tolerable slop when levelling the boat?

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Jay382

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May 16, 2009, 7:10:53 PM5/16/09
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Hello all,

I'm a bit frustrated after spending all day trying to level my boat in
preparation for beam mount installation. I was expecting everything
to square up perfectly in an hour or so :) but the best I seem to be
able to get is all four corners within 1/8" of each other. It might
not be builder error - I am building outside with wooden form frames,
so it's easily possible that I got a little bit of warp that caused
things to be just slightly to be out of whack.

That said, 1/8" out over this particular distance doesn't seem that
bad to me - on any other project I'd probably be happy with that and
call it good, but on the F22 I'm just not sure how much slop the beam
mount installation will tolerate. Looking through the beam mount
installation process, I _think_ a 1/8" error would be easily
compensated for when the mounts are installed and levelled. Thinking
logically about this there has to be some tolerance in the building
process design because nobody is perfect. Or am I just trying to
justify giving up early? Would love to hear comments or insights
from anyone else that has run into this.

Jay
F22 #25
http://www.seattle-f22.blogspot.com



Jay382

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May 17, 2009, 1:23:59 PM5/17/09
to F22 Builders
Well after a good night's sleep I gave it another try. After a few
more hours work, I'm pleased to announce better results this
time....I've now got it down to only one corner off by 1/16"-minus.
Unless someone tells me different, I'll be considering this "good
enough".

The problem: I was using an automotive bottle jack to raise one
corner or the other, then screwing blocks to the side of the strong
back to hold the boat cradles up at that new level, then taking the
jack out. I finally realized that after I removed the jack, there
was just an ever so slight amount of "settle" that was making the
boat's new level not match what I had measured with the jack in place
(maybe I have a "weakback" instead of a strongback). I was chasing
this settle back and forth yesterday without realizing it. After I
started compensating for that, the boat started to level out much
better. And thank goodness for electronic levels - I have a lot of
respect for anyone who can do this with a water level.

I'm not actually ready for beam mounts - this was a dry run, to see
how bad the situation was. So...back to trimming on the anchor
well.... :-)

thx,
Jay

Bill Scott

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May 17, 2009, 2:34:04 PM5/17/09
to Jay382, F22 Builders
Jay
Excellent. I don't think I was quite that close.
Bill

Menno

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May 18, 2009, 3:32:45 AM5/18/09
to F22 Builders


Hello Jay,

Nice to see you're building again.

When working on the beam mounts I had the same doubts on how much
tolerance is acceptable. Me and my brother worked hard to get
everything right but still I'm sure the mounts are not installed
perfectly. This sunday I'll install my floats + folding system and
then I'll know if I haven't been too tolerant. Fingers crossed.

The good news is a really small error when levelling the boat is, as
you guessed, no problem. It can and will be corrected when installing
the mounts.
The bad news is, you ain't seen nothing yet. When installing the
mounts there is much more reason for (nagging) doubts than when just
levelling the boat. I found it more difficult than expected to check
if everything was leveled and lined up correctly - it's not so easy to
check levels and distances, because all kinds of jigs are in the way.

So, it's good to install the mounts as best as you can, but it's
probably a bad idea to try to get it perfect. Maybe it's possible for
a professional builder, but in my opinion not for diy builders with
normal skills & tools.

Menno
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