Die Casting

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Nov 17, 2006
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If one had acess to a die casting machine and reasonable die fees do you think a sculpted handle design could be die cast for a reasonable materials and time investment? I have never done any casting outside of rings and such and am not shure of the time or process involved in die casting. Anyone have experiance in this field?
 
Are you sure you want 'die casting' ? This is a production method, are you going to make 1000 ? Or do you mean investment casting [lost wax method ] ?
 
I do mean Die. I would assume investment or lost foam would both be cheaper and easier to do on a small scale. However I may have acess and the ability to use a small scale Diecast setup. The person setting it up for me doesnt really know knives or casting though. All I really know about die casting is that it allows much better detail to be cast in due to the metal bieng under pressure until it hardens, thus filling in the smallest details of the mold ect. I am trying to find out if the machine uses multiple molds at once or just a single one at a time. Just been trying to figure if theres anything I can use it for and have it be cost effective compared to other ways to get the same results. I was thinking carved/sculpted handle scales. I was figuring making 20-30 scales from the die would offset the cost of having it made.
 
The cost of the die casting is the die .That's why tool and die makers are paid so well !! Single or multiple depends mostly on size of the part .Also the metal is a factor. For 20-30 scales investment cast is the way to go .With a silicone mold you can copy the original wax pattern multiple times. With investment there are no restrictions as to type of metal .
 
Jim, Let us know what the pricing you get is. Unless your friend is going to do this at no cost,I would be doubtful that any quantity less that several 100 (probably thousands) will be cost effective. At 20-30 you shouldn't even begin to recover costs .You could end up spending about $100 each set of scales or more.
Stacy
 
with proper investment and good finishing of the wax you can get microscopic detail with lost wax casting, i dont know what kind of detail you'd need but it seems like that should be fine...
 
I can't imagine a die costing any less than $10,000, but maybe there are companies that would do it for a little less. I agree that investment casting is the way to go here.
 
Wow. I used dies for cutting in the fashion industry and they were pretty large and they were cheap compared to 10,000 (probably the difference in 2d outlines vs. 3d details I would guess). If dies cost that much I can see how costly setup could be. My understanding is that the machine is designed for small scale work, but obviously die setup will still be needed. I think I would have acess to the machinery but would need to cover material and any operating costs involved so while it my be cheap on that end thwere is no way I'm coughing up 10,000 for any die. I suppose the longevity of such an item can easily offset initial cost over time, but I dont have any designs that I think would sell in those nubers if at all lol. =P Thanks for the input. I wanted to put some feelers out before bothering die makers for qoutes.
 
Hi BigJim , A zinc or alum mold that will cast a knife handle size part will cost you mucho bucks. I think boones estimate of 10 grand is very low, unless you have a retired moldmaker working for free :) . That will be a pretty good size "tool" with many weeks (or more) of time & material going into it. You would need to cast a whole bunch of parts to recoup your cost (thousands of parts). Not trying to discourage you but you said that you had no experience in this area. There really is a lot more to making and getting the mold to run than meets the eye. Just trying to be helpful.;)
 
Thanks for all the info folks. I guess I will have to pass up use of this machine until I reach Onion status (starts holding breath). I must say though I am suprised to see such a cost put on what is basicly a mold. Materials for a die the size of a single handle scale wouldnt be more than a few thousand dollars even if it was made of pure platinum. Since they are made of even cheaper metals and materials, most of the cost must be in workmanship. Well if $10,000 is a conservative estimate, then someone is getting payed $10,000 in labor on top of the materials cost? For the life of me I cannot see how this could be justified. I could get solid italian mable carved into a statue by a famous artist for less (minus the cost of the marble). Ken Onion himself would probably find it hard to sell a knife for 10k over materials cost. So what the heck are die makers doing thats so artistic or complex? My doctor makes less money after going to school for 10 years according to these figures (unless your talking surgeon). I dont mean any disrespect to die manufacturers at all, im just boggled by such a high cost for any small piece of metal. Am I missing something about die creation? I would assume it is computer aided nowadays if not close to fully automated. Am I wrong about that to? just curious. Maybe I should make dies. =P
 
OK , I deleted a long post prior to your last post describing the "die set" , I guess I shouldn't have. As a Mold Maker I feel compelled to "justify cost" First of all a die set that would cast a knife size set of scales will probably be about the size of your kitchen table ( L X W x H ) , yes that big. It consists of 2 halves . The "live" half and the "cover" half. Each "half" contains (usually) a "cavity" (basically the negative of what you're casting) made from (usually) H13 that has to go through heat treat like a blade would. The cavity is a very precision tool that must exactly mimic your part. The mold maker must take into consideration shrinkage of the material being used. All die sets for zinc & alum. have a network of cooling holes going through the entire die to keep it cool while casting. The live half also has what is called an "ejector plate" consisting of pins that move forward when the die opens after the material has been injected.Depending on the part the mold might have a series of slides or cores that move in and out of the mold as it opens & closes to create pockets , holes etc. that might prevent the part from being ejected from the mold after casting . All of these parts must work in unison for the tool to produce a good part. This is a very simple,shortened description of a mold . If you ever saw one and witnessed the engineering and skill and time that is involved in the making you would think twice about your statement justifying the cost. Most mold makers serve a 4 yr. apprenticeship working under a journeyman while also going to school after work for 4 yrs taking everything from advanced math and engineering classes , die, mold design and theory , blueprint reading and sketching classes and more. If you want to "make dies" you should probably set aside the next 4-6 yrs of your life .:) Computer aided? Yes. Fully automated? Not even close . Take a look a every part in your car , home , computer etc., to get an idea of the "artistic" and "complex" work that Tool & Die Makers do. ;)
 
David said it well. A car costs $20,000, the steel/aluminum/plastic in it costs,$500(maybe),the labor costs $5000. So they make a lot of money - Right? NO!!! The factory costs $500,000,000 and the dies to make all the parts (for just one model of car) cost $50,000,000. That is why , when the auto sales dip to ONLY a couple hundred million units sold a year, they have to close plants down.The profit margin on a $20,000 car is actually very small.
This same situation with dies shows why most inventors and small manufacturing companies make simple tools and items one at a time (basically) to avoid the die costs. If you aren't going to sell many thousands (or millions) of units, it is cheaper to do it by a slower and cheaper method (turn on lathe, cast,etc).Cell phones cost almost nothing now because of the volume stamped out.I remember when they cost $5000. Same for computers. Volume of sales is the only way to recover tooling costs.
Stacy
 
Yes, David nailed it. I used to design plastic parts for paper towel dispensers. It was rare to get by with a mold that cost less than around $50,000, even for the smaller parts. Molds are huge and very complex to design properly and build. We essentially never got them in less than 18 weeks, and that's if things went smoothly. There is extremely expensive setup and teardown time. (Remember, these machines should be producing lots of dollars per hour to justify their several hundred thousand dollars each. They don't want to spend time tweaking in the molds.) Runs are normally in the hundreds of thousands of parts or millions of parts, not dozens. These molds were made in better materials and finished to a higher degree than die casting molds would have to be, but there are definite similarities, and I wanted to give Jim a feel that the stuff is darned expensive.
 
>Materials for a die the size of a single handle scale wouldnt be more than a few thousand dollars even if it was made of pure platinum.

Jim, platinum's about $1140 per ounce, so it better be a small die. ;) :D
 
Wow, That makes alot more sense. I have never seen die casting in action, so I did'nt know the dies were so big or internaly complex. Like I said I dont think I'd pay 10k plus to get the relief of something carved into metal, but I see how much more is involved. Thanks for the insight. I certainly never figured the die would exceed the size of the cast part by so much. When I spoke of materials costing a few grand I was assuming a much samller size die.
 
The dies I use at work are flex dies, made to be mounted on a magnetic cylinders in a printeing/converting press. Releif is around .08" off the top of my head. About the simplest dies to make, I think, and they start out at $800. Just for comparison.

Time to learn about lost-wax casting, sounds like :)
 
hehe, thanks Gibsonfan, All info is helpfull. Thats more the price I was thinking around. Lost wax is probably the way to go, but since this machine wont help me I will probably put off my thoughts of sculpted metal handle scales for a few years. I have had sandcasting suggested to me from another source but dont want to start researching it as I dont have a real project that needs em. Just thought I might be able to take advantage of the offer to use the machine. On the up side, i now have time to refine some design ideas.
 
some of you guys have recomended inbvestment and lost wax casting.
i understand making a rubber mold to cast the wax and then you make a disposable mold from the wax before you melt it out, but i was just wondering what do you make the mold from that can withstand the heat of molten steel?

brett
 
Investment casting molds are ceramic. When you have your wax pattern, that is dipped into a slurry of ceramic .That's dried then baked to melt out the wax . The steel or other metal is then poured into the mold. When you are making a one of a kind piece you carve a wax pattern and coat that with the ceramic.
 
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