Mk 3 Quorn!

[Jo]

Cutter grinders look to be very expensive that side of the pond 

Jo

[steamer]

Cutter grinders look to be very expensive that side of the pond 

Jo

That reference was a CHEAP one......$2k TO $4k is more "normal"...
And unfortunately for me....that cheap one is 3000 miles away and is local pick up only.....

A cuttermaster, perhaps missing the air spindle would be a good fit...and be near $1K....  I have a Weldon air spindle tucked away....That could bolt on ...

Dave

[ChuckKey]

Up until yesterday, My money would be on,......as far as home shop cutter grinders designs is concerned....The Glen Wilson design...it's specifically for lathe tools and end mills...both tips and flutes, and has an air bearing....though I think he had a large quantity of bits of Coldrolled steel....because everything was made up of many bits.   I'd probably combine some parts and reduce parts count.
An ER20 collet in the air spindle would be the way to go for me I think.  The design tilts the work head such that the front face of the spindle centerline is the origin of rotation...which makes set up pretty easy.

From the pictures, that design seems to completely ignore the desirability of keeping grinding grit out of the works.

[steamer]

Up until yesterday, My money would be on,......as far as home shop cutter grinders designs is concerned....The Glen Wilson design...it's specifically for lathe tools and end mills...both tips and flutes, and has an air bearing....though I think he had a large quantity of bits of Coldrolled steel....because everything was made up of many bits.   I'd probably combine some parts and reduce parts count.
An ER20 collet in the air spindle would be the way to go for me I think.  The design tilts the work head such that the front face of the spindle centerline is the origin of rotation...which makes set up pretty easy.

From the pictures, that design seems to completely ignore the desirability of keeping grinding grit out of the works.

Only the top slide bearings....the bottom slides are covered....the quorn is far worse...

[steamer]

Up until yesterday, My money would be on,......as far as home shop cutter grinders designs is concerned....The Glen Wilson design...it's specifically for lathe tools and end mills...both tips and flutes, and has an air bearing....though I think he had a large quantity of bits of Coldrolled steel....because everything was made up of many bits.   I'd probably combine some parts and reduce parts count.
An ER20 collet in the air spindle would be the way to go for me I think.  The design tilts the work head such that the front face of the spindle centerline is the origin of rotation...which makes set up pretty easy.

From the pictures, that design seems to completely ignore the desirability of keeping grinding grit out of the works.

Only the top slide bearings....the bottom slides are covered....the quorn is far worse...

And Frankly....with a little "tin knocking", a nice little cover could be made for the top slide without too much trouble.  the micrometer screw could also be replaced with a Micrometer thimble....which is pretty sealed up

Dave

[Neil-Lickfold]

The mk3 really does look to be quite impressive. I use a Deckel SO cutter grinder quite often. Mainly D bits or special shaped single edge tools.
It is all exposed slides etc. We just brush it down before moving anything and keep it clean. I think the real secret is to keep it clean and dry. Any oil anywhere just becomes a lapping pastes and they wear out real quick. Keeping all the edges next to the shafts etc very sharp and not de burred , also help to keep the junk out too.
A second hand Deckel grinder goes for over 3k, while a new Asian one is like near 2k but not as good as a near worn out Deckel.
I would be keen to hear from anyone who has made the kit, or from plans, what they think of the finished machine.
Neil

[Chipswitheverything]

Just taken another look at the information that Hemingway have published about their Mark 3 improvement on the time honoured design of the Quorn.
 
 Will be interested, when Dave has received his drawing package and had a chance to look through it, as to whether the components really are easier to machine: such as I can gather an impression of, including the well drawn "sample drawings" page of the wheelhead castings, look very much like the bits that I have tangled with in recent months.
 
 Obviously I did use a mill where helpful, and the Professor's 1970's machining notes do concentrate mainly on lathe set ups rather than assuming the mill as well.   However, having chewed over alternative set ups, mill or lathe, I did decide to go along with some of Prof. Chaddock's lathe set ups for certain castings, as perhaps being the best approach even though the mill was there.   So I suppose that my feeling would be that even with more workshop equipment tricks up one's sleeve than just a Myford and a drill, the machining may not be simplifiable to a very great extent.  But we will see!   

  Just for fun, here are some photos grabbed while doing the tilting bracket( I modded it with a suggested alternative clamping by split bush for the Rotating base spindle )…    Dave

[steamer]

Myself as well Dave.    those set ups aren't terrible, but some of the fast thread stuff just doesn't play well with my equipment...

We'll see

Dave

[steamer]

The mk3 really does look to be quite impressive. I use a Deckel SO cutter grinder quite often. Mainly D bits or special shaped single edge tools.
It is all exposed slides etc. We just brush it down before moving anything and keep it clean. I think the real secret is to keep it clean and dry. Any oil anywhere just becomes a lapping pastes and they wear out real quick. Keeping all the edges next to the shafts etc very sharp and not de burred , also help to keep the junk out too.
A second hand Deckel grinder goes for over 3k, while a new Asian one is like near 2k but not as good as a near worn out Deckel.
I would be keen to hear from anyone who has made the kit, or from plans, what they think of the finished machine.
Neil

Neil.....quite right.   Hardened bearing surfaces run dry and kept clean is pretty much ideal for something like a cutter grinder.

Dave

[Stuart]

Dave
I have built a mk2 years ago but fitted a 300w three phase motor with a vfd , it was cheaper than the preferred face mount single phase one

I built the head with a er Collette holder with a 100mm long shaft much like the mk3 pics show

The fast thread for the rise and fall could be subtiuted the a feed screw on the load side of the column much like a cross slide but vertical

It’s only there to help with the adjustment but as drawn it by the prof. It has a vertical slot to enable quick up and down, so if you do not lock the stop coller it can drop on you , if I built one now I would use a feed screw to lift the head may be slower but it safer , you rarely have to move the head vertically any way ,then only small amounts . The rocking screws in the head take care of the very small adjustments


Stuart

[steamer]

Dave
I have built a mk2 years ago but fitted a 300w three phase motor with a vfd , it was cheaper than the preferred face mount single phase one

I built the head with a er Collette holder with a 100mm long shaft much like the mk3 pics show

The fast thread for the rise and fall could be subtiuted the a feed screw on the load side of the column much like a cross slide but vertical

It’s only there to help with the adjustment but as drawn it by the prof. It has a vertical slot to enable quick up and down, so if you do not lock the stop coller it can drop on you , if I built one now I would use a feed screw to lift the head may be slower but it safer , you rarely have to move the head vertically any way ,then only small amounts . The rocking screws in the head take care of the very small adjustments


Stuart

Hey Stuart,

What is the machined part count for the Quorn?...is it over 50?

[Stuart]

I would have get the old drawings out (BTW they are of the time when the prof. Drew they all crammed on to one sheet ) but yes there will be more than 50 bits it’s the bits you cannot see inside the adjustments ,wipers , labyrinth seals etc. It’s about a years work to build , I am glad I did , would I do it again no

It’s the maths the full kit is £620 plus del. here in the UK you can buy a SO  Far East clone for £900


Have look at Stefan gottwinters you tube for some info also robin resetty you tube for the mods he did

Let me look up the links


<a href="https://www.youtube.com/watch?v=ELTL9qTJg-o" target="_blank">http://www.youtube.com/watch?v=ELTL9qTJg-o</a>


<a href="https://www.youtube.com/watch?v=MXRMmeRd1pc" target="_blank">http://www.youtube.com/watch?v=MXRMmeRd1pc</a>

Stefan shows it here but it pops up in the rest of his video when he makes cutter for his pantograph engraver


Note I did get a lot of satisfaction in making the quorn mk2

There are some tricky machining operations

There is a build on the web about a quorn without castings that uses a belview /sp dished washer to pre load the magneto bearings for the spindle

Stuart

[steamer]

Thanks Stuart,

The WTC is 51 machined parts........so there's that

I've watched both of those vids...."it's a kit of parts" is a good description....

I've looked at the single lip grinders, and I own a Gorton 265-6....Similar to this one on ebay

https://www.ebay.com/itm/Gorton-Cutter-Grinder-No-265-6-101321-/133009744203

They won't do flutes on end mills and I tend to trash those as well as ends

It would be nice to be able to accurately grind form tools for the lathe as well...The WTC will do all of the above
I would like to sharpen gear cutters, and the fixturing for that isn't terribly complicated....so I could add that

Dave

[Stuart]

Dave

The quorn will do the end of a milling cutter ok
But on anything less than 12mm it’s a bit hit and miss on the flutes , the difficulty is there is no provision to retract the cut , you use a finger run off the end but then it’s difficult to get back to the start
Also you really need a air bearing work head to control the end mill smoothly enough


As to form tools I chicken out on those , as I only do hobby work for myself  I use gauge plate (soft tool steel) a tapered end mill and let the CNC mill do it’s thing , harden and draw it back a bit , lap the top surface and bobs your uncle a form tool , personally I think for my use it’s a better solution


Stuart

Please do not let my remarks put any one off from making one it’s one hell of a project as you need to work to a high standard else the resultant grinding will show up your errors

[steamer]

Dave

The quorn will do the end of a milling cutter ok
But on anything less than 12mm it’s a bit hit and miss on the flutes , the difficulty is there is no provision to retract the cut , you use a finger run off the end but then it’s difficult to get back to the start
Also you really need a air bearing work head to control the end mill smoothly enough


As to form tools I chicken out on those , as I only do hobby work for myself  I use gauge plate (soft tool steel) a tapered end mill and let the CNC mill do it’s thing , harden and draw it back a bit , lap the top surface and bobs your uncle a form tool , personally I think for my use it’s a better solution


Stuart

Please do not let my remarks put any one off from making one it’s one hell of a project as you need to work to a high standard else the resultant grinding will show up your errors

Thanks for the reply Stuart.    All of your comments are why I like the WTC instead of the Quorn.   It has an Air spindle workhead and clearance for the retract. 

The stuff I do needs lathe tools, endmills and Dbits and gear cutters primarily...everything else is very rare.