Wright Stuff C
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Re: Wright Stuff C
I need to correct the last sentence of my post on February 15, 2020 regarding Larrabee props.
My subsequent research confirmed that Professor Eugence Larrabee of MIT developed design theories for minimizing induced loss in a propeller to achieve maximum efficiency for a given power input. However, his theories produced the optimum blade planform, i.e. the outline of the blade, for a given P/D ratio and maximum chord, and not the distribution of the angle of the blade along the radius. I assume that maximum efficiency still requires a true helical blade shape.
My subsequent research confirmed that Professor Eugence Larrabee of MIT developed design theories for minimizing induced loss in a propeller to achieve maximum efficiency for a given power input. However, his theories produced the optimum blade planform, i.e. the outline of the blade, for a given P/D ratio and maximum chord, and not the distribution of the angle of the blade along the radius. I assume that maximum efficiency still requires a true helical blade shape.
Last edited by calgoddard on February 19th, 2020, 3:23 pm, edited 1 time in total.
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Re: Wright Stuff C
Ikara has just come out with an 8 cm diameter prop supposedly designed for WS 2020. The new Ikara prop has two blades.
It has wide chord blades that are much sturdier than the thin plastic blades of the typical indoor Ikara prop.
The blades also appear to have a much higher pitch than the typical indoor Ikara prop.
See
https://www.wind-it-up.com/collections/ ... p-assembly
Hopefully it is not too late for some of you to experiment with this new WS 2020 prop from Ikara. It should yield higher times when compared to those achieved with a 6-inch indoor Ikara prop that has been cut down to meet the 8 cm maximum diameter rule. The new 8 cm Ikara prop should be less prone to breakage than the cut-down indoor Ikara prop.
It has wide chord blades that are much sturdier than the thin plastic blades of the typical indoor Ikara prop.
The blades also appear to have a much higher pitch than the typical indoor Ikara prop.
See
https://www.wind-it-up.com/collections/ ... p-assembly
Hopefully it is not too late for some of you to experiment with this new WS 2020 prop from Ikara. It should yield higher times when compared to those achieved with a 6-inch indoor Ikara prop that has been cut down to meet the 8 cm maximum diameter rule. The new 8 cm Ikara prop should be less prone to breakage than the cut-down indoor Ikara prop.
Last edited by calgoddard on February 19th, 2020, 10:38 am, edited 2 times in total.
Re: Wright Stuff C
My first inkling is to inquire what your base time was, but that aside, what's the new pitch? it seems like higher pitch may in fact be the way to go, but that seems counter-intuitive to me (assuming one isn't starting from such low pitch as to have an essentially flat prop)
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Re: Wright Stuff C
how do you change pitch?lechassin wrote: ↑February 19th, 2020, 2:58 pmMy first inkling is to inquire what your base time was, but that aside, what's the new pitch? it seems like higher pitch may in fact be the way to go, but that seems counter-intuitive to me (assuming one isn't starting from such low pitch as to have an essentially flat prop)
South Brunswick High School Captain '22
2020 Events: Protein Modeling, Ping Pong Parachute, Wright Stuff, Sounds of Music
2021 Events: Protein Modeling, Sounds of Music, Ornithology
2022 Events: TBD
Reality is merely an illusion, albeit a very persistent one.
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2020 Events: Protein Modeling, Ping Pong Parachute, Wright Stuff, Sounds of Music
2021 Events: Protein Modeling, Sounds of Music, Ornithology
2022 Events: TBD
Reality is merely an illusion, albeit a very persistent one.
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Re: Wright Stuff C
On an Ikara prop, you carefully twist the spar inboard of the blades. Best with two needle nose pliers.
However, if anything more than small changes, it will break after 2-3 adjustments. So pitch them initially to get them the same, and pitch them to a range of pitches (separate prop for each pitch) rather than plan on adjusting multiple times to find an optimum.
Coach Chuck
However, if anything more than small changes, it will break after 2-3 adjustments. So pitch them initially to get them the same, and pitch them to a range of pitches (separate prop for each pitch) rather than plan on adjusting multiple times to find an optimum.
Coach Chuck
Coach, Albuquerque Area Home Schoolers Flying Events
Nationals Results:
2016 C WS 8th place
2018 B WS 2nd place
2018 C Heli Champion
2019 B ELG 3rd place
2019 C WS Champion
AMA Results: 3 AAHS members qualify for US Jr Team in F1D, 4 new youth senior records
Nationals Results:
2016 C WS 8th place
2018 B WS 2nd place
2018 C Heli Champion
2019 B ELG 3rd place
2019 C WS Champion
AMA Results: 3 AAHS members qualify for US Jr Team in F1D, 4 new youth senior records
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Re: Wright Stuff C
what do you mean by twist? Are you rotating the spar along its own axis or bending it?coachchuckaahs wrote: ↑February 19th, 2020, 6:07 pm On an Ikara prop, you carefully twist the spar inboard of the blades. Best with two needle nose pliers.
However, if anything more than small changes, it will break after 2-3 adjustments. So pitch them initially to get them the same, and pitch them to a range of pitches (separate prop for each pitch) rather than plan on adjusting multiple times to find an optimum.
Coach Chuck
South Brunswick High School Captain '22
2020 Events: Protein Modeling, Ping Pong Parachute, Wright Stuff, Sounds of Music
2021 Events: Protein Modeling, Sounds of Music, Ornithology
2022 Events: TBD
Reality is merely an illusion, albeit a very persistent one.
-Albert Einstein
2020 Events: Protein Modeling, Ping Pong Parachute, Wright Stuff, Sounds of Music
2021 Events: Protein Modeling, Sounds of Music, Ornithology
2022 Events: TBD
Reality is merely an illusion, albeit a very persistent one.
-Albert Einstein
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