OpenTube

Vanessa Center of Gravity Machine

tsawyer148

88,984 views

One of our RC club members introduced us to this apparatus known as the "Vanessa CG Machine". I have seen and read about different versions of this set-up but hearing someone else rave about how well it worked I figured I would put one together and give it a try. It was very cheap and easy to put together, ($10.00 +/- and 45 minutes or so of your time), and I am very impressed with the results. The information about this rig can be found here :

http://home.mindspring.com/~the-plumb...

Credit to the original poster Fred McClellan who names Jim Archer as the designer and originator.

20 Comments

@AmruMagdy 5 months ago

شكرا ❤😊

@frankiejr99 9 years ago

you are the man

@Vdubin64bug 9 years ago

I have used this same set up.. It works great and works on many types of wings.. Great video..

@MarkRobinson555 6 years ago

Excellent, really well explained, thank you

@sotm2 1 month ago

One thing you are NOT telling everyone is that the vanessa rig cross bar must be perfectly in line with your wing profile or the plumb bobs will be forward or aft of the true CG location. Don't miss this important step.!! And the vanessa rig can't/doesNOT balance your plane it only tells you where the CG should be you must still balance someother way!!!

@sotm6078 1 month ago

EXCEPT!! One thing you are NOT telling everyone is that the vanessa rig cross bar must be perfectly in line with your wing profile or the plumb bobs will be forward or aft of the true CG location. Don't miss this important step.!! And the vanessa rig can't/doesNOT balance your plane it only tells you where the CG should be you must still balance someother way!!!

@Tallguysrc 7 years ago

I use the 2 paper trick...

@sotm6078 6 months ago

I thought the slings went around the fuselage in front of and behind the wing, NOT around the wing???

@josephkerkau2520 4 years ago

To protect the wings from the string scratching the wings. use round Styrofoam pipe insulation. Cut off 1" and stick it on the wing. Under the string.

@poisonoverdose1 2 years ago

So...what about the center of lift of the wing vs. center of gravity of the airplane? Do you know anything about the center of lift of a ram air wing? I'm not trying to be a smart ass, but I really want to know this stuff, since I plan to design and build a full-scale version of a wing-in-ground effect craft, that I can climb aboard and fly in person. I really don't want to die the first time I try fly it. Any knowledge you can share would be very appreciated.

@archiguitarchi 8 years ago

Having a tailplane that has an airfoil shape complicates this a bit, but thanks for the video as it will apply to the other 90% of RC models that are provided with a GC location. it does tick me off that I was given "a range" of millimeters from the leading edge for the CG of my Wargo Yak. I still haven't got it flying reliably..

@wanger0690 10 years ago

Archimedes had nothing on you, pal!

@jimburkhart58 11 years ago

just a follow up on your vanessa cg rig...built one..works great for most of my planes...only issue I want to touch on...level on the rear stab...before cg stuff...how do you establish what IS LEVEL when hanging plane...(most rear stabs are CURVED a bit) egs..P51.... so level varies on where ON the rear stab you put this level ...is it basically an eyeball thing???
ps..I hung a small weight on fishing line the same weight as the level (7grms} on the nose to equal out weight of the little level

@sieghardboke7216 10 years ago

Let's assume that the manufacturer of an RC plane provided the wrong CG. Does this rig allow one to find the correct CG on the plane ??

@jimburkhart58 11 years ago

if I read correctly..this gets rid of flipping plane up-side-down...I.should STILL retract gear..right....Im buildind this...(trying to flip a twin engine mosquito..gear up..battery installed..& using fingers..lol TRY THAT!!!).. this looks bang on bud

@richardjolley6648 9 years ago

I made one of the machines and it works well. Thanks. The only problem I have found is determining the point to put the spirit level on. Most stabilizers are curved and finding the point where you are at zero degree incidence is a bit hit and miss unless you have an incidence machine. Using an incidence machine I generally can find a point on the plane which is the same, and this often is the battery/Rx tray. Any ideas?