the back and tighten up. Just something I discovered after having trouble with my first effort. It does not have the chucking and unchucking speed or through hole capabilities of a commercial 5C collet chuck but for hobby work it is useful. If anyone wants some photos let me know .
Just as a side note if you use a MT type chuck don't over tighten the draw bar as Morse Tapers are very shallow tapers and have quite powerful wedging capabilities and you could bulge a thin spindle with excessive force on the drawbar.

Originally Posted by Acco

Big Shed shows how he did his one here.

That is a nice job by Bigshed , I might have a go at something like that as it does give you through hole access when I work up the courage to attack a cam lock plate .

This is what I use on the AL960B. It's a stock Vertex item. I went for ER40 for the extra capacity, the taper is the 5MT that fits the spindle taper with no adapter needed. The draw-bar is a piece of M16 all-thread with a plastic sleeve to protect the spindle. The bush sits in the outer end of the spindle bore to centralise the draw-bar and the hand-wheel is used to tighten it up. I originally used a M16 nut but ended up making the hand-wheel so I didn't tighten things up too much. As others have said, you don't need to tighten the MT up much at all.

The only downside of this set up is that you are limited to the length of stock you can chuck up, I drilled and bored though the back of the ER40 adapter into the draw-bar threaded section and bored out the inner end of the internal threaded section that takes the draw-bar leaving a couple of inches for the draw-bar to thread into, that gives me another 3 or 4 inches of depth.

If that ends up being too short then I can always drill and bore the end of the draw bar or convert it to a draw tube.

I have 3 dummy D1-4 pins I put in the chuck receiver holes in the spindle when I'm using this to keep stray swarf out - not really essential but it saves cleaning them out each time.

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Originally Posted by Gavin Newman

This is what I use on the AL960B. It's a stock Vertex item. I went for ER40 for the extra capacity, the taper is the 5MT that fits the spindle taper with no adapter needed. The draw-bar is a piece of M16 all-thread with a plastic sleeve to protect the spindle. The bush sits in the outer end of the spindle bore to centralise the draw-bar and the hand-wheel is used to tighten it up. I originally used a M16 nut but ended up making the hand-wheel so I didn't tighten things up too much. As others have said, you don't need to tighten the MT up much at all.

The only downside of this set up is that you are limited to the length of stock you can chuck up, I drilled and bored though the back of the ER40 adapter into the draw-bar threaded section and bored out the inner end of the internal threaded section that takes the draw-bar leaving a couple of inches for the draw-bar to thread into, that gives me another 3 or 4 inches of depth.

If that ends up being too short then I can always drill and bore the end of the draw bar or convert it to a draw tube.

I have 3 dummy D1-4 pins I put in the chuck receiver holes in the spindle when I'm using this to keep stray swarf out - not really essential but it saves cleaning them out each time.

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That is a nice adaption Gavin , Having the hand wheel rather than a long drawbar bolt makes it easy to fit up and less chance of overtightening . The dummy pins in the cam lock stud holes is a good idea I will pinch that one if you don't mind.

You can also get ER chucks with plain straight adaptors that you mount in a chuck. Once you have it mounted you have the repeatability of the ER chuck but you can dial in or out any offset you want. Granted most people wouldn't use it often but its an option depending on the work you do.

Stuart

P.s. It just occurred to me that you could turn up an MT3 to straight shaft adaptor to achieve the same result yet still have fast mounting when you wanted to be on center.

My hot tip is a washer to align the thread. It's retained by split pins.

Here's a 5MT ER32 collet chuck with a hollow drawbar which allows long work to pass through the spindle. The cap with split pin at the LH end is normally left in place in the end of the drawbar to protect it when giving it a tap with a hammer to release the taper. It is removed when long work needs to pass beyond the full length of the headstock spindle

Frank.

Frank did you make that or buy it?

PS: Martin, ditto.

Thank you all very much.
Y
our invaluable information has filled in many gaps for me and brought me up to date. I am leaning towards a E 32 chuck attached to a back plate as I saw one at Tools4cheap last night for US$52. The back is something Id have to get else where . Same $ again as postage ,I suppose

Chucks/face plates are the 3 pin camlock sortt which makes it a D1.4 ( I think)
I shall look for a back plate and of course set of collets.

Thanks again

Grahame

You will find both the collet chuck and the back plate will fit in a flat rate box for the same postage price, I think you could get a set of collets in there as well if he has them.

Dave