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wchilton

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Everything posted by wchilton

  1. UKandy, I think the machine that can do what you are asking about is what they call a 5-axis CNC mill. It can move the part in the normal X, Y, Z linear axes and also can rotate around two axes to make under-cuts and other complex cuts that require the cutter to have access to places a simpler 3-linear-axis machine cannot reach. As mentioned earlier, you still need to be able to design what you want in CAD, and you would also need 5-Axis CAM software to generate the more complex toolpath instructions. Even with all that, there are things that 3-D printing can do that 5-Axis machining could never do. Physical machining always needs a way to get the cutting bit inside the shape where 3D printing can create completely sealed objects with interior structure. For a simple example consider if you wanted to "machine" a hollow sphere. Can't be done using any conventional machining. Is relatively easy with conventional machining if you do it in two halves to be attached together. Creating it by 3D printing is possible, just need some support points to hold it in place as the layers are built up.
  2. A few things you can try. First is that if you know there is an issue with topcoat, no need to try new things on a fully shaped, built, lip and eyes installed lure that you spent a lot of time on. Just use an approximate lure shape that is quick to make until you have a working topcoat solution. Sand and paint same as a lure so you test the same finish, just on a "model" that is fast to create. I cannot tell if your issue is with the paint wrinkling underneath the topcoat or if topcoat is not sticking. It could be a little of both. For paint wrinkling, you can try heat-setting the acrylic paint with a hair dryer. Many acrylics become more permanent after some mild heating and then are less likely to wrinkle due to solvents or plasticizers in the top coat. For top coat not sticking well it is usually oil contamination. There could be an oil or plasticizer in the acrylic paint or it can come from your hands. Try wiping the lure clean with alcohol and the let excess alcohol dry just before applying topcoat. Isopropol alcohol from the drug store is fine. Try to find some with lower water content (around 70% alcohol or more) since that will dry faster.
  3. The glycerin is acting as a plasticizer. Corn syrup (also many sugars) helps to retain moisture and can also act as a plasticizer to some extent. Thank you for the link to that recipe. I may give it a try sometime. Another recipe that may be useful to those following this thread is one I found for authentic gummy bears. The Sorbitol in the recipe helps make the pieces "springy". I don't think you need the sugar, but there's so much in the recipe that it could make a difference. I definitely think the citric acid can be eliminated (it's a flavoring in the small amounts used) and skip the candy flavor for something more appropriate in baits. Some citric acid may be useful as a preservative but I'd try excluding it first just to avoid possibility of something that acts as a deterrent. Here's a link to the recipe with Sorbitol. https://dolcefoglia.com/blogs/flavor-recipe-blogs/step-by-step-instructions-to-make-a-real-gummy-bear-recipe?ref=tfrecipes
  4. Theoretically, but thick coat vs thin coat is not going to be noticeably different when it comes to heat dissipation. On the lure you're only talking about a layer that's a fraction of an inch thick and the lure itself can absorb some heat. In a small (mixing) cup with mixed epoxy you may be talking about as much as 1-in thickness, compared to 1/4in or 1/8in depth if poured into a larger drinking cup while being used. If you want to try a little experiment, try comparing a small blob of epoxy in a cup in a hot water bath compared to same size blob in an unheated cup. A very general rule for chemical reaction kinetics in a first-order reaction is the reaction will happen twice as quickly for each 10 deg C rise in temperature. Note, that's 10 deg C or 18 deg F. So if room temp is 75 deg F and you compare to curing at say 110 deg F, you should expect epoxy to harden around 4 times as fast (1/4 the time for the warmer one). When a reaction generates heat, it can warm up the reaction products a lot more than that. There's a type of polyurethane casting resin that turns from transparent brown color to creamy white color as it hardens. You can really see this heat effect in a top-pour mold filled with this. The "thick" areas (main body) will turn white much faster than the thin areas (small appendages) and sometimes you can see a thin layer of uncured resin at the edges of the mold (before full cure) because material at the edges is actually kept cool from contact with the relatively cool mold.
  5. Turn by hand is an option if you just do a few baits. Turner becomes more essential the more baits you make. You don't have to keep turning for a full thirty minutes with "30-min epoxy". It will set up to a point that it won't run/drip in a lot less than 30 min. It will still be tacky so you will need to hang it after initial solidification. The 30 min time is to cure to hard/usable strength. Hardness/strength will continue to increase for 24 hrs or more. If you need a bit more working time, pour the epoxy into a cup that's big enough to spread it out flat (while still liquid) rather than in a compact thick mass (think cube, cylinder, sphere). Epoxy heats up while it cures so the thinner the layer the easier heat is dissipated and then accumulated heat won't be able to accelerate the cure like it will in a thick mass.
  6. I think you may have identified the problem in information in your post! Polyurethane expands with heat (shrinks with cold) quite a bit. I wonder if the epoxy-coated baits are creating stress (tension) in the polyurethane foam when the lure is cooled down from the cool water...just a guess. I'd think the effect might be worse for larger baits.
  7. I have used clay to create mold box for open pour. Have also used it to create a quick/dirty master. Clay will leave a matte finish where the silicone contacts it. I kind of like that look for top and sides of a mold. Do not use clay with any sulfur content. Have heard that it can mess with silicone curing. I just use Plastillina #1 modeling clay from the art supply store.
  8. The reason I put it on the bend is so it doesn't make the opening any smaller. I know, probably doesn't matter. The copper wire is just what I had laying around to see how this would work. Was surprised how little wire it took to get a few 10ths of a gram. It's a lot easier to work with using a longer piece than needed while wrapping! I just cut it with nail clippers and clear coated with UV resin since I have it on hand.
  9. I'm pretty sure going with stronger hook will work and is the right thing to do if you have a lot of baits to deal with. In the meantime, came up with the following. Just wrapped some fine-diameter copper wire (from speaker wire I had out in the garage) around the bottom of each bend in the treble and added a clearcoat to the wraps to keep them from shifting. Easily added 0.3gm to a single treble hook. This would be the way to test out whether adding weight to the hook achieves what you want, then could look for a hook that gives you the correct weight.
  10. Adding paint will change the weight but won't affect the buoyancy much because paint is around same density as water. So I think you're on the right track with heavier hooks. Maybe try 2X or 3X strong hooks that have heavier wire in the same hook size?
  11. Looks a lot like a Radtke Pike Minnow
  12. I was just suggesting he doesn't need to experiment on a finished or nearly finished lure. Anything with representative geometry and surface prep would work to test the process.
  13. Like mentioned before "thin coat of super glue" or you can try a contact cement. You don't need to experiment on lures you've spent a lot of time on. You can test the process on dowel rod or other scrap that has been sanded/prepped like a lure but doesn't require nearly the amount of time to get to that point.
  14. I've used a scroll saw, two bench-top bandsaws and a 14-inch floor-standing bandsaw. I use the big bandsaw for most things. It will cut straight if you do your part and don't rush. A table saw is best for straight cuts, but that's a whole different beast. Of the two benchtop units I've got a 3-wheel version and a 2-wheel version and the 2-wheel one gets a lot more use. Have used the little 2-wheel bandsaw even for cutting brass sheet up to about 1/8 inch but it is a bit difficult to do straight cuts. If all I had was a scroll saw I'd use it for detail work and do the straight cuts (for blanks) with a hand saw.
  15. It's possible you have foil with no glue on the back, but you can still use it, just have to add your own glue. I think I've done that with either super glue or contact cement. Just realized there's a hot melt product sold at fabric stores (for patching) that you just iron on with a hot iron. It's on a piece of glossy paper with a thin layer of the glue on one side. The other thing you could try if stamps aren't working is a heat gun. I've got a little $10 craft heat gun that works great for small stuff like heating jig heads for powder paint dip and it doesn't get so hot that it melts the lead. I could see using that to apply foil with hot melt. Just need to affix the foil where you want it (maybe with tape or rubber bands) and hit it lightly with the heat gun.
  16. I'd suggest you try one before buying if at all possible. They can be very slow. Try some cutting like you expect to be using it for. I use a bench-top bandsaw a lot more than the scroll saw.
  17. I've noticed that once a spot in the plastic starts to burn the scorching continues from that spot. Waves bounce around inside the microwave oven and sometimes there can be a "hot spot" where more waves converge. Make sure the fan is turning freely (fan inside is used to scatter waves) and also make sure there are no rust spots, etc that could change the way waves bounce around. Might also try stirring a little more or more often, especially after plastic has gelled. The thicker plastic cannot distribute heat as much by convection (currents) but mostly by conduction which is a much slower process.
  18. "That would make sense. Would using isopropyl alcohol work as a solvent for epoxy or do I have to use acetone." Either should work. I would use isopropyl alcohol.
  19. Same oil as the plasticizer in your soft plastic...Diisononyl Phthalate (DINP). Here's a link https://www.p65warnings.ca.gov/fact-sheets/diisononyl-phthalate-dinp It is not mineral oil. Mineral oil will ruin plastic worms and I wouldn't recommend vegetable oil of any kind either. There are some plasticizers now that a phthalate-free, don't know what those are.
  20. Temperature can sometimes make a difference. Try hanging one in a hot car for a day and see if it cures up. You can also try wiping the surface with alcohol to get rid of the tackiness.
  21. When you first start mixing epoxy, do you notice that it is not quite transparent? I mix my epoxy until it returns to fully transparent and then for another 5-10 seconds.
  22. If swim test is not to your liking and weight/balance are pretty close I'd suggest building up the back-side of the bill to be more like the original. Back side can influence vortex formation. I'd use super glue + baking soda or hot melt glue.
  23. Be careful with strong degreaser...strong caustic can attack/corrode aluminum. Strong acids, same thing. I'd probably try some type of aluminum-safe mag wheel cleaner. If what you're seeing is a grey-colored finish that is still smooth it might just be aluminum oxide, in which case I would leave it alone unless it's causing you some kind of problem. Aluminum oxide is used as a "finish" for a lot of aluminum products and is harder than the aluminum itself and is a protective finish.
  24. Part of the problem is that sharpness and longevity of the edge are always a trade-off. For the utility blades you probably have a 14-deg angle where a pocket knife might have 25-deg angle. If you want the edge to last longer it has to have larger angle and then will never be quite as sharp as the original smaller angle. You might find that resharpening is not as razor sharp as the original edge, but it will maintain the sharpness you give it for a longer time. If you are going to resharpen, no point in getting titanium coated blades, that's a very thin coating and resharpening takes it right off. I've found that the easiest way for me to sharpen without a guide is a diamond "steel". This is basically a rod, covered with diamond bits and with a handle at one end. It looks like a "steel" used to put an edge on a blade but it removes more material than a normal steel would. Here's an example of a diamond "steel" on Amazon that's reasonably priced https://www.amazon.com/Kota-Japan-Professional-Sharpener-Sharpening/dp/B06W9J9RTN/ref=sr_1_1_sspa?crid=19MD2OW2R1JI0&keywords=diamond+steel+knife+sharpener&qid=1649151623&sprefix=diamond+steel%2Caps%2C230&sr=8-1-spons&psc=1&spLa=ZW5jcnlwdGVkUXVhbGlmaWVyPUFKUFlERDVRWkc4R1UmZW5jcnlwdGVkSWQ9QTA2MjAwMDYzQkgzWDJBN0lQWjBCJmVuY3J5cHRlZEFkSWQ9QTAwMTAyNTNCRURLQU0zTTRaT0wmd2lkZ2V0TmFtZT1zcF9hdGYmYWN0aW9uPWNsaWNrUmVkaXJlY3QmZG9Ob3RMb2dDbGljaz10cnVl Here's a video that talks about edge angles https://www.worksharptools.com/what-is-the-best-knife-angle-and-how-do-i-tell-what-angle-my-knife-is/
  25. Total weight mixed was (37+37+7.25) = 81.25g Weigh the bait you cast with this mixture, let's say it was 50g Ratio of your bait to total mix is (50/81.25) = 0.615 Multiply each of you components 0.615 to get weight you should have used 37x.615 = 22.76 @ a and b 7.25x.615 = 4.46g MB 22.76 + 22.76 + 4.46 = 49.98g I would mix a few grams extra overall so maybe use 24a + 24b + 4.8 microspheres then you will have a small amount leftover and some loss to sprue and sides of container.
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