New Ball Turner

Do these have 1/2" shanks like I've read you talk about? TIA, JR49

No, the solid carbide are 1/4 shank. In the carbide tipped ones I use, I buy 1/2 inch shank where possible. Using a 1/4 shank in the mill just means you have to be a little less greedy with the cut. All of the corner rounders that I use are HF 1/4 shank, they work fine, but you do have to be a bit gentle with them.
 
Another update:

This is the main body. Pocketing a starter hole for the 15/16 drill bit. I wanted it to run in straight so starting with a 3/4 inch deep, on-size pocket should help.

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Then drill with the 15/16 drill bit. This was then reamed to 0.9685 because that is the closest reamer I had to 1 inch. So I turned a 0.968 shaft.

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Here is where the pucker factor went up again, drilling the 0.093 clearance/anti-stress holes through 1 7/8 thick, gummy, sticky aluminum. About 2500 RPM, and just go down and touch the bottom, retract to clear, rinse, repeat. Don't let the drill bit load up. :confused: Made it through both holes without a problem.

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Pocketing the clearance for the dovetail. 3/8 solid carbide, 2 flute. Running about 2800 RPM, 10 IPM, 40% stepover, 0.060 DOC. Kerosene coolant.

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And cutting the dovetail. About 0.010 step over, 1200 RPM. You don't see any coolant coming out of the nozzle, it runs about a half cup / hour. That's all you need. No fog either, it creates micro droplets. There is so little flow that there is no residue when the job is done. Just evaporates.

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And the finished dovetail

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Next is put some wrench flats on the modified nut. This nut started out life as a standard 7/8-14, stainless steel, nyloc nut, highly modified to fit the application. I could have set up the 4th axis and done this, but the main body makes a great 4 sided ''collet holder''. Screw nut on backwards and tighten against the washers with channel locks (polish later :grin:). It ain't gonna move for this operation. Do one side, flip it over and do the other. 1/4 inch solid carbide router bit.

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Of course a special nut needs a special wrench. I dug this out of the miscellaneous tool stash. It's is hard, but I could file it. It's 22 mm and I need 26mm to fit the nut. So we'll just open it up a bit. Clamped a chunk of MDF in the vice, screwed and clamped the wrench down, and located it with the spindle laser. No the laser is not extremely accurate, but for this operation close is good enough.

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I grabbed a router bit that had the corners of the end chipped but most of the cutter was unused, so I went 3/8 deep to utilize the unused portion of the flutes.

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And it fits ! :)

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Next step is to make a Weldon shank for my saw arbor. Milling the flats, using a 1/2 inch rougher.
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Then next is machine the 45° chamfer on the edges. I picked up a few of these what I think are fiberglass drills. Was at the local metal supply one day and they had a bunch of these for $3.00 each. Solid carbide. They have a 90° included angle.
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And done
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Setting up to make the slot. First I turned a tight fitting aluminum slug exactly the same length as the main body. The goal here is two fold. First I don't know how stable the aluminum is, and I don't know if it will want to close up on the slitting saw once it breaks through, so the slug will keep that from happening. Secondly, this will eliminate any burr in the bore caused by the slitting saw.

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And the slug clamped in place so the saw can't walk it out. I will be cutting about 1/16 into the slug on the final pass.

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And here it is cutting, about 2/3 of the way through. I was being pretty gentle because I have never done this before. 280 RPM, 7 IPM, about 0.010 step over. I think I could have been a lot more aggressive with the cut. Probably could have doubled those numbers with no problem. Kerosene coolant, the nozzle is hiding behind the tool holder. The HF ''4 inch'' saw blade worked perfectly....almost, the teeth are not quite on the same centerline as the center hole so it was only cutting with about 4 teeth out of 24. Also, the 4 inch blade is actually 3.773 diameter. They shorted me a 1/4 inch :mad: :grin: On the other hand it's only $5 ;)

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And here is all of the parts. Still have a couple things to do but I'm tired. :faint: So they will wait for tomorrow.

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Very nice build, keep getting better with each one built. Now we need to add power feed to the Turner. Shouldn't be to hard to do. Couple limit switches adjustable of course 12 volt gear reduction motor and a variable speed pot. Easy peasy , in my future if I live through the operations. I do like that they all incorporate some thrust bearing s ..
 
The next step is to mount the handle to the set collar. It needs to be at about a 5° angle for clearance. So mill a flat and D&T the 3/8-24 hole.

Poor man's sine vice. ;)
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Centering the hole the easy way. Flip an endmill upside down in the collet and use the shank as an alignment pin.
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Too much thread, so manually plunge down veeerrrrryy carefully with a 11/16 endmill. It's a 3/4 hole. Chew it out until it is flush and clean up the edges to match the arc of the ID.
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And installed. Also the stops are finished. I don't like the washers on the stop pins, so they need to be modified. I'll see if I can find some #10 USS hard washers and drill them out. Also need to get some 5/8 long shoulder screws, the 3/4 are too long, but that's what my local Ace Hardware had. Well, it's almost time to put this thing to work.

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Of course the first job of any new radius turner is to make a knob for the handle. So I had a piece of 1.25 x 2.5 long brass round bar. Perfect for the handle ball.

First cut it in half. It was too short to hang on to in the horizontal band saw, so over to the vertical. But how do you hang onto a piece of round stock? ......Simple.....Vice grips :) And no danger of getting fingers bit.

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Worked as planned, had full control over the part. Drilled & tapped the blank for 5/16-24, then build a stub arbor to screw it onto.

For a tool bit I started looking at the geometry of the standard boring bars rather than making up a tool holder. So grab an old carbide tipped bar, a little grind here and a little grind there and bang, instant radius tool bit. Still not quite right, but close enough.

And starting the ball. Working good so far. Very smooth action. The handle is about 10 inches long. The stops were a great idea, saved a lot of thinking :rolleyes:
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And we have a ball knob. :grin::beer:

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And installed

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I hope you all enjoyed the show. I'm going to call this one a success !

:dancing banana:

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Jim, question on using the boring head as a taper attachment. How do you keep the boring head horizontal when installing into the tail stock?
 
1.5 years later, has the Conquest taken over ball turning duties? :grin:

Yes, pretty much. Just did a run of the parts below. These are the parts that I built the ball turner to do. Takes about 40 minutes to run them on the manual lathe, several tool changes and setups. On the Conquest the run time is about 3 minutes, most of that time is drilling and tapping the end. Has a 5/16-18 x 1 inch deep tapped hole in the end. 304 SS, nasty stuff to work with. It is nice, put a 45 inch bar in, press go, and come back in an hour to collect the parts. And they hold +/- 0.0001 as near as I can measure.

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Jim, question on using the boring head as a taper attachment. How do you keep the boring head horizontal when installing into the tail stock?

My lathe is level so I use my 6 inch precision level on the flat of the boring head to level it with the lathe bed.
 
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