Manticore And Fishing Weights

[strick]

I wanted to clarify something that I posted in the Centerline thred that Basstrackerman started...also I watched  Video that Andy had made comparing led to gold nuggets. 

On  a recent water hunt I had noticed that some fishing weights I had dug were clearly off of the centerline. And when I got home I tested them on the grass and it was the same result. So I did  little more testing and what I found is this: 

1. Large Irregular shaped Lead fishing weights do indeed hit off the centerline These were Pyramid and Egg shaped sinkers. 

2. Smaller lead fishing weights of the same shape will read on the centerline. 

3. Flat lead sinkers of all sizes will hit on the centerline. 

Photo #1 5 oz pyramid sinker

Photo #2 1 oz pyramid sinker

Photo #3 3 oz  egg shaped sinker

Photo #4 1 oz egg shaped sinker. 

Photos #5-#6 are the sinkers tested. 

Conclusion: Centerline stability for lead fishing sinkers is dependent on the size and shape of the sinker. Smaller sinkers will read touching the center line while bigger pyramid shaped and egg shaped sinkers will read off the centerline.

I did test all the modes in factory and it seemed to be the same for each. I just wanted to clarify as this may help those of us that hunt beaches and fresh water swimming holes. 

strick 

[Rick N. MI]

That's interesting. It's good it not in the iron area.

[abenson]

I've suspect this will be the same with Civil War bullets to some extent and will depend on their orientation in the ground. I have a .58 cal minie buried in my test garden and depending on which direction I sweep it, it does come off the center line. Not as much as what you're showing, the blob is just barely not touching the line. So shape is definitely playing a part in how something shows up on the trace.

[TampaBayBrad]

Thank you Strick! We are all learning Manticore.  I don't run in to too many sinkers since my beaches are mostly flooded with swimmers during the busy season but info is good to know.

[JCR]

I was thinking that some of the newer fishing sinkers were made out of some other metal besides Lead. I know automotive wheel weights are now primarily Zinc or some sort of sintered aberration.. You can't hardly find real Lead ones anymore at the tire shops. They were the best base material for hard cast bullets.

[Chase Goldman]

23 hours ago, abenson said:

I've suspect this will be the same with Civil War bullets to some extent and will depend on their orientation in the ground. I have a .58 cal minie buried in my test garden and depending on which direction I sweep it, it does come off the center line. Not as much as what you're showing, the blob is just barely not touching the line. So shape is definitely playing a part in how something shows up on the trace.

 

13 hours ago, JCR said:

I was thinking that some of the newer fishing sinkers were made out of some other metal besides Lead. I know automotive wheel weights are now primarily Zinc or some sort of sintered aberration.. You can't hardly find real Lead ones anymore at the tire shops. They were the best base material for hard cast bullets.

Good points, Andy and JCR

Noting from strick’s results and statements that the similar shaped sinkers varied as to whether they touched the line based on their mass and or volume (i.e., the higher mass/volume sinkers were further from the center line) but also the blob shape appeared to be roughly consistent for each sinker shape group.  This might indicate that there is not only a mass/volume bias in the 2D tracing algorithm independent of material composition with the implication that larger target magnetic fields might be considered by the algorithm more likely to be ferrous but that the algorithm is potentially assessing induced field symmetry for target tracing.  

Understanding these nuances and what the algorithm “thinks” it is seeing wrt to the target attributes would be key to unlocking more utility out of 2D target trace.  Wish ML would give us more insight in that respect.  Something (like a Treasure Talk article > do they still do those?) that supplements what they provided below in the user guide.

For the targets that were less symmetric in one axis (e.g., the pyramidal sinkers) was also wondering, to Andy’s point, how the trace would vary based on the coil swing direction vs. the orientation of the target with respect to the coil.

Also wondering if the line attachment shank played a role.

On 3/2/2023 at 9:50 AM, strick said:

I wanted to clarify something that I posted in the Centerline thred that Basstrackerman started...also I watched  Video that Andy had made comparing led to gold nuggets. 

On  a recent water hunt I had noticed that some fishing weights I had dug were clearly off of the centerline. And when I got home I tested them on the grass and it was the same result. So I did  little more testing and what I found is this: 

1. Large Irregular shaped Lead fishing weights do indeed hit off the centerline These were Pyramid and Egg shaped sinkers. 

2. Smaller lead fishing weights of the same shape will read on the centerline. 

3. Flat lead sinkers of all sizes will hit on the centerline. 

Photo #1 5 oz pyramid sinker

Photo #2 1 oz pyramid sinker

Photo #3 3 oz  egg shaped sinker

Photo #4 1 oz egg shaped sinker. 

Photos #5-#6 are the sinkers tested. 

Conclusion: Centerline stability for lead fishing sinkers is dependent on the size and shape of the sinker. Smaller sinkers will read touching the center line while bigger pyramid shaped and egg shaped sinkers will read off the centerline.

I did test all the modes in factory and it seemed to be the same for each. I just wanted to clarify as this may help those of us that hunt beaches and fresh water swimming holes. 

strick 

Strick - Thanks for doing the test and for the screen shots.  Learned a lot.  If you have any further thoughts on the speculation above based on how you conducted those tests, would welcome your comments.

For reference I am including some excerpts from the M-core user guide regarding how to interpret TT shapes and positions.

[strick]

Thanks fellas...yes I was thinking also if the sinkers metal composition might play a role as well as the metal shank. The large egg singers have no shank. The targets read the same sweeping 360 with them laying flat in their side so I don't know what they would read if you changed the orientation pointing vertical...I can cut the shank off one of the larger pyramid sinkers to find out...and then stick the pointy end into the grass as well lol. I have  5 gallon bucket about 1/2 full of sinkers so I can test some of the older looking ones to see if they respond the same my feeling is they will. If you look closely even the smaller sinkers read at the bottom just touching the line...How this plays out in our different dirts we'll have to see.

strick 

[TampaBayBrad]

30 minutes ago, strick said:

I have  5 gallon bucket about 1/2 full of sinkers so I can test some of the older looking ones

As gravediggermax would say...."gray matter". 🙂

[Chase Goldman]

8 hours ago, strick said:

The targets read the same sweeping 360 with them laying flat in their side so I don't know what they would read if you changed the orientation pointing vertical...I can cut the shank off one of the larger pyramid sinkers to find out...and then stick the pointy end into the grass as well lol.

Didn't know you did the pyramids 360 and it didn't change the trace shape much.  Probably not worth it to go through the effort.   Seems then that mass/volume is the most significant attribute especially in regards to how it pushes the target off the centerline.  Thanks for the additional info, strick.

[CoinShooter]

Interesting thread.

I haven't dunked my Manticore in the water yet, but plan on doing so tomorrow morning for a few hours. I'll be sure to pay attention to the screen when digging to see if I come up with the same results as you.

Also, I dug a handful of Minie balls a few weeks ago and the blob wasn't tight on the centerline either. Additionally, the numbers scattered when sweeping back and forth. However, the sound was worth investigating and out comes Minies that were fairly deep.

John