I went on a bit of a mission over the weekend to make this portable fishfinder suction mount with a GPS on the side. I first modified my fishingski hatch to open forwards. It used to open on the side. I then also covered the lid with black perspex ( Or some sort of signage plastic, they joys of working at rent a store you find some interesting things in the waste skip). A while ago I added a suction mount to my fishfinder. I made a suction mount for the gps but thought that is a waste. Lets just make one suction mount. So this was the final product below in the video.
Portable fishfinder Suction mount with a GPS on the side.
In this link is still my mount for the transducer and battery. I am thinking about getting a smaller battery so will change the battery box to make portable fishfinder more portable.
The mounting of the ski uses two double pulleys and a single one. I used “awning pulleys” which maybe a risk as they do not state the load capacity. However the ski should not normally weigh more than about 35 to 40 Kg with some kit left inside. But I suggest using pulleys that are a little bigger than the 25mm dia. ones I used. The double pulleys I purchased came in a set and cost about R50.00 but the better ones sell single and are about R50:00 each. I am sure there will be a mechanical advantage as pulling it up on ones own does take some effort. As you can see from the photos until I decide how I feel about “awning pulleys” I have used two orange “safety ropes” at the ends of the ski for the time being. With Moms new car below the ski is the least of my worries.
The pulley are connected using “D” shackles and again they are cheap ones ( no load specified ) as the ski should not weigh that much. You may need one or two per pulley application depending on the pulley eye. My pulleys have fixed eyes so I had to use two shackles to orientate the pulley for the rope run. However some of the others have a swivel eye so they should only need a single shackle. Shackles cost about R6:00 to R 15:00 for the cheap ones. The expensive ones go for above R 45:00. The shackles are connected to 10mm eye bolts which I ran through the roofing timbers at 75 mm up from the bottom. Also suggest that one goes as high as is possible to just clear the rope runs as this will get the ski hanging higher up.
I have used a flat belt around the ski to spread the weight load across a larger area of the body of the ski as opposed to a rope ( which I tried first ). The current flat belt will change when I can to one that is prepared with a “D” and hook sewn into the belt as opposed to the current huge granny knot. The important thing is to get a “snug” fit to reduce the height at which the ski hangs down.
The most important thing is to get the “correct rope” for the pulleys. Do not use ski rope as that is cheap and nasty and does not keep its round profile and so easily slips into the gap betreen the pulley roller and the roller body. Ask me I did that and ended up with the ski jambed in mid air when the ski rope slipped off the roller and wedged the pulley. Luckly Mark was there to rescue me as I was stuck at the side wall holding the two ropes and too afraid to leave them and try get to the ski lest it decide at that moment to release. The rope just loops around the normal double lug rope trap as is often used on flag poles.
The costs were
10 mm eye bolts X 3 at R 15:00 = R 45:00
Double 25 mm dia. awning pulley set = R50:00
Single awning pulley = R30:00
Safety hooks to clip to belt from rope X 2 = R30:00
Rope trap = R 15:00
Flat belt ( not sure as this I got as scrap )
6 mm polypropylene rope 15 m X R 10:00/m = R150:00
Total for job excluding screws for rope trap = R320:00
I am fortunate that I have the large structural laminated beam across the garage at that point and so can hide a ski on either side if need be.
Thanks very much Stan for this info and allowing me to put this on my website.