OK -- I've now developed a means for ensuring the clamp cups do not slide off the Portland Pudgy's transom. I will update this post with photos and explanations later.
[Edit]
My approach was to find a simple and easy assembly solution to ensure the motor and its C clamp assembly would not twist off the transom with the resultant loss of the motor to the deep.
Parts used:
1. Approx 12 inches of galvanized pre-drilled metal angle bracket (just laying around in my garage
😉 )
2. Stainless Phillip head screws and washers larger than holes in the metal angle bracket(less than $5)
Here's a photo of the Portland Pudgy's transom fitted with a sturdy steel plate that stiffens the transom and provides a strong surface for the screw cups to push on. You can easily see the area where the screw caps press onto this steel plate near the top of the transom from their scuff marks -- they are just too close to the top of the transom for my comfort. Note that this steel plate can be removed via the 4 black plastic embedded nut toggles shown (this is a stock item for the Pudgy). Behind this steel reenforcing plate sits a solid gray plastic plate with V shaped ends. The gray plastic plate can be removed after the steel plate is removed by sliding it up out of the transom.
This photo shows me holding the pre-drilled metal angle bracket sawn to length ready for me to screw down onto the top surface of the transom.
This photo shows how the angle bracket overlaps the top surface of the transom and leaves a gap that is sufficient for the clamp cups to slide up into. (sorry about it not being in focus)
This photo shows the angled bracket after stainless screws and washers used to fix it to the top surface of the transom.
Finally, this photo shows how the steel angle bracket allows the screw caps to be positioned under the vertical angle of the bracket. The cups simply cannot move upwards and off the transom without of course pulling the steel angle bracket off.
Another photo showing the screw caps positioned under the bracket. I may need to place two more screws in through the bracket closer to where the screw cups engage the bracket just to be sure it all holds together when motor running flat out.
Rear view showing how the motor C clamp's rear surface is correctly flush with the transom's vertical surface -- as it needs to be.
Photo showing that the vertical shaft is at the perfect 90 deg angle with the water level.
🙂
Job completed.
With the dinghy held fast to the swim step via the davits I slowly applied motor power to test how well the steel angle bracket resisted the motion of the screw cups to move upwards. It did a good job and gave me great comfort the motor should be safe from twisting off into the water. This was a more severe test as normally the dinghy would be free to move forward under power and would therefore exert less twisting on the transom and the C bracket.
I did get an unexpected bonus from this steel angle bracket. Because of it being angled it adds bending stiffness to the transom -- much like for the stock steel plate is designed to do. Apart from maybe adding two more stainless screws and washers I think I'm done with this project.
😎
