My days of lifting 30-pound planes onto a mechanical balancer are over. So are the days of "good enough" CG's.
Xicoy Digital Weight & Balance CG Meter Pro
High-tech accuracy plus simplicity for balancing RC planes
Text, photos and video by Tom Hintz
Posted – 1/24/2020
I realize that this Review will be decried as “extravagance” because it is A: “computerized” and B: expensive. While both are true my having now exceeded 70 years of age, means getting big planes onto more traditional mechanical balancers without damage to the plane or myself is increasingly difficult. However, I can lift one wheel at a time and put the “balancer” under the plane. While the Xicoy Digital Weight & Balance CG Meter Pro is ideal for giant scale planes, it is just as accurate on most planes flown in today’s RC world. I have used it on everything down to my foamy EDF jets.
The Basics
The Xicoy Digital Weight & Balance CG Meter Pro consists of three high-end, puck-style load cells with a capacity up to 50 kg / 110 lbs. The unit works with tricycle or tail-dragger landing gear. The load cells have a concave upper surface that helps center the wheels to enhance accuracy. The load cells are connected to the processing/touch screen unit with three included, 40”-long, male-to-male servo extensions. That lets the Xicoy Digital Weight & Balance CG Meter Pro handle a huge range of sizes right out of the box.
The heart of the Xicoy Digital Weight & Balance CG Meter Pro system is the processing unit that displays the plane’s total weight, current CG position and calculates the amount of weight needed to attain the desired CG location. The processing/touch screen unit has internal memory that can store data for up to 100 aircraft. The unit has a Micro SD slot through which you can back up data and update firmware when needed. To make the Xicoy Digital Weight & Balance CG Meter Pro totally portable it is powered by a battery in the 5v-9v range, something most RC’rs have on hand.
A key feature of the Xicoy Digital Weight & Balance CG Meter Pro for me and others who fear math exceeding a PIN number is the near instant, automated calculations. Xicoy Digital Weight & Balance CG Meter Pro processor has an accuracy resolution of 1 gr/ 0.03 oz and can measure the CG position within 1 mm/ 0.05 in. Try being that accurate balancing a 20lb model on somebody’s fingertips or any of the known CG “machines” is a fool’s folly, on a good day.
Input screens tell you what they need to compute
he CG.
Weights can be displayed in grams or lbs, selected in the Tools section through the touch screen. We can also choose from metric or Imperial length formats. I decided to use the metric system because it is easier to be precise than reading small fractions. This is a good demonstration of why learning the metric system makes lots of sense.
The touch screen is 50mm wide by 38mm tall and while very easy to read makes using human-sized fingertips to enter data a bit awkward. I found using a shop-made piece of wood with a small point suffices for a stylus and makes entering data accurately much easier.
Angle Sensors
This version of the Xicoy Digital Weight & Balance CG Meter Pro comes with angle sensors that let us set up control throws with a precision not available with most other methods. They are simple, small circuit boards that are attached to the control surfaces with double-sided tape.
The instruction manual must be downloaded. To me this is a plus as this allows for on-the-fly updating if necessary, so you get the current version automatically. The manual is better than many so operating the Xicoy Digital Weight & Balance CG Meter Pro is not difficult.
Model Setup
For the Xicoy Digital Weight & Balance CG Meter Pro to perform so accurately we must give it accurate dimensions. The center of the main wheels to the CG point, center of the main wheels to the center of the tail (or nose) wheel and the distance from the center of the main wheels to where we want to add/remove weight to correct the cg as needed. Get these dimensions entered correctly, and the Xicoy Digital Weight & Balance CG Meter Pro tells you exactly how much weight needs to be added or subtracted. I must admit “checking” the Xicoy Digital Weight & Balance CG Meter Pro predictions with my fingers and CG machine I already had. Without fail the Xicoy Digital Weight & Balance CG Meter Pro was right.
While none of these measurements are difficult, we need to be as precise as possible. That includes leveling the model. With some of my planes I made a block that goes under the tail wheel to get the plane level with the world on a table. Then I can put on load sensor under each wheel, including on that block and the plane remains level. A friend of mine found a very nice Micro Trader Scissor Lift Lab Stand that makes this leveling process easier yet. See Resources below for my Review of this stand.
In the Shop
I anticipated needing a bunch more information to describe the Xicoy Digital Weight & Balance CG Meter Pro, but using it is just simple. The biggest time burner is measuring the model and entering that info in the Xicoy Digital Weight & Balance CG Meter Pro. After that add the amount of weight it tells you to and look at the display. You might have to go back and forth with a tiny amount of weight change to get it just right but there is no grunting or groaning. The no grunting part has much significance to me.
The optional Angle meters get plugged into the same extensions the load sensors were in. Bring up that screen and zero the sensors out. Here again, you get to see exactly what is happening at the control surface as you dial in needed changes to get the correct throws for your plane. Like the CG section, getting the setup right is simple, and very accurate. I can’t imagine being this precise with a ruler or protractor.
Conclusions
I realize that the $384.99 (1-10-2019) price tag is way more than most CG machines but since getting it I have gotten my planes balanced better and faster, without having to take a break and sit-down a while. Once you convince yourself that it really is that accurate, using it is ridiculously fast and simple.
Now that I have several planes under my Xicoy Digital Weight & Balance CG Meter Pro “belt” I’ve stopped digging out my old CG machine to check the Xicoy Digital Weight & Balance CG Meter Pro. I balance my plane, put the Xicoy Digital Weight & Balance CG Meter Pro away and go flying with no CG-related trepidations.
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