Tweet
I read the invite on Eric Foster's site and thought I'd drop in.
Interesting enough, I'm also in the process of building a sidescan sonar based on Dan Fountain's design.
I've read all of the messages on the list and can give you some of my thoughts.
Just this week I received most of the pieces to put the unit together.
Dan's unit is built using the following major pieces: PVC 2" Schedule 80 for fish. The fish consists of three pieces (nose cone/tow plate section - also where the lead is; transducer section - potted so you don't have to worry about water, air hoses, etc.; and the tail section). All three of these sections are glued together using 1.5" Schedule 80 PVC and obviously PVC glue.
The wing's and tail section on Dan's unit uses aluminum.
The 4 tranducers are connected to RG-58 A/U coax cable and run up the a Fishfinder. Dan fed his into a Lowrance Mach 1 fishfinder (paper graph). The paper graph is the old type of fishfinder as opposed to today's LCD screens. The benefit of the paper graph is a hard copy which you can review later and higher resolution. The downside is the expense of paper and getting a hold of an old working unit.
Dan used 4 Lowrance PD-W transducers and I did the same since they are identical to the transducer used on my Lowrance 350A. The PD-W provides a 20 degree beam. You can also get an 8 degree beam. There are advantages and disadvantages to both. Paid around $60 per transducer.
I picked up two paper graphs for my fish. One is a Mach 1 (same as what Dan uses) ... paid $100. I also picked up a Lowrance X-16 which is a little more advanced (some nicer options) for $250. I should note that the prices mentioned came with transducers and power cables too.
There are still a few of these "paper graphs" out there.
On the cable ... Dan first tried to use a 300' cable and then cut it to 175' for better resolution. I will make mine at 250' length and go down from there ... much easier to make it shorter than longer and the cable is only 17 cents per foot (in Alaska anyway).
I have the ability to plug the fish/cable into either of my Lowrance fish finders (Mach 1, X-16, LMS-350A). The LMS 350A has more than twice the power of the MAch 1 or X-16. I am hoping that it has enough power to drive the longer cable. If it does, I can always make an additonal 200' cable for the paper graphs.
In e-mail conversations with Dan, I believe he told me that he can reach out to 1000', but gets better results within 600'(horizontal).
Some of the changes I have made from Dan's design include using Delrin (4 times the cost of PVC) for all of the fish parts (fins, tow plate, body). I am also using solid delrin rod to connect the three body pieces as opposed to glueing so that if I trash the tail section I can replace it on the spot with a spare. I might change my mind on the tow plate and either make it out of 1/4" aluminum or SS rather than delrin.
Dan's fin design was a basic rectangle. I am looking at an alternate design where they would flare back and am also going to soften the tail fin leading edges making them more hydrodynamic.
I am also using solid Delrin rod for the nose cone and will machine it down to a bullet shape. I want this to be very streamlined so that there will be as little wobble as possible.
Dan has located wrecks with his unit and made my life much easier by providing the initial thought as well as listening and responding to some of my ideas.
I should note that Dan's unit is used in frshwater, not saltwater. I will not be shocked if I do not have the range or resolution that he does ... we'll see.
Dan's idea was to make a very inexpensive sidescan that works.
One of my ideas was to run another cable down to a totally separate transducer (PD-W) on the bottom of the fish. This would allow me to know how close I was to the bottom. I would have used a Lowrance 3500 depth finder. I called Lowrance and they told me that it would max out at about 60' of cable. Their was not enough power in the unit. I guess I could hook it to another fishfinder which has more power.
Some thoughts based on the messages I have read to date ....
Keep it simple. All of the commercial sidescans look like rockets, not planes. Expand on other's ideas as opposed to re-inventing the wheel. I wish I could use a PC instead of the fishfinder! The more cables or thicker cables in the water, the more resistance/drag there will be which will float the fish at a shallower depth.
I'm not an electronics type, machinist, mechanical engineer, or programmer. If I can put this together, anyone (with a brain) can. Feel free to ask any questions.
Patrick
Interesting enough, I'm also in the process of building a sidescan sonar based on Dan Fountain's design.
I've read all of the messages on the list and can give you some of my thoughts.
Just this week I received most of the pieces to put the unit together.
Dan's unit is built using the following major pieces: PVC 2" Schedule 80 for fish. The fish consists of three pieces (nose cone/tow plate section - also where the lead is; transducer section - potted so you don't have to worry about water, air hoses, etc.; and the tail section). All three of these sections are glued together using 1.5" Schedule 80 PVC and obviously PVC glue.
The wing's and tail section on Dan's unit uses aluminum.
The 4 tranducers are connected to RG-58 A/U coax cable and run up the a Fishfinder. Dan fed his into a Lowrance Mach 1 fishfinder (paper graph). The paper graph is the old type of fishfinder as opposed to today's LCD screens. The benefit of the paper graph is a hard copy which you can review later and higher resolution. The downside is the expense of paper and getting a hold of an old working unit.
Dan used 4 Lowrance PD-W transducers and I did the same since they are identical to the transducer used on my Lowrance 350A. The PD-W provides a 20 degree beam. You can also get an 8 degree beam. There are advantages and disadvantages to both. Paid around $60 per transducer.
I picked up two paper graphs for my fish. One is a Mach 1 (same as what Dan uses) ... paid $100. I also picked up a Lowrance X-16 which is a little more advanced (some nicer options) for $250. I should note that the prices mentioned came with transducers and power cables too.
There are still a few of these "paper graphs" out there.
On the cable ... Dan first tried to use a 300' cable and then cut it to 175' for better resolution. I will make mine at 250' length and go down from there ... much easier to make it shorter than longer and the cable is only 17 cents per foot (in Alaska anyway).
I have the ability to plug the fish/cable into either of my Lowrance fish finders (Mach 1, X-16, LMS-350A). The LMS 350A has more than twice the power of the MAch 1 or X-16. I am hoping that it has enough power to drive the longer cable. If it does, I can always make an additonal 200' cable for the paper graphs.
In e-mail conversations with Dan, I believe he told me that he can reach out to 1000', but gets better results within 600'(horizontal).
Some of the changes I have made from Dan's design include using Delrin (4 times the cost of PVC) for all of the fish parts (fins, tow plate, body). I am also using solid delrin rod to connect the three body pieces as opposed to glueing so that if I trash the tail section I can replace it on the spot with a spare. I might change my mind on the tow plate and either make it out of 1/4" aluminum or SS rather than delrin.
Dan's fin design was a basic rectangle. I am looking at an alternate design where they would flare back and am also going to soften the tail fin leading edges making them more hydrodynamic.
I am also using solid Delrin rod for the nose cone and will machine it down to a bullet shape. I want this to be very streamlined so that there will be as little wobble as possible.
Dan has located wrecks with his unit and made my life much easier by providing the initial thought as well as listening and responding to some of my ideas.
I should note that Dan's unit is used in frshwater, not saltwater. I will not be shocked if I do not have the range or resolution that he does ... we'll see.
Dan's idea was to make a very inexpensive sidescan that works.
One of my ideas was to run another cable down to a totally separate transducer (PD-W) on the bottom of the fish. This would allow me to know how close I was to the bottom. I would have used a Lowrance 3500 depth finder. I called Lowrance and they told me that it would max out at about 60' of cable. Their was not enough power in the unit. I guess I could hook it to another fishfinder which has more power.
Some thoughts based on the messages I have read to date ....
Keep it simple. All of the commercial sidescans look like rockets, not planes. Expand on other's ideas as opposed to re-inventing the wheel. I wish I could use a PC instead of the fishfinder! The more cables or thicker cables in the water, the more resistance/drag there will be which will float the fish at a shallower depth.
I'm not an electronics type, machinist, mechanical engineer, or programmer. If I can put this together, anyone (with a brain) can. Feel free to ask any questions.
Patrick
Comment