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2017 POTD Thread Archive
- Thread starter jpfabricator
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- Feb 2, 2017
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- 1,237
Jerry,
Thanks! I have some ATF that I can try. A thought I had this morning was to burnish the finish rather than try to cut it. Not sure what I'd use, but was thinking about just rounding off and polishing a HSS blank.
We've got friends that have a place in Copperopolis--can't remember the name, but it's a golf community. We've been up there once and it's really nice in the Sierra foothills.
Evan
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Just saw a video by (?) sorry. He was using a shear tool on copper with spectacular results. Guess you could face with a shear tool, might have to grind a slight radius on the front so the corners don't contact the surface.
Greg
Greg
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- Feb 2, 2017
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Greg,
Thanks for the tip. I checked out Tubal Cain’s video on shear tools and will give it a shot.
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I have a nice Starrett back plunger dial indicator set, complete with a bar to clamp into a tool holder. Its threaded to accept the 5/16 rods the set uses. The bar is small for the shaper lantern so I thought I'd make a 5/8 x 1 3/8 one and thread the end for the Starrrett rods. Not so. They use a proprietary thread, somewhere between 10-28 and 1/4-28. Had to make a new rod with 1/4 -28 threaded end.
Greg
Greg
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- Feb 17, 2013
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Sorry, 12-28 is what I meant,
A 12-28 tap fits loose in the Starrett hole.
Greg
A 12-28 tap fits loose in the Starrett hole.
Greg
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- Sep 5, 2013
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I'm still playing around with the little horizontal milling machine I picked up in the summer. When I got it, it was running different drive pulleys other than what should have been on the machine. The previous owner, or a previous owner, had already purchased two new reproduction pulleys of the proper sizes but hadn't installed them. When I decided to put them on I could see why.
The larger of the two, in this case a proper Zamak casting of the Atlas part, had such a brutal shimmy in it that I immediately took it off again. Hmmm, what to do? Well I'll just true it up a bit on the lathe and see if it'll come around. Nothing to lose, eh.
Yeah ok, that worked not so good and even worse when the thing slowly disintegrated and eventually fell completely apart. Like, one side of a sheave just came off while I was turning it. Guess it's on to Plan B -- make completely new pulley from scratch.
Long story short, my Atlas 618 clears three-and-a-bit inches over the ways and the largest sheave is 4-1/2 inches in diameter. Not a lot of room to get in front for turning, and I figured the only way to do it would be in two pieces. This actually worked ok. I turned a shallow boss on one part and a shallow relief on the other, just like mounting a chuck to a back plate. Four machine screws hold the two sides together nicely. I got a lot of chatter though when I was doing the bottoms of the grooves, my setup was just too whippy with everything extended to the max.
The story really should end here, but after I had faithfully reproduced my brand new aluminum pulley to all my nice specifications, it didn't mesh up quite as nice as I might have liked with the small pulley. Dang! Guess the only thing to do is make a new one of those too!
So I did. It went a lot smoother, partly because of the smaller diameters and also because I could make it from a single blank. Here's the blank being faced. If I'm not mistaken, my cutter is patterned off a Mikey-style square tool I ground a few years ago. They cut real nice.
Here's one of my setups for cutting the grooves. I ran straight in to depth with a parting tool first, then switched to a slim taper for working the angled cheeks. I think I had to use four different tool block configurations in order to get the various setups from the appropriate directions.
In the end though, both parts worked out just fine. The fit like a glove, the belt runs smooth and true, and they're not shaking themselves to bits in the process.
Thanks for looking!
-frank
The larger of the two, in this case a proper Zamak casting of the Atlas part, had such a brutal shimmy in it that I immediately took it off again. Hmmm, what to do? Well I'll just true it up a bit on the lathe and see if it'll come around. Nothing to lose, eh.
Yeah ok, that worked not so good and even worse when the thing slowly disintegrated and eventually fell completely apart. Like, one side of a sheave just came off while I was turning it. Guess it's on to Plan B -- make completely new pulley from scratch.
Long story short, my Atlas 618 clears three-and-a-bit inches over the ways and the largest sheave is 4-1/2 inches in diameter. Not a lot of room to get in front for turning, and I figured the only way to do it would be in two pieces. This actually worked ok. I turned a shallow boss on one part and a shallow relief on the other, just like mounting a chuck to a back plate. Four machine screws hold the two sides together nicely. I got a lot of chatter though when I was doing the bottoms of the grooves, my setup was just too whippy with everything extended to the max.
The story really should end here, but after I had faithfully reproduced my brand new aluminum pulley to all my nice specifications, it didn't mesh up quite as nice as I might have liked with the small pulley. Dang! Guess the only thing to do is make a new one of those too!
So I did. It went a lot smoother, partly because of the smaller diameters and also because I could make it from a single blank. Here's the blank being faced. If I'm not mistaken, my cutter is patterned off a Mikey-style square tool I ground a few years ago. They cut real nice.
Here's one of my setups for cutting the grooves. I ran straight in to depth with a parting tool first, then switched to a slim taper for working the angled cheeks. I think I had to use four different tool block configurations in order to get the various setups from the appropriate directions.
In the end though, both parts worked out just fine. The fit like a glove, the belt runs smooth and true, and they're not shaking themselves to bits in the process.
Thanks for looking!
-frank
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