Hemingway Quorn Mk3

[ErichKeane]

Did some easy through bolt holes. They are for mounting the quoin to a bench, but I went ahead and did them now. They are 8mm holes (.3150") so I will be able to make a fixture plate to make clamping up in a vise easier, and tap 3 x 8mm holes in them. I guess the plan has shifted to Superglue + mounting the castings once joined, to a fixture plate instead of straps or drilling and tapping the parts themselves.Not sure if I need an angle plate, or if mounting on a faced piece of Alu or steel will suffice. I have tons of steel and aluminum in my scrap closet (literally tons of aircraft grade "scrap") So we shall see.

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Not what I was thinking, but if you can get the holes in place, should be good work holding!

 

[Christianstark]

Not what I was thinking, but if you can get the holes in place, should be good work holding!

Not what I was thinking either but the holes are per the plans. When I saw them I figured what the hell! Single point boring shouldn’t put too much stress in the set up so I’m 90% convinced this will work out. I’ll probably thread one hole, and mount it to a square of thick aluminum, and tap the part in square and transfer punch the other 2. Bore the 2 base bar holes in situ.

 

[twhite]

Not what I was thinking either but the holes are per the plans. When I saw them I figured what the hell! Single point boring shouldn’t put too much stress in the set up so I’m 90% convinced this will work out. I’ll probably thread one hole, and mount it to a square of thick aluminum, and tap the part in square and transfer punch the other 2. Bore the 2 base bar holes in situ.

Then can you lay that setup on its back and bore the single hole perpendicular to the others.?


Cutting oil is my blood.

 

[Lo-Fi]

I just bored them separately, making sure to use the same bit of leadscrew on my X axis. Came out spot on with nothing more than the usual precautions for precision work. I'm running less than a thou clearance for the sliding fit, rather than the 3 that I think was specified. The proof is sliding the second rod through and have it meet the second casting perfectly, which is most satisfying.

My worry with glueing them together would be if the glue joint breaks mid operation. If you do go the glue route, be very careful with heat! Be fine for finishing but the initial cuts to get under the cast skin can be quite brutal.

It's a great project, you'll have a lot of fun! Looking forward to updates.

My thread in case it's helpful:

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

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...

www.hobby-machinist.com

Matty's workshop and MetalMill52 both have good recent series in the project too, in case you've not seen them.

 

[Christianstark]

Then can you lay that setup on its back and bore the single hole perpendicular to the others.?


Cutting oil is my blood.

That is the plan! I think the next step in this order of operation would be to drill and bore out where the cotter will be going, and then prepping a piece of brass to loc-tile in,

 

[Christianstark]

Did a little milling today.

First pic is both base castings bolted on to a scrap piece of steel that was drilled and tapped to hold the castings co-planar to their machined sides. First step was to plunge mill the cotter cavity. the base bar holes are still casting size.



Now I need to cut a brass .75" slug and glue it into that hole to bore the base bar holes. Flipped the part 90 degrees to do the boring. I just cleaned up the "non-cotter" bore to see how it was cutting. My issues today are:

1 - My boring bars for my boring head are too short to bore the entire 2 parts in one set up.
2 - IF I find a boring bar that is long enough, I MAY run out of Y axis to do so. I need about a 5" bar to get through both castings. 6 will be too long with my Y travel.

I am working today, so I only get periodic 10-15 minute breaks to look at hobby stuff.

 

[ErichKeane]

Well, you can always cut a boring bar if you buy one too long I've definitely done stuff like that in the past.

 

[twhite]

Great way to utilize an old A plate from a mold.


Cutting oil is my blood.

 

[Christianstark]

Well, you can always cut a boring bar if you buy one too long I've definitely done stuff like that in the past.

Yeah. Used a cheap kit bar and cut it. Its easy to forget you can cut metal things when working in your hobby machine shop...LOL

 

[ErichKeane]

Heh, I had that moment in a setup I just worked on. I couldn't for the life of me get clearance for the job I wanted to do with the boring head, and spent a long time moving things/trying to get it setup, when I realized: The shaft on my boring head is too long for the collet anyway, I can just cut it

30 seconds on the bandsaw plus 20 on the grinder and it bought me 1" of room!