Thanks much for that detailed explanation. My cockpit module aligns
nearly perfect with the canoe without any cajoling. I could only
measure a 0.1-deg misalignment along the longitudinal axis, and that
is within the tolerance of my digital inclinometer. So I went ahead
and cleco'd the module to the firewall and canoe sides, then removed
it, and I am proceeding with populating the module.
On Thu, Aug 18, 2011 at 5:47 PM, Greg Fuchs <gregoryf.flyboy@comcast.net> wrote:
>
>
> Hi Andrew,
>
>>What I often find confusing with the manual is that it says what to do, but
> it doesn't say why. As a scientist,
>> I hesitate to do something until I understand why.
>
> I am the same way, and predict many other builders out there are as well. It
> makes for a lot of thinking testing and preplanning before assembling. Many
> times one can create better ways (than what is in the manual) to put this
> thing together but it also eats up a lot of time. I find myself asking this
> question often when starting up a new task...Whats more important, precision
> or time? Most often, precision wins out. It is an airplane after all, and
> one can't expect to 'pull over' up there in the big blue skyways. Oh well,
> long precise build it is :) .
>
> When building the module up, one needs to check for clearances between the
> controls (plywood strengtheners, fuel lines, etc), and the bottom of the
> fuselage ..many times. The bearings (or the flange lips) for the control
> arms (or the lower side of the control arm bracket) can hit the bottom of
> the fuselage. The manual tells you to get them as low as possible ..but they
> can be too low. I also remember needing to grind the top layer glass and
> PVC away from the bottom of the fuse. (and re-glass to add the strength
> back) in the rear where the controls were binding, because they needed
> another 1/8" (or so) clearance (Bud has seen this too, apparently ..notice
> his reference to CS08). ...other things needed nips and tucks to get to fit
> properly. A builder could easily miss these small clearance issues if they
> are not careful, resulting in a lot of binding (and a bunch more unexpected
> work) once the module is sucked up to the fuse while clecoe-ing or strapping
> pre-gluing. During the process of populating the module with controls (and
> stuff), I found it convenient to finalize the position of the module at an
> early state. If that is not done, the module can slide around too much, and
> it just makes it difficult to know where to do the nips and tucks to get
> everything to work well together. I am sure you can wait until just before
> bonding the cockpit module to the fuse before drilling the placement holes,
> if you were very careful to realign it over and over again during the
> clearance checks. I opted for aligning it just once in the beginning. There
> are sure to be other methods, and possibly better ones out there....but this
> one worked well.
>
> The two holes were placed up front where the module would not deform over
> time. It is very strong up in the front around the tunnel area. The lower
> part of the tunnel was positively contacting the inside of the fuselage, so
> the small bolts went through the forward, lower flange of the module and
> through the firewall in that area. The top of the tunnel was not a good
> candidate for the bolts, because there was a slight clearance between the
> tunnel top and the firewall (other planes might be different?). Putting a
> positioning bolt there would cause instability and straining on the module
> and the firewall. Better to let the glue fill that in when the big day
> arrives.
>
> I hope that covered it a little better..
>
> Greg Fuchs
>
>
> -----Original Message-----
> From: owner-europa-list-server@matronics.com
> [mailto:owner-europa-list-server@matronics.com] On Behalf Of Andrew Sarangan
> Sent: Wednesday, August 17, 2011 9:32 PM
> To: europa-list@matronics.com
> Subject: Re: Europa-List: Trial fitting cockpit module
>
>
> I think my question may have been misunderstood. I realize the importance of
> CM alignment to the fuselage. My question is, isn't this alignment best done
> after the control tubes and fuel tank are installed rather than on an empty
> CM? I was thinking that some deformations to the CM may creep in during the
> work, so drilling the alignment holes through the firewall may be best done
> when the CM is nearly finished. Or, is the empty CM is significantly lighter
> and hence easier to align?
>
>
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