Forms not lining up under string line

[anthony karakas]

Greetings everyone,

I just set the forms on the strong back and i am noticing that about 4 forms are off when measured at the string line on top. The worst one is about 3/16" out of line. I pulled it off and checked the centerline on it. It was ok. I took great care in leveling the strong back and laying out the centerline. If the centerline on the strong back is straight, and the centerlines on the forms are straight, why would i be off at the top of the forms (under the string line?)

I hope i explained that clearly. All suggestions most welcome!

[Rabbit]

have you checked that the face of the station that mates to the strongback is at 90 degrees to the centre line? i had my stations cnc machined but still found that some of them were out by a hair. 3/16 sounds like a lot, at least to me, but i'm only on my first build.

[alick burt]

I agree with rabbit
I think your 90 degree line must be slightly out.It could also be that your forms match each other when they are stacked on top of each other but if one or two are stacked with left and right on opposite sides( e.g they are flipped over in comparison to the others)the error may be doubled.
Suggest you try turning the offending forms around and see if they line up better.If all the forms are out but still line up with each other you should still be able to make a straight boat even if the whole thing is tilted on it's side whilst being built.
Hope this is clear and I haven't confused you too much.
Cheers
Alick

[anthony karakas]

Thanks guys; I made several adjustments overall; the strongback was not completely level side to side under the station most out of line. Then i reconfigured the string line. In the end it turned out pretty close to perfect.

[Rabbit]

that's good news anthony

hopefully the rest of your build will go smoothly now.