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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. |
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#1
Posted to rec.crafts.metalworking
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A Better Hinge
http://tacklemaker.info/index.php?ac...sa=view;pic=31
You shouldn't need to be logged on to see the image. This is a pretty typical lead casting (sinkers, jigs, spinnerbaits, etc) mold. The hinge shown works pretty darn well. It moves easily, and does a good job of helping to hold the mold halves in alignment at the hinge end. The opening (handle side) end has two alignment pins with radius ends that mate the plates at that end. Over all my customers are atleast acceptably happy with it. However to make a mold like this that finishes as to 1/2 inch (apx) plates with a hinge I start out by throwing away a third of the raw material. Basically I start with 3/4 inch flat bar and remove 1/4 inch to leave the 1/4" hinge bosses. It just irks me to throw away 33% of the raw material on every one of these molds. No. Bolting a flat metal hinge to the ends is NOT a better way. It simply will not hold up over time, and even if its handled with kid gloves the heat cycling will cause it to work loose. I've seen molds made by other mold makers with tacked on hinges, and they get pretty beat up and very sloppy over time. It often results in damage to the mold itself. Especially if cores, pins, and other inserts or materials need to be placed in the mold before casting. These one piece boss pinned hinges last through thousands of heat cycles. I've done larger molds this same way that customers have told me they have literally run tons of lead through. It would also require another setup to drill and tap to tack on a sheet metal hinge. Casting a billet with preformed mold bosses is not a great answer either. The aluminum that results is more porous with the type of foundry I could setup, and my quantity is to small to have them forged cost efficiently. I think it might also drive up the per unit cost too much unless I could cast or forge them in great quantities. On top of that castings or forgings then have other machining that needs to be done to make them useable. One mold company sells cast "blanks, but I absolutely hate to work with them because the metal doesn't machine as nicely and the surfaces are more of a pain to square up and also keep the hinges squared up with both haves coming out aligned. I did think of maybe using a third piece between the two plates with 4 pins instead of the two I use now, but then it would not help as much with mold alignment. It would also be slower and more cludgy for the customer to use the mold. Every idea I come up with is also more manual work, or more secondary setup work. Maybe they way I am doing it is the best way to get a decent result within my work constraints, but I can't help but wonder if there isn't a better way. Tangent: If anybody is curious. No I do not use a round over mill to get the hinge bosses. I tried that in the past and I was not happy with it at all. I cnc mill a radius on the boss with a .001 depth of cut and then sand smooth when it comes off the mold. It would be faster to use a round over mill, but because of the lead on the cutting flutes and lack of consistency from one to the next it would waste part of the useable surface of the mold plates. Make larger mold blanks to make up for it then means slightly higher (few cents per unit atleast) material cost and higher machine time clearing the face of the blank. It works out to be a wash on that for cost and produces a CNC cutting the radius gives better result in my opinion. |
#2
Posted to rec.crafts.metalworking
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A Better Hinge
"Bob La Londe" wrote in message news
http://tacklemaker.info/index.php?ac...sa=view;pic=31 You shouldn't need to be logged on to see the image. This is a pretty typical lead casting (sinkers, jigs, spinnerbaits, etc) mold. The hinge shown works pretty darn well. It moves easily, and does a good job of helping to hold the mold halves in alignment at the hinge end. The opening (handle side) end has two alignment pins with radius ends that mate the plates at that end. Over all my customers are atleast acceptably happy with it. However to make a mold like this that finishes as to 1/2 inch (apx) plates with a hinge I start out by throwing away a third of the raw material. Basically I start with 3/4 inch flat bar and remove 1/4 inch to leave the 1/4" hinge bosses. It just irks me to throw away 33% of the raw material on every one of these molds. No. Bolting a flat metal hinge to the ends is NOT a better way. It simply will not hold up over time, and even if its handled with kid gloves the heat cycling will cause it to work loose. I've seen molds made by other mold makers with tacked on hinges, and they get pretty beat up and very sloppy over time. It often results in damage to the mold itself. Especially if cores, pins, and other inserts or materials need to be placed in the mold before casting. These one piece boss pinned hinges last through thousands of heat cycles. I've done larger molds this same way that customers have told me they have literally run tons of lead through. It would also require another setup to drill and tap to tack on a sheet metal hinge. Casting a billet with preformed mold bosses is not a great answer either. The aluminum that results is more porous with the type of foundry I could setup, and my quantity is to small to have them forged cost efficiently. I think it might also drive up the per unit cost too much unless I could cast or forge them in great quantities. On top of that castings or forgings then have other machining that needs to be done to make them useable. One mold company sells cast "blanks, but I absolutely hate to work with them because the metal doesn't machine as nicely and the surfaces are more of a pain to square up and also keep the hinges squared up with both haves coming out aligned. I did think of maybe using a third piece between the two plates with 4 pins instead of the two I use now, but then it would not help as much with mold alignment. It would also be slower and more cludgy for the customer to use the mold. Every idea I come up with is also more manual work, or more secondary setup work. Maybe they way I am doing it is the best way to get a decent result within my work constraints, but I can't help but wonder if there isn't a better way. Tangent: If anybody is curious. No I do not use a round over mill to get the hinge bosses. I tried that in the past and I was not happy with it at all. I cnc mill a radius on the boss with a .001 depth of cut and then sand smooth when it comes off the mold. It would be faster to use a round over mill, but because of the lead on the cutting flutes and lack of consistency from one to the next it would waste part of the useable surface of the mold plates. Make larger mold blanks to make up for it then means slightly higher (few cents per unit atleast) material cost and higher machine time clearing the face of the blank. It works out to be a wash on that for cost and produces a CNC cutting the radius gives better result in my opinion. *************** I sure need to remember to proof read before I hit send. |
#3
Posted to rec.crafts.metalworking
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A Better Hinge
On Friday, July 21, 2017 at 5:59:05 PM UTC-4, Bob La Londe wrote:
http://tacklemaker.info/index.php?ac...sa=view;pic=31 You shouldn't need to be logged on to see the image. This is a pretty typical lead casting (sinkers, jigs, spinnerbaits, etc) mold. The hinge shown works pretty darn well. It moves easily, and does a good job of helping to hold the mold halves in alignment at the hinge end. The opening (handle side) end has two alignment pins with radius ends that mate the plates at that end. Over all my customers are atleast acceptably happy with it. However to make a mold like this that finishes as to 1/2 inch (apx) plates with a hinge I start out by throwing away a third of the raw material. Basically I start with 3/4 inch flat bar and remove 1/4 inch to leave the 1/4" hinge bosses. It just irks me to throw away 33% of the raw material on every one of these molds. No. Bolting a flat metal hinge to the ends is NOT a better way. It simply will not hold up over time, and even if its handled with kid gloves the heat cycling will cause it to work loose. I've seen molds made by other mold makers with tacked on hinges, and they get pretty beat up and very sloppy over time. It often results in damage to the mold itself. Especially if cores, pins, and other inserts or materials need to be placed in the mold before casting. These one piece boss pinned hinges last through thousands of heat cycles. I've done larger molds this same way that customers have told me they have literally run tons of lead through. It would also require another setup to drill and tap to tack on a sheet metal hinge. Casting a billet with preformed mold bosses is not a great answer either. The aluminum that results is more porous with the type of foundry I could setup, and my quantity is to small to have them forged cost efficiently. I think it might also drive up the per unit cost too much unless I could cast or forge them in great quantities. On top of that castings or forgings then have other machining that needs to be done to make them useable. One mold company sells cast "blanks, but I absolutely hate to work with them because the metal doesn't machine as nicely and the surfaces are more of a pain to square up and also keep the hinges squared up with both haves coming out aligned. I did think of maybe using a third piece between the two plates with 4 pins instead of the two I use now, but then it would not help as much with mold alignment. It would also be slower and more cludgy for the customer to use the mold. Every idea I come up with is also more manual work, or more secondary setup work. Maybe they way I am doing it is the best way to get a decent result within my work constraints, but I can't help but wonder if there isn't a better way. Tangent: If anybody is curious. No I do not use a round over mill to get the hinge bosses. I tried that in the past and I was not happy with it at all. I cnc mill a radius on the boss with a .001 depth of cut and then sand smooth when it comes off the mold. It would be faster to use a round over mill, but because of the lead on the cutting flutes and lack of consistency from one to the next it would waste part of the useable surface of the mold plates. Make larger mold blanks to make up for it then means slightly higher (few cents per unit atleast) material cost and higher machine time clearing the face of the blank. It works out to be a wash on that for cost and produces a CNC cutting the radius gives better result in my opinion. Why not make the mold bosses separately, and have them drop into pockets in the mold, then get pinned or bolted in place? You could make them rectangular to keep them in alignment. Much like a mortise & tenon. |
#4
Posted to rec.crafts.metalworking
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A Better Hinge
On Fri, 21 Jul 2017 14:58:58 -0700, "Bob La Londe"
wrote: Basically I start with 3/4 inch flat bar and remove 1/4 inch to leave the 1/4" hinge bosses. It just irks me to throw away 33% of the raw material on every one of these molds. Unequal leg angle or a custom extrusion are the two thoughts that come to mind. -- William |
#5
Posted to rec.crafts.metalworking
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A Better Hinge
Bob La Londe wrote:
http://tacklemaker.info/index.php?ac...sa=view;pic=31 You shouldn't need to be logged on to see the image. This is a pretty typical lead casting (sinkers, jigs, spinnerbaits, etc) mold. The hinge shown works pretty darn well. It moves easily, and does a good job of helping to hold the mold halves in alignment at the hinge end. The opening (handle side) end has two alignment pins with radius ends that mate the plates at that end. Over all my customers are atleast acceptably happy with it. However to make a mold like this that finishes as to 1/2 inch (apx) plates with a hinge I start out by throwing away a third of the raw material. Basically I start with 3/4 inch flat bar and remove 1/4 inch to leave the 1/4" hinge bosses. It just irks me to throw away 33% of the raw material on every one of these molds. No. Bolting a flat metal hinge to the ends is NOT a better way. It simply will not hold up over time, and even if its handled with kid gloves the heat cycling will cause it to work loose. I've seen molds made by other mold makers with tacked on hinges, and they get pretty beat up and very sloppy over time. It often results in damage to the mold itself. Especially if cores, pins, and other inserts or materials need to be placed in the mold before casting. These one piece boss pinned hinges last through thousands of heat cycles. I've done larger molds this same way that customers have told me they have literally run tons of lead through. It would also require another setup to drill and tap to tack on a sheet metal hinge. Casting a billet with preformed mold bosses is not a great answer either. The aluminum that results is more porous with the type of foundry I could setup, and my quantity is to small to have them forged cost efficiently. I think it might also drive up the per unit cost too much unless I could cast or forge them in great quantities. On top of that castings or forgings then have other machining that needs to be done to make them useable. One mold company sells cast "blanks, but I absolutely hate to work with them because the metal doesn't machine as nicely and the surfaces are more of a pain to square up and also keep the hinges squared up with both haves coming out aligned. I did think of maybe using a third piece between the two plates with 4 pins instead of the two I use now, but then it would not help as much with mold alignment. It would also be slower and more cludgy for the customer to use the mold. Every idea I come up with is also more manual work, or more secondary setup work. Maybe they way I am doing it is the best way to get a decent result within my work constraints, but I can't help but wonder if there isn't a better way. Tangent: If anybody is curious. No I do not use a round over mill to get the hinge bosses. I tried that in the past and I was not happy with it at all. I cnc mill a radius on the boss with a .001 depth of cut and then sand smooth when it comes off the mold. It would be faster to use a round over mill, but because of the lead on the cutting flutes and lack of consistency from one to the next it would waste part of the useable surface of the mold plates. Make larger mold blanks to make up for it then means slightly higher (few cents per unit atleast) material cost and higher machine time clearing the face of the blank. It works out to be a wash on that for cost and produces a CNC cutting the radius gives better result in my opinion. How about machining the ends to use something like size 50 motorcycle chain. Basically a pivot on each half. Then machine in 2 more alignment pins to ensure proper closure. That would allow you to start with 1/2". Sort of how hinged hand cuffs work. -- Steve W. |
#6
Posted to rec.crafts.metalworking
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A Better Hinge
"Bob La Londe" wrote in message
news http://tacklemaker.info/index.php?ac...sa=view;pic=31 You shouldn't need to be logged on to see the image. How does MIG welding a thicker bar on the end compare in cost and effort? You could mill steps for the beads in the end to retain strength and minimize cleanup. |
#7
Posted to rec.crafts.metalworking
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A Better Hinge
"William Bagwell" wrote in message
... On Fri, 21 Jul 2017 14:58:58 -0700, "Bob La Londe" wrote: Basically I start with 3/4 inch flat bar and remove 1/4 inch to leave the 1/4" hinge bosses. It just irks me to throw away 33% of the raw material on every one of these molds. Unequal leg angle or a custom extrusion are the two thoughts that come to mind. -- William I may not go this way, but those are both ideas I had not thought of. Unequal leg angle would be very good if I could find the right one. Think they make one that's 1x6x1/2? Suitable unequal leg angle would probably have to be your second idea. A custom extrusion. Maybe a couple of them. If my work volume gets that high I might consider something like that. |
#8
Posted to rec.crafts.metalworking
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A Better Hinge
"Steve W." wrote in message news
Bob La Londe wrote: http://tacklemaker.info/index.php?ac...sa=view;pic=31 You shouldn't need to be logged on to see the image. This is a pretty typical lead casting (sinkers, jigs, spinnerbaits, etc) mold. The hinge shown works pretty darn well. It moves easily, and does a good job of helping to hold the mold halves in alignment at the hinge end. The opening (handle side) end has two alignment pins with radius ends that mate the plates at that end. Over all my customers are atleast acceptably happy with it. However to make a mold like this that finishes as to 1/2 inch (apx) plates with a hinge I start out by throwing away a third of the raw material. Basically I start with 3/4 inch flat bar and remove 1/4 inch to leave the 1/4" hinge bosses. It just irks me to throw away 33% of the raw material on every one of these molds. No. Bolting a flat metal hinge to the ends is NOT a better way. It simply will not hold up over time, and even if its handled with kid gloves the heat cycling will cause it to work loose. I've seen molds made by other mold makers with tacked on hinges, and they get pretty beat up and very sloppy over time. It often results in damage to the mold itself. Especially if cores, pins, and other inserts or materials need to be placed in the mold before casting. These one piece boss pinned hinges last through thousands of heat cycles. I've done larger molds this same way that customers have told me they have literally run tons of lead through. It would also require another setup to drill and tap to tack on a sheet metal hinge. Casting a billet with preformed mold bosses is not a great answer either. The aluminum that results is more porous with the type of foundry I could setup, and my quantity is to small to have them forged cost efficiently. I think it might also drive up the per unit cost too much unless I could cast or forge them in great quantities. On top of that castings or forgings then have other machining that needs to be done to make them useable. One mold company sells cast "blanks, but I absolutely hate to work with them because the metal doesn't machine as nicely and the surfaces are more of a pain to square up and also keep the hinges squared up with both haves coming out aligned. I did think of maybe using a third piece between the two plates with 4 pins instead of the two I use now, but then it would not help as much with mold alignment. It would also be slower and more cludgy for the customer to use the mold. Every idea I come up with is also more manual work, or more secondary setup work. Maybe they way I am doing it is the best way to get a decent result within my work constraints, but I can't help but wonder if there isn't a better way. Tangent: If anybody is curious. No I do not use a round over mill to get the hinge bosses. I tried that in the past and I was not happy with it at all. I cnc mill a radius on the boss with a .001 depth of cut and then sand smooth when it comes off the mold. It would be faster to use a round over mill, but because of the lead on the cutting flutes and lack of consistency from one to the next it would waste part of the useable surface of the mold plates. Make larger mold blanks to make up for it then means slightly higher (few cents per unit atleast) material cost and higher machine time clearing the face of the blank. It works out to be a wash on that for cost and produces a CNC cutting the radius gives better result in my opinion. How about machining the ends to use something like size 50 motorcycle chain. Basically a pivot on each half. Then machine in 2 more alignment pins to ensure proper closure. That would allow you to start with 1/2". Sort of how hinged hand cuffs work. ************ Yeah Steve I have considered a connecting link type design. I'm not convinced its equal or better, but it would definitely reduce wasted raw stock. Its a good idea. |
#9
Posted to rec.crafts.metalworking
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A Better Hinge
"Jim Wilkins" wrote in message news "Bob La Londe" wrote in message news http://tacklemaker.info/index.php?ac...sa=view;pic=31 You shouldn't need to be logged on to see the image. How does MIG welding a thicker bar on the end compare in cost and effort? You could mill steps for the beads in the end to retain strength and minimize cleanup. ******** I hadn't thought of that. I do have a MIG with a spool gun for welding aluminum. I'm not very good, but I expect for a repetitive weld I could setup, make a couple practice passes, and then do several at a time. I'm not sure that overall its the best solution for me, but it is a good idea. P.S. When I was learning to make molds, I had my first ultralight CNC mill, and stock was more precious to me since I wasn't making any money with it I often welded up mistakes in a plate and remachined it. |
#10
Posted to rec.crafts.metalworking
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A Better Hinge
Bob La Londe wrote:
"Steve W." wrote in message news How about machining the ends to use something like size 50 motorcycle chain. Basically a pivot on each half. Then machine in 2 more alignment pins to ensure proper closure. That would allow you to start with 1/2". Sort of how hinged hand cuffs work. ************ Yeah Steve I have considered a connecting link type design. I'm not convinced its equal or better, but it would definitely reduce wasted raw stock. It’s a good idea. Machine one up and beat it to death in testing. -- Steve W. |
#11
Posted to rec.crafts.metalworking
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A Better Hinge
"rangerssuck" wrote in message
... On Friday, July 21, 2017 at 5:59:05 PM UTC-4, Bob La Londe wrote: http://tacklemaker.info/index.php?ac...sa=view;pic=31 You shouldn't need to be logged on to see the image. This is a pretty typical lead casting (sinkers, jigs, spinnerbaits, etc) mold. The hinge shown works pretty darn well. It moves easily, and does a good job of helping to hold the mold halves in alignment at the hinge end. The opening (handle side) end has two alignment pins with radius ends that mate the plates at that end. Over all my customers are atleast acceptably happy with it. However to make a mold like this that finishes as to 1/2 inch (apx) plates with a hinge I start out by throwing away a third of the raw material. Basically I start with 3/4 inch flat bar and remove 1/4 inch to leave the 1/4" hinge bosses. It just irks me to throw away 33% of the raw material on every one of these molds. No. Bolting a flat metal hinge to the ends is NOT a better way. It simply will not hold up over time, and even if its handled with kid gloves the heat cycling will cause it to work loose. I've seen molds made by other mold makers with tacked on hinges, and they get pretty beat up and very sloppy over time. It often results in damage to the mold itself. Especially if cores, pins, and other inserts or materials need to be placed in the mold before casting. These one piece boss pinned hinges last through thousands of heat cycles. I've done larger molds this same way that customers have told me they have literally run tons of lead through. It would also require another setup to drill and tap to tack on a sheet metal hinge. Casting a billet with preformed mold bosses is not a great answer either. The aluminum that results is more porous with the type of foundry I could setup, and my quantity is to small to have them forged cost efficiently. I think it might also drive up the per unit cost too much unless I could cast or forge them in great quantities. On top of that castings or forgings then have other machining that needs to be done to make them useable. One mold company sells cast "blanks, but I absolutely hate to work with them because the metal doesn't machine as nicely and the surfaces are more of a pain to square up and also keep the hinges squared up with both haves coming out aligned. I did think of maybe using a third piece between the two plates with 4 pins instead of the two I use now, but then it would not help as much with mold alignment. It would also be slower and more cludgy for the customer to use the mold. Every idea I come up with is also more manual work, or more secondary setup work. Maybe they way I am doing it is the best way to get a decent result within my work constraints, but I can't help but wonder if there isn't a better way. Tangent: If anybody is curious. No I do not use a round over mill to get the hinge bosses. I tried that in the past and I was not happy with it at all. I cnc mill a radius on the boss with a .001 depth of cut and then sand smooth when it comes off the mold. It would be faster to use a round over mill, but because of the lead on the cutting flutes and lack of consistency from one to the next it would waste part of the useable surface of the mold plates. Make larger mold blanks to make up for it then means slightly higher (few cents per unit atleast) material cost and higher machine time clearing the face of the blank. It works out to be a wash on that for cost and produces a CNC cutting the radius gives better result in my opinion. Why not make the mold bosses separately, and have them drop into pockets in the mold, then get pinned or bolted in place? You could make them rectangular to keep them in alignment. Much like a mortise & tenon. ************ That is a possible consideration. It deserves atleast weighing the extra operation time vs the time saved roughing off stock and the better cost efficiency on material. A press fit dovetail with a locking screw might make for quick assembly. If I do a really good job it might even eliminate one of my other secondary operations. Another good idea to think about. |
#12
Posted to rec.crafts.metalworking
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A Better Hinge
"Bob La Londe" wrote in message
news "Jim Wilkins" wrote in message news "Bob La Londe" wrote in message news http://tacklemaker.info/index.php?ac...sa=view;pic=31 You shouldn't need to be logged on to see the image. How does MIG welding a thicker bar on the end compare in cost and effort? You could mill steps for the beads in the end to retain strength and minimize cleanup. ******** I hadn't thought of that. I do have a MIG with a spool gun for welding aluminum. I'm not very good, but I expect for a repetitive weld I could setup, make a couple practice passes, and then do several at a time. I'm not sure that overall it's the best solution for me, but it is a good idea. P.S. When I was learning to make molds, I had my first ultralight CNC mill, and stock was more precious to me since I wasn't making any money with it I often welded up mistakes in a plate and remachined it. Personally I'd sub that job to a certified welder friend who is much better than I'll ever be, and ask him how he wanted the parts prepared so that the beads stay below the upper and lower surfaces. I am better on steel and build up shapes like bending brake hinge forks that would require removing a lot of metal from a solid block. -jsw |
#13
Posted to rec.crafts.metalworking
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A Better Hinge
"Jim Wilkins" wrote in message news
"Bob La Londe" wrote in message news "Jim Wilkins" wrote in message news "Bob La Londe" wrote in message news http://tacklemaker.info/index.php?ac...sa=view;pic=31 You shouldn't need to be logged on to see the image. How does MIG welding a thicker bar on the end compare in cost and effort? You could mill steps for the beads in the end to retain strength and minimize cleanup. ******** I hadn't thought of that. I do have a MIG with a spool gun for welding aluminum. I'm not very good, but I expect for a repetitive weld I could setup, make a couple practice passes, and then do several at a time. I'm not sure that overall it's the best solution for me, but it is a good idea. P.S. When I was learning to make molds, I had my first ultralight CNC mill, and stock was more precious to me since I wasn't making any money with it I often welded up mistakes in a plate and remachined it. Personally I'd sub that job to a certified welder friend who is much better than I'll ever be, and ask him how he wanted the parts prepared so that the beads stay below the upper and lower surfaces. ********* Now that's something I won't do. I used to just try to take certain types of welding jobs over to the professional shops and leave it. I'd ask how long, and that's when I'd come back to pick it up. I would never bother them in between. The job was never ever done when they said. Not one time. Usually I was told 2 more weeks several times (after an intitial 3-6 week time window) before they finally did the job The last two times it was done wrong. I just quit. Sure I get that Mr big farm owner or Mr government contractor is a more important customer. I knew that up front that's why I just asked how long and left. Its why I ultimately bought a decent dual gun MIG welder and learned to weld aluminum in the first place. No point in taking paying work to them if I can't get it done. I'm not good, but my welds don't break either and ultimately they get done when I want them done. Had nothing to do with money. I spent a lot on the welder. I took a lot of years to pay it off. I'd have rather just had somebody do it and not worry about it. Its why I work on a lot of my own stuff. |
#14
Posted to rec.crafts.metalworking
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A Better Hinge
On Sat, 22 Jul 2017 15:57:07 -0700, "Bob La Londe"
wrote: "Jim Wilkins" wrote in message news "Bob La Londe" wrote in message news "Jim Wilkins" wrote in message news "Bob La Londe" wrote in message news http://tacklemaker.info/index.php?ac...sa=view;pic=31 You shouldn't need to be logged on to see the image. How does MIG welding a thicker bar on the end compare in cost and effort? You could mill steps for the beads in the end to retain strength and minimize cleanup. ******** I hadn't thought of that. I do have a MIG with a spool gun for welding aluminum. I'm not very good, but I expect for a repetitive weld I could setup, make a couple practice passes, and then do several at a time. I'm not sure that overall it's the best solution for me, but it is a good idea. P.S. When I was learning to make molds, I had my first ultralight CNC mill, and stock was more precious to me since I wasn't making any money with it I often welded up mistakes in a plate and remachined it. Personally I'd sub that job to a certified welder friend who is much better than I'll ever be, and ask him how he wanted the parts prepared so that the beads stay below the upper and lower surfaces. ********* Now that's something I won't do. I used to just try to take certain types of welding jobs over to the professional shops and leave it. I'd ask how long, and that's when I'd come back to pick it up. I would never bother them in between. The job was never ever done when they said. Not one time. Usually I was told 2 more weeks several times (after an intitial 3-6 week time window) before they finally did the job The last two times it was done wrong. I just quit. Sure I get that Mr big farm owner or Mr government contractor is a more important customer. I knew that up front that's why I just asked how long and left. Its why I ultimately bought a decent dual gun MIG welder and learned to weld aluminum in the first place. No point in taking paying work to them if I can't get it done. I'm not good, but my welds don't break either and ultimately they get done when I want them done. Had nothing to do with money. I spent a lot on the welder. I took a lot of years to pay it off. I'd have rather just had somebody do it and not worry about it. Its why I work on a lot of my own stuff. I don't know if it is worth the bother but you might want to look at Lyman bullet molds. The hinge is in the handles and the mold is simply two blocks aligned with pins. see https://tinyurl.com/yamk6h5f -- Cheers, John B. |
#15
Posted to rec.crafts.metalworking
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A Better Hinge
"Jon B. Slocomb" wrote in message ... On Sat, 22 Jul 2017 15:57:07 -0700, "Bob La Londe" wrote: "Jim Wilkins" wrote in message news "Bob La Londe" wrote in message news "Jim Wilkins" wrote in message news "Bob La Londe" wrote in message news http://tacklemaker.info/index.php?ac...sa=view;pic=31 You shouldn't need to be logged on to see the image. How does MIG welding a thicker bar on the end compare in cost and effort? You could mill steps for the beads in the end to retain strength and minimize cleanup. ******** I hadn't thought of that. I do have a MIG with a spool gun for welding aluminum. I'm not very good, but I expect for a repetitive weld I could setup, make a couple practice passes, and then do several at a time. I'm not sure that overall it's the best solution for me, but it is a good idea. P.S. When I was learning to make molds, I had my first ultralight CNC mill, and stock was more precious to me since I wasn't making any money with it I often welded up mistakes in a plate and remachined it. Personally I'd sub that job to a certified welder friend who is much better than I'll ever be, and ask him how he wanted the parts prepared so that the beads stay below the upper and lower surfaces. ********* Now that's something I won't do. I used to just try to take certain types of welding jobs over to the professional shops and leave it. I'd ask how long, and that's when I'd come back to pick it up. I would never bother them in between. The job was never ever done when they said. Not one time. Usually I was told 2 more weeks several times (after an intitial 3-6 week time window) before they finally did the job The last two times it was done wrong. I just quit. Sure I get that Mr big farm owner or Mr government contractor is a more important customer. I knew that up front that's why I just asked how long and left. Its why I ultimately bought a decent dual gun MIG welder and learned to weld aluminum in the first place. No point in taking paying work to them if I can't get it done. I'm not good, but my welds don't break either and ultimately they get done when I want them done. Had nothing to do with money. I spent a lot on the welder. I took a lot of years to pay it off. I'd have rather just had somebody do it and not worry about it. Its why I work on a lot of my own stuff. I don't know if it is worth the bother but you might want to look at Lyman bullet molds. The hinge is in the handles and the mold is simply two blocks aligned with pins. see https://tinyurl.com/yamk6h5f ************* Thats a decent idea John. I actually have some Lyman and Lee stuff, and atleast on paper I am a dealer for Lee Precision. Unfortunately those molds do not open far enough to load hooks, pins, screws locks, wire forms, etc, easily. Its definitely a good form for bullet molds and allows a home boo-lit caster to own several molds and only one set of handles. Thanks for the thought John. |
#16
Posted to rec.crafts.metalworking
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A Better Hinge
On Friday, July 21, 2017 at 2:59:05 PM UTC-7, Bob La Londe wrote:
This is a pretty typical lead casting (sinkers, jigs, spinnerbaits, etc) mold. The hinge shown works pretty darn well. It moves easily, and does a good job of helping to hold the mold halves in alignment at the hinge end. The opening (handle side) end has two alignment pins with radius ends There's some options with extra parts (mainly, though, I don't like loose parts...). In particular, your alignment pins could go through the mold and a wedge can snug the halves together. On a lathe, it's only gonna take a bit of a head on the protruding pin end, that engages an external wedge of the sloped-metal-with-keyhole type. With a CNC setup, the wedge can be simpler, if you slot the pin, but that might eventually score the mold. Internal wedge (like for Morse taper release) also needs a radius'ed edge; |
#17
Posted to rec.crafts.metalworking
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A Better Hinge
On Friday, July 21, 2017 at 2:59:05 PM UTC-7, Bob La Londe wrote:
This is a pretty typical lead casting (sinkers, jigs, spinnerbaits, etc) mold. The hinge shown works pretty darn well. It moves easily, and does a good job of helping to hold the mold halves in alignment at the hinge end. The opening (handle side) end has two alignment pins with radius ends Just to go further outside the box, if you have a hydraulic press you could bend a short L on the end of your bar to give you the raised material for your hinge. You'll get some distortion between the edge of the die and the bend so you will have to make your mold maybe 1/2" or 3/4" longer than before. Either keep the radius large to prevent cracking or set up a torch (or crab pot propane burner) and firebrick oven with a slot just big enough to stick in the end you are about to bend and experiment with how hot you need. The $30 harborfreight IR thermometer (frequently on sale or coupon for $20) goes to 968F for easy measurement. Most cheap ones don't go nearly that high. Not sure what the emissivity of aluminum is up there so you need to calibrate if you want actual accuracy but reproducibility should be good and you will just keep trying an indicated 25F higher each time until you get a good bend so who cares :-). Definitely want a real press brake or air over hydraulic for speed, then quench in water immediately after bending. I've done the heat and bend but never bothered with this but if you want maximum strength you could age at 400F for an hour to get the region you heated somewhere near T5 while the rest should still be pretty much T6. -- Regards, Carl Ijames |
#18
Posted to rec.crafts.metalworking
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A Better Hinge
"Carl Ijames" wrote in message news
On Friday, July 21, 2017 at 2:59:05 PM UTC-7, Bob La Londe wrote: This is a pretty typical lead casting (sinkers, jigs, spinnerbaits, etc) mold. The hinge shown works pretty darn well. It moves easily, and does a good job of helping to hold the mold halves in alignment at the hinge end. The opening (handle side) end has two alignment pins with radius ends Just to go further outside the box, if you have a hydraulic press you could bend a short L on the end of your bar to give you the raised material for your hinge. You'll get some distortion between the edge of the die and the bend so you will have to make your mold maybe 1/2" or 3/4" longer than before. Either keep the radius large to prevent cracking or set up a torch (or crab pot propane burner) and firebrick oven with a slot just big enough to stick in the end you are about to bend and experiment with how hot you need. The $30 harborfreight IR thermometer (frequently on sale or coupon for $20) goes to 968F for easy measurement. Most cheap ones don't go nearly that high. Not sure what the emissivity of aluminum is up there so you need to calibrate if you want actual accuracy but reproducibility should be good and you will just keep trying an indicated 25F higher each time until you get a good bend so who cares :-). Definitely want a real press brake or air over hydraulic for speed, then quench in water immediately after bending. I've done the heat and bend but never bothered with this but if you want maximum strength you could age at 400F for an hour to get the region you heated somewhere near T5 while the rest should still be pretty much T6. -- Regards, Carl Ijames ************** Yer jacking with me right? (pun intended) |
#19
Posted to rec.crafts.metalworking
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A Better Hinge
On 7/21/2017 5:58 PM, Bob La Londe wrote:
http://tacklemaker.info/index.php?ac...sa=view;pic=31 You shouldn't need to be logged on to see the image. This is a pretty typical lead casting (sinkers, jigs, spinnerbaits, etc) mold. The hinge shown works pretty darn well. It moves easily, and does a good job of helping to hold the mold halves in alignment at the hinge end. The opening (handle side) end has two alignment pins with radius ends that mate the plates at that end. Over all my customers are atleast acceptably happy with it. However to make a mold like this that finishes as to 1/2 inch (apx) plates with a hinge I start out by throwing away a third of the raw material. Basically I start with 3/4 inch flat bar and remove 1/4 inch to leave the 1/4" hinge bosses. It just irks me to throw away 33% of the raw material on every one of these molds. No. Bolting a flat metal hinge to the ends is NOT a better way. It simply will not hold up over time, and even if its handled with kid gloves the heat cycling will cause it to work loose. I've seen molds made by other mold makers with tacked on hinges, and they get pretty beat up and very sloppy over time. It often results in damage to the mold itself. Especially if cores, pins, and other inserts or materials need to be placed in the mold before casting. These one piece boss pinned hinges last through thousands of heat cycles. I've done larger molds this same way that customers have told me they have literally run tons of lead through. It would also require another setup to drill and tap to tack on a sheet metal hinge. Casting a billet with preformed mold bosses is not a great answer either. The aluminum that results is more porous with the type of foundry I could setup, and my quantity is to small to have them forged cost efficiently. I think it might also drive up the per unit cost too much unless I could cast or forge them in great quantities. On top of that castings or forgings then have other machining that needs to be done to make them useable. One mold company sells cast "blanks, but I absolutely hate to work with them because the metal doesn't machine as nicely and the surfaces are more of a pain to square up and also keep the hinges squared up with both haves coming out aligned. I did think of maybe using a third piece between the two plates with 4 pins instead of the two I use now, but then it would not help as much with mold alignment. It would also be slower and more cludgy for the customer to use the mold. Every idea I come up with is also more manual work, or more secondary setup work. Maybe they way I am doing it is the best way to get a decent result within my work constraints, but I can't help but wonder if there isn't a better way. Tangent: If anybody is curious. No I do not use a round over mill to get the hinge bosses. I tried that in the past and I was not happy with it at all. I cnc mill a radius on the boss with a .001 depth of cut and then sand smooth when it comes off the mold. It would be faster to use a round over mill, but because of the lead on the cutting flutes and lack of consistency from one to the next it would waste part of the useable surface of the mold plates. Make larger mold blanks to make up for it then means slightly higher (few cents per unit atleast) material cost and higher machine time clearing the face of the blank. It works out to be a wash on that for cost and produces a CNC cutting the radius gives better result in my opinion. --- This email has been checked for viruses by AVG. http://www.avg.com Build the hinge separately, then dowel and bolt it to the ends of the mold halves. |
#20
Posted to rec.crafts.metalworking
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A Better Hinge
On Mon, 31 Jul 2017 10:04:41 -0700, "Bob La Londe"
wrote: SNIP Greetings Bob, I'm curious about your description of the faults of round over cutters. I use some HSS ones but for steel I use mostly carbide cutters. In fact, I use carbide cutters almost exclusively now. I have old HSS ones in many sizes and only use them when I don't have a carbide one. If I have to do a lot of milling I buy another carbide one if all I have is the HSS version. But even the HSS ones cut accurate radii. As far as neding extra mayerial all the cutters I use would be able to mill the bosses as shown. I also have and use cutters that can mill the bosses in one pass but you would need to stand the molds up which would require another setup. One of the reasons I like the carbide cutters is that they are ground with a finer finish so the parts look better. I also sometimes use carbide router bits meant for wood to machine metal, even stainless steels. They typically have a pretty rough grind on them which leaves a poor finish on the parts. To correct this I make a brass lap, charge it with diamond paste, and lap the router bit cutting edges to a much finer finish. This process doesn't take long. Carbide router bits have saved my butt a few times when I have forgotten to order a cutter or when a cutter fails for some reason. Living on an island makes getting cutters in a hurry tough. Eric ********************** I have only purchased a few round over mills, but they all have all seem to have a slight angled lead to the radius area. Also, I haven't found a standard for the overall geometry and dimensions for the rest of the cutter that I can use to program the cut. I use them all the time to rough radius the end of alignment pins on the lathe, but on the mill I would only use them on outside edges. The inside edge needs a clearance cut on those I have in order to cut the radius. I did that before, but I only over did them on the manual mill to finish after the mold was complete. I never cared for it. That was time I WAS NOT spending doing design and setup work. The other issue I have is power and speed. The round over mills really are not IMO well suited for high speed milling. I can't low speed mill on the 24K high high speed spindles. They really have about zero torque under 10K. Oh, yes. I have used router bits in a pinch many times. Since I also have a small CNC router I do have a decent selection of router bits on hand at any given time. Bob-you can run a .375 dia. carbide round over bit at 20,000 RPM on aluminum. The carbide bits I use have a lead into the radius but the complete 90 degrees of curve is there. They have a different grind than the HSS ones. And as my mom would say "They go like sixty". Eric |
#21
Posted to rec.crafts.metalworking
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A Better Hinge
"Steve Walker" wrote in message
... On 7/21/2017 5:58 PM, Bob La Londe wrote: http://tacklemaker.info/index.php?ac...sa=view;pic=31 You shouldn't need to be logged on to see the image. This is a pretty typical lead casting (sinkers, jigs, spinnerbaits, etc) mold. The hinge shown works pretty darn well. It moves easily, and does a good job of helping to hold the mold halves in alignment at the hinge end. The opening (handle side) end has two alignment pins with radius ends that mate the plates at that end. Over all my customers are atleast acceptably happy with it. However to make a mold like this that finishes as to 1/2 inch (apx) plates with a hinge I start out by throwing away a third of the raw material. Basically I start with 3/4 inch flat bar and remove 1/4 inch to leave the 1/4" hinge bosses. It just irks me to throw away 33% of the raw material on every one of these molds. No. Bolting a flat metal hinge to the ends is NOT a better way. It simply will not hold up over time, and even if its handled with kid gloves the heat cycling will cause it to work loose. I've seen molds made by other mold makers with tacked on hinges, and they get pretty beat up and very sloppy over time. It often results in damage to the mold itself. Especially if cores, pins, and other inserts or materials need to be placed in the mold before casting. These one piece boss pinned hinges last through thousands of heat cycles. I've done larger molds this same way that customers have told me they have literally run tons of lead through. It would also require another setup to drill and tap to tack on a sheet metal hinge. Casting a billet with preformed mold bosses is not a great answer either. The aluminum that results is more porous with the type of foundry I could setup, and my quantity is to small to have them forged cost efficiently. I think it might also drive up the per unit cost too much unless I could cast or forge them in great quantities. On top of that castings or forgings then have other machining that needs to be done to make them useable. One mold company sells cast "blanks, but I absolutely hate to work with them because the metal doesn't machine as nicely and the surfaces are more of a pain to square up and also keep the hinges squared up with both haves coming out aligned. I did think of maybe using a third piece between the two plates with 4 pins instead of the two I use now, but then it would not help as much with mold alignment. It would also be slower and more cludgy for the customer to use the mold. Every idea I come up with is also more manual work, or more secondary setup work. Maybe they way I am doing it is the best way to get a decent result within my work constraints, but I can't help but wonder if there isn't a better way. Tangent: If anybody is curious. No I do not use a round over mill to get the hinge bosses. I tried that in the past and I was not happy with it at all. I cnc mill a radius on the boss with a .001 depth of cut and then sand smooth when it comes off the mold. It would be faster to use a round over mill, but because of the lead on the cutting flutes and lack of consistency from one to the next it would waste part of the useable surface of the mold plates. Make larger mold blanks to make up for it then means slightly higher (few cents per unit atleast) material cost and higher machine time clearing the face of the blank. It works out to be a wash on that for cost and produces a CNC cutting the radius gives better result in my opinion. --- This email has been checked for viruses by AVG. http://www.avg.com Build the hinge separately, then dowel and bolt it to the ends of the mold halves. *********** Thanks for the suggestion. |
#22
Posted to rec.crafts.metalworking
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A Better Hinge
"Bob La Londe" wrote in message
news "Steve Walker" wrote in message ... On 7/21/2017 5:58 PM, Bob La Londe wrote: http://tacklemaker.info/index.php?ac...sa=view;pic=31 You shouldn't need to be logged on to see the image. This is a pretty typical lead casting (sinkers, jigs, spinnerbaits, etc) mold. The hinge shown works pretty darn well. It moves easily, and does a good job of helping to hold the mold halves in alignment at the hinge end. The opening (handle side) end has two alignment pins with radius ends that mate the plates at that end. Over all my customers are atleast acceptably happy with it. However to make a mold like this that finishes as to 1/2 inch (apx) plates with a hinge I start out by throwing away a third of the raw material. Basically I start with 3/4 inch flat bar and remove 1/4 inch to leave the 1/4" hinge bosses. It just irks me to throw away 33% of the raw material on every one of these molds. No. Bolting a flat metal hinge to the ends is NOT a better way. It simply will not hold up over time, and even if its handled with kid gloves the heat cycling will cause it to work loose. I've seen molds made by other mold makers with tacked on hinges, and they get pretty beat up and very sloppy over time. It often results in damage to the mold itself. Especially if cores, pins, and other inserts or materials need to be placed in the mold before casting. These one piece boss pinned hinges last through thousands of heat cycles. I've done larger molds this same way that customers have told me they have literally run tons of lead through. It would also require another setup to drill and tap to tack on a sheet metal hinge. Casting a billet with preformed mold bosses is not a great answer either. The aluminum that results is more porous with the type of foundry I could setup, and my quantity is to small to have them forged cost efficiently. I think it might also drive up the per unit cost too much unless I could cast or forge them in great quantities. On top of that castings or forgings then have other machining that needs to be done to make them useable. One mold company sells cast "blanks, but I absolutely hate to work with them because the metal doesn't machine as nicely and the surfaces are more of a pain to square up and also keep the hinges squared up with both haves coming out aligned. I did think of maybe using a third piece between the two plates with 4 pins instead of the two I use now, but then it would not help as much with mold alignment. It would also be slower and more cludgy for the customer to use the mold. Every idea I come up with is also more manual work, or more secondary setup work. Maybe they way I am doing it is the best way to get a decent result within my work constraints, but I can't help but wonder if there isn't a better way. Tangent: If anybody is curious. No I do not use a round over mill to get the hinge bosses. I tried that in the past and I was not happy with it at all. I cnc mill a radius on the boss with a .001 depth of cut and then sand smooth when it comes off the mold. It would be faster to use a round over mill, but because of the lead on the cutting flutes and lack of consistency from one to the next it would waste part of the useable surface of the mold plates. Make larger mold blanks to make up for it then means slightly higher (few cents per unit atleast) material cost and higher machine time clearing the face of the blank. It works out to be a wash on that for cost and produces a CNC cutting the radius gives better result in my opinion. --- This email has been checked for viruses by AVG. http://www.avg.com Build the hinge separately, then dowel and bolt it to the ends of the mold halves. *********** Thanks for the suggestion. One-piece dowel plus bolt: http://www.palmerbolt.com/product/14...tripper-bolts/ |
#23
Posted to rec.crafts.metalworking
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A Better Hinge
On 2017-08-01, Jim Wilkins wrote:
"Bob La Londe" wrote in message news "Steve Walker" wrote in message ... [ ... ] Build the hinge separately, then dowel and bolt it to the ends of the mold halves. *********** Thanks for the suggestion. One-piece dowel plus bolt: http://www.palmerbolt.com/product/14...tripper-bolts/ Note that I have bought socket-head stripper bolts and discovered that the thread was not truly concentric with the shoulder. (It might have been concentric with the OD of the threads, but the PD was certainly not concentric. Luckily, it was close enough so I could make it work, but the upper piece would cycle as I turned the screw into the lower piece. Enjoy, DoN. -- Remove oil spill source from e-mail Email: | (KV4PH) Voice (all times): (703) 938-4564 (too) near Washington D.C. | http://www.d-and-d.com/dnichols/DoN.html --- Black Holes are where God is dividing by zero --- |
#24
Posted to rec.crafts.metalworking
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A Better Hinge
"DoN. Nichols" wrote in message
... On 2017-08-01, Jim Wilkins wrote: "Bob La Londe" wrote in message news "Steve Walker" wrote in message ... [ ... ] Build the hinge separately, then dowel and bolt it to the ends of the mold halves. *********** Thanks for the suggestion. One-piece dowel plus bolt: http://www.palmerbolt.com/product/14...tripper-bolts/ Note that I have bought socket-head stripper bolts and discovered that the thread was not truly concentric with the shoulder. (It might have been concentric with the OD of the threads, but the PD was certainly not concentric. Luckily, it was close enough so I could make it work, but the upper piece would cycle as I turned the screw into the lower piece. Enjoy, DoN. I used them to assemble a lathe milling vise and had no such problem. There was a slight variation in tightening torque but no movement. The brand is "Precision Socket Screw, Inc." Holo-Krome claims "perfect concentricity between threads and shoulder". -jsw |
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