digitech

My Feedback: (10)

he used the video as a reference on the end of the video you see the real values from the app and if you compare those with the other 2'ultra flashes you can see they are all close.
basicly it means the wizard is spot on measurements.

pcskyhi

Hope the pictures help. It looks like my friend has done it right. On the CG stand it is at 230mm. As you can see it is level on the CG stand. The distance from front to mains is 810mm and the distance from CG to mains is 73mm. The CG wizard says the balance point is 62mm on a plane already balanced on the CG stand so it should be close to 73mm not 62mm, right?

ScaleCrazy

What I don't understand is if you're balancing from a certain point whether it be on the CG wizard or the EZ balancer they both should jive. The ballance point is the same.

causeitflies

What is the distance from the back of the sensor to the center of the axle?

ScaleCrazy

if asking me. 51mm

pcskyhi

My friend said about 25mm

digitech

My Feedback: (10)

so here some pictures and i tried to emulate your outcome.
remember our Ultra flashes all 3 of them fly!.
you can see the range from 220-240mm
to emulate yours i had to add a lot of weight to the tail.
and the result is scary , its about 245-250 behind the leading edge and not 230mm.
have you flown it like this?
you can see on the last 2 pictures this is my CG its 230mm behind LE thats 74 on the wizard.
yours is at 61mm thats 245-250mm behind LE.
i guess something is off , and personal i would not fly it like you measured it.
i would be in doubt if our 3 ultra flashes flew nose heavy , saying this , all 3 need about 1mm up elevator to fly level.
in landing they all come in in high alpha , Crow 13mm up , flaps 89mm , Down elevator -16.
so please weight it on your ez balancer , fly it and report back.
double check those rulers and the measuring methods please.

daniel-arg

Normally, it should be 44mm. The sensor si made to make the contact point of the wheel (aka the perpendicular point of the axle) stay at 44mm from the back of the sensor.

daniel-arg

Unfortunatelly I can't see clearly the 73mm on the picture, it looks like is closer to 65 rather than 73...
The other point is how can you be sure that the balance pount is at 230mm using the stand ? I find that is quite difficult to transpose a point on the underside of the fuselage to the top side of each wing.

Cheers

pcskyhi

I added a photo to the post with the pictures showing his 73mm marking. He sent it to me and I overlooked it

pcskyhi

The jet has not been flown yet (brand new with Kingtech 120). It will maiden this weekend. The plan is to get together this weekend and put other aircraft on the Digitech system (my Habu 32 and another UF that maiden last week) that are flying with the proper CG. My other friend who maiden his UF last week is going to bring his Xicoy unit and we will double check the UF before its maiden. My friend is going try a few other things before the weekend. I will report back his findings before the weekend if significant.
Thank you very much for taking the time and making the effort to help us. Your pictures help a lot. My friend want to trust the Digitech system but "old faithful" EZ Balancer shows it to be balanced at 61. These two systems should be agreeing not disagreeing. We will get it figured out. Stay tuned.

digitech

My Feedback: (10)

no need for more confusion , put the other UF on the scale and tell us where that points at.
Like Daniel said how did you get the measurements on top of the wing?.

Bob_B

My Feedback: (11)

I have balanced two models so far. The first was my super viper which I felt was nose heavy and the CG Wizard validated this.
I like to take a before and after picture along with the model on the scales that way I can see the weight shift and should I want to go back and doublecheck that particular model I have data to rely on. Using the phone with Bluetooth makes this extremely handy

digitech

My Feedback: (10)

Great to hear Bob.
i also fly a carf viper and we weighted 3 of them on the wizard.
there is a lot of weight change between empty and full tank

Custmachr

My Feedback: (3)

I am not sure but the fuel in the plane could be the issue. On the ez balance any fuel may move to a different location forward/aft while upside down vs being on the gear on the scales???

digitech

My Feedback: (10)

yes it will do, on the ultraflash and on any other model.
that it is why it is important to keep the model flight level .
in case of a short front leg it needs to be raised to be flight level.

pcskyhi

I said I would report back this weekend. I met my friends on Saturday at the field. My friend with the Navy scheme U/F brought my CG Wizard to the field. Our other friend who had just maidened his Air Force scheme U/F was at the field so we set up the wizard and put his U/F on the wizard. The Air Force U/F was set up using the other CG system. Unfortunately we got the same readings we were getting with the Navy scheme U/ F. What the hell!
so I took my CG Wizard home and put my Habu on the wizard. The figures for the Habu are nose to mains = 376mm. The CG for the Habu is 115mm from leading edge which made the magic number 76mm from CG to mains. When I saw the 62mm on the screen I wanted to scream. The Habu was CG on the ez balancer and has over 100 flights. Sitting at the kitchen table I noticed something...the plane was not flight level

pcskyhi

Once I made the plane flight level thing changed...just look at the photos...1mm from the magic number

pcskyhi

just to verify what happened I did it again with my Sebart Mini Avanti. First with no leveling. The Mini Avanti is 471mm nose to mains. the CG is 145mm from leading edge which made the magic number 94mm from CG to mains.

pcskyhi

Now flight level. I actually had to move the battery 4mm back towards the rear of the planeto get the 95mm. for now I will leave it at the original spot since it is flying well. When I get the courage I will try the CG Wizard's 95mm spot.

pcskyhi

Well I am happy to say the CG Wizard works but more emphasis must be put on MAKING THE AIRCRAFT FLIGHT LEVEL. I am not sure if that was even mentioned in the video. WE (my friend and I) got too caught up with repeating what we saw on the video just placing the aircraft on the scale and waiting for the magic to happen.
I went back and looked at the manual and there is no mention of making the aircraft flight level and as you can see that is a major step. If you follow the manual you just take your measurements and put your aircraft on the scale. Dum Dums like me don't think about making the aircraft level and I am sure I am not the only dum dum out there. I am glad I found what I am doing wrong but I would suggest you redo your video and your manual emphasizing flight leveling the aircraft. Everyone is not going to read this thread so you have to make sure the proper info goes out with your product. I am glad I made this purchase.
I shared my results with my friends who have the U/Fs and the one who owns the other electronic CG device said they emphasize making the aircraft flight level. After seeing what a difference it makes he is going to re CG his U/F flight level this time on his machine.

digitech

My Feedback: (10)

to be honnest yes you are right its not in the manual however it does mention all must be level.
saying this if you balance a model on your finger or the EZ its also known that when the model is level your CG is right.
why would this be any different on our CG wizard?.
you can also CG measure a Taildragger , also this must be level
we will put a add on in the manual , to make sure everyone understand this.
we only once had this question from a customer that was weighting a Tail dragger.
but then problem is solved and it seems the Wizard does what it was made for..
we all learned from this , so how did your first Flight went?.

siclick33

The mini Avanti pic looks to me like you have now set it nose down. The area behind the canopy where you have your level placed slopes down (and is not parallel with the aircraft in flight attitude).

I would just level it by eye.

digitech

My Feedback: (10)

or set it on the elevator those are most of the time level or just -1 or +1 degree

ScaleCrazy

How do you determine flight attitude? Some planes fly with nose up. Where is there a chart to calculate at what position the wings or plane is in "level" flight?