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Expanding my lathe's capabilities - cutters/millers etc

Opinions sought on headstock/mandrel cutting tool mounting...

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Steven Greenhough24/04/2015 20:21:38
144 forum posts
54 photos

Evening knowledgable folk.

Firstly this is going to be quite long, secondly it's hypothetical (mostly) but a few words of wisdom would be appreciated...

In a few weeks time I'm off to Harrogate and I intend to get there early on Friday in the hope of grabbing a bargain or two.

One of the 'requirements' I'm evaluating is the ability to hold various rotating cutters at the headstock/spindle end of the lathe. Things like slitting saws, fly cutters, maybe even end mills and slot drills.

Now my lathe is a CJ18. I bought it from Simon at SPG tools at last year's show. For anyone who doesn't know it's a lathe that is essentially also sold by Warco (Super Mini), Amadeal (7x14 mini lathe) and Chester (Conquest)

Again, for those who are unfamiliar, the mandrel doesn't have a nose thread, instead the spindle has an integral flange with a locator step. The flange does the job of a backplate and a chuck of the same outside diameter (mine is a 100mm version) and with a matching recess fits to the flange-plate-thingy. The flange is integral, it cannot be removed, See Pics20150421_192106.jpg:20150421_192019.jpg

The spindle bore is 20mm (ish) with MT3 taper. Which brings me back to mounting my (so far imaginary) cutters.

I know I could buy 'quite cheaply' (or potentially even make, 'quite slowly' arbours for my various requirements, from soft stub mt3 blanks (equipped with drawbar threads) BUT Alex Collin's Idris build thread has highligted an issue with lathes like mine in that there isn't much room if you seat (in his example) an MT3 arbour within the mandrel for the the workpiece (I'm thinking about making multiple parallel incisions here, along a long workpiece). What alex ended up doing was mounting his MT? arbour in his chuck, quite extended to get the room, which worked but he acknowledged himself that it wasn't exactly ideal...

What I'm actually thinking is that an ER type collet chuck would be a better proposition in that it would allow the use of standard milling tools etc in a suitable sized collet, hold small round work more concentrically than the chuck, and take straight-shafted arbours for saws, fly cutters etc. The benefit over traditional tapered arbours would be that the chuck body and collet retainer would push whatever cutter that bit further (I'm guessing around 20-30mm depending on which ER size I plump for) away from the flange. When the cutter holder itself is taken into account we could obtain some useful distance!

This leaves another quandry though: I could get an MT3 collet chuck, like I believe are sold for milling machines really (apologies to ARC for the use of your info):

**LINK**

or I could get one of the more bespoke flange mounted ones that ARC, RDG, etc. sell:

**LINK**

So, my question to anyone who's managed to read this far, what would you do?

1.) Buy/make MT3 arbours for whatever cutter I'm using, with as much length as can be found?

2.) Buy (or I suppose even make, but I think the ER system requires more that I'm yet capable of) a MT3 & drawbar style ER collet chuck (and a few collets abviously)?

3.) As above, but the spindle/flange mount version?

D.) Something different Steven, you obviously don't have a clue!?

Thanks in advance for any replies, I know that this has been a bit of an odyssey.

Steve, Manchester

JasonB24/04/2015 20:31:49
avatar
25215 forum posts
3105 photos
1 articles

I'd go flange mounted ER, preferably 32 for milling cutters and flycutter.

As for saws you can either use a straight shank arbor in the ER or use a longerMT3 "stub milling arbor" rather than a slitting saw arbor

Nick Wheeler24/04/2015 20:35:47
1227 forum posts
101 photos

Life's too short; buy the flange mounted ER32. Then you can mount milling cutters, or use it for work holding.

Mine was one of the few things I kept when I sold the mini-lathe when I upgraded to a bigger machine. Although I did need to make an adapter to use it.

Steven Greenhough24/04/2015 20:40:47
144 forum posts
54 photos
All my verbosity and you guys sort it out in a couple of lines! Cheers fellas.
Les Jones 124/04/2015 20:46:30
2292 forum posts
159 photos

Hi Steve,
I agree with Jason for a few reasons. 1 Each ER collet covers a range of 1mm (Except for the very small collets - under about 2.5mm) Morse taper collets only hold the marked size. 2 You can grip lengths of material that will fit through the headstock which saves having to cut it into short lengths with the resultant waste. If any of the collet chucks have exactly the right size spigot to fit your lathe then get that one. If not make your own adapter plate and machine the spigot to fit the chuck as the last operation to ensure it is concentric. (This is with the plate fastened to the spindle of your lathe in the way it will be used. ie NOT held in a chuck.)

Les.

Michael Cox 124/04/2015 20:57:54
555 forum posts
27 photos

I would go with a flange mounted ER32 collet chuck. Why ER32? Because it can take a 20 mm cutter/workpiece and this matches the bore of the spindle.

It is not too difficult to make the ER32 chuck ( see http://mikesworkshop.weebly.com/er32-collet-chuck.html) but I would buy the collets and the closing nut. CTC tools in Hong Kong can provide these at a good price.

Mike

Steven Greenhough24/04/2015 21:05:20
144 forum posts
54 photos
So a flange mount ER chuck would preserve the ability for work to pass through the spindle? This I did not know!
Robin Graham24/04/2015 21:38:15
1089 forum posts
345 photos

Yes, the flange mount ones do let you pass work through the spindle, at least mine does. I couldn't find one with a register to match my similarly sized lathe, but it's easy enough (even for a rank amateur like me) to make up a backplate to make it fit.

Robin.

Nick_G24/04/2015 22:21:15
avatar
1808 forum posts
744 photos

.

I have got an ER32 flange mounted chuck from ARC as per your link that I bought several months ago.

I have not as yet used it as I need to buy another backplate to fit my lathe for it. I have however checked it out for accuracy and run-out and it was totally 'spot-on'

For such an economically priced item it is well made and finished and most importantly accurate. - Recommended.! yes

Nick

Gordon W25/04/2015 09:28:36
2011 forum posts

Agree with all the above, I got a ER 32 collet chuck and collet set from ARC that bolted straight on my lathe. Have hardly used anything else since.

Hopper25/04/2015 09:55:22
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7881 forum posts
397 photos

I just grip the milling cutter, or mandrel with cutter mounted on it, in the 3 jaw chuck. Works for me.

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