Humminbird Side Imaging Forums
General => General Discussion => Topic started by: Whistler on December 05, 2011, 08:39:01 PM
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I just recently purchased and installed a 798 on my trolling motor using the Transducer Shield and Saver. It's a great mount, but I'm not sure that I like having the transducer turn when I turn the TM.
I've been doing some web searches to try and find someone that has constructed a fixed position bow mount for SI and I've also been thinking about how to design such a contraption. So far I haven't been able to find anything so I thought I'd ask around here to see if anyone has run across or built anything like this. IMO there are some serious flaws in having the SI transducer turn with the TM. Specifically, the difficulty in getting a clear image while turning, and the impact on scan coverage and resolution of objects at a distance due to the progressively increased distance between the SI ping beams as you travel out further from the rotating transducer axis.
Seems to me that a setup like you would typically find on the transom would provide much better results. To be practical, I think this would still need to mount to the TM upper shaft or TM mount and would need to be retractable, and have breakaway and reset capabilities for transducer protection. Has anyone heard of or seen something like this?
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Whistler
Before you invest in making any changes you may want to review Doug's 9 part seminar one of which reviews using an SI transducer on the trolling motor. I found it compelling and reinstalled the SI transducer back on my trolling motor. also recommend that you take the time to view all 9 parts, it will help you get more out of your unit.
--> http://www.dougvahrenberg.com/Videos.html (http://www.dougvahrenberg.com/Videos.html) <----
George
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Thanks George, I've already seen all of the videos and many of the others on Doug's site. The info he has provided has been most helpful in understanding how to use and interpret my two units.
I have no intentions of removing SI from the bow of my boat. I'm just looking for a way to get better SI images from it. I believe fixing the SI transducer so that it doesn't rotate when I turn my Tm may be a way to do that.
I hope others out there may have run across such a solution or at least have wondered about it.
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Go to www.podunkideas.com (http://www.podunkideas.com) when you get there click da ducer apparatus.
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Thanks Denny,
At the most basic level that is the idea. However I'm looking for a design that is a little more simple and hopefully a little more elegant and that mounts to the TM in some way.
Guess I may be building it myself.
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I agree with you on the ducer mounted on the T M. I made a mount out of 3/4 conduit PVC and clamped it to the T M shaft. I have it set about 4" under the water and never damaged it in a couple of years of fishing,and it works great. I posted pictures on here along with a post but I can't find it now. I will take some shots tomorrow and post them.
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Whistler, here are the photos of my transducer mount and support. The reason I did this is because I didn't like the picture smeared when I turned the T M. Hope it helps. Don't know if I got all 3 photos posted or not. RAY
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I see I did not so here are 2 more. RAY
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Ray,
Is it as simple as heating the PVC and adding that bend or is there more to it than that? I was wondering how easily this can be done without the PVC pipe collapsing.
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Hi Greg, I just took a piece of scrap 3/4" plywood ,cut out the offset I wanted then put the pvc in the exaust pipe of an old lawn mower and ran it until it got flexable, sat it in my jig until it hardened an "violla"I made the Ducer mount out of a piece of about 1/16" stainless and the 4 clamps out of the same material. Don't use stainless bolts in the clamps, the threads on them gall before getting the clamps tight enough. I used grad 8 1/4" bolts as a final solution.
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Thanks for the pics Perch Jerker. That's certainly more in-line with what I am looking to do.
How much drag does that add to the trolling motor? Have you noticed any impact to trolling motor speed since adding it? How about turning? Any negative impact there?
Finally, how rugged is it? That will be the first thing that I crash into docks :o So I hope it can take beating.
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Just glad to be of help Whistler. I have not noticed any drag at all, it is only about 4" deep so usually I see obstacles and avoid them, I have hit stick-ups a few times without any damage. the PVC has a lot of give to it. RAY
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Well, I've finally gotten around to taking some pics of the mount that I wound up building and thought I would share. The mount is really easy to make and so far it is holding up beautifully even in rough water. The only real question now is what happens when I get into heavy grass? Luckily I rarely deal with that.
Enjoy.
[attachimg=1]
[attachimg=2]
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Well done Whistler
Maybe HB/Jonson could develop this idea which could eliminate the problems we are seeing on this forum with electrical intereferance from trolling motors.
Would the head of the trolling motor obscure transducer readings? What do you have the wires connected to on the other end and are you getting good clear images
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Thanks Enufzed.
This does NOT eliminate any noise issues and wasn't intended to address them. If you look closely at the image you'll see that there is a second wire running along the transducer cable and terminating on the upper part of the trolling motor shaft. That is there to eliminate the noise I initially had and which is now completely gone.
This mount was intended to improve SI images from the front of the boat and I must say it works extremely well. I get SI images that are just as clear as those I get on the console. The trolling motor head is not visible to the sonar so no issues there. Trial and error and some minor geometry helped me move the transducer to a position forward enough to so that the tm head is outside of the SI and 2D sonar beams.
I'm not real sure what you are asking regarding where my cables are connected. They actually run through the inside of the pipe and out the top of it so they are almost completely protected from any possibility of damage save the very small exposed area where the cable enters the transducer itself and that can be easily covered.
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Yeah ok
Thanks
Whistler
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Hi Whistler , Nice design and execution ! need a little more info on the grounding wire you mentioned. Exactly where does each end connect? I am after solving some interference problems.Thanks Ray.
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One end attaches to the upper section of the TM shaft. I just stripped the insulation off of enough of the wire so that the bare wire would wrap completely around the shaft then tightly taped it to the shaft.
The other end runs to the negative wire that comes off of the 798 power cable. That essentially just grounded the TM shaft and completely eliminated the interference for me.
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I took a different approach on mounting mine in the front. I took an old small bow mount trolling motor and turned it into a transducer mount. I got rid of the head unit and the motor on the bottom and just used the folding frame and the shaft. If I'm fishing a bank, which I mostly do, I can turn the transducer a little putting that side bean ahead of me giving me a idea of what's coming up.
"gene"
[attachimg=1][attachimg=2][attachimg=3]
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I took a different approach on mounting mine in the front. I took an old small bow mount trolling motor and turned it into a transducer mount. I got rid of the head unit and the motor on the bottom and just used the folding frame and the shaft. If I'm fishing a bank, which I mostly do, I can turn the transducer a little putting that side bean ahead of me giving me a idea of what's coming up.
"gene"
(Attachment Link) (Attachment Link) (Attachment Link)
That’s what I would call the sonar version of “spotlighting”!
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Gene, I see more and more of the trolling motor shaft with a johnny ray mounting bracket for transducer mounting.
It does make the placement of the transducer varible and at different depth.
One drawback is to not run it above trolling speed. It can thru water pressure break the hingepin on the shaft motor.
We have used the exact arrangement on SAR to look under banks cutouts, and under docks. We have even used the thing from a side of the bank location and rotated the head by hand.
Kind of like what the ice fishermen do...
It is not a true sector scan but the next best thing..
Chuck
Chuck
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hey chief can you elaborate on the dammage on shaft from pressure i am building a similar mount for si/di and 360 later on from an old johnson scissor lift motor and can use all tips before hand , thanks . ;)