Mk 3 Quorn!

[steamer]

Looks and sounds sexy to me.    Looks like it uses the original castings, but have redesigned a lot of the complications out.....

http://www.hemingwaykits.com/acatalog/Quorn__Mk3__T_C__Grinder.html

Anybody have an inside line on this one?

Dave

[steamer]

I just bought the drawing package....I'll let you know....

Looks good!.....and same size as the 265-6 spot on the bench......

Dave

[Jo]

The main problem with the Quorn is the time it takes to set it up to grind the tools (and it is limited to the type of tools it will regrind but  horizontal milling machines these days are not as common so that matters less ) .

These days few people actually regrind their milling cutters as the Chinese are supplying carbide ones so cheap that commercial cutter grinders went through a stage when they were being thrown away (I ended up with two cutter grinders so sold my Quorn bits)

The book "Building the Quorn" by Prof Chaddock is a must as it explains all the required grinding techniques for the cutters.

Jo

[PJPickard]

I'm curious about this too. I have a Quorn that is about 75% built. The ER collet sounds great and the new toolholder. I wonder if the toolholder will work with the old parts I have?

[Chipswitheverything]

This move by Hemingway should at least relieve the Quorn users ( mostly builders ) forum of requests about sourcing castings etc. now that Ivan Law and MES are of the past.   
  I am about 60% through a Mark 2 Quorn build from MES castings bought in 1983 !!,  (have done most of it during this year..) ( NB, the spindle in the photo is an EMCO 8mm spindle that I'm hoping to adapt, it has the same body size as the Quorn one ).  But a couple of years ago I spent (far too) long helpfully rebuilding a working Quorn Mark 1 from a couple of badly machined and unusable examples that a friend had acquired on Fee Pay. Having persuaded this Quorn into working condition at last, I sharpened a few hundred end mills and slot drills, and more for another friend, so it has been a useful exercise. 
  But I would agree with Jo that the Quorn is not that easy to set up, though Hemingway states that some of this has been addressed by their reconfiguration. Though not mentioned in the procedure notes for Quorn use, what I found very helpful was to have the machine on a flat baseboard ( thick MDF or such ) so that a stylus type of dial indicator on a suitable handy base could be brought into use to check height adjustments and parallelism as the setting up was being done.
 However, the making of the Quorn is an interesting exercise in machining ingenuity and a satisfying project for those who like some toolmaking along with model making.  Dave

[steamer]

Hi Jo,

Yes I'm aware of the set up short comings of the Mk 1 and Mk2...as I've made a study of all this before.   What I was interested in was the changes in the Mk 3?    It states that they've addressed most of these set up issues..and I was wondering about the details.    I can't find ANYTHING on the Mk 3 other than at Heminway.

For end mills, well.   End mills here are still pricey...and I'd like to resharpen the larger ones , especially the good quality carbide ones I have...they are pricey indeed

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.

But......there's the MK3...and I wanted to give it a fair shake, and I like looking at the various designs to gain the insight.

Hi Dave,    We have access to castings for the Mk1 and Mk2 by way of Martin Model and Pattern.   Nice castings they are!...    That would reduce the cost of shipping to the USA pretty dramatically....thou a full set of castings is about $350 here...

PJ....it seemed to be intimated that the castings haven't changed....but there were changes in detail.     That was the focus of my initial post....

Dave

[steamer]

The other annoying aspect of the design is the fast pitch thread on the column....I don't really have a provision for driving the spindle through the leadscrew like the Myford does...and the quickest pitch I can cut on my lathes is 4 threads per inch...which I suppose is fast enough.....

I have a milling head that I can put on either head and essentially thread mill the slot.....just not the pitch in the print.....

Dave

[Jo]

It does not have to have that fast pitch thread: it is only there to fast raise and lower the head. If you are happy to turn the height adjuster round the column a few more times I would go with that - over the life time of using the tool it will probably take less time than cutting the thread.

Jo

[steamer]

The Darex E90 would do the trick as well....

Dave

[PJPickard]

Steamer,

What is the Glen Wilson design?

[steamer]

Hi PJ

I looked for a half hour on google, and could not find a picture of it!....The plans were published in MetalWorking Vol 4 No 2 in 1991.     It was later republished in Projects in Metal book 2

Here's a amazon link to this book
https://www.amazon.com/Metalworking-Best-Projects-Metal-1990/dp/094165317X

It looks much like a Darex E90, but smaller and the plans include an Air bearing spindle workholder for end mill flutes and a lathe tool work head.

the design is a bit lacking in the spindle bearing department, but a Quorn spindle here would work fine, and there are plenty of plans for that floating around,

What it has going for it is it's a lot easier to build than a quorn, though you trade that for not being able to do some things like grind taps, or saw blades....it's really all about endmills and lathe tools...  that said, I think most of us really would only have interest in Endmills and lathe tools with the occasional need to sharpen a gear cutter, which is pretty easy with some simple additions to the wilson design.

The plans utilize a ton of 1/4 and 3/8 steel plate and welding....He must of had a bunch of bar stock in his inventory.   The cobbled together components could stand to be combined in many area's in the interest of reducing parts count further.     The slide system is very basic, but cleverly thought out, and quite suitable to home shop manufacture, and unlike the qourn, are protected from swarf and grit by some very clever dust shields.     I personally would use hardened thompson rod and hardened steel drill bushings , thou the plans don't call for that

The base is a weldment, though I'd probably make it out of plate and screw it together, or just hog it out of a thick piece.

Dave

[steamer]

PJ

Here's a overall pictures from the first page of the build article

If your interested in it.....I looks like Amazon is the only place I've found for the book

It appears to be out of print at Village Press

Dave

[PJPickard]

Thanks for the info, a friend has all those books. There are so many of these cutter grinders out there!

[steamer]

PJ

If you have a good supply of plate for the base.   This could be a very cheap solution...but if you're buying all the stock...it starts to get pricey.

I have some big pieces of aluminum, but I really wouldn't want to make the base from that I think..

Dave

[steamer]

OK...so if I buy the Q Mk3 whole kit.....EVERYTHING...to make the MK3....that includes motor, electrical switch components, fully machined spiral column, wheels, belts castings raw material,  plans and instructions it's about 631 "quid" + 114 quid to ship to the US. or about $913.   Martin model and pattern has a full Mk2 casting set for about $350 plus shipping here in the US, but then you have to source everything else, so I think the price will probably be a bit cheaper but not super significantly.     I'd say maybe $600 as a build budget, but with more time invested sourcing the off the shelf and materials required to finish it.

The HOPE here is that the components are now far less onerous to machine!

AS a comparison....I sourced the base materials for the Wilson T&C grinder including a Blanchard ground top plate, and CRS bar for the sides with the intent of bolting the base and that came in around $140 plus the rest of the machine...so Honestly, I'd estimate the cost at $500 for materials for the WTC.   

Again ....all this assumes you're buying the materials new on the retail market and not digging into the scrounge pile or the "lucky box"....some of us have bigger piles than others.

So the question then is begged....is it worth it to build one?   I love the idea of doing it myself...but I'm not physically able to do the hours in the shop that I once was.....this leg isn't the same as it was, which is frustrating....

I'll ponder.....I'm a stubborn ()*#(*@( !
.....then again

https://www.ebay.com/itm/Darex-E-90-Tool-Grinder/254318858495?_trkparms=aid%3D111001%26algo%3DREC.SEED%26ao%3D1%26asc%3D20160908105057%26meid%3D393851d0c9424d15ae525aa6736a0505%26pid%3D100675%26rk%3D2%26rkt%3D15%26sd%3D261402197025%26itm%3D254318858495%26pmt%3D0%26noa%3D1%26pg%3D2481888&_trksid=p2481888.c100675.m4236&_trkparms=pageci%3A7330eda2-c5cb-11e9-9112-74dbd180d83a%7Cparentrq%3Abf85ee0c16c0a9e8a241e90fffed7d13%7Ciid%3A1

Dave


Full disclosure,  the Darex can't do lathe tools.....which the other two can.....I'm not convinced that's a show stopper as I have a baldor style grinder that does lathe tools already.....