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Ball Turning Attachment

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silverhawk

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#1
I think the boring head ball turning attachments are novel, but I worry that they are changing the direction of stress where the tools cut into the work in relation to the headstock. So, I started building my own ball turning attachment out of 5"x12"x5/8" plate steel. I marked it and drilled the corners, then cross drilled the pivot point, and drill-cut the inside edge.



Then I spend too much time at the bandsaw cutting it out :











I subsequently used a grinder to clean it up. I still have yet to open up the pivot holes, install bushings, and broach the swing arm to hold the small tool holder in place. I think it will do, though.
 

Rooster

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#2
Greetings, looks like you got a good start on it, what size lathe is it for.
 

Rooster

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#4
Thanks, been thinking of making something similar for my Atlas 618.
 

brino

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#5
That's a great start, thanks for sharing.
I am "watching" for the next instalment.

-brino
 

Silverbullet

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#6
YUPP getter done , looks like it should , the plus of those is turning an arc in the shaft to build a handle grip. Handy tool to add to your lathe.
 

Hawkeye

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#7
I like your approach to saving metal. I made a similar type for my lathe, but welded the arms together. The visegrips are a temporary handle.
PA080092a.jpg

To improve stiffness for smaller radius turning, I added a second set of pivots, and later, a post to replace the 'C', mostly for concave pockets. And, of course, you have to use the tool to make the handle for it.
PA080095a.jpg
 

silverhawk

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#8
I finally got a change to work a little more on it. I was worried about making sure the axis on one end and the axis on the other were lined up. I didn't dare do it on the drill press, and in a fit of inspiration, I realized I could use a live center, a drill bit in the collet, and use those to line up the holes for the pivots. The frame was drilled to 3/8", and the swing arm was drilled to 1/4". On the swing arm, it was smaller than the swing of the lathe, so I had to put a board between the ways to keep it from catching on a drill bit and spinning out of control.



I threw a 3/8" rod through the two holes to ensure the axis on the holes lined up (so that things could turn).



Then, I cut the bushings out (0.500" flange, 0.375" outside minor diameter to match the 3/8" hole in the frame) and drilled them to 0.250" (1/4" to match the holes in the swing arm).



I pressed them into the frame.



Once in, I threw a 1/4" rod through it all to ensure it functioned like I wanted.



Now I just need to broach that hole to square, drill set screw holes in the swing arm for the pivot rods as well as a set screw for the square hole for the tool. That will leave just a handle on it. A little bit at a time!
 

silverhawk

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#9
Well, I finally have time to post an update. I don't always get a chance to be out in the shop lately, so I take what I can get. My next task was to get a square hole for 1/4" tool holders :



Notice the square broach. I built a broach out of 7mm HSS. Being a stupid idiot, I first tried turning it on a lathe. That is a bad idea - it will break your carbide tooling, and does nothing to the square. Next, I used a grinder to make it "round" and cut "reliefs" in it. This did nothing more than get it jammed into the round hole. So, I used files to make the hole a little more square, then fed a 6mm HSS blank through it (squared up the hole to 6mm, still less than the 1/4" I wanted for tooling). So, I then fed the 7mm "rounded" broach. I was puckered up a little, but I ended up with a square hole. I then locked it onto my mill, cut a flat, and then drilled a hole for a set screw. Another note, I didn't see many options for a #12 set screw, so I had to go up to a 1/4" set screw.





After tapping that, I took all-thread, and put a bend in it using heat and a press, then put it all together. All I need now is an XL tool holder for the AXA, and I can tell everyone I have balls of steel!





Not bad for a hack job, though I still need to try it and prove I was successful. I'll probably use it to turn a half ball for the top rod (with the all thread), and do a better job of that grab-something-from-waste-pile job.
 

Suzuki4evr

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#10
Hi Silverhawk.

I've noticed all the natural light you have going there on your mill. Is the machine standing outside or am I mistaken? It would be GREAT if you could actually working outside doing what you like and enjoy being outdoors at the same time, but it's not practical. So how does your setup work for interest sake?
O by the way it's looking good.

Michael
 

silverhawk

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#11
Hi Silverhawk.

I've noticed all the natural light you have going there on your mill. Is the machine standing outside or am I mistaken? It would be GREAT if you could actually working outside doing what you like and enjoy being outdoors at the same time, but it's not practical. So how does your setup work for interest sake?
O by the way it's looking good.

Michael
It is actually outside. Most people have a shop. I have a 5x20 shed that houses shelves containing stock, planter boxes, yard Froo froos, roto tillers, ladders, door frames, etc. This shed also houses my machine tools, and those have wheels so I can move them to where I have room to work.

When you have limited space, you have to figure out how to deal with what you have. I do have a shop in my future, but it hasn't happened yet.
 

Suzuki4evr

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#12
Well are making it work. I thought maybe it was on wheels,hope it is stable enough. Enjoy working outside.
 
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