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

Lo-Fi

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H-M Supporter - Silver Member
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I purchased a set of casting from evilbay a couple of years ago. They're for, I think, the MK1.

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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.

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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...
 
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:

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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.
 
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:

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

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It's starting to take shape:

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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****.

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After much musing, I came up with this:

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

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

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

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The casting is a bit all over the place:

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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:


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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:

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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:


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

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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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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 :laughing:

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