MASS/PULL meter - measuring stand for F5J-open
competitions
Following text will be
transformed to right english in February (if my doughter come
home from London).
If someone can help me with this text sooner, it will be welcom...
Follow the pictures step by
step:
(CLIC in the picture for
enlargement)
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Measuring stand must be installed in solid table or state...
Standard kitchen scales for 0-5 kg can be used, if weight
+ pull isn´t bigger as 10 kg
Hinge must be installed 33,3% from front of lever if you
like used gear ratio 2:1
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Holder for the model (in front side of lever) must be
solid and stable
1-st step: press start button
of scales and wait for ZERO
2-nd step: imput the model
into holder in up to nose position (RC is ON but motor is
OFF)
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Attention: Surround of propeller must be free of hurdless
!!!
3-rd step: look at the scale
and write weight (MASS parameter) in computer or calculator
4-th step: press TARA button
and wait some seconds for ZERO
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Scales recall weight and you will see, that "PULL"
is ZERO
5-th step: switch ON the
power unit of the model. Attention, propeller rotate !!!
6-th step: wait 5 s, then
look at the scale and write PULL parameter in computer or
calculator.
7-th step-> CALCULATIONS:
Now we can calculate motor running time
for HANDICAP mode of competitions or penalty factor
for PENALTY mode of competitions.
We must divide value of MASS (M) and value of PULL (P).
We receive power factor (Q) or penalty
factor (1/Q).
For HANDICAP mode of competitions now
we can calculate ALLOWED motor running time
for measured model. If standard motor running time for
1/1 mass/pull is e.g. 30 seconds, then ALLOWED motor running
time for measured model will be 30 x Q (or 30 x M/P).
For example from the pictures - mass of the models is
2x449=898g and pull is 2x539=1078g.
This model will have been launched 30 x 898/1078= 30 x
0,833 = 24,99 => 25 seconds before BEEP, which will
open windows for gliding.
For PENALTY mode of competitions we need
calculate only penalty factor 1/Q (pull/mass). For the
same example from the pictures it will be:
P/M =1078/898=1,200.
If this measured model need for climb e.g. 20 second of
motor running time, then will be deducted 20 x 1,200 =
24 penalty points from gliding poits.
If gliding time in this case will be e.g. 530 seconds,
competitor receive 530 - 24 = 506 points...
But this computing method is a bit simplified,
because allowance of other factors (e.g. relationship
between pull and screw pitch in the air...) have also
plumbless effect for speed of climbing the model.... I
hope, we can improve this computing method very soon.
