fishordie79 Posted November 10, 2019 Report Share Posted November 10, 2019 Hey there TU community! I made a glide bait body tonight that I am really happy about and I was thinking about the best way to weight it so that it sinks parallel and relatively slowly. I see a lot of people talking about "center of buoyancy" and I was wondering if you guys could give me some suggestions on some good methods of finding this. What I have done until this point is just kind of eye the bait, drill holes where I think they need to be, pour some lead and then do a swim test. Then I just add or reduce weight how I see fit until I achieve the sink rate/position I am looking for. This has worked fairly well thus far but there has to be a more scientific approach to this. What do you guys suggest? Quote Link to comment Share on other sites More sharing options...
jigmeister Posted November 10, 2019 Report Share Posted November 10, 2019 (edited) You can move lead ballast around mounted externally outside the body of a prototype to get an idea how much weight you need and where to place it first for a particular design . Once you arrive at the weight required and drill into the lure body you will be losing a slight amount of buoyancy and slightly altering the center of gravity you had previously established with the weight on the outside and may have to make slight adjustments . I have taken a drill and slowly removed lead from a weight I had glued in for ballast after testing to get the balance back after moving the ballast inside the body . Not the scientific answer you were looking for but that's how I have done it ……. Edited November 10, 2019 by jigmeister omission 1 Quote Link to comment Share on other sites More sharing options...
Vodkaman Posted November 11, 2019 Report Share Posted November 11, 2019 When a lure is floating stationary, the CoB is ALWAYS directly above the CoG. This relationship determines whether the lure is nose up or down depending on where you fit your weights. To find the CoB you can find the balance point of the plain, unweighted blank, over a knife edge or just your finger. Dave 1 Quote Link to comment Share on other sites More sharing options...
BobP Posted November 11, 2019 Report Share Posted November 11, 2019 Like Dave says, I balance the bait on the side of a knife blade, ruler, etc, then nudge it until it begins to fall off. That point on a he edge is the center of balance. 1 Quote Link to comment Share on other sites More sharing options...
Vodkaman Posted November 11, 2019 Report Share Posted November 11, 2019 Before hardware is added (plain blank) it is the centre of buoyancy (CoB). After adding all the ballast and hardware it is the centre of gravity (CoG). If the two are the same distance from the nose then the lure will float level. I use this information when designing a lure on CAD, arranging the ballast locations so that the lure is predicted to float in the attitude that I want. Dave 1 Quote Link to comment Share on other sites More sharing options...
fishordie79 Posted November 12, 2019 Author Report Share Posted November 12, 2019 @jigmeister @BobP @Vodkaman Great suggestions and thank you all!! @Vodkaman what CAD software are you using? Quote Link to comment Share on other sites More sharing options...
Vodkaman Posted November 12, 2019 Report Share Posted November 12, 2019 2 hours ago, fishordie79 said: @jigmeister @BobP @Vodkaman @Vodkaman what CAD software are you using? I use Catia V5 Dave 1 Quote Link to comment Share on other sites More sharing options...
woodieb8 Posted November 25, 2019 Report Share Posted November 25, 2019 On 11/10/2019 at 10:01 PM, Vodkaman said: When a lure is floating stationary, the CoB is ALWAYS directly above the CoG. This relationship determines whether the lure is nose up or down depending on where you fit your weights. To find the CoB you can find the balance point of the plain, unweighted blank, over a knife edge or just your finger. Dave well stated. 1 Quote Link to comment Share on other sites More sharing options...
eastman03 Posted November 26, 2019 Report Share Posted November 26, 2019 This is a somewhat related video about finding the center of buoyancy (not my video). It's based on a topwater lure, but the principles would be the same. Check out his other videos, very informative youtube channel. 1 Quote Link to comment Share on other sites More sharing options...
fishordie79 Posted November 27, 2019 Author Report Share Posted November 27, 2019 @eastman03 Thanks man! Checked out some more of his videos as well and discovered color-shift airbrush paints:) 2 Quote Link to comment Share on other sites More sharing options...
eastman03 Posted November 27, 2019 Report Share Posted November 27, 2019 No problem @fishordie79, I really like his approach and information that he gives about all aspects of lure building. His channel is newer, so youtube doesn't really push it quite yet. 1 Quote Link to comment Share on other sites More sharing options...
fishordie79 Posted November 28, 2019 Author Report Share Posted November 28, 2019 @eastman03 I can't tell you how freaking glad I am to have to discovered this community. Everyone here has been so damn helpful it's just amazing! Quote Link to comment Share on other sites More sharing options...
