Bought a Quorn, have som questions

[Thomas StauboParticipant @thomasstaubo12021]

Greetings!

I just bought a Quorn ready made, for what I think was a good price, about £200.

It looks well made, but needs painting and some finishing touches. It came with the book, but without any grinding wheels or spindles to mount them on. Otherwise looks complete to my eye. The grinding wheel spindles would be easy to make.

Here in Norway they don't come up often, so I think I was lucky

Two home made dividing heads also came with the quorn, one to mount on the rear of the myford lathe spindle. The other has a use not known to me, but is very well made and will be adapted to gear making probably.

I will add pictures within 24 hours.

The questions:

1. If I need a spiralling head, do I have to buy castings from USA or Australia? Or is it possible to still get castings from Model Engineering Services? Their website doesn't exist anymore.

2. Is 100mm grinding wheels a good size? I have a diamond grinding wheel laying unused, but can't remember what size it is.

I know of the Yahoo group, but isn't a member yet.

[Thomas StauboParticipant @thomasstaubo12021]

[EmgeeParticipant @emgee]

Hi Thomas

£200 is a very good price for you if the machine is accurately built, especially with the dividing head which can also be used on the lathe.

I look forward to seeing the pictures and can then answer more of your questions.

Emgee

[Thomas StauboParticipant @thomasstaubo12021]

Thank you! More questions likely to come when I start using it

Is the spiralling head for grinding endmill flutes and the like? I havent got the book home yet…

[Martin KyteParticipant @martinkyte99762]

Good old you.

I made mine about 20 years ago. Unless you actually want to make cutters you will not need the spiralling head but if you want to build it for the sake of completeness,personally I would fabricate it. I made one that has never been used. 100mm is a good size wheel for a quorn.

I made a stack of wheel arbors when I turned the taper in the spindle, if you do worry about matching the angles you make a load of blanks then set up the spindle as per the book (still readily available) and skim the taper and finish the blanks off with the same topslide setting. I have made additional arbors since just by angular setting without problems so take your pick. One thing I would have done differently had I realised is used split cotters (George Thomas style) instead of slitting the castings which went all ways once the stress came off them but as your is complete that is a moot point. I have an ER16 chuck with a parallel shank which is a useful fit to the tool head.

They are a little confusing to use at first with so many clamps but you will get used to it.

regards Martin

[Martin KyteParticipant @martinkyte99762]

PS endmill flutes are ground by self indexing with a finger (metal one not one of your digits).

Martin

[Thomas StauboParticipant @thomasstaubo12021]

Aha! Good advice, Martin! Probably not going to need it then.

I have the index finger.

[Thomas StauboParticipant @thomasstaubo12021]

It came with the recommended 1/6th hp motor, but I have a cute little 3-phase motor and a VFD that I concider using instead. It's very neat adjusting the speed on the fly, from 0 to 3000rpm or more

[Ian S CParticipant @iansc]

Just watch that you don't over speed the grinder wheel, they all (should) have the max RPM marked on them.

Ian S C

[Thomas StauboParticipant @thomasstaubo12021]

Good point!

[Thomas StauboParticipant @thomasstaubo12021]

Picture time!

You can see all the pictures if you follow this link: http://imgur.com/a/ZlhQN (Click on each one to enlarge.)

I tried to post a few as links her, but it didn't work.

Edited By Thomas Staubo on 26/01/2017 14:08:44

[Roderick JenkinsParticipant @roderickjenkins93242]

I seem to recall from my Quorn days that the spiralling head was designed to sharpen the flutes of throwaway cutters which were too small to use with an indexing finger. Chaddock had determined that the various sizes only used a few helix angles between them so made the spirals to suite. I never made one, with throwaway cutters the clue is in the name

Rod

Edit:  I've just had a look at your pictures.  The dividing head is the major part of the George Thomas Versatile Dividing Head   .  The staking tool looks like part of the George Thomas Universal Pillar tool

 

Edited By Roderick Jenkins on 26/01/2017 14:35:19

[Thomas StauboParticipant @thomasstaubo12021]

Posted by Roderick Jenkins on 26/01/2017 14:22:47:

Edit: I've just had a look at your pictures. The dividing head is the major part of the George Thomas Versatile Dividing Head . The staking tool looks like part of the George Thomas Universal Pillar tool

You are very observant, Roderick. Thank you!

I see that I can buy the basic kit Ref: HK 1501 for the VDH, and add my dividing head to it

[Thomas StauboParticipant @thomasstaubo12021]

Just figured out why I couldn't embed pictures.

But again, please follow this link if you want to see all of them in hi-res glory.

[Thomas StauboParticipant @thomasstaubo12021]

I tried the second dividing head on my ML7 today, and it fit right on like this:

It's not he most solid mount, as the belt cover is held on with just two bolts. But I think it will work…

If anyone has more information about this dividing head, please inform me.

[Martin KyteParticipant @martinkyte99762]

Not the most stable arrangement as you say. Could you come up with an arragement that uses the change wheel studs as anchor points perhaps.?

Martin

[Thomas StauboParticipant @thomasstaubo12021]

I will look into it

[EmgeeParticipant @emgee]

Hi Thomas

You certainly had a good buy with all those parts, one thing I notice you may have a clash of locking handles with the rotate and tilt functions.

Emgee

[Thomas StauboParticipant @thomasstaubo12021]

You may be right, Emgee. I have just played with it a little so far.

It seems to be something not quite right, when tilting the work head. But I have to disassemble a lot of things, just to put a thicker/thinner washer under one of the lower ball handles.

I do noticed that I have to exert a bit more pressure than I like, when clamping the workhead base to the front bar. I have to press on that ball handle quite hard. It may be that the bore is a bit over 1" (25.4mm)? Could it be that the bore opened up a tad, when the casting was slit?

I know that axle collars often are partially slit on the opposite side of the bore, to achieve greater clamping pressure.

Like this:

Is that a possible solution on the Quorn, or will it weaken the cast iron too much?

 

.

I'm in the process of ordering two CBN grinding wheels for use on HSS. And if I can find it, I have a dished diamond grinding wheel for carbide, whic hmay fit.

But arbors for these have to be made, until then I can only admire it and try to figure out how to set it up for grinding. I also have to make a holder for square lathe and shaper tools.

 

Edited By Thomas Staubo on 01/02/2017 13:17:47

[EmgeeParticipant @emgee]

Thomas

After tightening by hand I have a short length of 1" brass rod which I use to lock off the important axis by a light tap with the rod, you certainly don't want any movement from the set position or the job will be ruined.

Emgee

[John HaineParticipant @johnhaine32865]

Posted by Thomas Staubo on 01/02/2017 13:16:54:

I do noticed that I have to exert a bit more pressure than I like, when clamping the workhead base to the front bar. I have to press on that ball handle quite hard. It may be that the bore is a bit over 1" (25.4mm)? Could it be that the bore opened up a tad, when the casting was slit?

You're not wrong! I find that too, it can be disconcerting. Also clamping the front bar so it doesn't rotate.

There was a series of articles in Home Shop Machinist (I think) on a "Very Much Improved" Quorn that's worth reading, some good ideas for improvements. My Quorn was made by my father, and used 3C collets, as he had a set for his Southbend lathe. Most of them went with the lathe so I only have a couple, so I have made a new chunkier workhead that takes R8 collets which I use on my mill. Also a couple of other changes which make it a bit easier to use. (Not that I do use it much as I find it underpowered for forming tools and too fiddly to set up, so have made an Acute sharpener for everyday.) I'll try to post some photos.

[Thomas StauboParticipant @thomasstaubo12021]

The clamping of the front bar to the base is much tighter, and needs much less force.

By the way, I will buy a 1" straight shank ER collet chuck to use in the work head. I'm not sure if ER20 or ER25 is best.

If there was room (i doubt it), I would go with ER32, as I have a full collet set in that size.

Edited By Thomas Staubo on 01/02/2017 17:12:39

[Simon Williams 3Participant @simonwilliams3]

Hello Thomas,

There IS room for an ER32 collet holder, because I've tried it. I had to grind a shoulder on the rear of the threaded portion of the holder (behind the nut) as this diameter fouled the detent knob which projects forward of the face of the Quorn toolholder.

This is the knob of the spring loaded peg, which acts as the detent for a dividing wheel located on the rear of the toolholder. It's located in the toolholder casting just below the one inch bore where the collets were designed to fit.

But it was no problem to do this, I just put a handle on the back of the ER 32 holder – on the one inch portion sticking out of the toolholder and held it up to the grinding wheel until I'd let out enough sparks to make the ER32 holder fit snugly against the tool holder where it belongs.

I don't know of any real advantage of the ER32 size over the smaller one, as either will take a 16 mm endmill to sharpen it. But the Quorn that I bought did not have the tool holder collets included, so I thought buying something to use the ER collets was an easy answer.

I also changed the original 0 – 360 calibrated dial for one which was calibrated 4 times +/-45 deg, as I only use it to sharpen end mill and slot drills with either 4 or 2 flutes.  I don't bother with the detent idea for this, it's quicker to index the cutter being sharpened on my 45 deg scale.  Oh, and I've abandoned the pretty but ineffective threaded collet thing that clamps onto the outside of the one inch tool holder, in favour of a simple split clamp with a tangential cap screw.

HTH, if you would like to see pictures I can do that but it's cold and dark out there just now!

Best rgds Simon

Edited By Simon Williams 3 on 01/02/2017 22:41:51

Edited By Simon Williams 3 on 01/02/2017 22:48:42

[Martin KyteParticipant @martinkyte99762]

I use an ER16 on mine which has the advantage of not projecting so far forwards. Someone has already commented that the Quorn is not good at mass metal removal (well it is a cutter grinder after all) it's proper function is restoring sharp edges not really rough shaping lathe tools. It is more convenient to have the edge of the tool somewhere near the centre of the rotating base as you find you need to make less adjustments when setting your angles. One thing I did do is fit a small perspex block angled like a prism that fits into the lug on the tilting brcket flush with the scale on the rotating base. It carries the fiducial line on the inside which enables accurate setting of the rotating base when looking from the side. When you wish to change the angle with a half ground tool already in the work head you don't want to remove the work head to see the scale setting and it's difficult to see under everything.

Sorry for the muddled explanation it would be better if the machine was in front of me but I'm working from memory.

regards Martin

[Thomas StauboParticipant @thomasstaubo12021]

Posted by Martin Kyte on 02/02/2017 09:09:09:

One thing I did do is fit a small perspex block angled like a prism that fits into the lug on the tilting brcket flush with the scale on the rotating base. It carries the fiducial line on the inside which enables accurate setting of the rotating base when looking from the side. When you wish to change the angle with a half ground tool already in the work head you don't want to remove the work head to see the scale setting and it's difficult to see under everything.

Sorry for the muddled explanation it would be better if the machine was in front of me but I'm working from memory.

regards Martin

I would be great to see a photo of this, if it's possible.

I see that's it's near impossible to see the scale setting, when the work head is mounted.

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