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McCauley 1A105 SCM7053
Diameter range 70” max. -68.5” min.
Static r.p.m. at maximum possible throttle setting (cross wind) :
Not over 2400, not under 2300 r.p.m.
No additional tolerance permitted
Code: Select all
<?xml version="1.0" encoding="UTF-8"?>
<!--
**************************************************************************
McCauley 1A105/SCM 7053 Propeller
Copyright (c) 2015 Richard Senior
This program is free software: you can redistribute it and/or modify
it under the terms of the GNU General Public License as published by
the Free Software Foundation, either version 2 of the License, or
(at your option) any later version.
This program is distributed in the hope that it will be useful,
but WITHOUT ANY WARRANTY; without even the implied warranty of
MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
GNU General Public License for more details.
You should have received a copy of the GNU General Public License
along with this program. If not, see <http://www.gnu.org/licenses/>.
**************************************************************************
-->
<!--
Configuration notes:
Original configuration generated with Aeromatic:
Inputs:
horsepower: 100
pitch: fixed
max engine rpm: 2800
prop diameter (in): 70
The last four digits in the designation of a McCauley propeller give the
diameter in inches and the geometric pitch of the propeller.
The geometric pitch is the circumference of the propeller disc at the blade
station multiplied by the tangent of the blade angle at that point. The blade
station is the point at 0.75 of the radius.
The blade pitch angle can be calculated using this Python snippet:
GP = 53
D = 70
(180 / math.pi) * math.atan((GP) / (D * 0.75 * math.pi))
The pitch angle has been rounded to the nearest degree.
References:
1. Continental Overhaul Manual for Aircraft Engine Models C75, C85, C90 & O-200
http://www.culvercadet.com/manuals/C85_overhaul_manual.pdf
2. McCauley Propeller Systems Owner/Operator Information Manual
http://www.mccauley.textron.com/mpc26ow.pdf
-->
<propeller name="McCauley_1A105-SCM-7053">
<ixx>2.31</ixx>
<constspeed>0</constspeed>
<diameter unit="IN">70.0</diameter>
<minpitch>18.0</minpitch>
<maxpitch>18.0</maxpitch>
<numblades>2</numblades>
<gearratio>1.0</gearratio>
<p_factor>5.53</p_factor>
<table name="C_THRUST" type="internal">
<tableData>
0.0 0.0339
0.1 0.0325
0.2 0.0311
0.3 0.0286
0.4 0.0257
0.5 0.0227
0.6 0.0183
0.7 0.0139
0.8 0.0075
1.0 -0.0026
1.2 -0.0133
1.4 -0.0240
</tableData>
</table>
<table name="C_POWER" type="internal">
<tableData>
0.0 0.0228
0.1 0.0228
0.2 0.0222
0.3 0.0217
0.4 0.0204
0.5 0.0187
0.6 0.0172
0.7 0.0144
0.8 0.0118
1.0 0.0042
1.2 -0.0067
1.4 -0.0203
1.6 -0.0344
</tableData>
</table>
<!-- thrust effects of helical tip Mach -->
<table name="CT_MACH" type="internal">
<tableData>
0.85 1.0
1.05 0.8
</tableData>
</table>
<!-- power-required effects of helical tip Mach -->
<table name="CP_MACH" type="internal">
<tableData>
0.85 1.0
1.05 1.8
2.00 1.4
</tableData>
</table>
</propeller>
jwocky wrote:I think, I miss here something
if you hang a propeller with a max rpm for 2400 on an engine with a max rpm of 2750, you don't have a gear ratio of 1.0
jwocky wrote:the other thing is, this is wood, the ixx appears a little high and you have a high p-factor, so that explains this enormous torque. Can it be, you work here with a too high propeller weight? .
jwocky wrote:Or maybe I just need more coffee to understand it ...