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Old Sep 30, 2012, 09:36 AM
Who needs a pilot??
danstrider's Avatar
Alexandria, VA
Joined Jul 2002
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Component weights

I tore everything out of an old broken fuse and weighed the stuff that came from inside. With the exception of the rudder pushrod & teflon tubing, the elevator pull string, and the stab mount, I get 84g. Measured breakdown:

4x400mah & jack: 38g
Wing wiring + servo mount: 5g
V8R7 Rx: 8g
2x JR285: 19g
Ballast: 15g
Total: 84g (scale round-off error 1g)

Obviously my 15g ballast is an easy place to look for weight savings. This points to my tail group, boom layup, and stab mount. The nose/tail length ratios are ~3:1 on this plane, so 5g tail savings could eliminate all 15g of ballast.

Curious if a couple folks can post their actual component weight break-downs to suggest if I'm basically on weight target or if I should trade $ for g (looking at the tail specifically).

Dan
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Old Sep 30, 2012, 03:31 PM
Father of Fr3aK, DLG Pilot
tom43004's Avatar
USA, OH, Worthington
Joined May 2002
6,570 Posts
Wing 130g
Fuse 42g
Horizontal 6.5-7g
Vertical 6-6.5g
Wing servos 19g
Fuse servos 13g
Receiver 7g
Regulator 4g
Battery 23g
Pushrods, horns, bolts, and throwing blade (hdwe) 6-8g

I don't typically use a wiring harness... normally I thread the wing wiring up to the receiver when I assemble the airframe.

Good tails at 13-14g a set can make an airframe. If you're over 16g on your tails (with mount), you are probably flying heavier than you could be.

PS... I have that same Horrible Freight scale and it's simply awful. Buy a good scale with .1g or .01g increments.
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Old Sep 30, 2012, 07:54 PM
Team Hong Kong F3K
ThomasLee's Avatar
Hong Kong
Joined Sep 2010
2,845 Posts
Wing: 105-120g
Fuse: 37-45g (newer ones all below 40g)
Tailset: 12g FG, 14.5g Carbon (will need to get individual weights when I have some on hand)
Battery 18g
Switchjack 5g
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Old Oct 01, 2012, 02:24 PM
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pyrsly's Avatar
Poland, Śląskie, częstochowski
Joined May 2008
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wing 135g
fuse 42g (super strong 47g)
tails 12-13g

airframe 190g

2x DS H-09 18g
2x JR DS 285 18g
battery 30g
Rx + regulator 15g

gear 81g
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Old Oct 01, 2012, 05:35 PM
Registered User
United States, CA, Tehachapi
Joined Jun 2011
3,069 Posts
On my Mystic I'm flying now:

Wing 100g
Pod 20g
boom 13g
tails 10g
250mAh NiMh 25g
receiver 9g
aileron servos 18g
elevator servo 5.7g
springs, peg, linkages, etc 16g

Brandon
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Old Oct 01, 2012, 09:25 PM
Who needs a pilot??
danstrider's Avatar
Alexandria, VA
Joined Jul 2002
1,148 Posts
Great info guys. Thanks for posting weights. From what folks admitted ahead of the CG, I'm seeing that I should look much harder at my tail set, stab mount, and boom layup for overall weight reductions... Maybe I'll take a ruler and measure nose moments at ECHLGF to see if my pod is also too short :-o

To fill in all my data:
wing less servos: 141g
wing servos: 17g
fuse: 47g
horizontal: ~9g
vertical: ~10g
stab mount: 1g
battery + switchjack: 38g
rx: 8g
fuse servos: 19g
wing harness: 5g
ballast: 15g
pushrod/pull-spring: 3.1g
AUW: 313g (as measured RTF)
Total: 313g (fudged tails to match AUW)

Thanks,
Dan

PS: Yes Tom, I hate that scale too. Haven't made a Harbor Freight run in a while, but know I need to get a better scale.
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Old Oct 01, 2012, 10:16 PM
Registered User
Congress, AZ
Joined Sep 2001
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What is the distance between the wing TE and the stab LE?

Can you check where the cg is on the empty fuse? It would not be uncommon to have more weight in the boom than others might have.

Gary
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Old Oct 02, 2012, 09:39 AM
Father of Fr3aK, DLG Pilot
tom43004's Avatar
USA, OH, Worthington
Joined May 2002
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Good point Gary. I was building fuses last year at 37-39g pretty consistently but they were balancing between the hingeline and TE. I had to add about 6-7g more noseweight to make those ships balance correctly. Since then I've changed my process and materials a bit and have been making 42-43g fuses that balance closer to the front bolt, and require only a gram or two for balance. They have three more layers of kevlar in the stress areas though so essentially they're MUCH stronger for the same AUW... even though they weigh more if you look at component weight.
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Old Oct 02, 2012, 10:15 AM
One Idiot is plenty...
Dbox's Avatar
Planet Earth
Joined Jun 2005
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Great thread guys.
Just lacking NAMES of the planes You are flying.
Yuri
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Old Oct 02, 2012, 10:17 AM
Father of Fr3aK, DLG Pilot
tom43004's Avatar
USA, OH, Worthington
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<<<<<--------- Name plane is right under name of poster
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Old Oct 02, 2012, 10:25 AM
Aurora Builder
United States, MD, Lusby
Joined Nov 2003
3,374 Posts
Dan,

What wing is that? Either your scale is off (I have 3 and they are calibrated), or its a different wing than I am thinking.

19g for a tail set? Ouch, that is 24g of extra mass (6*3+6g). I don't think its quite that bad but maybe. Now you know why 12g tail sets cost $100+.

Aurora typical weights:

1) Wing: 130g
2) Tail set: 12g
3) Fuselage: 42g
4) Stab mount: 1.5g incl. bolts
5) Throwing peg: ~2g+carbon patch

Mass of fuselage electronics
1) 7 ch. FrSky Rx, V8R7 HV (7.7g)
2) 1x JR DS285 (9.8g)
3) 1x JR SM22 (9.4g)
4) 2S 350 mAh Zippy LiPo (21.1g)
5) Paul Daniels Voltage Reg (6.1g)
6) 14.4g of lead
7) 5g wing wiring harness
Total=73.4g

Things I'm not using but weighed for reference:
Aircraft switchjack=1.2g
4x400 NiMH=34.6g
500 mAh 2S LiFe=30.7g

Also measured pushrods:
1) 0.021" steel+ #20 teflon=2.4g
2) 0.032" carbon+ #18 teflon=2.1g.

I wonder what a spring+line weighs, I'd bet sub 2g easily.

-Sam
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Old Oct 02, 2012, 10:25 AM
Will fly for food
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Bellevue WA,
Joined Dec 2003
6,478 Posts
When I built the TS3 all the components that went into the nose were 50g. 2 HS45 JR6255 350 2C Lipo and regulator and wire harness. No servo tray was used and after it was done the installation added 51.5g.
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Old Oct 02, 2012, 12:42 PM
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Quote:
Originally Posted by Dbox View Post
Great thread guys.
Just lacking NAMES of the planes You are flying.
Yuri
NEO please don't confuse with Neos
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Old Oct 02, 2012, 02:30 PM
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C Robinson's Avatar
Oregon, USA
Joined Nov 2006
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Quote:
Originally Posted by danstrider View Post
Curious if a couple folks can post their actual component weight break-downs to suggest if I'm basically on weight target or if I should trade $ for g (looking at the tail specifically).

Dan
A simple spreadsheet can be a useful tool for recording component weights during the build. This becomes a good reference for targeting areas to shave weight on future builds or rebuilds, even if the goal is only a few grams here and there.

This is a sample from my Sunrise #1 scratch build. It actually needed a few grams tail weight before changing the battery to lipo (nose length is 9" from wing L.E.). According to the sheet for Sunrise #3, it is on target to loose about a quarter ounce and is nearing completion

Craig
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Old Oct 02, 2012, 04:38 PM
Who needs a pilot??
danstrider's Avatar
Alexandria, VA
Joined Jul 2002
1,148 Posts
Nice spreadsheet Craig. I'll add it to my assimilation of the data from this thread. You seemed to have the most complete list!

Dan
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