Little Creeper Baits Posted September 23, 2015 Report Share Posted September 23, 2015 I am trying to make some hard molds to produce some original designs. The designs are apparently too difficult to have made in aluminum. I have tried a few things and am getting decent results but have not been able to produce a mold that I consider worthy of production. Just thought I would ask if anyone has tried to make good production worthy molds themselves and succeeded. My main problems have come with making the masters to actually reproduce a good set of molds from. I've been working with silicone mainly with resin as a final mold material. I am about to try urethane for the master. Any good methods would be helpful. Thanks, Benno Quote Link to comment Share on other sites More sharing options...
JRammit Posted September 24, 2015 Report Share Posted September 24, 2015 You should talk to Saltwater.. He has a great method for making fiberglass molds He was kind enough to give me a detailed tutorial some time ago... I have yet to try it, but only because i swamp myself with new projects Quote Link to comment Share on other sites More sharing options...
Vodkaman Posted September 24, 2015 Report Share Posted September 24, 2015 If you have been told that machining in aluminium is a problem, it is probably because there are undercuts. 3-axis machining cannot deal with undercuts. If your master is a hard material and has undercuts, then for the same reasons as you cannot machine in 3-axis, you will probably have problems making a mold from a hard material like plaster or resin. RTV is probably the best solution in this case. Plaster, resin and RTV, all produce good quality castings, but that quality is totally dependent on the surface of your master. Each material does have its own issues and has a learning curve to be climbed before you achieve good results: Plaster of Paris - a brittle, porous material. Molds must be thicker to avoid breakages as a thin mold will snap under clamping. The material must be sealed otherwise the surface finish will be rough due to the porous nature, also bubbles may be a problem. Once sealed, an excellent material and very cheap. Filled Resin - I am talking about filled resins like Bondo. Easy to use, good surface finish, doesn't require sealing. The biggest problem is slight shrinkage, also the material will soften when used with a hot pour like plastic or more so with lead. If the mold halves are backed with plywood, this issue goes away. Clear resin - Shrinkage is a huge problem, rendering it useless as a mold material. RTV - very good mold material. the only downside is the cost. Common to all the above is life span. None of these materials can match aluminium for longevity. But having said that, there are TU members who have been regularly using plaster molds that they made 20 - 30 years ago. If you take care of your delicate molds, there is no reason why you cannot produce thousands of quality castings. I have used all the above and my choice would be plaster backed with plywood. DAve 1 Quote Link to comment Share on other sites More sharing options...
JRammit Posted September 24, 2015 Report Share Posted September 24, 2015 One more There was a thread about this recently, it looks like the real deal... But plaster fits my budget better Make your own soft plastic injection lure mold: Quote Link to comment Share on other sites More sharing options...
Vodkaman Posted September 24, 2015 Report Share Posted September 24, 2015 JR - great video. Exactly what I was talking about, cutting the masters into modelling clay. Dave 1 Quote Link to comment Share on other sites More sharing options...
JRammit Posted September 24, 2015 Report Share Posted September 24, 2015 JR - great video. Exactly what I was talking about, cutting the masters into modelling clay. Dave Yes, many good videos showing this technique.... I was set in my ways, but my ways arent working for the new project... Getting the clay is holding me up, but it wont be long Quote Link to comment Share on other sites More sharing options...
Little Creeper Baits Posted September 24, 2015 Author Report Share Posted September 24, 2015 I appreciate the responses. I should have mentioned that I run a small bait company ( Little Creeper Baits ) and have a lot experience making molds. We primarily make swimbaits, and I make all of our molds for them. I am trying to make some creatures I have designed and as someone mentioned undercuts and texture are the difficulty for cutting into aluminum. I have been able to make an original mold from silicone. But silicone will not work for a final mold material. My issue is with making the mother for reproducing my production molds. A clay bed two part will not work with the complexity of the design. No way to be 100% accurate with the parting line. I am now making a solid silicone mold and cutting it in half. The issue has been silicone to silicone reproduction. They just don't come apart cleanly enough. I am about to try a urethane reproduction once the material arrives. I want to make my final molds from a heat resistant resin. I am not too worried about the resin material. There seem to be many that could work. The temp of plastic comes down so fast that even smooth cast 300 has been working for prototype molds without any issues. The problem is producing molds that don't have any or at least a tiny amount of flash at the seems. For production I can't spend a ton of time cleaning each bait. Thanks for the feedback. Quote Link to comment Share on other sites More sharing options...
Vodkaman Posted September 24, 2015 Report Share Posted September 24, 2015 A clay bed is the way to go, to get the mother master, even if it takes a few goes to get it perfect. Pity you cannot show us a pic, but I understand. Dave Quote Link to comment Share on other sites More sharing options...
Little Creeper Baits Posted September 24, 2015 Author Report Share Posted September 24, 2015 Here are a couple of screen shots of the baits I am talking about. These are the first designs I have done on a computer. These are screen shots from the program. The models are 3D Printed on a Form1 printer. I have been really happy with the results so far. Not much easier to design on a computer but much better for prototyping with out losing original detail, or for for making different sizes. 1 Quote Link to comment Share on other sites More sharing options...
alsworms Posted September 24, 2015 Report Share Posted September 24, 2015 Those are impressive!! Quote Link to comment Share on other sites More sharing options...
Vodkaman Posted September 24, 2015 Report Share Posted September 24, 2015 Woa there, I see your problem. That is a CAD model by someone who has no understanding of molding or was not told it was for molding. I do not see a side view, but the only chance that you have got, is with RTV. If your master is very soft, you may be able to make a hard mold, but getting neat seam lines would be very difficult. If you want a realistic looking craw, you have to compromise and have casting abilities in the front of your thoughts from the beginning to the end. Here are 3 versions of a craw CAD model that I created a while back. With a little more work, these will all be machinable by 3-axis. Just to give you an idea. Dave Quote Link to comment Share on other sites More sharing options...
Little Creeper Baits Posted September 24, 2015 Author Report Share Posted September 24, 2015 Woa there, I see your problem. That is a CAD model by someone who has no understanding of molding or was not told it was for molding. I do not see a side view, but the only chance that you have got, is with RTV. If your master is very soft, you may be able to make a hard mold, but getting neat seam lines would be very difficult. If you want a realistic looking craw, you have to compromise and have casting abilities in the front of your thoughts from the beginning to the end. Here are 3 versions of a craw CAD model that I created a while back. With a little more work, these will all be machinable by 3-axis. Just to give you an idea. thin.jpg folded.jpg deep.jpg Dave Yeah my problem is I design first. Get a prototype that does what I want it to and then try to make molds. Our swimbaits are very different and work very well but they are hand poured 3D. Injecting is another animal. I am trying to prove concept for making the molds. I understand the compromises that need to be made in order to have them cut from aluminum, I am just not willing to make them. I may make small changes to get better molds but texture and action are something I won't change just to get a bait on the market. If I can't get them done then, oh well, we will just continue to make swimbaits. I love to make bugs though and would like to make them for the public. Unfortunately our baits will need to be expensive because of our production methods. I just want them to be different enough to be worth the money they will have to cost. The creature bait market is so competitive from a price stand point that it is pointless to get into it unless what we bring to the table is different enough to be worth it. We will never be able to compete for the mass market. We will be happy to make smaller amounts and be original, then hope enough people like them to add one more design to our line up. We will never get rich doing this. We just want to do things that add something new and effective, then let the market decide our fate. 1 Quote Link to comment Share on other sites More sharing options...
mark poulson Posted September 24, 2015 Report Share Posted September 24, 2015 Good luck! I love your swimbaits! Quote Link to comment Share on other sites More sharing options...
Little Creeper Baits Posted September 24, 2015 Author Report Share Posted September 24, 2015 Good luck! I love your swimbaits!thanks Mark. If you could fish these bugs I think you would love them too. I just hope we can find a way to get them out there. If not at least we will have some for ourselves and a few friends. 1 Quote Link to comment Share on other sites More sharing options...
Vodkaman Posted September 24, 2015 Report Share Posted September 24, 2015 OK, I see your point of view and what you want to achieve. Realism is everything. You need to have a chat with an experienced machinist. There may be a solution there with acceptable compromises. One of the machining problems is external corners on the master, they need to be radiused. This is the main problem on my models. 3D printing is an option. Surface finish is the big issue here, but your textured surface may help hide the problems. Certainly for producing a master. But I have tried 3D printing a mold and it was not very successful, mating surfaces and excessive flashing being the issue. Re-alignment of claws and legs to a plane would help a lot, keeping in mind that once cast in soft plastic, they are not going to hold their shape anyway, they are going to hang. Someone put a lot of work into achieving that surface texture in the model. I certainly would never attempt such a surface, purely on the time constraints. Sorry that I cannot offer a solution, other than talk to an experienced machinist. DAve 1 Quote Link to comment Share on other sites More sharing options...
