Weighing the aircraft

[Carlos151]

Has anyone used one of these heavy duty scales to weigh an RV? Capacity is listed as 660 lbs per scale so it seems adequate for our use just not sure about accuracy and longevity. Price is very reasonable compared to "certified" aircraft scales.
A few additions and subtractions have been made to my -8 over the years and it would be nice to have an updated W&B.

 

[Bill Boyd]

Just be sure you understand how the zeroing process works with these, although I am sure there are work-arounds.

 

[PilotjohnS]

Did It Both Ways

I did it first using the balance beam method, consisting of a lever arm that divides the weight by 1/2. I used digital scales from Target to actually record the weight and then multiplied by lever multiplier. This was hard because the scales would turn off after a few minutes.

At the EAA hangar, prior to first flight, i used the digital scales you show. This was much easier.

The results were off by a few pounds, not sure which one was most correct, so i picked one.......

 

[Ironflight]

I have four of those and have used them numerous times for weighing light aircraft. Calibrations done with water-softener salt bags (different ones used to average things out). Seem good to a pound or two at the top end of their range.

Paul

 

[Dugaru]

Our experience

I got three of the 660-pound ones when they were on sale, and we recently used them to weigh my -9A and a buddy's Cessna 120. We'll also be using them to weigh our Zenith 801 project, which just got an engine intalled.

We used small pieces of plywood as a "step" in front of each scale so that the airplanes would roll up onto them easily. We also put plastic bags on top of each to reduce any issue with side loading etc.

They read within a pound of each other. Overall we're quite happy with them, and the price was certainly right.

Has anyone used one of these heavy duty scales to weigh an RV? Capacity is listed as 660 lbs per scale so it seems adequate for our use just not sure about accuracy and longevity. Price is very reasonable compared to "certified" aircraft scales.
A few additions and subtractions have been made to my -8 over the years and it would be nice to have an updated W&B.

 

[Mikeyb]

I weighed my -8 with one of those platform scales moved to each wheel with wood blocks the same height on the others and then with a set of 3 calibrated A/C scales on each wheel. The measured weight agreed within 3 pounds or 0.3 percent

 

[Kyle Boatright]

I weighed my -8 with one of those platform scales moved to each wheel with wood blocks the same height on the others and then with a set of 3 calibrated A/C scales on each wheel. The measured weight agreed within 3 pounds or 0.3 percent

Beyond this, make sure you have the appropriate stack up of wood blocks to position the craft level fore and aft (or whatever the weight and balance document specifies). A local builder got a really bad initial cg location when he didn’t properly level the airplane. When he did properly level the airplane, the empty cg was fine.

 

[Carlos151]

Thanks all. I'll have to put three of these on my Christmas wish list. 0.3% sounds pretty good to me.

 

[Blw2]

What are the requirements for A&P's to use for certified aircraft? I mean are there specific types of scales required, a certain precision spec? NIST traceable?

 

[Walt]

These are the ones I use made by Intercomp

 

[JonJay]

These are the ones I use made by Intercomp

Great. Are they $60 like the ones the OP was asking about ?

 

[Walt]

Great. Are they $60 like the ones the OP was asking about ?

No, but someone asked about what professionals use and I was merely replying to that.

 

[JonJay]

No, but someone asked about what professionals use and I was merely replying to that.

Just teasing Walt. Do you know what aprox. that grade of product costs? They don’t publish it.

 

[Walt]

Just teasing Walt. Do you know what aprox. that grade of product costs? They don’t publish it.

I think they run about 3 AMU’s (3k ish).