rolling mill questions
br wrote:
Hello all, I've been a lost-wax caster for over thirty years, and I never really learned to use a rolling mill. I never even bought one, because I could always figure out how to get along without it. I have several questions for you bench experts concerning rolling gold wire. For an upcoming line, I need long bands of 18K yellow gold to then have disks punched out, 1/10th. of a millimetre thick and 8mm in diameter. How many operations/reductions am I looking at to roll down a 1.2mm wire to a 0.1mm x 10mm ribbon? Is this too thin to be done reasonably? Could I do this, with good repeatability (thickness-wise I'd like to stay between 0.09mm and 0.11mm), using an off the shelf rolling mill? Do standard mills have well polished rollers, and will I have a problem getting an easy polish on the ribbon after the final reduction? I'm hoping to need about 10 meters a year, lets say 1000 pieces. What are the do's and don'ts for doing these myself? Perhaps I'd be better off getting them made? I have kilns and temp. control for annealing. That's no problem. I'd appreciate any and all ideas, comments, etc. B.RANDALL http://www.srdfrance.com JUst an update for you. Ive checked out Via the Swiss chamber of commerce if my paillion supplier, Bayeler&co. Geneva are there and still in business. I!st contact with them was in 1969, last in 1978. Yes!! they are!! So im writing to them today to ask if they would like to quote to supply you with 1000 1/10mm by 8mmdia 18 ct gold discs. as soon as I have a reply ill mail the group. It would help if you mentioned what you plan to do with them. I need to contact them again anyway, as I need some more of their paillions myself. Fancy doing some enamelling again. It will be interesting to see what they will want in terms of cost, delivery times and business payment details. Probably half the cost up front. well see. Ted. |
rolling mill questions
Abrasha wrote:
Peter W.. Rowe, wrote: On Sun, 17 Sep 2006 07:52:26 -0700, in rec.crafts.jewelry Abrasha wrote: Not true! Ted, there you go again! Once again you speak of things you do not know about, a bit too soon. Lets not get personal, shall we? And why not, if he has made a factual sounding statement that is not correct? [[this paragraph edited by moderator]] And though I'd agree with you, Abrasha, about rolling down wire, Ted's not entirely wrong either, Oh yes he is. IF his experience and comments refer more to rolling down stock that starts out wider. If you start with an ingot that's an inch or two wide, and then likely around a quarter inch thick Oh give me a break Peter. That is not wire! That is heavy plate! Any wire, I repeat ANY wire, whether is is 1.2 square or round or 10, or 20 mm, will spread laterally a great deal more than 2-4%. And the bigger the reduction in thickness each step when rolling, the bigger the lateral growth. such as most ingot molds produce, Like I said, that is not wire, but an ingot, which is plate (or sheet, if it is thinner). I rest my case. the lateral spreading will be a fairly low percentage. No doubt this is where Ted's comments spring from. No it is not. The original poster was clearly talking about 1.2 mm wire. And Ted's response was: "IE your 1.2mm wire will go down to the thinness you want BUT wont get any wider!!." Well its time to run some tests. I suggest Abrasha gets some 1/4in dia copper rod, say 12 in long. Ill do the same and well stand or fall by our results. Ill roll the rod down to say 30./1000th/in and measure how wide it becomes.. Abrasha does the same. I wont cheat!! what ever comes out ill write it down!! for all to see. Now Abrasha, are you prepared to stand by results or not? like i am? ted frater |
rolling mill questions
ted frater wrote:
If you roll say 2in wide by 1/8in thick it doesnt get wider. it gets longer. I would cast silver 4in long by 2in wide by 1/4in thick and tuern that into 1/16in thick strip. Uhm Ted, you may not have noticed, but FYI, the OP was talking about 1.2 mm wire, not what you describe. 2 x 1/8" indeed! Come on guy, wake up. Never got wider. yuor probably right with the sizes your talking about. I never had the need to work round/square wire to flat strip. So why do you give advice about matters that you have absolutely no experience with? This is not fair to people who come here for real answers. If you don't know, just be quiet please. Don't say things like "This one is something I can help you with.", since obviously you can't. You only confuse the person asking the question in providing inaccurate information by claiming expertise. Abrasha http://www.abrasha.com |
rolling mill questions
ted frater wrote:
Well its time to run some tests. I suggest Abrasha gets some 1/4in dia copper rod, say 12 in long. Ill do the same and well stand or fall by our results. Ill roll the rod down to say 30./1000th/in and measure how wide it becomes.. Abrasha does the same. I wont cheat!! what ever comes out ill write it down!! for all to see. Now Abrasha, are you prepared to stand by results or not? like i am? ted frater I have better things to do, than to prove something to a guy who doesn't know the difference between 1.2 mm and 1/4". -- Abrasha http://www.abrasha.com |
rolling mill questions
Peter W.. Rowe, wrote:
I have a table in a German training book for goldsmiths, that lists the thicknesses and widths one will end up with for a number of square starting stock. Comes in very handy from time to time. If there is interest, I can scan the page, and put it on my site for a few days. I'm sure there'd be interest. I for one, would enjoy seeing it. thanks for the offer. Peter The table is at: http://www.abrasha.com/misc/table.htm BTW, it must be noted, that the numbers are approximates, because the results vary depending on the material rolled, how well the pieces of wire are annealed, the size of the "bite", how many times the wire is run through the mill before annealing and rolling again, etc. See the translation of the German at the bottom of the page. Yo Ted! Pay particular attention the numbers for 1.2 mm wire. When rolled down to .6 mm, the width ends up to be 1.8 mm. By my calculation, that is an increase of 50%! And it is not even rolled out to .1 mm yet! 2 - 4% indeed! -- Abrasha http://www.abrasha.com |
rolling mill questions
br wrote:
"ted frater" a écrit dans le message de news: ... br wrote: Hello all, I've been a lost-wax caster for over thirty years, and I never really snip off getting them made? I have kilns and temp. control for annealing. That's no problem. I'd appreciate any and all ideas, comments, etc. B.RANDALL http://www.srdfrance.com JUst an update for you. Ive checked out Via the Swiss chamber of commerce if my paillion supplier, Bayeler&co. Geneva are there and still in business. I!st contact with them was in 1969, last in 1978. Yes!! they are!! So im writing to them today to ask if they would like to quote to supply you with 1000 1/10mm by 8mmdia 18 ct gold discs. as soon as I have a reply ill mail the group. It would help if you mentioned what you plan to do with them. I need to contact them again anyway, as I need some more of their paillions myself. Fancy doing some enamelling again. It will be interesting to see what they will want in terms of cost, delivery times and business payment details. Probably half the cost up front. well see. Ted. Thanks Ted for doing the leg work! I live and work about 40 minutes from downtown Geneva, so BAYELER is practically in my neighborhood. We usually avoid Swiss suppliers, because they are notoriously expensive, and I didn't even think to look so close to home! I'll contact them tomorrow about my disks, and why not, about their "paillons". Having no experience in watch-making, I'd never heard that word used for anything else than solder. My disks are for "gold triplets", covered with a clear quartz cap and backed with an acrylic disk to protect the thin gold from underneath. There are various ways to do this, of course, including electro-deposition, gold-filled sheet, etc., but I must use (for my client to qualify for the French government's "gold" retail labeling standards) "real" gold. I also have a supplier of gold leaf that can sell me the 0.1mm sheet I need, and they are looking into the possibility of cutting the disks, also. Thanks again. B.RANDALL Well its a small world!!. Bayeler's address is correct, but their phone no has changed as well as their postal zip code? If you do get to see them can you please update me as to their details maybe, get to see their tool room? f I dont hear back from them? withing a couple of days, If and when you get a price from your gold leaf suppier you could mention to Bayeler if the can match the price or even better it!!. Usual practice in industry to shop around. I could do the blanking for you if your sheet supplier is in the UK, What Id do is fly press them on my smallest!! press with a ultrasharp punch and die. I havnt thought to chase up my gold leaf/foil supplier here in the UK. It might just be worth mylooking at this for an order of 1000 discs. you dont need them tomorrow ? do you? Keep me posted. Ted. PS As i mentioned you will need to have it hard rolled where ever you get it.. to get a clean blanking cut. |
rolling mill questions
Abrasha wrote:
ted frater wrote: Well its time to run some tests. I suggest Abrasha gets some 1/4in dia copper rod, say 12 in long. Ill do the same and well stand or fall by our results. Ill roll the rod down to say 30./1000th/in and measure how wide it becomes.. Abrasha does the same. I wont cheat!! what ever comes out ill write it down!! for all to see. Now Abrasha, are you prepared to stand by results or not? like i am? ted frater I have better things to do, than to prove something to a guy who doesn't know the difference between 1.2 mm and 1/4". OK folks, Here are the results. Let the professional craftsfolk here and more importantly potential customers draw their own conclusions who writes the most bull/s. 1/4in pure copper rod 5&3/4in long fully annealed rolled to 30/1000 in thick went to 29in long. width went from .25in to .30in. thats a 50/1000in increase. 50/1000 in into .25in is a 20% increase in width. then I took a .50in wide by 3/16ths in thick by 6 &1/4in long copper strip fully annealed. This went to 32in at 30/1000in thick and went from .5in to .553in wide. I make that a 10%increase in width to all intents and purposes as makes no odds.. so my experience of 2in wide is about right. when previously I said a width increase of 2 to 4% depending on material. This test:- Annealing time 10 mins total rolling time 10 mins total. Writing time and measuring 30 mins. Bull/s time nill. Have a nice day, dont you say? Ted |
rolling mill questions
On Wed, 20 Sep 2006 01:43:19 -0700, in rec.crafts.jewelry ted frater
wrote: OK folks, Here are the results. Let the professional craftsfolk here and more importantly potential customers draw their own conclusions who writes the most bull/s. Careful how you define that, Ted :-) The thing that bothers me, and perhaps Abrasha too, is that you've still not tested the problem that the original poster brought up. That is how much WIRE spreads out when rolled. As has been pointed out, by me, by abrasha, and perhaps others, the diameter of the rolls makes a difference. smaller diameter rolls spread the wire less, with the same percentage reduction per pass. Because you've chosen to make this "test" with quarter inch rod, instead of the 1.2 mm wire that the whole thread was actually discussing, you're actually not testing the original question, but rather, nicely demonstrating the truth of the statement that rolls diameter matters, since you're using a rolls that, compared to the size of the "wire" being rolled, is about a tenth the diameter of what the situation would be if the same rolls were used to roll that wire instead of your heavy copper rod. Also, don't expect copper to give exactly the same degree of spreading as will gold. it starts softer, and work hardens more slowly. This affects the degree of lateral spreading too. (It's about the degree to which lateral forces are exceeding the elastic limit of the metal in relation to how the longitudinal forces are doing the same, as well as the tensile strength and springiness of the metal resisting or springing back from lateral stresses instead of permenantly spreading out. ) So, now try the real test. Start with the actual discussed wire size, 1.2 mm round, in annealed 18K yellow gold. You need not work with much. An inch long will do fine.. Roll that down to the specified foil thickness. See what the width is then 1/4in pure copper rod 5&3/4in long fully annealed rolled to 30/1000 in thick went to 29in long. width went from .25in to .30in. thats a 50/1000in increase. 50/1000 in into .25in is a 20% increase in width. then I took a .50in wide by 3/16ths in thick by 6 &1/4in long copper strip fully annealed. This went to 32in at 30/1000in thick and went from .5in to .553in wide. I make that a 10%increase in width to all intents and purposes as makes no odds.. so my experience of 2in wide is about right. when previously I said a width increase of 2 to 4% depending on material. No one has significantly disagreed with your estimate as it applies to rolling down strips of wider sheet metal instead of bar stock or wire. Your own figures here show that the bar stock spread out twice as much as your strip which was twice the width and started considerably thinner. The disagreement is in extrapolating the same degree of lateral spreading to wire stock, as you experience with this plate stock. As you'll find if you try it, that doesn't quite work. This test:- Annealing time 10 mins total rolling time 10 mins total. Writing time and measuring 30 mins. Bull/s time nill. Have a nice day, dont you say? Ted Thanks. I will. You too! Peter |
rolling mill questions
On Wed, 20 Sep 2006 01:36:06 -0700, in rec.crafts.jewelry Abrasha
wrote: Yo Ted! Pay particular attention the numbers for 1.2 mm wire. When rolled down to .6 mm, the width ends up to be 1.8 mm. By my calculation, that is an increase of 50%! And it is not even rolled out to .1 mm yet! 2 - 4% indeed! it's also informative to compare the degree of spreading when, say, rolled to half the starting thickness, for different initial guages of wire. Note that the heavier 4mm stock does not spread out as much, when rolled to 2 mm thickness, as the 1mm stock does when rolled to .5. That nicely illustrates the point I made about Ted's test with quarter inch rod, compared to smaller wire, and how it is explained by the ratio of the wire size being rolled to the diameter of the roll being used. Also, note that the chart shown uses square wire (actually, probably the almost square wire, with slightly chamfered corners as produced by the mill), not round wire, as the starting point. That's a practical assumption for those making their own stock, since the normal sequence is to roll a wire ingot in the square wire mill to get smaller square wire until it's the size needed to roll flat. It's not normally drawn to round wire prior to rolling flat. No need. And round wire spreads out less than does square wire. Thanks, Abrasha, for posting it. Peter |
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