Quorn Castings

[BazParticipant @baz89810]

John Haine, can the Worden or Acute sharpen the side flutes on milling cutters?

[Howard LewisParticipant @howardlewis46836]

Worden sharpening flutes of milling cutters?

I have a Worden, and have not tried it, but don't see why not once a suitable fixture has been made up.

Probably not a simple and straightforward device, but likely to be possible.

Howard

[John HaineParticipant @johnhaine32865]

Posted by Baz on 11/02/2019 14:06:00:

John Haine, can the Worden or Acute sharpen the side flutes on milling cutters?

They could with an appropriate fixture. But the Quorn can't either, very easily, because it is very hard to get a smooth spiralling movement where the work head mandrel turns smoothly and the tooth is held firmly against the tooth rest. I've tried it with mine and never succeeded.

I have seen a Quorn at an exhibition with a chromed mandrel and other modifications to allow this; and a series of US articles about making an air bearing spindle which isn't very easy either. But apart from the very end of the cutter the side flutes don't generally get much wear at least in our usage, it's the end teeth that get worn.

[Brian OldfordParticipant @brianoldford70365]

Isn't tackling a Quorn almost a rite of passage?

[Neil WyattModerator @neilwyatt]

Posted by Brian Oldford on 11/02/2019 19:30:06:

Isn't tackling a Quorn almost a rite of passage?

Acquiring a set of castings is

Neil

[John PParticipant @johnp77052]

Posted by Derek hall 1 11/02/2019 13:01:12

 

 

I did my apprenticeship in 1974 to 1978 and in the stores in the

first year they had some ME magazines, and in one or two issues

was the description of the Quorn…one day I thought, I want to

make one of them! 45 years later I got the castings!..

 

 

I hope that you stick with it.The Quorn is an enjoyable thing to

build and when it is done you will have a very useful piece of workshop

equipment.

 

I built mine 30+ years ago and have added to it over time.

The Quorn in it's basic form is unable to sharpen milling cutters
along the flutes with any great success along with many other
hobby type cutter grinders that use the same type of setup.

The problems are all the same the friction of the workhead and also
the guide rest in the flute of the cutter.
Even when attempting to do this there is a size limitation that
makes this impossible to do even if you were to have an air bearing
work holder.
In the first 20 years i had the Quorn i don't suppose that i tried to
sharpen along the flutes more than a dozen cutters, most of them
were not much better than before i started.

In the time since then i made this cnc grinder which uses the Quorn
head, up to now i have sharpened hundreds of cutters along the flutes
from 2,5 mm dia to 20 mm dia all of the cutters that i use, they
all come out as sharp as new cutters and in some cases sharper than
new cutters from some suppliers.
The resolution of the machine is 1/20 th of a degree and as such the
clearance angles can be set with this sort of accuracy.

John

[EmgeeParticipant @emgee]

John

Nice looking Quorn and a very well planned nest of swing out drawers, is that your design ?

When grinding along the flutes of milling cutters I thought the cutter should be ground on the periphery of the wheel but above centre to provide back clearance, how do you grind flute back clearance ?

Emgee

[John PParticipant @johnp77052]

Posted by Emgeere”> 12/02/2019 10:04:39

John

 

Nice looking Quorn and a very well planned nest of swing out

drawers, is that your design ?

 

When grinding along the flutes of milling

cutters I thought the cutter should be ground

on the periphery of the wheel but above centre to

provide back clearance, how do you grind flute back clearance ?

 

Emgee

 

Just a matter of space saving ,some angle iron supports hold

the wooden trays on a single strut.

 

The photo shows in the foreground a post that is secured to the

table, this is a zero reference to the workhead axis,using a

dti the tip of the cutter is set to a zero position using

this reference.

Looking at the photo rotating the cutter anti-clockwise

increases the angle from zero to the desired amount .The

grinding wheel is at a shallow angle relative the the work

axis ,as can be seen by the black line around the edge the

point of contact is small as it should be.

 

Early on when i first made and used this machine this is

how i would set up,now i use the same basic method but grind

first the secondary clearance. The Quorn book seems to show

the primary clearance as 6 deg ,in a Dormer handbook this is

shown as " Clearance on body teeth , this varies progressively

across the range from 10 deg on smaller diameter tools to 5 deg

on the largest diameter . Secondary clearance ,this is 15

deg across the range".

 

Setting 15 deg on the machine ,20 motor steps = 1 deg ,rotating

the work shaft 300 motor steps sets the 15 deg.

When the cutter is ground, the secondary clearance can be

measured on the machine as in the photo diagram ,since from

this the true angle is known it is a simple matter to rotate

the cutter to set the primary clearance angle.

Page 94 of the Quorn book makes reference to grinding

on the periphery of the wheel.

 

John

 

[HughEParticipant @hughe]

Hi Guys,

I resurrected this old thread on the 11th hopefully to get some answers to a couple of questions. So far no answers only responses regarding pro and cons of the Quorn. Some interesting can anybody out there answer my questions?

Hugh

[derek hall 1Participant @derekhall1]

Hugh,

I asked a guy (a well respected model engineer and I cannot recall his name) who was demonstrating the Quorn at this years Midlands Model Engineering exhibition, that I cannot seem to find anyone in the UK that supplies Quorn castings.

He responded that Ivan Law's son was involved now in the supply of Quorn castings and that I should contact him. Unfortunately I do not have his address or email. I am assuming this person is the same that is helping in the upcoming Model Engineering exhibition at Harrogate this year….

I also asked how long did it take him to build the Quorn…..?….his reply 4 months!

If you do find a UK supplier of Quorn castings then please let us know…

Best regards

Derek

[Neil WyattModerator @neilwyatt]

The situation regarding supply of Quorn castings is somewhat complex. Ivan and Mike have made efforts to get the castings available again and any delays are not due to their tardiness.

My hope is that something will be sorted in the future.

Neil

[steamdaveParticipant @steamdave]

If you are desperate to get a set of Quorn castings, you could always import some from the USA.

http://www.martinmodel.com/MMPtools-subfiles/Quorn/tools-quorn.html

Sorry, Can't help with a UK supplier.

Dave
The Emerald Isle

[Mike CrossfieldParticipant @mikecrossfield92481]

I have an MES Quorn kit, castings etc, which I bought 10+ years ago from someone who had made a start, but then put the project aside. Not much work done. Shortly after I bought it I picked up an Alexander 2CG in an auction, so it’s been in a box under the bench ever since. If anyone is interested send me a PM.

Mike

[HughEParticipant @hughe]

Thanks for your replies Dave and Neil,

I have a nearly complete Quorn Mk I that I picked up at a car boot sale for next to nothing. I am missing a few workhead casting which would help me to complete it. After all its a right of passage.

Hugh

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