Puffin - Trial and error engineering

[Scott T]

Sounds like you have plenty of thrust. You might add an intake baffle to suction the water below the waterline.

[Occupant]

water is drawn in from the bottom

[Scott T]

"movement and just under two amps will pull the assembly to the surface and start sucking air thru it. need to put this into the boat, run it in the pool vs static testing to get a better feel."

I read the sucking air but did not register the part about not in the boat static testing.

This is looking cool.

[Occupant]

Kind of like the jet ski other than the motor is attached to the rudder ball and moves as a unit pivoting about the vertical axis. spent the morning with google trying to figure out the impeller rudder ball paramaters. then spent the afternoon with Microsoft copilot doing the same. I'm finding that google is a lot more flattering with a lot less useful info while Microsoft will actually try and solv problems and do the math. playing the two agains each other like and believe the copilot info. changing a few things to try and optimize performance - thrust / amp. tore the cad model up a bit, changing to a 1.75" impeller, lengthening the et tube to move the motor out of the flow path and then just swept the 1.75 thru a radius and angle out the bottom - more streamlined. then aded feature to allow putting a flow restriction nozzle to help guage a taper at the end of the output see if it effects thrust / amp.

[Occupant]

In addition to trying to reinvent the jet pump have been fixing things didn't like in the last build. The fin servos used to slide into a keyway, had too much slop an a bit of movement. revised the interface to a t - slot, now nice and tight fit. In addition rotated the servos to get the servo horn and fin hor on the same plane. Finally revised the silicone potting down to a single pour vs top and bottom. In the process of doing the mold made a removable cap for one wall that used the servo sharft as a mount and block the silicone from encasing the top surface. i printed the cap out of TPU to get a little flex and have abit of compliance. think it turned out pretty well.