Balance point

[john corcoran]

hi just finished my spitfire one guy
tells me too balance it upside down
the other tells me too balance it upright
both of these lads have been modelling with many years what do you think

[nasa_steve]

hi ya john
i normally balance low wing upside down and hi wing the right way up it seems to work for me. bipes right way up but hand under upper wing as such
regards
steve

[john corcoran]

sound steve thanks for the advice

[Andy Green]

The C of G shown on the plan is just the starting point and it should not be a case of balancing on your fingers and forgetting it.

The C of G can only really be set up by flying the model. Andy Ellison wrote a rather good article in the RCM&E Special last year the same method can be found here - http://www.probuild-uk.co.uk/factsheets/trimchart.php

There is also a very good DVD on the subject (although it only talks about gliders it does have relevance to all flyers) by Radio Carbon Art called Performance Tuning For Gliders (http://www.radiocarbonart.com/Pages/perftunemain.html).

[john corcoran]

Thanks Andy I must look it up

[Dave Chatterton]

Hi John
On a low wing model I always balance with the model inverted as nasa steve suggests but I always use the Great Planes CofG balancer and it is spot on. Don't what I would do without it. Fingers are no good!!
DC

[john corcoran]

cheers dave,balanced it inverted,test flew
the spit today no problem,I agree with you
on the c of g machine, great investment its
too clumsy a job with fingers,sometimes we are inclined too move the fingers a little forward or back too convince ourselves that the balance is correct
ha ha ha

[Stephen Harrison]

A cheaper way of making a balancer is by getting some board with two dowels with pencil erasers on the end as the don't dent the model and works just as well.

[john corcoran]

yes Stephen i bought a kit one time and
the instructions advised me too balance the
aircraft by simply drilling two holes in a
square of ply , stick in two pencils rubber
side up,sit the plane up on this,very simple,very effective,costs nothing.

[Martin McIntosh]

On low wing models I use a piece of string lightly clamped between the fus. and wing to suspend the model from. Measure from the LE to the string to get each side the same.

[Paul Gregory]

I'm trying to determine the measuring point from the LE at which to balance my " wild thing " ( slope soarer ) which has sloping wings. As I bought it second-hand I do not have any measurements. Can anyone please help?

[Former Member]

[This posting has been removed]