A30 center of gravity

[Dharma]

Does anyone know where is center of gravity of an empty (no fuel, no water, no engine) A30? I'm designing a new trailer for Dharma and I would like to calculate where to put the axles...

Thanks

[Hirilondë]

I have absolutely no idea. But from what I have seen of boats on trailers more people should be asking that question. Good luck getting an answer.

[okawbow]

Does anyone know where is center of gravity of an empty (no fuel, no water, no engine) A30? I'm designing a new trailer for Dharma and I would like to calculate where to put the axles...

Thanks

You might think about putting your axles on a angle iron bracket that can be bolted to the frame, and slide up or back for adjustment. I built my trailer that way, and drilled evenly spaced holes in the brackets and frame to allow me to move the axles. I also attached the fenders to the angle braket so they would move to. You need to allow slack in the brake lines for this.

[Quetzalsailor]

I'll bet you could guess it within a foot. Eyeball the volumes. Eyeball the center of the ballast. It will likely be darned close to the middle of the waterline length in a CCA boat. Perhaps you could also do it with a travellift: let it down on a single block under the keel and play with the block location until both straps slacked at the same time. Clearly, you would not give the thing much chance to go astray!

If you were building a cradle to sit upon a trailer, you could plunk it on and adjust it to get the tongue weight where you wanted it. Ditto with the way the wheels were mounted. Baby boat trailers are sometimes made with the axle mountings bolted to the frame rather than welded. Shipping containers are often rolled on wheel assemblies which are pinned into place, so the idea is not so worrisome.

Looks like 'okabaw' and I are on the same page...

[Brodie]

It should be roughly where the center of the ballast is, which is usually a bit aft of the mast step. 1/2 of the water line length isn't a bad guess either, although I'd err on the aft side of that measurement as most boats have more volume in the back end than the front end.

[Dharma]

Thanks for the answers.

I like the idea of being able to move the axles to adjust the weight on the truck.... Will save me some stress about being right with my calculations. Also, for anyone else who could have the same problem, I found on a technical sheet that the center of gravity is 16' 1'' aft of the bow.

Thanks again