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Well, when you get the gears fixed, you have some tuning to do. All that hopping is bad, and probably didn't do the gears any favors either. It's hard to say, but I would start with trim angle, tilt the outdrive down a little bit, to add a some negative trim. This should stop the bow from shooting towards the sky, then falling flat. Moving weight forward can also help, but change one thing at a time.
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I will start with the trim, as it is the easiest to do (after all, I will need to break apart the drive system anyway!). Battery was already as far forward as I could move it. I also trimmed the right trim tab a bit down, as the torque was causing the boat to run tilted to the right. I will also give it a little of down thrust (negative angle) to run straighter and stop the bouncing. To be honest, I am not quite sure the bolt was there to start with, because there WAS some play in the drive prior to running it, and now that I put a new bolt in, there is no play (well, there is a tiny little bit, but nowhere near as much). The other thing I need to do is to flood the gear compartments with grease. I mean not just grease the gears, but grease the whole compartment, as there was water in there, and the grease can help block water from coming into the drive unit.
I am also considering taking the Lift strakes at the rear of the hull (at least the bottom ones) off.
If you look at the gears in the picture, it is obvious they were not meshed properly; the gears did not break, they just grounded each other because there was too much slop. I think they are perfectly capable of handling 4S if meshed properly, but we will find out soon enough! I ordered the gears (all of them) yesterday, and this time, I will take time to mesh them properly.Comment
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Nice scratch build, you boat need more weight in the front.Comment
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I think you have a good chance eliminating the bunny hops with angle adjustment. 33% should be enough, too much weight forward and the nose dives.
I’m hoping the drive isn’t too deep. You could easily tack on some 1/8” balsa sheet to see, after you have gone through the trim adjustments."Look good doin' it"
See the fleetComment
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EDIT: I just noticed it does not seem like it in the picture because of optics, but (1) the boat is balanced in the pic and not touching the ground (only the wooden posts), (2) the tape measure is aligned with the transom, and (3) the boat does measure 24" exactly
It is not quite at 33%. And the percentage depends on where you measure from, because my transom is angled. But, assuming it is the complete length of the boat, which is 24" on the dot (keel is a little less, but then you got the trim tabs!), and that CG is at 7 3/8" (this is where it was when I ran the boat), then the CG is at 30.7%, and that is nowhere near as far back as it would have to be to cause that hopping by itself. I think it is more the drive angle...
In any case, to move the balance point forward, I have no choice but to add weight, as I cannot move the battery further up.
The drive allows for quite a lot of negative angle if I so choose to. Right now (after the run) I set it at 5~6* down, but I can go significantly higher. I estimate I had it at 0~1* (up) when I ran it, so 5* down should be a significan difference. The other thing is that, thinking back, I am not 100% sure that bolt came loose while running. The unit had a lot of play before, and now that I put the bottom bolt back in, it has A LOT less play.Comment
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BTW, I decided to take the rear part of the strakes off. I took about 3" off the rear strakes, so we will see how much of a difference that will make next outing.
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Between that and the adjustment to the right trim tab, I hope the hull will run level now (side to side)
Luckily, I glassed the boat before putting the strakes in, so it was a fairly simple process to take out. Hull is not perfectly smooth, but I will try it as it is and see if it is worth putting more effort making the hull smooth or not.Comment
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