Hello All,
This posting is rather belated but nevertheless I think it is worth doing.
Some time ago, there was considerable discussion regarding the problem of
deformation of the doors and the method of attachment of the gas struts.
I now wish to announce to the world that I have adopted the principle and
now sing the praises of Ted Gladstone's brilliant idea which completely
eliminates all strain on the door as a result of the forces applied by the
gas strut.
Before carrying out this mod, I must admit to having first tried the
"alternative" method which I think most builders are now adopting. When I
did so however, I still found that the door deformed slightly where the
strut attached at its new location and also that the gap at the top of the
door opened up an extra 1.5mm. Further, on closing the door, there was a
large amount of distortion requiring it to be positively held in alignment
before it could be fully closed. Admittedly, there was no perspex in the
door to provide extra bracing but it was my desire that the perspex should
not have to contribute in this manner. I therefore went to the trouble of
laying up one ply of carbon fibre on the inner surface from the rear hinge
to 2/3 of the way down the back of the door. This strengthened the door
considerably but I was still not happy about the poor rear hinge having to
withstand the consistent 25 to 27 kg load. If you don't feel sorry for the
hinge, see how long you can hold the gas strut fully closed. I hadn't got
to replacing the new attachment point when I learned of Ted's idea and I
immediately recognised it as being what I consider the only true answer to
the problem found to date.
Because I am not constrained by limitations imposed by the PFA like Ted is,
I was able to make mine slightly different from Ted's in as much as I cut
the bottom out of the gas strut channel in order that I could make it a
little deeper which in turn allowed a little longer strut and slightly
differing geometry which I am pleased to be able to say has been most
rewarding. Anybody who is interested in this approach and who hasn't yet
installed the roll over bracing at the back between the doors would be well
advised to do the modified layup of the channels and the reinforcement
section all in one go because it provides a good opportunity to include a
couple of layers of uni from just below the lower end of the channel right
across to the same point on the opposite side.
The end result of all this is that I now have doors (still without perspex)
that close without the slightest sign of misalignment, that have absolutely
no residual strain on them when fully closed and have a much improved hold
open force which supports 4 x 1 kg bags of sand placed on the larger area of
the door when fully open. The only disappointment was that the carbon fibre
layups have been made completely redundant but I am certainly not going to
remove them now.
CAVEAT
This mod does require a reasonable amount of work and indeed patience and I
would suggest it is not for the feint hearted. If you like a bit of a
challenge then the reward is there for the taking.
For me, it is one of those things that when completed, makes me feel good
every time I operate it as opposed to being something that "I wish I had
done"
If there is sufficient interest, I would be prepared to draw up the
dimensions I finally arrived at. I have photos and a video of the operation
but unfortunately I don't know how to make the video condensed enough to
publish it on the web. If I am requested to supply details I wish to point
out that I have to do so with full acknowledgement to Ted Gladstone for the
advice and assistance provided by him to me several months ago for which I
am extremely grateful. Thanks Ted. Hope you haven't taken out a patent!!
Regards
Kingsley Hurst
Mono Classic 281 in Oz
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