Vodkaman

OK then, perhaps a lipless swimbait is not the thing to do at this stage. Best to stick with the type of bait that your friend is comfortable using and keep the swimbait as a future project. When you do tackle the swimbait, better with at least three sections, I prefer four. Lots of people do two piece, it depends on the type of swim action you want. Have a look through some videos to see the difference in the shape of the swim action and decide what you are looking for. It is important to be in control. Make the bait do what YOU want it to do, rather than just build and accept what the bait gives you. Dave

Lots of very good threads on this subject. The two basic screw eye replacements are haywire twist and barrel twist. My preference is the barrel twist, as it allows more room for the glue, but most prefer the simpler haywire, which is also well proven. Both these are excellent search words to bring up a short list of reading material. Dave

The perch body profile is very distinctive, with the bump from behind the head to the dorsal. If you want to represent the perch, you should find a profile from pics on the web and include this. The bump and the low head will actually help with the action on a lipless swimbait, if that is what you are going for. Dave

Even modelling on CAD, to produce those surfaces is often no walk in the park. Even with 30+ years experience on CAD engineering, I had to learn new tricks and techniques to get the surfaces that I wanted. Dave

When I played about with casting resin, I was using regular fiberglass resin. The density of regular resins is around 1.2gm/cm3 which is just heavier than water (1.0gm/cm3). The volume of micro-balloons (MB's) to get down to a density of even 0.7gm/cm3 is enormous and very thick for pouring. Featherlite (I have not used, but read the specs) is formulated with MB's at a density of just less than 0.7gm/cm3 and is pourable, and would be my choice if I could buy it locally. Resins are brittle to start off with, adding large amounts of MB's just makes the problem worse. Like JR, I too found that the casts were brittle, BUT hard as nails and very easy to work with, drilling, cutting, filling etc. Personally, I don't think the brittle thing is a big problem. A fresh cast will possibly snap if you drop it on a tiled floor, but once the lip, eyes and weights are glued in to the body and a top coat or two of epoxy is applied, the brittle problem goes away. When you throw a lure, it flies tail first and the flight is significantly slowed down by the trailing line. Even if you hit the rocks, the lure would survive (tested). The gnarliest musky will need a good dentist after chewing on a resin bait. Dave

Apdriver - great article, thanks for the link. Well worth reading. DAve

The sand cast molds that I have seen pictures of, are skimmed purely to achieve a good joint surface. Dave

The surface of a cast ingot has a very hard skin. When I worked in the aircraft design industry, I had to call up specs that defined how much of the surface had to be machined away, to leave behind a consistent material. It is this hard skin that you are experiencing, caused by the faster cooling at the mold surfaces. Dave

Desire and lots of spare time, I would say are the essential ingredients, because with these two, you can learn everything else. You need a CAD software, to get your model into the computer. CAM software to convert the CAD data into a language that the m/c can read. Although the CAD to CAM is largely automatic, it does not give perfect results and even makes grinding mistakes. You have to understand the code and be able to interpret and find the errors and even make improvements. It is almost a certainty that you will crash the machine at some point or even several. Parts will break and have to be replaced, so you will have to get familiar with the intimate workings of your machine. You will become so familiar that you will end up making modifications and eventually building your own machine from bits of others. You cannot decide not to do the CNC machine thing because you do not have the requisite knowledge. No one has unless they work in that industry. But, with the desire and the time, you will get there. Dave

Pine can be carved, it just needs more care and thought than with other woods. It has a tough grain spaced by softer wood. The density of pine varies depending on type and cut. It would be worth measuring and weighing a piece, to find what density you have: Density = weight (grams) / volume (cm3). Once you know the density, you can do a Google search on 'wood density' and compare the wood with other timbers and understand what you have to work with. Dave

I fish to be close to nature. Some of my most memorable fishing was in Sweden, fishing the mountain lakes. Glorious scenery. Catching the occasional rainbow did not interfere with the pleasure too much. I have tried the lakes here in Indonesia, but it is just not the same; too far to travel, way too hot and the mozzies are ferocious. Fishing the local ponds provides no enjoyment other than getting slimy catching lots of fish. This is what it looks like when the fish are not biting: Dave

After trying all the above, get hold of a tin of plumber's flux. Heat the hook and dip it in the flux. The idea is that this wets the surface of the hook metal and allows the lead to contact. This essentially makes more room for the lead to flow. I use this method when I am pouring ballast weights around stainless steel twisted eyes. Dave

My prototypes never get fished. They are built for a specific purpose, to obtain certain information. Holes will be moved, filled, re-drilled. Sometimes as many as a dozen or more prototypes will be built in order to find the best solution. Once the prototype has served its purpose and the information noted, it usually goes in the bin. The information goes back into the CAD model and updates the templates. Dave

Elrik - that is a sensible and reasonable request. I hope you find someone to help you out. Dave

All swimbaits swim horizontal. There is nothing to drive the lure down deep, like with a lipped crank. The only way to fish deep, is to weight the bait and let it sink before retrieval. Dave

Gone2long - real shame about your truck, but the video is top quality. You must have been feeling the urge to find a new home for the cell phone, perhaps in one of the guys vacant orifices. DAve

Here is another thread worth reading on swimbait roll. Dave

TWSniper - That video is demonstrating the . I wrote an article on the hinge explaining all. The big problem with 4-section (3 hinge) baits, is the fitting of all the hardware and having enough room to fit ballast lead and having the flexibility to move it around to achieve the best balance. There are currently 3 main types of hinge: 1 - Screw / screw - two interlocking screw eyes. These can be shop bought or twisted wire. The big problem is that both sides of the hinge require deep holes, severely limiting the ballast space. 2 - screw / pin - a screw eye mounted on a vertical pin. This solves the space problem on the pin side, giving 50% more room for the ballast. 3 - piano hinge - a single vertical pin, the eyes are carved into the body. This solves the ballast space problem and looks a lot more professional, but involves a lot more work in manufacture of the carved hinges. What I was finding with the S-movement lipless swimbaits, was that there was significant 'head shake'. I wanted a hinge that added more degrees of movement. The double pin arrangement allows the sections to move more where the water wants them to move, whereas, single axis only allows the hinge to move in an arc. I built several more test lures hoping to confirm the fixing of the head shake problem, but it was not to be, the head shake returned. There are several posts in the Vee joint thread about this, check out from No21 onwards. Actually, if you are going to build a hinges swimbait, the Vee Joint thread is worth reading from the start. Here is another important thread on body roll and head shake. So, the head shake failed, but I did like the smooth movement of the lure, the ballast space and the simpler construction compared to the carved piano hinge. For future builds, this will be my go-to hinge. BUT, the rear hinge needs to be double, you cannot get away with a single hinge, it allows too much roll, which you will see in the under water sequences of the videos. As for catching fish, these lures have never been outside the test tank. Dave

I keep thinking of more stuff: I played county soccer until 16 and also played in a table tennis league. I did gymnastics and was school high jump champion. I was very competitive as a kid, which caused problems. What was I supposed to do, lose on purpose! Dave

The Hud is a good design. I tried to design a soft swimmer for a customer. The weight distribution and the foam ended up very similar to the Hud, so I wasn't comfortable about that. But, I know how much work went into that design, to get the balance and the vertical stability. Dave

As with all vortex driven baits, there is a minimum speed for the action. Mine was around 12" per second. Dave

BobP - I tried so hard to find a scientific approach, a spreadsheet solution. But the variables are complex and cannot be reduced to such simple numbers. The best you can do, is understand the effect of any change that you make. I try to predict the result and then perform the change and whether I was right or wrong, I learn a little bit. One change at a time is the most important rule, if you are actually going to learn anything. If you tweak three variables, you may get a result, but you will never know why, what worked what didn't, what made no difference. My guess is that I do the same stuff as everyone else, I just consider each adjustment in a logical fashion. I still get stumped. I am stumped right now, as my bluegill paddletail does not paddle. I have ideas for why, but I get my disappointments the same as everyone else. Dave

If you have an original bait in your mind, you should at least take it to RTV or pop, for your own satisfaction. These molds will produce a very nice bait in the numbers that you require. If demand increases and you feel the need to go more professional at a later date then fine, or you can make more RTV molds from your master. Dave

The first step, having formed your idea, is to build a prototype. You have to prove that the bait swims as you see in your head, and that it actually catches fish. Sometimes the idea is good, but if the thicknesses, sizes and all the rest are not exactly right, that baby aint going to swim. To find this fact out after the design and machining phase is going to be VERY expensive. I suggest you whittle a master and mold it in RTV or some other mold material. Once you have a working lure. Send all the information to the machinist of your choice. The next stage, is to get that information into the computer in the form of a CAD model. The machinist may be able to do this step, but if the shapes are complicated, he may prefer to contract out the design or instruct you to sort out the CAD. The machinist will have more changes, as he is the expert on machining. There will likely be a test cut, to test the process and also an opportunity to test the venting, before the final mold plates are cut. There is a lot of time involved in the development of an aluminium mold, which has to be paid for, unless you know someone in the industry who does BIG favors. The machines are not cheap and you will have to pay your share in the costs, materials, tools, electric, taxes and all the rest. I am not trying to scare you off. Just trying to lighten the shock. There are plenty of people going through this process, producing ORIGINAL work, you are not alone. This is a bit different than buying a $40 mold from Ebay. Dave

Paul - you have certainly sparked my interest. A few ideas have arisen and they need exploring. Thanks. Dave