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*** CG Wizard *** by Digitech

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*** CG Wizard *** by Digitech

Old 05-19-2017, 01:51 AM
  #151  
kelly vallee
 
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Can this be used to find the CG on a plane?
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Old 05-19-2017, 05:40 AM
  #152  
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No. It helps you ballance the plane. You have to know where the CG is. There are easy to follow formulas on line to help you find the cg if you don't know where to start.
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Old 05-19-2017, 08:10 AM
  #153  
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It will find the CG but it is up to you to know where the CG should be and make weight adjustments to make sure it is in the right location.
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Old 05-19-2017, 09:25 AM
  #154  
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As confusing as it may sound. It DOES NOT tell you where the CG is. It ballanced the plane to the cg that you tell it to. You have to know before hand where the CG is. If you tell the wizard your cg is on the nose of the plane. The wizard will tell you the CG is on the nose of the plane. So.... You have to get the CG from your manual or from someone who knows where it is. Once you know where the CG is and put the correct info into the wizard the wizard will tell you were the CUTRENT / WRONG cg is. Then you add/ move/ or subtract weight untill the wizard cg is correct with what the "Target cg" should be. I could be saying it wrong. So the CG wizard....is the Ballance wizard ...lol
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Old 05-19-2017, 09:27 AM
  #155  
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Sandor,
Thank you, the unit looks very well made and easy to use.. angle meter was included, also case is very nice. Can't wait to try it out.. Need to figure out how to get the app for iPhone, and instruction manual.
Thank you,
Ron
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Old 05-19-2017, 09:34 AM
  #156  
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Yes it is confusing, But, there is no wrong CG. The center of gravity for any object is what it is until you change it to be where you want it to be. By using the scales you find where it is and what you have to do to get it to where you want it (the proper location).
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Old 05-19-2017, 12:55 PM
  #157  
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Originally Posted by RJE
Sandor,
Thank you, the unit looks very well made and easy to use.. angle meter was included, also case is very nice. Can't wait to try it out.. Need to figure out how to get the app for iPhone, and instruction manual.
Thank you,
Ron

Hi ron there should have been a short manual in there?
no problem here is the manual: https://dl.dropboxusercontent.com/u/...ard/manual.pdf

any questions? let me know
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Old 05-19-2017, 03:21 PM
  #158  
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Originally Posted by ScaleCrazy
As confusing as it may sound. It DOES NOT tell you where the CG is. It ballanced the plane to the cg that you tell it to. You have to know before hand where the CG is. If you tell the wizard your cg is on the nose of the plane. The wizard will tell you the CG is on the nose of the plane. So.... You have to get the CG from your manual or from someone who knows where it is. Once you know where the CG is and put the correct info into the wizard the wizard will tell you were the CUTRENT / WRONG cg is. Then you add/ move/ or subtract weight untill the wizard cg is correct with what the "Target cg" should be. I could be saying it wrong. So the CG wizard....is the Ballance wizard ...lol
Yes, you are saying it wrong, you put the airplane on the pads and the CG Wizard will tell you exactly where the CG is located, and you cannot tell the CG Wizard where the CG is, so it will not tell you the CG is on the nose. You put the airplane on the pads, the CG Wizard tells you where the CG is, then you have to decide if that's where it's supposed to be.
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Old 05-19-2017, 03:52 PM
  #159  
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I'm really confused. Lol. What is CG. I take cg as CENTER of gravity. That being ballanced. The CG is stated in your manual. When you put the plane on the scale yes it tells you where the CG is at that point. (Or thinks it is,) but the cg However IS not the ""true" cg. If you ballance your plane on the CG that the wizard gives you. I promise you will crash. You have to add / subtract/ move weight to make the wizards ( wrong cg) match the right CG that you know from your measurements / manual. Then your plane is ballanced. With that being said. Look at it like this... I put your plane on my wizard. It says the CG is 1" inch in front of your mains. I take it off give you your plane and tell you that the cg is one inch in front of mains...you then go home ballance it like that and next thing your mad at me because that wasn't the correct cg. But that's what the wizard said???
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Old 05-19-2017, 04:16 PM
  #160  
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double post.

Last edited by causeitflies; 05-19-2017 at 04:19 PM.
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Old 05-19-2017, 04:17 PM
  #161  
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It's not the "true" CG. You are talking about the correct "location" of the CG. So you adjust the weight to move the CG to to the correct location.
The first two questions to ask are "Where is the CG?" and "Where should the CG be?"
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Old 05-20-2017, 12:31 AM
  #162  
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I just balanced my Comparf Mig15

I put it on the scales, the rear sensors were 600mm from the front sensor. The weight was 12800g. The balance point was 49mm according to the app. My target distance is 120mm. This is from the rear of sensor to the correct cog which is 50mm forward of rear wing tube. I need to add nose weight.

Worked well.

Last edited by sonicboom; 05-21-2017 at 02:34 AM.
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Old 05-20-2017, 03:56 AM
  #163  
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Talking

Originally Posted by ScaleCrazy
I'm really confused. Lol. What is CG. I take cg as CENTER of gravity. That being ballanced. The CG is stated in your manual. When you put the plane on the scale yes it tells you where the CG is at that point. (Or thinks it is,) but the cg However IS not the ""true" cg. If you ballance your plane on the CG that the wizard gives you. I promise you will crash. You have to add / subtract/ move weight to make the wizards ( wrong cg) match the right CG that you know from your measurements / manual. Then your plane is ballanced. With that being said. Look at it like this... I put your plane on my wizard. It says the CG is 1" inch in front of your mains. I take it off give you your plane and tell you that the cg is one inch in front of mains...you then go home ballance it like that and next thing your mad at me because that wasn't the correct cg. But that's what the wizard said???
Your really sound confused.....The Centre of Gravity (C&G) will be were the Wizard tool tell you it's.....what you need to do is adjust the Weight and Balance of the plane until its where it should be as per aircraft instruction, by shifting equipment (S) or adding weight either on the nose if it need to move forward or the tail if you need to move it back.

Hope that help.....
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Old 05-20-2017, 07:29 AM
  #164  
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Maybe to help understandig what CGWizard shows on the screen, let me tell some words:

The value shown as "Balance point" is the current position of the "Center Of Gravity".
This doesn't means that is the good location of the CG. The rigth place of the CG is where you marked on the very first step of the balancing procedure.
And this mark must be set as per the manufacturer reccomendations.

Then, adding or removing weight, you need to match the "Balance Point" with the CG.

That's why I didn't wanted to name this value as "Center of Gravity", otherwise people may get confused.

May I suggest you to watch the video I made to explain this (excuse me because of my poor english):

Versions in spanish and franch are available as well

In the CG Wizard manual there are some pictures that may also clarify how this works

Nevertheless, all your comments or remarks are welcome, and this lets us enhance the product. We will compile and consider your suggestions in order to include them on next releases of the software, the hardware and the documentation as well.

Thanks again!

Daniel
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Old 05-20-2017, 07:33 AM
  #165  
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The exact same thing I was trying to communicate in post 159. I just sometimes don't explain things well.
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Old 05-20-2017, 07:35 AM
  #166  
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Originally Posted by ScaleCrazy
The exact same thing I was trying to communicate in post 159. I just sometimes don't explain things well.
doesnt matter we are all here to learn from each other...
this also helps us to make a better product.
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Old 05-20-2017, 08:03 AM
  #167  
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Has anyone ballanced there plane with the CG Wizard. Then confirm with a standard ballancer. The three planes I ballanced with the wizard were nose heavy on a standard ballancer. What were your results?
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Old 05-20-2017, 03:44 PM
  #168  
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We balanced our B-17 using the "competition" 2 weeks ago, took my CG Wizard over today and put the B-17 on it and got the exact same results as the "competition".
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Old 05-21-2017, 11:09 AM
  #169  
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Sandor,

A question was asked concerning using the CG Wizard to find the CG of a taildragger. The question was do you have to have the taildragger at the flying angle of attack, which wasn't anaswered. I am getting prepared to use the Wizard on a large taildragger and would like to know the answer to this question. Research I have done regarding full scale planes indicates the plane needs to be at flying angle of attack. Can you confirm this?

Jeff
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Old 05-21-2017, 12:42 PM
  #170  
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Originally Posted by nxtdoor
Sandor,

A question was asked concerning using the CG Wizard to find the CG of a taildragger. The question was do you have to have the taildragger at the flying angle of attack, which wasn't anaswered. I am getting prepared to use the Wizard on a large taildragger and would like to know the answer to this question. Research I have done regarding full scale planes indicates the plane needs to be at flying angle of attack. Can you confirm this?

Jeff
Hi Jeff .

Yes Aircraft needs to be level! , set tail wheel on the front sensor. use something to lift it to make it level (use the TARE button first to set sensor to zero incl the lifting tool!)
place main wheels on other sensors.
do measuring exactly the same, measure distance of sensors type in the app
and measure the CG from the main sensors toward the manufacturers CG location.
compare with Balance point and move weight as desired.
its the same basics only reversed.

if in Doubt my experience is always use 1/3 of the wing to find the "rough" cg ,

Last edited by digitech; 05-21-2017 at 12:44 PM.
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Old 05-21-2017, 06:22 PM
  #171  
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Default Leveling the aircraft

Since I have an interest in this product and there is quite a discussion going, I would like to add an opinion.
In full scale applications, which use individual scales such as this product - Leveling the aircraft is critical before taking any readings.
Each (full scale) aircraft has a means of indicating when it is level. It may be a plumb bob hanging in the cabin or inside the tailcone, etc. but we (Technicians) spend a considerable time jacking the aircraft to the level position. My point is, most of our model aircraft don't sit level on their gear, so I would assume shim blocks should be placed under each 'scale' to achieve level.
Personally I would use an incidence meter on the wing to find longitudinal (lengthwise) level.
What am I missing?
Jim
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Old 05-21-2017, 06:46 PM
  #172  
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Good point jim. I didn't level my plane I'll check to see if there is a difference. However I would think if I raised the nose it would put more weight on the mains. Meaning it would require more nose weight. I ballanced my plane 3 ways 1) EZ Ballancer indicated nose heavy. 2) xicoy indicated take out 50g from nose 3) CG Wizard indicated add 40g to nose. Im going to trst fly as is and see how she feels. But test flight won't be for another month or so.

Last edited by ScaleCrazy; 05-21-2017 at 06:57 PM.
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Old 05-21-2017, 09:41 PM
  #173  
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Originally Posted by A7Bldr
Since I have an interest in this product and there is quite a discussion going, I would like to add an opinion.
In full scale applications, which use individual scales such as this product - Leveling the aircraft is critical before taking any readings.
Each (full scale) aircraft has a means of indicating when it is level. It may be a plumb bob hanging in the cabin or inside the tailcone, etc. but we (Technicians) spend a considerable time jacking the aircraft to the level position. My point is, most of our model aircraft don't sit level on their gear, so I would assume shim blocks should be placed under each 'scale' to achieve level.
Personally I would use an incidence meter on the wing to find longitudinal (lengthwise) level.
What am I missing?
Jim
Hi Jim
the best way is still the "finger" method , but as our models grow bigger and bigger the finger method did hurt on many occasions :-).
so we started the use wires and a broomstick to hold the model of the ground , or in advanced mode we would make a couple of hooks to our ceilings.
then came the Pro balancers , 200 dollar metal frame with 2 hinge points. works also.
and at last someone used scales to calculate the balance point.
i found out that all of them worked.!
the nice thing about electronic scales is : the model doesnt break your fingers , doesnt fall from the ceiling or tips over from a metal balancer.
saying that they all have their little issues.
yes the electronics scales need to be on level ground to get more accuracy , and yes ideally they would need to be set strait.
however i tested the wizard in real life and not only on my workbench typing manuals and making pictures.
i found out its pretty accurarate also outside.
when the ground is not level it shows on the scales one side more heavyer then the other.
also wind was a factor.
the thing that scared me the most however , was the actual fuel!.
where everyone is scared about 40 grams more or less , i have seen the CG shift over 25-30mm from its sweet spot.
a difference of 1.2 kilos on the front gear was also no exeption.
when we defueled or refueled then the cg was completely off.

so what is suggest to everyone , weigh your model as if you would come in for landing uat full , tank 1/5 fuel left , use the suggested manufaturers CG for start!.
most of them have a "safe"option so that the model is more nose heavy then should be to ensure that it will fly.
the perfect cg can be found by looking for expericanced Pilots who actually fly them , they should have the CG spot on.
as Daniel and me used the CG wizard a lot in field testing before releasing , we asked a bunch of guys that flew models to check their models on CG and total weight.
we asked them where is your CG now and how much does it weight.
i tell you NO ONE was correct , they all started out with their manufacturer CG and went further backwards , the total weight was also shocking most of the models where up to 2 kilos more then they expected.
finnaly they tended to land "safe"with more then 35% fuel left in their tanks.
so it is safe to say the CG wizard works great , even if your off a little it makes no difference at all.
even if you measure a few mm wrongly about the sensors it doesnt make a big difference.
remember the "finger"method i am sure everyone did this and if you look at a finger the witdh is more then 20mm , and that is what we used to balance our models on! and they still flew.
the CG Wizard is a ideal check tool , where you can spend lots of time moving around your internals until you are happy with the setup.
i would even suggest everyone , when you used the Wizard and flew your model and you did the final tweeks , put it back on the scale and see what did actually changed.
now saying this we welcome all suggestions! , we also learn.
the software now is simple , easy to understand.
i have been following the competition also and the thing that struck me was the complex setup and measurements needed.
a 50 pages long manual , this will scare customers and users away.
there at that point i relalised that a simple mistake will give you lots of problems.
we fixed this by using only 1 entry into the calculation on the application.
this eliminates a lot of mistakes.
e use a nice short manual with pictures and until now it seems everyone knows how to use it , and got good feedback.
also with recomended changes to be done to the app.
so please everyone share your experiances good or bad , Daniel and me did our best to offer you the best solution that is affordable for everyone.
and we are always open for suggestions.
the software now it the first release , changes are comming but we dont want to put out one release every week.
as we continue we are talking also to a few People who would like to be our distributor for the US.
but made no decisions yet , the tool seems to be become more popular , and its hard to keep up manufacturing them.
so we do look for a distributor that can also service them , repair them and help you with any issues.
Thank you all for having a interest in our products.!
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Old 05-22-2017, 04:38 AM
  #174  
Chris Smith
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Once we learn how full scale aircraft are balanced, we realize verifying a model CG on a conventional model airplane "teeter" machine is kind of crude. Ever wondered how a 747 or better yet, a C-5 CG is found?
Most cargo loads are very different day-to-day. How do we suppose they calculate the balance point after each load? Same with an airliner. One day all of the fat people move to the back of the plane, another day they sit up front.
I have never been able to find the big balance machine and crane they use to lift the aircraft up before pushing back from the gate. I must be asleep when they balance the plane!!
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Old 05-22-2017, 04:52 AM
  #175  
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Sorry for the sarcasm. One note of importance. Making sure an aircraft is "level" is NOT necessarily a requirement. As has been said it should be placed on the scales in "Flight attitude" which may not always be "level".
At work our full scale aircraft is required to be balanced at 4 degrees nose down. That is how it flies in cruise flight, not level. However, most model jets will appear to fly level so that is an acceptable way to start. You must lift the tail of a tail dragger so that the aircraft is on the scales in "flight attitude". Why? Because if the tail is low on the scales, the weight bias is aft and affects the calculations. tail draggers do not fly around with their tails real low like on the ground. The CG should be verified for "flight attitude".
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