Collet Chuck or not ?

[HopperParticipant @hopper]

Dunno what all the fuss is about. 1" steel plate. 22mm cutter, cutting on both side and end of cutter. 3 jaw chuck.

End result:

 

Sorry about the sideways pics. I'm better at using 1930s technology than 21st C stuff! Maybe mods can fix?

Edited By Hopper on 26/03/2019 11:51:58

Edited By Hopper on 26/03/2019 12:13:41

Edited By Neil Wyatt on 26/03/2019 15:47:03

[JasonBModerator @jasonb]

So if you don't have a 4-jaw at the moment it is probably fair to assume that you also don't have a vertical slide in which case you will want a cutter that can sweep the 20mm thickness in one pass so the work is not disturbed.

I would also go with a flycutter as was mentioned above, cheaper than a 4 flute end mill over 20mm diameter and easily sharpened. One with a straight shank will do fine and it won't be bothered if held in a 3-jaw.

Just clamp the work to teh cross slide on some packing to get it roughly on ctr height and skim one side. Rotate work 90degrees and clock in the face you have just machined so it is true then machine the second side, repeat until all 4 are done.

[HopperParticipant @hopper]

Yes, flycutter can do just about anything as far as facing work goes. (And boring at a pinch . That poor little lathe had no idea what it was in for when it left the factory in 1937. )

.

Edited By Hopper on 26/03/2019 12:15:16

[mechman48Participant @mechman48]

FWIW… I have ER25 collet set & holder for my mill I have also a MT4 collet holder to fit into my lathe headstock which works fine with minimum runout… .01mm / .0005". What I have found that make small jobs easier is I use my Stephenson Hex / block collet holder in the 3 jaw chuck, set to the best jaw runout position & marked for consistency. Saves me removing / changing chucks, surprisingly accurate for my small needs. I also have a Stephenson square block / holder if I need to make 2-4 flats using my mill. That could be the most economical way for you to set up, with a ER32 collet size which will let you use up to 20mm cutter.

George.

[BazyleParticipant @bazyle]

Posted by Dave Springate on 26/03/2019 10:22:51:

Also would a two or 4 flute cutter be used for this operation.

A two flute cutter is also called a slot drill in the UK. This is because it is better for cutting slots than a 4 flute. If you think of a 4 flute in a slot there is always one flute flat on to the direction of travel which puts a strain on things when you do move. Look at a 2 flute and every half turn it is easy to move along. When cutting only on the side then a 4 flute is fine and gives more cutting edges. (3 flutes are a compromise that cost more).

For holding cutters not long stock consider a 2MT collet. Very cheap, holds the cutter close to the chuck for more rigidity, dead true to spindle. You can make a drawbar from 'allthread'.

In 3 jaw if not using brass as mentioned previously use a bit of paper that also just gives that extra bit of grip and an extra sheet can compensate for runout.

[Dave SpringateParticipant @davespringate]

Thank you all very much for all your input, loads of information for me to take in. This really is a great forum !

[HopperParticipant @hopper]

You're welcome. Plenty to think about there!

One question for the collet users (You guys have got me thinking about them now, dammit!):

What is the preferred type of collet chuck for a Myford type threaded spindle? One that fits in the internal taper with drawbar? A "nose" that screws on the end of the spindle? Or the type that bolts on to a small faceplate and can be adjusted to get the collet holder running dead true?

[not done it yetParticipant @notdoneityet]

First thing to consider is that any draw bar or morse taper limits the length of material in the holder….

[Michael GilliganParticipant @michaelgilligan61133]

Posted by Hopper on 26/03/2019 22:36:00:

What is the preferred type of collet chuck for a Myford type threaded spindle? One that fits in the internal taper with drawbar?

.

I'm sure that Myford [as was] would, with good reason, recommend its patent system.

MichaelG.

.

https://www.haythornthwaite.com/128%20Myford%20Collets.pdf

https://www.model-engineer.co.uk/forums/postings.asp?th=129870

Edited By Michael Gilligan on 26/03/2019 23:26:19

[AdrianRParticipant @adrianr18614]

Dave,

You could face your block by using a faceplate, if you have one.

Harrold Hall's page

[IanTParticipant @iant]

Hopper,

Both mine are the ER32 backplate type.

Several reasons really. At the time they were quite a bit cheaper than the 'screwed nose' type (which wasn't available for the EW anyway), I already had 'spare' backplates and finally I thought it might be useful to be able to adjust for any potential small runout (having heard various tales of problems in that area). So they were fitted with slightly 'loose' registers and clocked true. I used to check them from time to time but they don't seem to have moved, so don't tend to these days.

I probably use the EW ER chuck more often, as it's very useful for small boiler fittings (I have a range of tapped/threaded fittings – master/slave style). Also when tapping, it holds work far better than my 3-jaw scroll chuck. In the S7 I do use the ER to hold milling cutters but again it is very handy for work holding – I'm just making a small mandrel (to hold some cylinders I'm machining for a friend) and it will have replaceable 'slides' to grip different size cylinders – as I have others to do eventually. So a bit like on the EW – I can make an accessory and then re-use it and still have it run pretty true. And of course – all these bits can be moved to my other ER stuff if required.

OK sorry – I'm rambling (again). Hopper – the backplate type works for me.

Regards,

IanT

P.S.  I also have a MT2 ER32 chuck for use on my mills but don't use it on the lathes – harder to remove and no through headstock work possible.

Edited By IanT on 27/03/2019 09:50:27

Edited By IanT on 27/03/2019 09:54:41

[Andrew TinsleyParticipant @andrewtinsley63637]

My Myford 2MT collets and also my Arrand, screw on nose, ER25 collet set give very little run out at all. I choose the appropriate style of collet for the job in hand. As usual horses for courses.

Andrew.

[VicParticipant @vic]

I’m not sure of the situation at present but when I bought my first collet chuck the ER32 was the most popular and there certainly seemed to be more fixtures and fittings that took this collet size. I have ER32 collet chucks for my mill and both lathes. The maximum bore of my lathe is 20mm so there was no point in going any larger. As well as chucks I have several collet blocks and a spin indexer that take ER32 collets. I also bought ball bearing nuts for my chucks and a small number of imperial collets for convenience.

[JasonBModerator @jasonb]

If you do go down the ER route then don't forget you can buy "oversize" ones typical ER32 collets can be had upto 25mm or 1" for the imperialists.

 

Do any of the Myford owners use 5C, I find that easier to use with a standard chuck key and the smooth extended end is better for delicate work particularly if you want to get your hands near the work.

Edited By JasonB on 27/03/2019 12:01:56

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