sock66

This may be a stupid question but what is the typical way to weigh a finished model? The instuctions normally tell you what the model should weigh when you are finished but it just seems to bulky for the old bathroom scale?????

DF_Flyer

I picked up a baby scale at a local yard sale. I checked its calibration with some known weights and it seems pretty accurate for anything under 30#. That's plenty for anything I'll ever fly.

BTW, it cost me $3.00.

DF_Flyer

Sorry, I forgot to mention that my scale is graduated in ounces, so I am only accurate to within 1 oz. This is fine for my purposes. If you want much more accuracy, you'll probably have to spend more than $3.00.

DeadMeat

Good question. I am working on my second plane and have no idea how heavy it will turn out. I was thinking of picking up one of those fish scales you get from a sporting goods store. I would just hang it from the ceiling in my garage and make a rope sling for my plane. What do you folks think?

Tom

Jazzy

Bathroom scale will give you a good idea.
Fish scale... I got one from Stren and found it's accuracy way off and inconsistent. Mine was 12oz heavy at 9lbs.
Baby scale? Good idea!

I went to the office supply store and bought a 10lb digital postal scale. It was $85 but at least now I know exactly what things weigh. The 'wife' uses it to split up ground meat into 1lb freezer bags!
The 5lb scale was only around $45...

I have found that if you're building from a kit and know how to build light you should end up in the lower half of the weight range. If you've put together an ARF expect to be in the upper half of the weight range.

gpmikemorse-RCU

I use my wife's kitchen scale. It goes up to 5 pounds in ounces. Not sure how much it cost, but it couldn't have been too much. For most planes, I have to weigh the wing and fuse separately.

ReallyUglyStick

My Feedback: (5)

you can get on your bathroom scale and weigh yourself. then get on it holding your model. the difference is the weight of your plane. but like someone above said: it may not be real accurate.

RC Pilot56

My Feedback: (4)

I use my scale that I use for weighing refrigerant bottles. It is a spring load scale and I also checked it with known weights and find it to be pretty accurate. cost was around 40.00. I use to use a digital fish scale and discovered that one of my planes weighed 12lbs. today and it might weight 18lbs. tomorrow. I guess that's
how all those fishing stories get started. lol.

Carlos Murphy

My Feedback: (72)

My friend has a five pound scale and a eighteen pound airplane.
We know this because we weighed the plane four times.
The first three times it weighed five pounds and the fourth time it weight three pounds.

DF_Flyer

No, no, no, Carlos. If you're going to weigh it multiple times, on trials 2 and 4 you have to turn the plane upside down, then add the negative readings to the positive readings from trials 1 and three to arrive at the true weight expressed in kilopascals, which is then divided by the wing area, correcting for the weight of the rubber bands. If there are no rubber bands, then you need to add some, and this is obviously why a plane that should weigh 5 # came out so heavy.

Hope this helps.

Carlos Murphy

My Feedback: (72)

But the plane DOSE weigh eighteen pounds...

All you do is punch in "Times 4" and then "Minus #4" on your scales keyboard, simple.

DF_Flyer

Ok, now you have me confused. Are you serious? I thought you were kidding about weighing an 18# plane on a scale that only goes up to 5# max. How did you do it?

Carlos Murphy

My Feedback: (72)

HaHaHaHaHa, got ya!!!

Dave Barrow-RCU

I picked up a Berkley digital fish scale from eAngler for $30, it will weigh up to 50LB.

MinnFlyer

My Feedback: (4)

ROFLMAO! God I love this forum!

Volfy

My Feedback: (23)

I recalibrated the bathroom scale to keep the wife happy, so I can't weigh my planes accurately with it.

Seriously, I use a 15lbs digital fish scale for weighing planes and a 5lbs postal scale for weighing engines. Try to pick a scale where you're staying between 1/4 and 4/5 full scale. Too light and it won't be accurate; too heavy and you're liable to damage the strain gauge inside (if it uses one).

Carlos Murphy

My Feedback: (72)

How are you calibrating it? So she weighs more or less?
(Sorry, I can't help it...)

DF_Flyer

You da man, Carlos!

Sawyer692-RCU

My Feedback: (6)

I use a Berkley digital fish scale. I just hook it into the muffler opening and it is accurate to 1/100 of an ounce.

Volfy

My Feedback: (23)

Carlos, I wired a mood detector inline with the calibration circuit, such that it will automatically read 5lbs less when she's in a foul mood.

Sawyer692, are you sure about the accuracy? ±0.01 Oz is more accurate than some laboratory scales.

Sawyer692-RCU

My Feedback: (6)

Acually no. Now that I think about it, it tells me pounds and ounces. For instance, my Kombat 40 weighed 6.4 lbs according to this scale.

fastcat

An easy way to weigh your model is to get a cheap 10 Lb. kitchen scale from Wal-Mart. Weigh each wheel with the model held level and add 'em up. This will work well if they are under 30 Lb. total.

OldRookie

My Feedback: (13)

I use to be one of the people that thought digital fish scales were accurate. One day my wife bought a new 5 pound bag of sugar, and I weighed it on what I thought was an accurate digital scale. It weighed in at 6.2 pounds.
I junked it out and went back to my DeLiar spring fish scale. At least the spring scale read the bag of sugar a 5 pounds.

Greg

Volfy

My Feedback: (23)

Man... instead of junking it, you could have sent it to me. I would have gladly pay the shipping to take it off your hands.

Greg, any scale, digital or not, need to be recalibrated every so often. Besides, are you sure that 5lbs bag of sugar really weighs 5 lbs 0 Oz.?