Vodkaman

I worked on the water displacement method before developing the 'dunk test', which incidentally I discovered here on TU, in an old thread. I rigged up jars with connecting pipes but no matter how hard I tried, I just could not achieve the accuracy that I required for small lures. The method works well for large objects as the error becomes less significant with size. I now own a gram scale that has an accuracy of 0.01g. With my old 0.1g scale I could get very close to suspension, but the new scale will nail it every time. Suspension is a lot more complex than an accurate scale though. You have to take into account the paint and top coat, hooks and eyes. The 'dunk test' can only put you in the right ball park, the rest is up to you. Dave

I have had a 'taker ' for my offer. But unfortunately my work situation has changed, and paid contract work has to take precedence. My customer understands the situation, and I fully intend to fulfill my offer, and the shrimp will be delivered, but timescales are out of my hands. Regretfully, I have to withdraw the offer for anyone thinking of taking me up in the near future, but I may well open the offer again. I find this work interesting and challenging, even comparing with my normal work as a car designer. Dave

I agree with the message, but this vid didn't cover the subject. I expected more - sorry! Dave

Great video, very informative. Nice action on the swim test too. Dave

People are always accusing me of over-thinking ideas. But I am an engineer, that is what we do! Dave

That is an amazing offer. I hope someone takes you up on this opportunity. Good attitude I will chip in with some free CAD design work if anyone needs it, to support the above offer. DAve

Very nice video, enjoyed it a lot. I wonder what effect the solar eclipse has on fish. My guess is that the fish will go into a feeding frenzy, as they think they have missed supper. Dawn and dusk are catching times in my experience. Dave

I have just moved into a new place. I had plans to set-up shop again. I solved the ventilation problem, as my new shop would be out-doors, under the cover of an awning roof. Unfortunately, I have rediscovered my love of fishing, and do two competitions every day. They will not allow me to use lures, which was rather distressing, but it is still fun beating the locals. On average I win a prize 2 out of 3 days. Dave

I design my molds with the injector built-in. For the first pour, I block off the exit of the injector cavity, and then fill the injector. This gives me my injector piston. Probably not a good idea for hot plastic, but I only pour resins, for which this method works perfectly. Dave

I also use No3 for two part molds. I also design my mold master so that the two halves are identical, this way I only need one 3D printed master. Also, because all the silicone halves are identical, I don't need to match them as they are all the same. Dave

I totally agree with Rosko2 - eye position is probably the most powerful adjustment that you can make. This is a good one to experiment with and learn. Eye position is key to attaining depth. DAve

The only thing that I can add to the marvelous and knowledgeable comments above; is when you modify your bait to improve, change only one thing at a time and make a note of its effect. If you change more than one thing, you learn absolutely nothing because you do not know the effect that each individual modification had. Yes, it is a lot of work, but with each change, you EARN knowledge that will reap short-cuts in the future. An experienced designer/builder has a 'feel' for what needs to be done. This comes from the knowledge of what each adjustment will do. That is why I say 'Earn'. Pay now with the work and effort, earn the knowledge, and apply it freely in the future. Dave

Ha! - Probably a lot. They wouldn't notice, except for the desire to 'burp' at the top (swim-bladder expansion) Dave

No

Mark - yes, I miss my test tank immensely. Dale - I worked on the suggestion that you are making many years ago, about vortices canceling or doubling. It does not work like that, in fact in my post, I am likely over simplifying. Vortices will adjust automatically to fit in with each other and form a system. Example: if you swim two lipped lures side-by-side, they will 'kick-in' at different points, they may naturally have slightly different cycle lengths, but they will swim in perfect unison. They form a system of balance; one swimming slightly faster than its natural period, the other slightly slower (my guess, not proven). DAve

Good post Travis. Polyester has its place, as you say, particularly for prototyping and low production runs, which is all I ever do. I use floor polishing wax, purely because it is cheap and can buy by the kilo. A blast from the propane torch smooths everything out. This is prototyping, not fine detail. Dave

The speed is fine. Dave

I will try that next time. Dave

Baitjunkys - yes, that is my experience. The polyester mold (Bondo equivalent) softens when molding lead (in my case). I was still happy with the results which were non-dimensional critical, being ballast weights. If enough molds are made to allow for rotation and adequate cooling between pours, Bondo can work. Dave

DaleSW - what you have mentioned is correct, but the boot still creates its own vortices. The idea is to minimize the vortices created at the front end so that you achieve pure waggle. A few years ago, I decided to combine both sets of vortices to try and create a hunting soft plastic swimbait. The idea was to have a bulbous nose to create significant vortices, these would change the direction of the lure on retrieval. The boot would create its own vortices and waggle independent of the nose vortices. The result did not quite achieve what I wanted, but the result is interesting. You can see the evidence of both sets of vortices. It is a strange, non-standard action, but I bet it would still catch fish. I still have the master, but I lost the mold somewhere along my house movings. I didn't have any plastisol, so this was poured with agar agar and glycerine (breaks too easily). Dave

Keep in mind that the human eye/brain cannot see anything beyond approximately 20 cycles per second, this is why video is set at 25fps. Depending on lip width, around 4 - 5m/s this magic number is reached. Either send me the data or read up on Strouhal formula. Dave

Are you sure that it has stopped wagging. As retrieval speed increases, the frequency of the waggle increases. With this increase in waggle speed, the width of the waggle does not have time to achieve the same width at lower speeds. If you only tried low speeds and high speeds, then the lure may still be waggling, but you cannot see it. Try at a low speed were you can definitely see the movement. Count the cranks of the reel per approximate second. Increase the speed on the next retrieve, again counting. Notice the faster and narrower waggle. Write down the numbers. Especially make a note of the numbers when the waggle appears to stop. Back at your workshop, measure the length of line retrieved by one crank of the reel. With this information, all the numbers can be converted to metres per second. I am guessing that around 5m/s (metres per second) the waggle appears to stop. You can send me all the raw data and I will do the sums for you and explain to you why the lure appears to stop waggling. Dave

I do the same, I always add polyester resin to my Bondo equivalent. It cures just as well, but flows better. Dave

Gliders - I have just checked my in-box, nothing there! Dave

I feel your pain. I had a lot of problems with image capacity a few years ago. I paid a subscription which granted my a larger capacity. But, when I stopped the subscription I lost many hundreds of images, this is why all the pics are missing from my old posts. Modern digital cameras will give you file sizes in the megabyte range, but websites have to pay for the storage of these huge files, and so TU can only afford to give you a limited space. You have to use editing software that is capable of trimming and compressing your image from a multi-megabyte image down to 100Kb or even less. This compression sounds enormous, and yet the image quality is more than good enough for web display. Personally I use Photoshop, but there are many other software solutions that I am sure others will chime in with suggestions. But, your BIG problem is that you have filled your capacity. You need to talk to TU management about this issue, to find out what can be done. It may mean deleting some of your images, but talk to the moderators first. For me; the best solution to your problem is to open an account on a photo hosting site such as Photobucket, then post a link to the Photobucket image. This way, there are no capacity issues, other than the Photobucket limitations which are pretty BIG. Dave