Brian,
I used a small handsaw blade used in modelling with a myriad of small teeth
and only 1/2 mm thick. It is about 125mm long and 35mm deep, a very deep
blade that is reinforced along its top edge by a folded sheet metal
stiffener that at one end is shaped into a handle for inserting a small
diameter timber handle. The blade is rivetted in 3 locations to the
stiffener which I drilled out to remove the blade. I then used an aluminium
edge as a guide and this maintained a perpendicular cut. I taped the blade
such that when the tape reached the top of my aluminium guide on the
downstroke it was cutting through the skin and NOT going into the trim tab
leading edge. This method worked really well and gave a beaut cut, albeit a
bit hard on the hands as you are trying to grip a very thin blade and cut
with it. Mask it up to give it a better grip. It only took about 20-30
minutes, or maybe even less than that ( my memory may well not serve me
correctly, but I would prefer to say longer than shorter). I dont see that
the cut needs to be on an angle as the tab side is contour sanded away for
the closeout and the tailplane side will be sanded back to give deflection
clearance for the tab. Have I missed something?
By the way, the cutting of the tab "tip" cut! I made sure that the bottom
skin cut was directly under the top skin cut so that when the tab rotates
about the hinge line it is not geometrically limited. To do this I used an
adjustable set square to template the angle of the top to bottom skin
surfaces, measured chordwise from the trailing edge forward ( parallel with
the longitudinal axis). I transposed this onto the large side face of a
piece of 100mmX30mm that was about as long as the length of the tab tip cut
( about 150mm).This V shape was cut away from one end to look like something
with its mouth open and this was slipped over the trailing edge and forward
such that one flat face became the guide. I then needed to ensure it
remained exactly perpendicular so I screwed a timber out the side such that
it sat ontop of the top skin, perpendicular to my guide and parallel to hte
trailing edge. This guide timber was in contact with the top skin and the
guide face was at 90 degrees. I used my little hand saw and was able to hold
it with 2 hands both above and below the tailplane. Took about 10 minutes to
cut away, and I hope to be able to maintain a really small gap once I
reattach them.
Hope this helps.
>I used the cut off wheel on the dremel to just cut through the surface of
the glass and then go through a second time on the angle. If u don't have
one I recommend aquirring one u will use it a lot.......Gavin Lee
>
>----------
>> > Brian, I wouldn't worry to much about the weight done on a bathroom scale.
>> > My tailplanes also weighed 12 lbs. on it. On my paint scale they weighed
>> > 9.25 lbs. each. I have tried the hairdryer idea, and can say it works
>> > great! My thanks to the gent who posted it.
>
>>
>> My log book clearly shows the tailplane at 12 lb on monday, but I weighed
>> them again last night, and now they come out at 9lb. I can only assume
>> that it was operator error... or the universe is playing tricks on me.
>>
>> While I have everyone's attention, I would like to ask about cutting off the
>> trim tabs. The cut on the bottom needs to be at a sharp angle, but I have
>> not had much luck with keeping the knife along a straight line while at an
>> angle. It tends to drift underneath the straight edge I am using. My plan
>> is to cut a piece of foam as a knife guide, and run the knife/foam
combination
>> along a straight edge weighed down to keep it from moving. Does anyone have
>> a simpler plan?
>>
>> Thanks!
>>
>> Brian
>>
>
>
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