Vodkaman

I am not going to advise you on your choices because I do not have practical experience of those choices, all I can do is pass on experience gained from the choices that I made. There is simple math to help you with deflection questions. You can Google deflection calculations. You can then decide whether it is a good solution for you to support your cutter carriage on the threaded drive. Decide in your head what is an acceptable deflection, say 0.5mm. This would give a cutting error of 1mm (twice the deflection error). Then collect all the required information and do the calculation. Other problems to be considered in your design are spindle alignments. You have three major spindles spanning the machine; the woodblock spindle, the master spindle and the cutter carriage spindle, and ALL must be in perfect alignment. If the side plates are cut by CNC or a skilled machinist then the alignment problems will be minimal, but if you are cutting yourself then you had better build in some adjustment, and figure out some procedure for performing those adjustments. I am not trying to discourage you, merely identifying the problems that you will face. Best advice is to build the first prototype with the understanding that a 2nd prototype WILL be necessary to solve the problems identified in the first build. My first two builds never got as far as mounting motors, they were both hand cranked. Proto3 was slated to use a 12v car wiper motor. Dave

OK, now you are getting down to the real BONES of duplicator problems; the drive screw. The two major drive screw problems are deflection and slop. In my first duplicator build I basically ignored these two issues. Deflection - sling a threaded bar between two bearings and hang a 2Kg weight on the thread and there IS going to be deflection of the bar. The deflection depends on the diameter of the bar, the distance between the support bearings, the mechanical properties of the bar and the weight of the carrier. Slop - Basically the tolerance of the thread and the fixed nuts in the carrier. If you are using precision drive screw then the tolerances will be tight and the problem eliminated with $$$s. If you are using standard issue threaded rod (as I did) then you are in for a world of problems with repeatability. Slop and deflection will give you an end product that is significantly different to your master. For me, an expensive machined drive screw was not an option, but in terms of cost and availability. I had no choice but to go with standard threaded rod. Even though I did not deal with deflection and slop, I was happy with my results, but the differences between the master and the product were a concern, but the results were consistent. However, before I could build the design that tackled the problems of deflection and slop, I was evicted from my house and lost everything that I had done, my workshop, templates, machines and tools were all gone. I did build a second machine before I lost the workshop. It addressed the deflection issue, but it was not a good solution. If I were to build a third prototype, I would still use 12mm dia standard threaded rod with a 1mm thread pitch, I would support the weight of the cutter machine on separate rails, thus leaving the threaded rod to push and pull the carriage with no bending loads. The slop can be taken care of with some thoughtful, creative design. I found solutions by Google. Dave

Good choice of cutter, you seem to have a good understanding. The solution is gearing. The travel threaded spindle rotates at half the speed of the master and woodblock spindles. You can see in the image that the master and woodblock spindles are driven by the motor. What you don't see is the bicycle chain gearing to the motor carrying spindle geared at a ratio of 2:1 Dave

JD - The spherical domain enclosed by the tall man's spell of 4πr³/3 is an intriguing and fascinating subject. It is the simplest shape and yet the most difficult to carve. I have actually experimented with spherically derived shapes and the resulting actions are interesting. If you pull a sphere through water you get a pure spiral action. I do most of my cranial development work while sleeping, so you could say that I work in an alternative universe Dave

The forces are at the edge and rear face of the lip, but let's not make this a science class pop-quiz. Dave

Often to understand a function or concept you have to take the idea to extremes. I offer up a ball and dinner plate analogy. The spherical ball can be forced through the water with very little effort, but the flat plate requires a relatively HUGE effort to move through the water even though the diameters are the same. It is natural to think that water resistance is caused by the weight or force of the water trying to get out of the way of the object, the water pressing on the lip as it is pulled through the water. The actual truth is a most unnatural concept to grasp which is why I rarely mention it; water resistance is the vortices pulling back on the edge and rear of the plate. Water resistance is NOT water pushing the plate, it is water pulling on the plate. When watching Olympic swimming events, I noticed that the best swimmers seemed to have a much slower cadence than the also-rans. These super-swimmers have mastered the vortex tow. The irony is that they don’t know why or how they are doing it and neither do their coaches. Next time you are in a pool or lake, pull your hand hard through the water. You will notice that your hand pulls left and right as the vortices form. As a vortex peels off and a new vortex starts to form then there is less water resistance, less swimming force. The secret is to control the vortices, to hang on to the single vortex as long as possible without it peeling off. If you pull too hard or fast then the vortex peels off and power is lost. The double irony; I have not been swimming since I discovered this stuff! Dave

JD - I don't even know how critical or effective the chamfer is, but builders who have worked with many materials claim that the thinner fiber boards are the most effective, and this fits with theory. I like 2mm polycarbonate for all my lures. I only build small lipped lures 3" length. I don't bother with the chamfer. If I was selling and looking for a little bit extra then I would chamfer for sure. Dave

Lip function – to create the vortices that cause the lure’s waggle action. It is fact that a sharp edge causes a stronger vortex than a blunt edge. This would suggest that a thin lip would be better, BUT, the knife edge can be achieved with a chamfer. Bending – lip materials do bend. The bending is a function of material thickness, free length, width and the mechanical properties of the material. How much bending is acceptable? Is some bending desirable? Weight distribution – obviously the thicker the lip then the more the COG of the lure is affected. The thicker lip dragging the COG forward, thus affecting the distribution of ballast. This could be good or bad, but it is all a part of the lures balance. If you double the lip thickness and keep everything else the same then the balance of the lure changes. Dave

I agree with Exx1976. if you can manufacture a lure body, ballast, harness, twisted eyes and all the rest, then why should lips be such an issue. Using someone else's pre-cut lip is a bit like the 'tail wagging the dog'. Dave

Good plan. I liked 10 at a time. The advantage is that you become more skilled at each operation, with an appropriate improvement in time. This will sound 'nerdy' but you need to do a time and motion study on yourself. You will be amazed with the time that can be picked up with secondary movements like tool placement; by placing the wire cutters in the same place on the bench every time, then no time is lost searching for the tool. By placing the tool on the bench at a certain angle, the tool can be picked up and ready for use without the need for a juggling act. If you record the real time for each operation, then you can calculate what your production capability is. Do not be tempted to make it a competition, always going for personal best times, this is not what it is about. Then, you may decide that a good alternative would be a day of lead work rather than 12 at a time, and so on. Lots to think about on this subject of time and motion. Dave

Mirrors are a good thing, they do help with light distribution. BUT, it is not just about lighting up the lure, it is all about the distance the light travels, it is about the light strength. If the distance doubles you might think that the strength halves. You would be wrong. The strength reduces to 1/8th. Over-reliance on mirrors could be the problem, something to consider. Dave

Good comments. Keep searching for that bit extra that will make your lure more desirable than the rest. I know, it is not easy chasing rainbows, but not impossible either. If you don't chase the rainbow then you are unlikely to stub your toe on the pot of gold Dave

People do not buy hand made baits because they are cheap, they buy because the lure is unique and of the highest quality. Your bait has to gain a reputation for catching MORE fish than the chunk of plastic on the shelf at Walmart. Yes, you need a pro angler on board who believes in your lure. A Kevin Van Dam is not going to get the job done, people will not attribute his success to the lure but to the man himself. I would take my lure to a struggling pro, get him to try the lure, prove that it is a fish magnet, then you can both retire on the lure's success. Only my opinion; charging $10ph is not doing you or your lure's reputation any good at all, you might as well just give them away. No, I am not rich. I cannot afford to live in my birth country of UK and certainly could not afford to live in USA. A few years ago, I lowered my charge rate to $25ph to do some mold design work. I regretted that decision, it stuck in my throat and formed an indigestible knot in my belly. I vowed never to do that again. My last paid design job was $100ph although I could be tempted out of bed for $70ph for a short engagement. Like I said, not rich. My philosophy was always work to live, not live to work. Here is a quote from George Best: "I spent a lot of my money on booze, birds and fast cars, the rest I just squandered." Dave

My charge rate is significantly higher, which is why I never entered the lure market. Dave

For a mechanical duplicator; the cutter has to be capable of removing the material effortlessly from the stock on a single pass. Stock removal is about 1" per minute depending on the mechanical design. A standard router bit is the worst tool for the job in my opinion. A ball end router is better, but it will blunt quickly and unless you sharpen your own, it will be a VERY costly item to replace. I do not see a Dremel cutter keeping up with the volume of material being removed or coping with the cutter depth. Dave

It is or will be a digital version of the mechanical duplicator, were the master is a digital 3D model. I believe the solution is only two axes (but I will leave this to the CNC engineers to define); rotation and cutter direction. It seems simple to me, I cannot believe it has not been done digitally before. Dave

Band saws are relatively safe, but I certainly understand the expensive argument. The belt sander is a good choice for the first major tool investment, you will enjoy this and will find many benefits beyond fishing lures. My belt sander is the same style as JDs (above). I did actually make a jigsaw cutter for Lexan. It is featured in this video at 2'41". Not as good as a bandsaw but it worked. Dave

1 - a band saw and a belt sander would make all your Lexan problems go away. But if you do not plan to tool up a man-cave then the only alternative that I see is a sanding disk attachment for a regular power drill. 2 - the swivels idea will work, but your problem is going to be drilling the hole down the center of the body. This can be achieved with a drill press, but without a press it would be a difficult task. I like the slot along the back of the body and drop holes down for the hook loops. The slot is easily filled and tidied up. Another solution is to start with two halves, soft glued together for the carving and shaping process. Split, fit the harness and hard glue. 3 - We will need photos and more build information for this problem. Dave

There is no precision pouring lead into a hole. No matter how accurately you calculate the hole depth, you will be lucky to get withing 2 grams of your target weight. In addition, the hole surfaces are charred, there is no adhesion, just a loose slug of lead. I pour my lead cylinders in a wood mold, and then trim to achieve the exact weight that I require. If you want a spreadsheet, then write down a specification of what inputs you want to make and outputs you expect, pm me and I will construct the sheet for you. Dave

2Marshall8 - I freely admit that I am well beyond personal experience here, but you do not require experience to apply logic. Plastic is an insulating material, in other words, it does not transmit heat easily through the bulk. When you switch on a Presto pot, the heating element raises the temperature of the plastic in contact with the surface of the pot that is being heated. Because the heat transfer properties of the plastic is low, it cannot pass that heat energy to surrounding plastic fast enough and overheats, even though the surrounding plastic is cool. Either you stand over the pot and continually stir while the plastic is being raised to operating temperature or you employ a stirrer. If you do not stir constantly then you will scorched half your plastic yellow before you even reach production temperatures. Once the plastic is at production temperature, the thermostat will kick in and try to hold that temperature by switching the heat on and off. You still need to keep the plastic moving but not to the same extent, an occasional hand stir being sufficient. If I were to design a pot, I would include a low audible warning when heat was being applied to the plastic as a warning to stir. Alternatively, I would have the stirrer move slow when the heating element is off and faster when heating element is on. I would include a holder on the stirrer for the injector when not in use to avoid any fouling between stirrer and injector. Yes, there are mechanical limitations to this idea, but none that are insurmountable, it is just a design problem, there will be solutions. Design is ALWAYS a compromise; a mechanical stirrer for heating up and a manual stir when temperature is achieved is the accepted compromise. Dave

Neoprene tubing. It is one of those things that are hard to find when you want it but occasionally come across when you don't. If I see it when out shopping I will always buy a meter or two. Dave

Big Epp - We are here for those questions and concerns, this is the whole point of the TU site. Dave

I like double pin joints, this gives maximum freedom to the hinge as one joint has two pivots. Strength-wise, the load is distributed along the length of the pin, perpendicular to the pull direction, you would have to rip the lure in half to break it. There are so many joint solutions and I cannot say that any are particularly bad. Whether a joint will fail or not all comes down to your design; screw-eyes too short, area around pin to thin, inadequate sealing, etc. Hinges are all about free movement, even the slightest resistance to movement will cancel out the action. Rear facing V-joint shape: head < < < - tail, this gives a wide 'S' action, reverse the 'V' gives a narrow 'S' action, therefore by deduction, a flat hinge face will give something in between. If aesthetics are important to you then a stepped 'piano hinge' style may be appealing. It is all personal choice, you cannot go wrong Dave

Shouldn't be a problem as you NEVER let ANY resin product touch your skin. If you can smell it then you need ventilation, mix it outside or use a fan. Dave