Home |
Search |
Today's Posts |
|
Metalworking (rec.crafts.metalworking) Discuss various aspects of working with metal, such as machining, welding, metal joining, screwing, casting, hardening/tempering, blacksmithing/forging, spinning and hammer work, sheet metal work. |
Reply |
|
LinkBack | Thread Tools | Display Modes |
#1
Posted to rec.crafts.metalworking
|
|||
|
|||
Machining a ball
My Garmin NUVI 500 for my bicycle uses a ball mount. The one that I
purchase from a third party is hollowed plastic and broke from vibration. I adapted the broken piece to my light bar and it broke again at the ball. I toyed with several methods. One buy a ball turning tool, two find a ball and mount it to a post. The ball was .670 inches and I didn't find any one that size. I decided to make a form tool for a section and move around the ball shape. The critical section is smooth as the female move up to the major diameter and that the major diameter size is maintained. The down side also needs to be smooth for a short distance. I Machined a rectangle piece of aluminum leaving the head 3/4 inches, in three direction. The post section is 3/4 X 1/2 inches. Pictures are here. http://www.billcotton.com/nuvi500.htm |
#2
Posted to rec.crafts.metalworking
|
|||
|
|||
Machining a ball
On Sun, 24 Jan 2010 13:36:42 -0800 (PST), mac
wrote: My Garmin NUVI 500 for my bicycle uses a ball mount. The one that I purchase from a third party is hollowed plastic and broke from vibration. I adapted the broken piece to my light bar and it broke again at the ball. I toyed with several methods. One buy a ball turning tool, two find a ball and mount it to a post. The ball was .670 inches and I didn't find any one that size. It would have been 17mm Mark Rand RTFM |
#3
Posted to rec.crafts.metalworking
|
|||
|
|||
Machining a ball
"mac" wrote in message ... My Garmin NUVI 500 for my bicycle uses a ball mount. The one that I purchase from a third party is hollowed plastic and broke from vibration. I adapted the broken piece to my light bar and it broke again at the ball. I toyed with several methods. One buy a ball turning tool, two find a ball and mount it to a post. The ball was .670 inches and I didn't find any one that size. I decided to make a form tool for a section and move around the ball shape. The critical section is smooth as the female move up to the major diameter and that the major diameter size is maintained. The down side also needs to be smooth for a short distance. I Machined a rectangle piece of aluminum leaving the head 3/4 inches, in three direction. The post section is 3/4 X 1/2 inches. Pictures are here. http://www.billcotton.com/nuvi500.htm It looks like this worked well enough for you. In the optical lens industry, spheres and spherical sections are generated using a cup-shaped grinding tool. The workpiece is rotated, the tool axis is at an angle to the workpiece and spun more quickly. The edge of the cup is aligned over the apex of the workpiece, and then the tool is moved into the work parallel to the workpiece axis. Here is a rough diagram of how it works: http://www.britannica.com/EBchecked/...ave-and-convex The radius generated will depend on the diameter of the tool and the angle. It can make very precise spheres that are the ready for (very) fine grinding and final polishing. Perhaps you can do this with a tool post grinder on a metal lathe. |
#4
Posted to rec.crafts.metalworking
|
|||
|
|||
Machining a ball
On Jan 24, 5:39*pm, "anorton"
wrote: "mac" wrote in message ... My Garmin NUVI 500 for my bicycle uses a ball mount. The one that I purchase from a third party is hollowed plastic and broke from vibration. I adapted the broken piece to my light bar and it broke again at the ball. I toyed with several methods. One buy a ball turning tool, two find a ball and mount it to a post. The ball was .670 inches and I didn't find any one that size. I decided to make a form tool for a section and move around the ball shape. The critical section is smooth as the female move up to the major diameter and that the major diameter size is maintained. The down side also needs to be smooth for a short distance. I Machined a rectangle piece of aluminum leaving the head 3/4 inches, in three direction. The post section is 3/4 X 1/2 inches. Pictures are here.http://www.billcotton.com/nuvi500.htm It looks like this worked well enough for you. In the optical lens industry, spheres and spherical sections are generated using a cup-shaped grinding tool. The workpiece is rotated, the tool axis is at an angle to the workpiece and spun more quickly. *The edge of the cup is aligned over the apex of the workpiece, and then the tool is moved into the work parallel to the workpiece axis. *Here is a rough diagram of how it works:http://www.britannica.com/EBchecked/...68/Cross-secti... The radius generated will depend on the diameter of the tool and the angle. It can make very precise spheres that are the ready for (very) fine grinding and final polishing. *Perhaps you can do this with a tool post grinder on a metal lathe. I serve my apprenticship at the Frankford Arsenal in Philadelphia PA. Bldg 45 made the metel holderfor the lens blanks. The grinding was done in Bldg 108, the optical shop. Back in the old, old days, the military didn't just others to to percision work. It was all done in house. When I came along in the earlier fifty, work begun to be contracted out. |
#5
Posted to rec.crafts.metalworking
|
|||
|
|||
Machining a ball
On Sun, 24 Jan 2010 13:36:42 -0800, mac wrote:
My Garmin NUVI 500 for my bicycle uses a ball mount. The one that I purchase from a third party is hollowed plastic and broke from vibration. I adapted the broken piece to my light bar and it broke again at the ball. I toyed with several methods. One buy a ball turning tool, two find a ball and mount it to a post. The ball was .670 inches and I didn't find any one that size. I decided to make a form tool for a section and move around the ball shape. The critical section is smooth as the female move up to the major diameter and that the major diameter size is maintained. The down side also needs to be smooth for a short distance. I Machined a rectangle piece of aluminum leaving the head 3/4 inches, in three direction. The post section is 3/4 X 1/2 inches. Pictures are here. http://www.billcotton.com/nuvi500.htm Making a bunch of taper cuts to rough out the sphere, then filing it 'round' on the lathe may work well, too. Your technique works, obviously, and would be the way to go if you need to make a ton of parts. Probably makes a more precise ball, too, if you get the contour of the tool correct. (In fact, this may be a good way to make something like a Cox engine connecting rod). -- www.wescottdesign.com |
#6
Posted to rec.crafts.metalworking
|
|||
|
|||
Machining a ball
On Sun, 24 Jan 2010 14:39:01 -0800, "anorton"
wrote: "mac" wrote in message ... My Garmin NUVI 500 for my bicycle uses a ball mount. The one that I purchase from a third party is hollowed plastic and broke from vibration. I adapted the broken piece to my light bar and it broke again at the ball. I toyed with several methods. One buy a ball turning tool, two find a ball and mount it to a post. The ball was .670 inches and I didn't find any one that size. I decided to make a form tool for a section and move around the ball shape. The critical section is smooth as the female move up to the major diameter and that the major diameter size is maintained. The down side also needs to be smooth for a short distance. I Machined a rectangle piece of aluminum leaving the head 3/4 inches, in three direction. The post section is 3/4 X 1/2 inches. Pictures are here. http://www.billcotton.com/nuvi500.htm It looks like this worked well enough for you. In the optical lens industry, spheres and spherical sections are generated using a cup-shaped grinding tool. The workpiece is rotated, the tool axis is at an angle to the workpiece and spun more quickly. The edge of the cup is aligned over the apex of the workpiece, and then the tool is moved into the work parallel to the workpiece axis. Here is a rough diagram of how it works: http://www.britannica.com/EBchecked/...ave-and-convex The radius generated will depend on the diameter of the tool and the angle. It can make very precise spheres that are the ready for (very) fine grinding and final polishing. Perhaps you can do this with a tool post grinder on a metal lathe. ========= or see http://littlemachineshop.com/product...1970&category= and http://littlemachineshop.com/product...2568&category= for some ideas on how to make your own. Unka George (George McDuffee) ............................... The past is a foreign country; they do things differently there. L. P. Hartley (1895-1972), British author. The Go-Between, Prologue (1953). |
#7
Posted to rec.crafts.metalworking
|
|||
|
|||
Machining a ball
On Sun, 24 Jan 2010 14:39:01 -0800, "anorton"
wrote: "mac" wrote in message ... My Garmin NUVI 500 for my bicycle uses a ball mount. The one that I purchase from a third party is hollowed plastic and broke from vibration. I adapted the broken piece to my light bar and it broke again at the ball. I toyed with several methods. One buy a ball turning tool, two find a ball and mount it to a post. The ball was .670 inches and I didn't find any one that size. I decided to make a form tool for a section and move around the ball shape. The critical section is smooth as the female move up to the major diameter and that the major diameter size is maintained. The down side also needs to be smooth for a short distance. I Machined a rectangle piece of aluminum leaving the head 3/4 inches, in three direction. The post section is 3/4 X 1/2 inches. Pictures are here. http://www.billcotton.com/nuvi500.htm It looks like this worked well enough for you. In the optical lens industry, spheres and spherical sections are generated using a cup-shaped grinding tool. The workpiece is rotated, the tool axis is at an angle to the workpiece and spun more quickly. The edge of the cup is aligned over the apex of the workpiece, and then the tool is moved into the work parallel to the workpiece axis. Here is a rough diagram of how it works: http://www.britannica.com/EBchecked/...ave-and-convex The radius generated will depend on the diameter of the tool and the angle. It can make very precise spheres that are the ready for (very) fine grinding and final polishing. Perhaps you can do this with a tool post grinder on a metal lathe. Om a metal lathe..CNC..it can be done in one simple operation. http://www.omni-turn.com/Pages/Examp...el%20ball.html If you think there may ba a market for your new mount..Id be happy to turn you onto people who could make these and other parts cheaply and quickly. You might have a new product!!! Gunner Whenever a Liberal utters the term "Common Sense approach"....grab your wallet, your ass, and your guns because the sombitch is about to do something damned nasty to all three of them. |
#8
Posted to rec.crafts.metalworking
|
|||
|
|||
Machining a ball
mac wrote:
I serve my apprenticship at the Frankford Arsenal in Philadelphia PA. Bldg 45 made the metel holderfor the lens blanks. The grinding was done in Bldg 108, the optical shop. Back in the old, old days, the military didn't just others to to percision work. It was all done in house. When I came along in the earlier fifty, work begun to be contracted out. I enjoyed your link. I used a couple Avocet 50's for many years to get a trip altimeter using barometric pressure. Finally, I ran out of units to piece a working one out of. Just before winter I bought a Garmin Colorado, the cadence sensor, and the heart rate monitor. It will be spring before I give it a test ride. The Colorado I have has topo maps and not street routable cartography though I'm told I can but that at extra cost. Wes -- "Additionally as a security officer, I carry a gun to protect government officials but my life isn't worth protecting at home in their eyes." Dick Anthony Heller |
#9
Posted to rec.crafts.metalworking
|
|||
|
|||
Machining a ball
On Sun, 24 Jan 2010 17:02:36 -0600, Tim Wescott
wrote: On Sun, 24 Jan 2010 13:36:42 -0800, mac wrote: My Garmin NUVI 500 for my bicycle uses a ball mount. The one that I purchase from a third party is hollowed plastic and broke from vibration. I adapted the broken piece to my light bar and it broke again at the ball. I toyed with several methods. One buy a ball turning tool, two find a ball and mount it to a post. The ball was .670 inches and I didn't find any one that size. I decided to make a form tool for a section and move around the ball shape. The critical section is smooth as the female move up to the major diameter and that the major diameter size is maintained. The down side also needs to be smooth for a short distance. I Machined a rectangle piece of aluminum leaving the head 3/4 inches, in three direction. The post section is 3/4 X 1/2 inches. Pictures are here. http://www.billcotton.com/nuvi500.htm Making a bunch of taper cuts to rough out the sphere, then filing it 'round' on the lathe may work well, too. That's exactly how I did it. It's not a precision thing, doesn't even have to be very round. Mine is still a bit oversize and tight. I'll whittle it down a bit more if I find that it needs it. Wayne |
#10
Posted to rec.crafts.metalworking
|
|||
|
|||
Machining a ball
On Jan 24, 6:24*pm, Gunner Asch wrote:
On Sun, 24 Jan 2010 14:39:01 -0800, "anorton" wrote: "mac" wrote in message ... My Garmin NUVI 500 for my bicycle uses a ball mount. The one that I purchase from a third party is hollowed plastic and broke from vibration. I adapted the broken piece to my light bar and it broke again at the ball. I toyed with several methods. One buy a ball turning tool, two find a ball and mount it to a post. The ball was .670 inches and I didn't find any one that size. I decided to make a form tool for a section and move around the ball shape. The critical section is smooth as the female move up to the major diameter and that the major diameter size is maintained. The down side also needs to be smooth for a short distance. I Machined a rectangle piece of aluminum leaving the head 3/4 inches, in three direction. The post section is 3/4 X 1/2 inches. Pictures are here.http://www.billcotton.com/nuvi500.htm It looks like this worked well enough for you. In the optical lens industry, spheres and spherical sections are generated using a cup-shaped grinding tool. The workpiece is rotated, the tool axis is at an angle to the workpiece and spun more quickly. *The edge of the cup is aligned over the apex of the workpiece, and then the tool is moved into the work parallel to the workpiece axis. *Here is a rough diagram of how it works: http://www.britannica.com/EBchecked/...68/Cross-secti... The radius generated will depend on the diameter of the tool and the angle. It can make very precise spheres that are the ready for (very) fine grinding and final polishing. *Perhaps you can do this with a tool post grinder on a metal lathe. Om a metal lathe..CNC..it can be done in one simple operation. http://www.omni-turn.com/Pages/Examp...el%20ball.html Yes if happen to have a CNC around, that would've been my choice. The history of my home machine shop, It was a belt sander and drill press with a cross slide vise. I had help a friend set up his three in one machine. I thought that if I could come up was a reason I would buy one also. A little while later I read about a free coasting gearing for a tandem bicycle. I shopped around for a unit to modify our tandem bicycle. A bicycle shop wrench, that the name they go by, said that this type is just a couple of BMX free wheeler mounted. The shop wanted 500 dollars for the set of gears. That was my excuse to spend 1500 dollars for the three in one. Bolt circles and other calculation made for a fun take off for my shop. I docketed many of the projects on my web page and posting on in this group. If you think there may ba a market for your new mount..Id be happy to turn you onto people who could make these and other parts cheaply and quickly. *You might have a new product!!! Gunner Thanks, but I don't see a market, Several are made for motorcycle that are stronger. *Whenever a Liberal utters the term "Common Sense approach"....grab your *wallet, your ass, and your guns because the sombitch is about to do *something damned nasty to all three of them.- Hide quoted text - - Show quoted text - |
#11
Posted to rec.crafts.metalworking
|
|||
|
|||
Machining a ball
mac explained on 1/24/2010 :
My Garmin NUVI 500 for my bicycle uses a ball mount. The one that I purchase from a third party is hollowed plastic and broke from vibration. I adapted the broken piece to my light bar and it broke again at the ball. I toyed with several methods. One buy a ball turning tool, two find a ball and mount it to a post. The ball was .670 inches and I didn't find any one that size. I decided to make a form tool for a section and move around the ball shape. The critical section is smooth as the female move up to the major diameter and that the major diameter size is maintained. The down side also needs to be smooth for a short distance. I Machined a rectangle piece of aluminum leaving the head 3/4 inches, in three direction. The post section is 3/4 X 1/2 inches. Pictures are here. http://www.billcotton.com/nuvi500.htm Get a good mount? http://www.touratech-usa.com/shop/sh...o?SKU=065-0015 I've used their mounts for a different model. I did make an addition so the mount could rotate on the bars Wayne D. |
#12
Posted to rec.crafts.metalworking
|
|||
|
|||
Machining a ball
On Sun, 24 Jan 2010 13:36:42 -0800 (PST), mac
wrote: My Garmin NUVI 500 for my bicycle uses a ball mount. The one that I purchase from a third party is hollowed plastic and broke from vibration. I adapted the broken piece to my light bar and it broke again at the ball. I toyed with several methods. One buy a ball turning tool, two find a ball and mount it to a post. The ball was .670 inches and I didn't find any one that size. I decided to make a form tool for a section and move around the ball shape. The critical section is smooth as the female move up to the major diameter and that the major diameter size is maintained. The down side also needs to be smooth for a short distance. I Machined a rectangle piece of aluminum leaving the head 3/4 inches, in three direction. The post section is 3/4 X 1/2 inches. Pictures are here. http://www.billcotton.com/nuvi500.htm Neat Bill, and good to hear from you. It's been a while. |
#13
Posted to rec.crafts.metalworking
|
|||
|
|||
Machining a ball
On Jan 25, 2:01*am, Don Foreman wrote:
On Sun, 24 Jan 2010 13:36:42 -0800 (PST), mac wrote: My Garmin NUVI 500 for my bicycle uses a ball mount. The one that I purchase from a third party is hollowed plastic and broke from vibration. I adapted the broken piece to my light bar and it broke again at the ball. I toyed with several methods. One buy a ball turning tool, two find a ball and mount it to a post. The ball was .670 inches and I didn't find any one that size. I decided to make a form tool for a section and move around the ball shape. The critical section is smooth as the female move up to the major diameter and that the major diameter size is maintained. The down side also needs to be smooth for a short distance. I Machined a rectangle piece of aluminum leaving the head 3/4 inches, in three direction. The post section is 3/4 X 1/2 inches. Pictures are here.http://www.billcotton.com/nuvi500.htm Neat Bill, and good to hear from you. *It's been a while. Thanks Don; Good to see your ping also. |
#14
Posted to rec.crafts.metalworking
|
|||
|
|||
Machining a ball
On Sun, 24 Jan 2010 14:39:01 -0800, "anorton"
wrote: "mac" wrote in message ... My Garmin NUVI 500 for my bicycle uses a ball mount. The one that I purchase from a third party is hollowed plastic and broke from vibration. I adapted the broken piece to my light bar and it broke again at the ball. I toyed with several methods. One buy a ball turning tool, two find a ball and mount it to a post. The ball was .670 inches and I didn't find any one that size. I decided to make a form tool for a section and move around the ball shape. The critical section is smooth as the female move up to the major diameter and that the major diameter size is maintained. The down side also needs to be smooth for a short distance. I Machined a rectangle piece of aluminum leaving the head 3/4 inches, in three direction. The post section is 3/4 X 1/2 inches. Pictures are here. http://www.billcotton.com/nuvi500.htm It looks like this worked well enough for you. In the optical lens industry, spheres and spherical sections are generated using a cup-shaped grinding tool. The workpiece is rotated, the tool axis is at an angle to the workpiece and spun more quickly. The edge of the cup is aligned over the apex of the workpiece, and then the tool is moved into the work parallel to the workpiece axis. Here is a rough diagram of how it works: http://www.britannica.com/EBchecked/...ave-and-convex The radius generated will depend on the diameter of the tool and the angle. It can make very precise spheres that are the ready for (very) fine grinding and final polishing. Perhaps you can do this with a tool post grinder on a metal lathe. A long time ago in American Machinist, there was an article that showed how to make a perfect ball on a Bridgeport (actually half a ball). Tilt the head at 45 deg. Put in a fly tool with exactly the radius you want, mount the part on a rotary table and start moving the tool to the part very slowly, while turning the table. Said to make near perfect hemispheres. In a small size, wouldn't take all that long, I'd guess. Karl Pearson |
#16
Posted to rec.crafts.metalworking
|
|||
|
|||
Machining a ball
On Sun, 24 Jan 2010 17:09:17 -0700, wrote:
On Sun, 24 Jan 2010 17:02:36 -0600, Tim Wescott wrote: On Sun, 24 Jan 2010 13:36:42 -0800, mac wrote: My Garmin NUVI 500 for my bicycle uses a ball mount. The one that I purchase from a third party is hollowed plastic and broke from vibration. I adapted the broken piece to my light bar and it broke again at the ball. I toyed with several methods. One buy a ball turning tool, two find a ball and mount it to a post. The ball was .670 inches and I didn't find any one that size. I decided to make a form tool for a section and move around the ball shape. The critical section is smooth as the female move up to the major diameter and that the major diameter size is maintained. The down side also needs to be smooth for a short distance. I Machined a rectangle piece of aluminum leaving the head 3/4 inches, in three direction. The post section is 3/4 X 1/2 inches. Pictures are here. http://www.billcotton.com/nuvi500.htm Making a bunch of taper cuts to rough out the sphere, then filing it 'round' on the lathe may work well, too. That's exactly how I did it. It's not a precision thing, doesn't even have to be very round. Mine is still a bit oversize and tight. I'll whittle it down a bit more if I find that it needs it. Wayne If you have a mill, a tiltable indexing head or rotary table and care to provide a valid email addy, I'll send you an article I wrote, in PDF format, about making balls and spherical cavities with a flycutter. I didn't invent this technique and I acknowledge and credit the previous article mentioned by another poster. I merely tried to discover and teach how to do it since previous documentation was vague. I derived the various formulae I presented, and verified them both theoretically and in the shop. I have reported examples of my work with this technique to RCM by reference to my website. I've since removed in favor of more current activities but will rehost if anyone is interested. |
#17
Posted to rec.crafts.metalworking
|
|||
|
|||
Machining a ball
On 2/2/2010 10:59 PM, Don Foreman wrote:
I have reported examples of my work with this technique to RCM by reference to my website. I've since removed in favor of more current activities but will rehost if anyone is interested. Yes, please. --Winston -- Support the blind and deaf. Hire a building contractor today! |
#18
Posted to rec.crafts.metalworking
|
|||
|
|||
Machining a ball
In article ,
Don Foreman wrote: On Tue, 02 Feb 2010 16:08:40 -0500, wrote: On Sun, 24 Jan 2010 14:39:01 -0800, "anorton" wrote: "mac" wrote in message ... My Garmin NUVI 500 for my bicycle uses a ball mount. The one that I purchase from a third party is hollowed plastic and broke from vibration. I adapted the broken piece to my light bar and it broke again at the ball. I toyed with several methods. One buy a ball turning tool, two find a ball and mount it to a post. The ball was .670 inches and I didn't find any one that size. I decided to make a form tool for a section and move around the ball shape. The critical section is smooth as the female move up to the major diameter and that the major diameter size is maintained. The down side also needs to be smooth for a short distance. I Machined a rectangle piece of aluminum leaving the head 3/4 inches, in three direction. The post section is 3/4 X 1/2 inches. Pictures are here. http://www.billcotton.com/nuvi500.htm It looks like this worked well enough for you. In the optical lens industry, spheres and spherical sections are generated using a cup-shaped grinding tool. The workpiece is rotated, the tool axis is at an angle to the workpiece and spun more quickly. The edge of the cup is aligned over the apex of the workpiece, and then the tool is moved into the work parallel to the workpiece axis. Here is a rough diagram of how it works: http://www.britannica.com/EBchecked/...s-section-of-a -curve-generator-for-concave-and-convex The radius generated will depend on the diameter of the tool and the angle. It can make very precise spheres that are the ready for (very) fine grinding and final polishing. Perhaps you can do this with a tool post grinder on a metal lathe. A long time ago in American Machinist, there was an article that showed how to make a perfect ball on a Bridgeport (actually half a ball). Tilt the head at 45 deg. Put in a fly tool with exactly the radius you want, mount the part on a rotary table and start moving the tool to the part very slowly, while turning the table. Said to make near perfect hemispheres. In a small size, wouldn't take all that long, I'd guess. Karl Pearson I developed and expanded on this in an article I wrote to go into a next version of Guy Lautard's "Machinist's Bedside Reader" which never happened. It's mine to share, ping me if you'd like a PDF of it by email. I's like a copy. The above email is real. Perhaps it would make a good addition to the Dropbox? Thanks, Joe Gwinn |
#19
Posted to rec.crafts.metalworking
|
|||
|
|||
Machining a ball
On Tue, 02 Feb 2010 23:25:39 -0800, Winston
wrote: On 2/2/2010 10:59 PM, Don Foreman wrote: I have reported examples of my work with this technique to RCM by reference to my website. I've since removed in favor of more current activities but will rehost if anyone is interested. Yes, please. --Winston OK http://members.goldengate.net/dforeman/balls I'll leave it up for a couple of weeks. |
#20
Posted to rec.crafts.metalworking
|
|||
|
|||
Machining a ball
On Wed, 03 Feb 2010 21:44:23 -0500, Joseph Gwinn
wrote: In article , Don Foreman wrote: On Tue, 02 Feb 2010 16:08:40 -0500, wrote: On Sun, 24 Jan 2010 14:39:01 -0800, "anorton" wrote: "mac" wrote in message ... My Garmin NUVI 500 for my bicycle uses a ball mount. The one that I purchase from a third party is hollowed plastic and broke from vibration. I adapted the broken piece to my light bar and it broke again at the ball. I toyed with several methods. One buy a ball turning tool, two find a ball and mount it to a post. The ball was .670 inches and I didn't find any one that size. I decided to make a form tool for a section and move around the ball shape. The critical section is smooth as the female move up to the major diameter and that the major diameter size is maintained. The down side also needs to be smooth for a short distance. I Machined a rectangle piece of aluminum leaving the head 3/4 inches, in three direction. The post section is 3/4 X 1/2 inches. Pictures are here. http://www.billcotton.com/nuvi500.htm It looks like this worked well enough for you. In the optical lens industry, spheres and spherical sections are generated using a cup-shaped grinding tool. The workpiece is rotated, the tool axis is at an angle to the workpiece and spun more quickly. The edge of the cup is aligned over the apex of the workpiece, and then the tool is moved into the work parallel to the workpiece axis. Here is a rough diagram of how it works: http://www.britannica.com/EBchecked/...s-section-of-a -curve-generator-for-concave-and-convex The radius generated will depend on the diameter of the tool and the angle. It can make very precise spheres that are the ready for (very) fine grinding and final polishing. Perhaps you can do this with a tool post grinder on a metal lathe. A long time ago in American Machinist, there was an article that showed how to make a perfect ball on a Bridgeport (actually half a ball). Tilt the head at 45 deg. Put in a fly tool with exactly the radius you want, mount the part on a rotary table and start moving the tool to the part very slowly, while turning the table. Said to make near perfect hemispheres. In a small size, wouldn't take all that long, I'd guess. Karl Pearson I developed and expanded on this in an article I wrote to go into a next version of Guy Lautard's "Machinist's Bedside Reader" which never happened. It's mine to share, ping me if you'd like a PDF of it by email. I's like a copy. The above email is real. Perhaps it would make a good addition to the Dropbox? Thanks, Joe Gwinn I'll respond by email. I don't want to put it out on the internet because I want to respect Guy here. I wrote it, gratis, for him to include in a forthcoming Machinist's Bedside Reader -- but that was a decade ago and TMBR4 still hasn't happened. The only version I still have contains some editing by him, though no material content. He did tell me he had no objection to my sharing it with individual interested metalworkers. I've not heard from him for several years now but he's still alive, his website is current. |
#21
Posted to rec.crafts.metalworking
|
|||
|
|||
Machining a ball
On 2/3/2010 7:56 PM, Don Foreman wrote:
On Tue, 02 Feb 2010 23:25:39 -0800, wrote: On 2/2/2010 10:59 PM, Don Foreman wrote: I have reported examples of my work with this technique to RCM by reference to my website. I've since removed in favor of more current activities but will rehost if anyone is interested. Yes, please. --Winston OK http://members.goldengate.net/dforeman/balls I'll leave it up for a couple of weeks. Extremely cool. Thanks Don! --Winston -- Support the blind and deaf. Hire a building contractor today! |
#22
Posted to rec.crafts.metalworking
|
|||
|
|||
Machining a ball
In article ,
Don Foreman wrote: On Wed, 03 Feb 2010 21:44:23 -0500, Joseph Gwinn wrote: In article , Don Foreman wrote: On Tue, 02 Feb 2010 16:08:40 -0500, wrote: On Sun, 24 Jan 2010 14:39:01 -0800, "anorton" wrote: "mac" wrote in message ... My Garmin NUVI 500 for my bicycle uses a ball mount. The one that I purchase from a third party is hollowed plastic and broke from vibration. I adapted the broken piece to my light bar and it broke again at the ball. I toyed with several methods. One buy a ball turning tool, two find a ball and mount it to a post. The ball was .670 inches and I didn't find any one that size. I decided to make a form tool for a section and move around the ball shape. The critical section is smooth as the female move up to the major diameter and that the major diameter size is maintained. The down side also needs to be smooth for a short distance. I Machined a rectangle piece of aluminum leaving the head 3/4 inches, in three direction. The post section is 3/4 X 1/2 inches. Pictures are here. http://www.billcotton.com/nuvi500.htm It looks like this worked well enough for you. In the optical lens industry, spheres and spherical sections are generated using a cup-shaped grinding tool. The workpiece is rotated, the tool axis is at an angle to the workpiece and spun more quickly. The edge of the cup is aligned over the apex of the workpiece, and then the tool is moved into the work parallel to the workpiece axis. Here is a rough diagram of how it works: http://www.britannica.com/EBchecked/...ross-section-o f-a -curve-generator-for-concave-and-convex The radius generated will depend on the diameter of the tool and the angle. It can make very precise spheres that are the ready for (very) fine grinding and final polishing. Perhaps you can do this with a tool post grinder on a metal lathe. A long time ago in American Machinist, there was an article that showed how to make a perfect ball on a Bridgeport (actually half a ball). Tilt the head at 45 deg. Put in a fly tool with exactly the radius you want, mount the part on a rotary table and start moving the tool to the part very slowly, while turning the table. Said to make near perfect hemispheres. In a small size, wouldn't take all that long, I'd guess. Karl Pearson I developed and expanded on this in an article I wrote to go into a next version of Guy Lautard's "Machinist's Bedside Reader" which never happened. It's mine to share, ping me if you'd like a PDF of it by email. I's like a copy. The above email is real. Perhaps it would make a good addition to the Dropbox? Thanks, Joe Gwinn I'll respond by email. I got it; thanks. I don't want to put it out on the internet because I want to respect Guy here. I wrote it, gratis, for him to include in a forthcoming Machinist's Bedside Reader -- but that was a decade ago and TMBR4 still hasn't happened. The only version I still have contains some editing by him, though no material content. He did tell me he had no objection to my sharing it with individual interested metalworkers. I've not heard from him for several years now but he's still alive, his website is current. Understood. Joe Gwinn |
#23
Posted to rec.crafts.metalworking
|
|||
|
|||
Machining a ball
On Wed, 03 Feb 2010 00:32:41 -0600, Don Foreman
wrote: On Tue, 02 Feb 2010 16:08:40 -0500, wrote: On Sun, 24 Jan 2010 14:39:01 -0800, "anorton" wrote: "mac" wrote in message ... My Garmin NUVI 500 for my bicycle uses a ball mount. The one that I purchase from a third party is hollowed plastic and broke from vibration. I adapted the broken piece to my light bar and it broke again at the ball. I toyed with several methods. One buy a ball turning tool, two find a ball and mount it to a post. The ball was .670 inches and I didn't find any one that size. I decided to make a form tool for a section and move around the ball shape. The critical section is smooth as the female move up to the major diameter and that the major diameter size is maintained. The down side also needs to be smooth for a short distance. I Machined a rectangle piece of aluminum leaving the head 3/4 inches, in three direction. The post section is 3/4 X 1/2 inches. Pictures are here. http://www.billcotton.com/nuvi500.htm It looks like this worked well enough for you. In the optical lens industry, spheres and spherical sections are generated using a cup-shaped grinding tool. The workpiece is rotated, the tool axis is at an angle to the workpiece and spun more quickly. The edge of the cup is aligned over the apex of the workpiece, and then the tool is moved into the work parallel to the workpiece axis. Here is a rough diagram of how it works: http://www.britannica.com/EBchecked/...ave-and-convex The radius generated will depend on the diameter of the tool and the angle. It can make very precise spheres that are the ready for (very) fine grinding and final polishing. Perhaps you can do this with a tool post grinder on a metal lathe. A long time ago in American Machinist, there was an article that showed how to make a perfect ball on a Bridgeport (actually half a ball). Tilt the head at 45 deg. Put in a fly tool with exactly the radius you want, mount the part on a rotary table and start moving the tool to the part very slowly, while turning the table. Said to make near perfect hemispheres. In a small size, wouldn't take all that long, I'd guess. Karl Pearson I developed and expanded on this in an article I wrote to go into a next version of Guy Lautard's "Machinist's Bedside Reader" which never happened. It's mine to share, ping me if you'd like a PDF of it by email. This is a good e-mail also. I'd appreciate a copy. Love to see neat ideas like that preserved and explained. Karl |
#24
Posted to rec.crafts.metalworking
|
|||
|
|||
Machining a ball
I made a mount for my Nuvi using a standard ball bearing for the ball -
heated it up to remove some of the temper and drilled it and threaded it, and then made a shaft to fit and appropriate mounting bracketry to hold it where I wanted it. I can't imagine any reason to make the ball - you can order bearing balls in brass or various other materials as well off of ebay or any of the usual suppliers "Joseph Gwinn" wrote in message ... In article , Don Foreman wrote: On Tue, 02 Feb 2010 16:08:40 -0500, wrote: On Sun, 24 Jan 2010 14:39:01 -0800, "anorton" wrote: "mac" wrote in message ... My Garmin NUVI 500 for my bicycle uses a ball mount. The one that I purchase from a third party is hollowed plastic and broke from vibration. I adapted the broken piece to my light bar and it broke again at the ball. snip |
#25
Posted to rec.crafts.metalworking
|
|||
|
|||
Machining a ball
On Thu, 04 Feb 2010 17:22:53 -0500, wrote:
On Wed, 03 Feb 2010 00:32:41 -0600, Don Foreman wrote: On Tue, 02 Feb 2010 16:08:40 -0500, wrote: On Sun, 24 Jan 2010 14:39:01 -0800, "anorton" wrote: "mac" wrote in message ... My Garmin NUVI 500 for my bicycle uses a ball mount. The one that I purchase from a third party is hollowed plastic and broke from vibration. I adapted the broken piece to my light bar and it broke again at the ball. I toyed with several methods. One buy a ball turning tool, two find a ball and mount it to a post. The ball was .670 inches and I didn't find any one that size. I decided to make a form tool for a section and move around the ball shape. The critical section is smooth as the female move up to the major diameter and that the major diameter size is maintained. The down side also needs to be smooth for a short distance. I Machined a rectangle piece of aluminum leaving the head 3/4 inches, in three direction. The post section is 3/4 X 1/2 inches. Pictures are here. http://www.billcotton.com/nuvi500.htm It looks like this worked well enough for you. In the optical lens industry, spheres and spherical sections are generated using a cup-shaped grinding tool. The workpiece is rotated, the tool axis is at an angle to the workpiece and spun more quickly. The edge of the cup is aligned over the apex of the workpiece, and then the tool is moved into the work parallel to the workpiece axis. Here is a rough diagram of how it works: http://www.britannica.com/EBchecked/...ave-and-convex The radius generated will depend on the diameter of the tool and the angle. It can make very precise spheres that are the ready for (very) fine grinding and final polishing. Perhaps you can do this with a tool post grinder on a metal lathe. A long time ago in American Machinist, there was an article that showed how to make a perfect ball on a Bridgeport (actually half a ball). Tilt the head at 45 deg. Put in a fly tool with exactly the radius you want, mount the part on a rotary table and start moving the tool to the part very slowly, while turning the table. Said to make near perfect hemispheres. In a small size, wouldn't take all that long, I'd guess. Karl Pearson I developed and expanded on this in an article I wrote to go into a next version of Guy Lautard's "Machinist's Bedside Reader" which never happened. It's mine to share, ping me if you'd like a PDF of it by email. This is a good e-mail also. I'd appreciate a copy. Love to see neat ideas like that preserved and explained. Karl Done |
#26
Posted to rec.crafts.metalworking
|
|||
|
|||
Machining a ball
On Thu, 4 Feb 2010 20:34:09 -0800, "Bill Noble"
wrote: I made a mount for my Nuvi using a standard ball bearing for the ball - heated it up to remove some of the temper and drilled it and threaded it, and then made a shaft to fit and appropriate mounting bracketry to hold it where I wanted it. I can't imagine any reason to make the ball - you can order bearing balls in brass or various other materials as well off of ebay or any of the usual suppliers I've done that too. Sometimes I don't want to pay $7 shipping and wait a week for something I can make in less than an hour. Being retired does tend to change one's attitude about time vs $$$. |
#27
Posted to rec.crafts.metalworking
|
|||
|
|||
Machining a ball
On Thu, 4 Feb 2010 20:34:09 -0800, "Bill Noble"
wrote: I made a mount for my Nuvi using a standard ball bearing for the ball - heated it up to remove some of the temper and drilled it and threaded it, and then made a shaft to fit and appropriate mounting bracketry to hold it where I wanted it. I can't imagine any reason to make the ball - you can order bearing balls in brass or various other materials as well off of ebay or any of the usual suppliers Here's why I made my own ball - turning an aluminum ball to the accuracy needed for this job is fast and easy. I made the entire mount from scraps I had in stock, in about 2 hours, and that included a lot of getting in and out of the car for test fitting. The mount is an 1/8" plate about 2" square and curved slightly in both dimensions. Welded to that at an angle is a 3/8" coupling nut drilled and tapped for a locking screw. The ball shaft telescopes in the coupling nut. The plate is attached in the perfect spot with two-sided tape to some dash plastic. Wayne |
Reply |
Thread Tools | Search this Thread |
Display Modes | |
|
|
Similar Threads | ||||
Thread | Forum | |||
A compressor, a tennis ball and a ball of string! | UK diy | |||
tennis ball steady rest - tennis ball.jpg (0/1) | Woodworking Plans and Photos | |||
tennis ball steady rest - tennis ball.jpg (1/1) | Woodworking Plans and Photos | |||
machining my first PCB | Metalworking | |||
You Want To See Big Machining? | Metalworking |