mounting jet drive to angled transom

[Bigfluffydog]

hi, I'm building a jet powered dinghy
it's kind of a "let's see if this will work project"
boat is being sanded, now is time to mount jet drive
Transom Is angled
boat is not
was thinking of fabricating a mount that extends the transom so the jet mounts at 90 degrees.
so, a plan is to make a box from fiberglass and epoxy through the transom

Ideas ?
ignore the green tape (holding in a gasket) and the pencil marks. thanks

 

[Julian]

Perhaps some wider photos?

 

[Liveto99]

Put a jet outboard on it?

 

[2kwik4u]

Looks like you have a 3D printer. That's a huge start here. I would look into makeing (2) pieces. One on each side with the correct cutout, and angle you need. That will move the flange you have pointing at the transom now just to the far side of the angle transom. Once you're happy with the shape/size/mounting take your 3D files to your local machine shop and have them CNC'd from aluminum. I'll be happy to help with the manufacturability side of it. You could also combine the two pieces on the left of the transom there into a single piece. Could easily CNC the two flanges, then weld some thick wall tubing into the shape you need. Really depends on the fitment, how many stock parts and pieces you want to use, and how much time/energy/money you have to throw at it

Something like this........(ignore the dimensions)

 

[tdonoughue]

Although... Seems like you have also an opportunity to add a trim adjustment. That outside piece @2kwik4u suggests could be fitted with a sliding mechanism at the top to trim a bit. Maybe with a screw drive that will then move the angle of that back part. Or equipped with shims to do the same thing manually, at least. That may be very handy when it comes time to tuning this thing up.

 

[2kwik4u]

Although... Seems like you have also an opportunity to add a trim adjustment. That outside piece @2kwik4u suggests could be fitted with a sliding mechanism at the top to trim a bit. Maybe with a screw drive that will then move the angle of that back part. Or equipped with shims to do the same thing manually, at least. That may be very handy when it comes time to tuning this thing up.

Agree. I can work up a mechanism, and then we would probably use a length of exhaust tubing to make it flexible. Could find some other solutions for flexibility there. Not sure how the trim on the waverunners work, but could simply plumb into that already developed mechanism?!?!?

 

[tdonoughue]

Dunno. But I do know that designing it in there has got to be easier than trying to add it later...

 

[Ronnie]

I’m no engineer and I don’t have a 3D printer or a CNC, that stated why not just cut a hole though the transom that closely matches that of the pump/pipe and seal it in accordingly with 3M 5200 or something similar? Altenatively or supplementally if you need to level the pump/pipe add a wedge/mount to the area between the deck/hull (NOT the transom) and the pump/pipe.