thrust to weight for 3d flying ?
05-14-2003 | 04:07 PM
#1
Thread Starter
thrust to weight for 3d flying ?
im building a GP cap 232 40 size, and im in the middle of a pickle, to say the least,
im getting alot of mixed reviews about a good 3d engine for the plane, i realy want to go with a 4 stroke,
but some people say .70. some say .90
and others say eather of those engines are to heavy for 3d.
i wont be doing alot to lighten the plane, micro throttle and such, i might buy a carbon fiber landing gear eventually, im not gonna change any balse or cut away at to much.
im new to 3d flying, i just want to build this plane capabile of some things more than just hover.
im guessing this plane will turn out about 6 and 1/4 pounds.
i just dont want to end up giving it enough power for vertical, and having to high of wing loading to do anything more than hover.
im getting alot of mixed reviews about a good 3d engine for the plane, i realy want to go with a 4 stroke,
but some people say .70. some say .90
and others say eather of those engines are to heavy for 3d.
i wont be doing alot to lighten the plane, micro throttle and such, i might buy a carbon fiber landing gear eventually, im not gonna change any balse or cut away at to much.
im new to 3d flying, i just want to build this plane capabile of some things more than just hover.
im guessing this plane will turn out about 6 and 1/4 pounds.
i just dont want to end up giving it enough power for vertical, and having to high of wing loading to do anything more than hover.
05-14-2003 | 07:54 PM
#2
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thrust to weight for 3d flying ?
Thrust to weight ratio required for:
Hover: 1
Fly out of hover: 1.25
Blast out of hover: 1.5
Descending Waterfall: 1
Nice Waterfall: 1.5
Small knife edge loop: 1.25
Nice knife edge loop: 1.5
How much does the plane weigh? If it is over 6 lb, you can forget about 70-class 4-strokers (about 7 lb. of thrust). Maybe Saito 80 or YS 63, swinging 14x4W, about 8 lb. of thrust.
OS has a new 70 4-stroke called "70 Ultimate". It's 16 oz (lightest in class supposedly), rated at 1.2 HP, although the current 70 which is rated at 1.1 HP outpulls the 1.2 HP Saito 72.
If you need more weight to balance, might as well go for a 91 Surpass, which is tested to have 9 lb. of thrust w/ 15x4W.
I am giving you these figures from flying experience (prop & rpm vs. plane weight). Thrust HP will give you results much higher than real life, so use at your own discretion.
Hover: 1
Fly out of hover: 1.25
Blast out of hover: 1.5
Descending Waterfall: 1
Nice Waterfall: 1.5
Small knife edge loop: 1.25
Nice knife edge loop: 1.5
How much does the plane weigh? If it is over 6 lb, you can forget about 70-class 4-strokers (about 7 lb. of thrust). Maybe Saito 80 or YS 63, swinging 14x4W, about 8 lb. of thrust.
OS has a new 70 4-stroke called "70 Ultimate". It's 16 oz (lightest in class supposedly), rated at 1.2 HP, although the current 70 which is rated at 1.1 HP outpulls the 1.2 HP Saito 72.
If you need more weight to balance, might as well go for a 91 Surpass, which is tested to have 9 lb. of thrust w/ 15x4W.
I am giving you these figures from flying experience (prop & rpm vs. plane weight). Thrust HP will give you results much higher than real life, so use at your own discretion.
