# Lo-Fi's Quorn tool and cutter grinder build (pic heavy)



## Lo-Fi (Aug 31, 2021)

I purchased a set of casting from evilbay a couple of years ago. They're for, I think, the MK1. 




Time to build it! The drawings in the book by Chaddock are AWFUL tiny things you have to squint at and worst of all in inch measeuments (sorry, but yuck). None-the-less, it's easy enough to CAD them up to a decent standard and in sane measurements. Hemingway have some modern plans available, but they're expensive and I believe still not metric. 

Start at the beginning with the base:

These need boring to close sliding fit on the bars. I've chosen siver steel because it's precision ground, more wear resistant than bright mild and not crazzy expensive.










The book goes into great detail on some completely insane "bolt it to the lathe cross slide" craziness as it was written before one could be reliably expected to have a mill of any sort in the home shop. Judos to those that built a complete steam loco on their Myford lathe, but life is WAY to short for that kind of shananigans when you own a Bridgeport. 

It's quite easy to get the fit perfect and the hole spacing accurate enough that both parts can be run up right next to each other with no binding. 3 thou clearance... Hah!

To be continued in multiple posts...


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## Lo-Fi (Aug 31, 2021)

I you're wondering about the spiral "quick start" thread, this is milled with the dividing head geared to the mill table, just like you'd produce a helical gear, except a small end mill is used vertically:






Chaddock apparently did this in the lathe with the leadscrew geared up. Noooooo thanks!

Again, this is selver steel, which milled beautifully with a 4mm carbide end mill. Sorry for the poor pics, my camera had oil on the lense.


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## Lo-Fi (Aug 31, 2021)

Something I've really come to appreciate in this build is my Wolhaupter automatic boring head. It's wonderful for spot facing large holes and surfaces:







I mde use of my right angle head to bore the through hole in one setup:





It's starting to take shape:


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## Lo-Fi (Aug 31, 2021)

By comparison, the smaller parts are fairly easy:


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## Lo-Fi (Aug 31, 2021)

And here's where I completely goosed it up, ruined the tilting bracket and had to seek advice from the forum. This thing is a B****.








After much musing, I came up with this:








It worked like an abolute charm. More on this part later....


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## JRaut (Aug 31, 2021)

Sign me up to watch!

I'm considering buying the new-and-improved one that they released recently.

(Nice Wohlhaupter)


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## Lo-Fi (Aug 31, 2021)

The next part is just as horrible for those of us without a giant lathe:





The casting is a bit all over the place:




So the only sane thing to do was make a tool steel (this is D2) shank in a single op and thread is to go into the rotating base:





The compound had been left at the 45 degree angle I set for machine the face in the gunmetal tilting bracket before, which dictated machining this part that way round.

Workholding the casting on the lathe is an nightmare. My solution was to weld a block of steel (this is a steel casting) to it for workholding:








The tool steel part fitted. Both are machined in a single op, so runout is down is really good. The spindle registers on a shoulder and short, close-fit bore. Fine pitch threads on both are machined again in the single setup, and I'm happy to say that extremely good runout and concentricity were achieved:








After much hand-wringing, I decided to cut the circular t-slot:




It's really not that big a deal. A custom round, sharp HSS tool made it quite a pleasant operation and I'm pleased with the result.


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## Lo-Fi (Aug 31, 2021)

JRaut said:


> Sign me up to watch!
> 
> I'm considering buying the new-and-improved one that they released recently.
> 
> (Nice Wohlhaupter)



Thanks!

The kit, I'd say, is great value from Hemingway and it's a super fun build. I'm really enjoing it!
Though many times I've found myself thinking that I really need a T&C grinder to grind up some tools to build it 

More to come, I'm still way behind where I'm actually with the build.


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## Lo-Fi (Aug 31, 2021)

Now for a little mod. It was found way after initial publication, that the tilting bracket had a habit of working loose. The solution is apparently to use 20 degree tapers and a split collar under the nut at the front. I was already some way down the rabit hole when I discovered this, so some reworking had to be done. Sadly I didn't take too many pics of this for some reason. I've opted to keep my tool steel rod for everything to ride on and machine a bushing to press into the  man casting. I had to make up an arbor to carry the tilting brackey to machine the tapers, bu this worked out quite well:


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## Lo-Fi (Aug 31, 2021)

I had a bash at the spiraling head next. Nothing special here:


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## Lo-Fi (Aug 31, 2021)

Now for some fun rotary table work with the tilting bracket. I wanted to finish the dial hand nicely and put a radius on it to make it look nice:







I don't think it came out badly!





I'l grab some better pics next time I'm in the shop. Next op is to machine the side of the upright, so another setup on the RT usign the blocks I used in the lathe:


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## pontiac428 (Aug 31, 2021)

Very nice!  I gave the Quorn a good hard consideration before buying my Checkel.  The quorn is the more versatile tool without doubt.  Thanks for posting!


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## Lo-Fi (Oct 10, 2021)

RIght, where did I get to?

More roating base work milling a pocket for the shaped plates that run inside the annular T slot:





And making the plates:





I didn't take many pics as it was a fussy, arduous job!

Next up, I decided I needed a break from the rotary table, so went to some of the castings for the wheelhead:


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## Lo-Fi (Oct 10, 2021)

Standard stuff here, nothing fancy. That leaves a single casting to be tackled: the workhead. The one with the dividing wheel! After far too much ummmmm and arrrr, I decided on using an ER20 straight shank collet fixture. I can, of course,still machine my own fixtures if needed, but that'll probably do for most stuff I want. I'm not sure ER series collets were even invented back when prof Chaddock was designing this thing!

Anyway, having ascertained that straight shank collet holders with a 25mm shank are readily available, I got to work:



It's a fussy little thing, this. As usual, the book assumes you only have a mini lathe and comes up with the usual bat**** crazy setups appropriate for models engineers of the era. I took the Joe Pie teachings to heart and dusted a few surfaces true on the top and bottom to give me solid registration. With this, order of ops is absolutely key! I wanted to do all the critical ops in a single setup, so setting it in the vice with the back facing up is the only way to go, allowing access to all three bores, relief, registration of for the backing plate and screws:







At this stage, it seemed prudent to machine tha backing plate itself. Holding thin plates is a pain, so I've taken to using Clickspring's "superglue arbor", except I weld the work to the arbor (awaiting welds):




The arbor allows machining of the bore, face and half the reverse face:






And on it goes:




Blue up the casting to finish the relief:





Bore the hole for the index pin:




I was having so much fun at this point that I forgot to take any photos.... They'll come later! Suffice to say, it's now assembled. I LOVE my Wohlhaupter boring head. I've made the pin out of some tool steel, which again I forgot to snap, but did for some reason take a pic of making the brass nobbly bit:


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## Lo-Fi (Oct 10, 2021)

I now needed a larger piece of plate for the indexing wheel. 10mm plate with the grinder is not my idea of fun and frankly, neither is chain drilling. I couldn't be bothered to set up the rotary table again, so chose too freehand "chain mill" the blank:




Zero stress and a decent result onto the same "hot metal glue gun" arbor:




Balanced cuts giving quite a passable finish on this gummy soft steel:






I ground up a radius tool for the cosmetic relief at the back of the wheel:





Got some half decent results with it too. A little more polishing and I'll pop it off the arbor to finish the other side. It'll be relieved as it sits against the backplate, and you can't really see from the photo that I've cut the taper already, the the remaining ops are not critical to get dead nuts on concentric or true. That's a job for anther day now, along with the split collet though


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## Weldingrod1 (Oct 10, 2021)

THAT is a safety label of awesomeness!

Sent from my SM-G892A using Tapatalk


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## Lo-Fi (Oct 13, 2021)

As promised:





The pin is silver steel machined with a step. There's a spring which bears against that and a step on the inside the housing. The end has a 10 deg taper. 

The great machine as it stands now:




The old workbench is getting messy. Must do something about that... So far I'm super pleased with how it's going.


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## Janderso (Oct 13, 2021)

Lo-Fi, you are a brave and talented soul.

Rex, have you seen this?


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## Janderso (Oct 13, 2021)

pontiac428 said:


> before buying my Checkel


I'm with you on that one.  Why do you say the Quorn is more capable?


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## Lo-Fi (Oct 13, 2021)

Janderso said:


> Lo-Fi, you are a brave and talented soul.
> 
> Rex, have you seen this?


Thanks! Either that or I'm an idiot who's binged too much all the machinist content on YouTube. The end result or lack of may tell!


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## pontiac428 (Oct 13, 2021)

Janderso said:


> I'm with you on that one.  Why do you say the Quorn is more capable?


The Quorn has more useable range in its tool swing, therefore a broader work envelope.  IMHO it's a step closer toward the Cutter Master in that regard.  The Deckel does not have much room when the workhead axis is pushed past the travel axis in the direction of feed for grinding certain angles, and the Quorn looks to have more space there.  The Cutter Master goes a full 180 degrees.


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## Lo-Fi (Oct 16, 2021)

Got a few more jobs buttoned up:






It needs engraving and the index holes drilled now, which is a job for the dividing head. Looking forward to that.

And started on my spindle:







This started as a commercial ER20 straight shank collet holder. Some grade of tool steel, but not crazy hard. I've designed for Nachi 7003 CDUP DB ground pair back to back at the business end supported by a shielded 6003 to take the pulley side load. It's basically a miniature Bridgeport spindle - I'll post the drawings later. At 17mm diameter journals it's quite a bit beefier than the somewhat skinny original design with magneto bearings and absolutely positively located by the precision nose bearing pair - no spring loading needed. External diameter will be 40mm, which is about as much as the wheelhead casting can take. It's demountable, of course. The spindle itself has come out well, so hopefully it'll be quite capable as a mini milling spindle too.


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## Lo-Fi (Nov 11, 2021)

I spun up a thread for the spindle build in its own right:









						Precision spindle build
					

As documented here, I've been building a Quorn tool and cutter grinder. This is something of an antiquated design, originating in the 70's way before the advent of affordable commercially available collets or, indeed, precision ball bearings. As such, it relies on what was available to the...




					www.hobby-machinist.com
				




It's coming along nicely:


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## rwm (Nov 12, 2021)

This is fantastic work! I don't feel like I have the patience for this. Hey what is "silver steel"?


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## Lo-Fi (Nov 12, 2021)

rwm said:


> This is fantastic work! I don't feel like I have the patience for this. Hey what is "silver steel"?


Thanks! It's kinda trying hitting tenths on a knackered Myford, but rewarding when it does go right.
You'd call it Drill Rod Stateside, I believe


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## Lo-Fi (Nov 20, 2021)

Detail in the spindle thread, but the spindle is done and came out well:




TIR is about 6 tenths (as well as I can measure) before re-machining the taper with the spindle running it it's own bearings. I'm hoping for sub-tenth runout once that's done. 

I feel like getting some mill time in, though, so might finish up the workhead castings and get the spindle and motor mounted up tomorrow.


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## Lo-Fi (Dec 4, 2021)

I made a big mess. Something satisfying about a big pile of chips.





The spindle looks great in its proper place!


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## Lo-Fi (Dec 30, 2021)

More stuff happened, like engraving the graduations and drilling the indexing holes:









The motor go mounted up:




Many split collets got made, a pulley found and modified and the guard mostly machined:




It's looking rather good if I do say so myself:





I'm waiting on some proper fasteners for much of it.

Still to do:

Micrometer mount for advancing the work into the wheel
Machine a die to punch and press the brass dust cover caps
Belt guard
Spindle pulley
Clean up to paint
Manufacture wheel mounting hardware


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