Stinger Placement in a Mono

[properchopper]

A whole lot of crazymaking going on here Rick - center the shaft line over the keel. The hull has a natural tendency to go straight as directed by the keel line. You want the prop thrust (as dictated by the stinger location) to be in agreement with this. As has been found, many hulls aren't symmetrical so use the keel line as the center of the hull regardless of what the ruler tells you.

[rickwess]

A whole lot of crazymaking going on here Rick - center the shaft line over the keel. The hull has a natural tendency to go straight as directed by the keel line. You want the prop thrust (as dictated by the stinger location) to be in agreement with this. As has been found, many hulls aren't symmetrical so use the keel line as the center of the hull regardless of what the ruler tells you.

That's the plan Tony. As soon as I had that eureka moment about no true way to know the extact centre, I was fine. Measure 2, 3, 4 times, cut once. But in the end, it could be 0.5mm out. It doesn't matter though.

[properchopper]

Since I've been drawn into this Granfaloon (google it) I looked into my crystal ball and saw the next question coming about aligning the turn fins to be parallel to the hull centerline to keep them from steering the boat. A laser works great.

DSC04977.JPG

[mattmak]

I started down that path while I was staring at the transom. This method relies on two accurate reference points. I can't even find 1. The sides and top of the transom do not have square edges.

Well then, you obviously need a laser scanning, self centering, CNC transom driller...

[rickwess]

Well then, you obviously need a laser scanning, self centering, CNC transom driller...

HobbyHobby has one on order for me.

Yes I over complicate things. I started down this path assuming perfect alignment was required, then realised after playing with it that it's impossible to do so given the nature of the transom. It just may come down to taking the perpendicular line off the seam where the two halves of the hull are joined and then straight edge off the keel.

[mattmak]

Naw, I wasn't saying you are over thinking it. I was just trying to be ridiculous for a laugh. If I had massively accurate and complex tools that can get things perfect, I'd use them for sure.

Any way to find good reference points from the inside of the hull? Or maybe attach precise/accurate things to the outside to create good reference points..?

I would think though that with just a basic caliper you can get to under 1mm of accuracy. Would there be a few tenths of a mm of adjustment with the bolts that hold the stinger to the transom?

[runzwithsizorz]

I've just spent the last 30mins using the search tool and came up empty. The info might be somewhere, but the typical thread tittle doesn't help the search.

My question is where on the transom to mount the stinger? How far up from the keel? I think I've read a long time ago that about 3mm between the keel to the bottom of the stinger housing/bracket. Does that sound right?

Then there there is the question of offset or not. Thoughts?

Thanks for your help.

I cannot find the thread, but a recent record holder, if not THE current record holder of P mono was using an offset.
I am about to drill a 31" Rico BTW.
Edit; there must be a reason, right? http://forums.offshoreelectrics.com/...1&d=1356814352