Topic: Seeking advice on SI transom installation

[bobblong]

Hello everybody,

I've been breaking my head over this and haven't come to any productive conclusion, so I'm asking for some advice on how to install the SI transducer on this problematic transom. As you can see in the images, to the left and right of where the motor mount is the transom is curved outwards from the mount and tilted out from the bottom of the hull. Towards the edge the curve becomes flatter and the tilt remains the same. The only solution I could think of is to install 2 transducers on either side of the transom and split with the Y cable. This solves the motor mount obstruction problem but does not overcome the slight curve on either side, which will cause each transducer to image at an angle somewhat not quite parallel with the boat. Not sure thats such a bad thing but may cause some inaccuracy when reading the screen. I'm aware of the SternMate product which will overcome the tilt but how does one kill the curve? I would appreciate everybody's input and any insight on how to end up with an optimal transom install on this boat.  Cheers.

[EZM]

Other than modifying the stern mate, which could be allot of trial and error, I would trace the profile of the concave surface, and trace it onto a block and cut it out.

The block material can be wood, but what i would do is laminate a few pieces of poly material transom transducer plate stuff.

You could cut one big piece into 4 pieces and sandwich with 5200 adhesive, clamp it overnight to get your starting block which will be 2" thick.

Once you band saw the profile (as traced), secure it to your boat as a transom plate and you have a flat mounting surface.

That's probably what I would do.

What kind of boat is that - looks neat ......

 

[EZM]

One more thought - if your transom is pitched, say at 14 degrees, tilt your bandsaw table at 14 degrees to ensure the compound curves will end up snug as a bug.

You will end up with a 90 degree flat surface to mount your transducer, a curved surface to mate tightly to your transom, without drilling holes in the transom every time you adjust your transducer.

The block could attach with 5200 as well - no holes in boats. Just sand off the mating surfaces a little and wipe them clean of dust.

Make sure you have 1/8" reveal (lift it up 1/8" up on the transom) to allow smooth water flow (so the block is not proud of the hull under the boat).

Hope that helps - total cost should be under $25.

[ITGEEK]

Based on what I can interpret from your photos:
If it were me, I'd try to install it on the rightmost
flat area to the right, bottom of the motor mount, lower than
the lowest portion of the motor mount.
That looks like that it has a clear line of site.
If that area is curved, you could always add washers
to keep the transducer looking perfectly horizontal.

I would put a small transducer mounting plate
made of starboard or polyurethane there, say 4" by 4".
That way, you only drill two holes in the transom, and
can move the transducer to find the sweet spot.
Being close to the propeller is not a good thing for
turbulent water, but with the way your boat is shaped, it
may be the best choice.

Good Luck.

[bobblong]

One more thought ....

Your idea is so awesome and is probably the most ideal thing one could do but I think think it's technically way beyond me. The boat is a thai version of a 13' bassboat . Thanks for your input.

[bobblong]

Based on what I can interpret from your photos:
If it were me, I'd try to install it on the rightmost
flat area to the right, bottom of the motor mount, lower than
the lowest portion of the motor mount.
That looks like that it has a clear line of site..........

Yeah that sounds like less of a headache than going for 2 transducers and will save money too. I have to check the clearance there.  You are talking about the black area that's stepped in or the red area where the motor is actually mounted? I'm wondering if that black area is ok. Thanks for your reply

[ITGEEK]

I'm talking about the red area that is 18" wide.
The rightmost bottom of it.
I would mount it as far right as possible.

[newkid4si]

bobblong
   Before I would start drilling holes, I would temporarily tape the transducer in your chosen location,
   then lower the motor to the running position. I'm concerned about the leading edge of the fin mounted to the outboard.
   It may be far enough forward to block part of the beams.

           Mike 

[bobblong]

I'll keep that in mind Mike. No rush to drill holes for sure. Thanks.

[EZM]

If you try mounting on the 18" flat part, I would definitely tape it on to see how it works. Keep in mind you are only 9" away from the middle of the boat.

The propeller is going to make some turbulance in that area. That's why they have you mount it to the right side, at least 18" away (as the rotation of the prop and the distance) should make this less of an issue.

I think its worth a try anyways. Who knows maybe the design of the hull would allow for less turbulance.

[newkid4si]

bobblong

    Have you contacted the boat manufacture for ideas?
   
           
                           Mike

[bobblong]

If you try mounting on the 18" flat part, I would definitely tape it on to see how it works. Keep in mind you are only 9" away from the middle of the boat.

The propeller is going to make some turbulance in that area. That's why they have you mount it to the right side, at least 18" away (as the rotation of the prop and the distance) should make this less of an issue.

I think its worth a try anyways. Who knows maybe the design of the hull would allow for less turbulance.

Yeah that is definitely a turbulant area, but I will try as you said to tape it on there and see how it goes. Otherwise it's going the 2 transducer left/right route.

[bobblong]

bobblong

    Have you contacted the boat manufacture for ideas?
   
           
                           Mike

I wish that were an option haha. It's a very cheap locally made boat and people don't really use sounders round here coz of the prohibitive costs so I dont expect the guys who made this boat, which costs less than the electronics going on it to know anything useful.

I'll post an update once things are up and running to let you guys know how it turned out. Still waiting for some parts to be shipped from the US.

[newkid4si]

bobblong

   I have an idea. It's not going to cost anything and might even work.
   If I were in your situation, I would try this first.
   Run a string/chalkline from the right side of the boat near the three white marks on the transom to the same location on the left side.
   Similar to the 53" yellow line in the second photo except under the boat.
   Now you have established a line perpendicular to the boats line of travel.
   Next I would semi-assemble the transducer and mounting bracket. Don't tighten the bolt with the Locktight on it.
   Take a carpenters square and place the short side parallel to the string. The long side of the square will give you the boats line of travel.
   Holding the transducer next to the long side of the square and bracket against the transom, you may find a location between the three
   white marks and the trailer bunk that will work.
   You my have to move the square left or right.
   I've looked at those photos so long that I've convinced myself that it will work. LOL
   Did I say it's FREE to try this. I do understand if your not interested.

            Mike


     
   
   
   

[bobblong]

bobblong

   I have an idea. ...... 
   
   

I kinda get you, so tell me from this picture below which orientation of the square you mean. black/blue/green with blue and green having the short side underneath the boat, parallel with the string . Anywhere on the transom except for right next to the engine bracket is blind to the other side I'm afraid. However on the underside of the transom there is a step (where you said the string should run across) that step has good view side to side and a nice flat surface, is that where you meant? Thanks for your efforts.



Ben

[newkid4si]

Bobblong

   [ Attachment Invalid Or Does Not Exist ]  I couldn't see this in your post.
   
               Mike

[newkid4si]

Bobblong.

      Amazing! As long as I looked at the photos, I didn't see the black step. I thought it was part of the trailer frame.
      As others have said, I would be worried about placing it near the prop.
      That said, I believe some of the BASS and FLW pros have their SI transducer mounted to their jackplate and a 2D inside the boat for high speed.
      In the end you will probably just have to try a location and see how it works. At least now you have options. Good Luck.

              Mike