What's new
Van's Air Force

The definitive Van's Aircraft support community! Buying, building or flying an RV? Join our exclusive family of mentors and enthusiasts!

RV-12 Nose Wheel Balancing

P

PilotBrent

Well Known Member
Having recently completed a dynamic prop balancing on an 912ULS RV-12 (approx. 1,100 hours) I could not continue to avoid addressing my unbalanced nose wheel. Replaced tire last year due to age (rubber was starting to crack but tire treads etc... still looked good). Vibration on climb out was very noticeable, could even see brief movement at the prop hub during these vibration periods on climb which was obviously not great. Mounted GoPro on wing to confirm/monitor and completed a very basic static balancing. Now considering a dynamic balance, but clearly the vibration is much less pronounced than before. Summarized process in video.

Static balancing RV-12 nose wheel

Brent Connelly
N913BC
Hackettstown, NJ
 
PilotBrent said:
Having recently completed a dynamic prop balancing on an 912ULS RV-12 (approx. 1,100 hours) I could not continue to avoid addressing my unbalanced nose wheel. Replaced tire last year due to age (rubber was starting to crack but tire treads etc... still looked good). Vibration on climb out was very noticeable, could even see brief movement at the prop hub during these vibration periods on climb which was obviously not great. Mounted GoPro on wing to confirm/monitor and completed a very basic static balancing. Now considering a dynamic balance, but clearly the vibration is much less pronounced than before. Summarized process in video.

Static balancing RV-12 nose wheel

Brent Connelly
N913BC
Hackettstown, NJ
Click to expand...
Thanks Brent. Very informative video. Being still in the build phase, I have two questions:
A. Did you consider tightening the nut one notch further so the tire cannot rotate that freely?
B. Off topic, did you use the tie down tap to mount your camera? I am thinking it might be good point to have one during the first test flights.
 
We had the same vibration issue and used pieces from a harbor freight motorcycle wheel static balancer to help us resolve the issue.
 
Baron71 said:
Thanks Brent. Very informative video. Being still in the build phase, I have two questions:
A. Did you consider tightening the nut one notch further so the tire cannot rotate that freely?
B. Off topic, did you use the tie down tap to mount your camera? I am thinking it might be good point to have one during the first test flights.
Click to expand...
A. Doesn’t work on the nose wheel. B. Yes, very convenient for temporary camera mounts.
 
Brent,

Looks like you've attached weights to both the inner circumference as well as the side of the rim. I'm not confident that the ones attached to the side of the rim will stay there. You could find some lead weights, or double up the weights on the inner circumference (double sided auto trim tape would be helpful here).
 
I had the same issue. I used this (Wheel Balancer) to balance when I had the wheel off at last C.I. I added the weights to the inner circumference and just to be sure, tacked them down with clear silicone. It's amazing the amount of vibration it can induce!!

Glad you fixed it, thanks for the video.
 
koupster said:
Brent,

Looks like you've attached weights to both the inner circumference as well as the side of the rim. I'm not confident that the ones attached to the side of the rim will stay there. You could find some lead weights, or double up the weights on the inner circumference (double sided auto trim tape would be helpful here).
Click to expand...
We were struggling with the fact that the closer to the axle the weights are applied, the less effect they have. The weights I put on the outer rim are held with JB Weld epoxy so I am reasonably confident they’re not gonna come off very easily. But something to monitor for sure.
 
Baron71 said:
B. Off topic, did you use the tie down tap to mount your camera? I am thinking it might be good point to have one during the first test flights.
Click to expand...

Nflight makes a great line of modular mounts, including one for tie downs as the attachment point.

www.nflightcam.com

NFlightCam Tie-Down Kit for Ball-Head Mount

Add this kit to our NFlightCam Exterior Ball-Head Mount to turn any tie-down mounting ring into a camera mount quickly and easily with the ratcheting handle and threaded spud of our NFlightCam Tie-Down Kit. Simply thread the handle through a tie-down ring on your plane and into the spud, then...
www.nflightcam.com
 
I balance my wheel on a static balancer when changing tires or if I have them off the plane for brakes, etc. If I am just checking balance I spin them up on the plane with this attachment on my drill. The 7” disk will get the tire to approximately 60 mph. The front tire spins easily on the bearings, for the mains I push the brake pads back so they don’t drag, the bearing friction is there but the wheel will still spin enough to test. During the spool down if the tire is out of balance the vibration on the gear leg is obvious. I add 2” square patches of duct tape, 3 at a time, on the tread and re-test then move to a different clock position or add more. The process goes fairly quick. Once it is balanced I weigh the tape on a gram scale and multiply by 3 then add that much weight to the wheel in the same clock position. This process saves the “go fly” part to check your work.

IMG_9558.jpeg
 
We had some vibration on front wheel after liftoff. I had pulled the wheel apart for the annual and might have messed up the balance.
So while apart I replace bearings and then designed and printed the balance frame with extension. It worked great for the front tire.
Just wanted to share if anyone is interested.

RV-12 3D Print Balance Frame

IMG_3615.jpeg
 
Before adding a bunch of weights, I found that if you rotate the tire on the wheel until it is best static balanced and don’t worry about the red dot. Use the red dot as a starting position. Also tires can become out of round as they wear or even come new out of round. No amount of balancing or weights will fix that.
 
ScottSchmidt said:
We had some vibration on front wheel after liftoff. I had pulled the wheel apart for the annual and might have messed up the balance.
So while apart I replace bearings and then designed and printed the balance frame with extension. It worked great for the front tire.
Just wanted to share if anyone is interested.

RV-12 3D Print Balance Frame

View attachment 108628
Click to expand...
Hi Scott - What type of wheel weights did you use, and where did you get them? I had a really hard time finding weights narrow enough to fit on the flat perimeter of the Matco nose wheel - ended up cutting square 1/2 oz weights in half and using new double side tape to stick them to each other and to the wheel. Matco used to sell the appropriate size weights, but said they are no longer available.
 
jsalley said:
Hi Scott - What type of wheel weights did you use, and where did you get them? I had a really hard time finding weights narrow enough to fit on the flat perimeter of the Matco nose wheel - ended up cutting square 1/2 oz weights in half and using new double side tape to stick them to each other and to the wheel. Matco used to sell the appropriate size weights, but said they are no longer available.
Click to expand...
I am pretty sure they were 1/8oz motorcycle weights.
 
For the nosewheel, I used to put the weights inside the wheel hub -- stick my finger in there...it was a little hit-or-miss whether the spot I wanted was doable..

Last year I figured I'd try to stick them to the left or ride side of the wheel hub .. on the outside (between the holes, on the flat surfaces). I was actually surprised that they're still on there.. I used alcohol to clean the surface.. and the 1/4oz. and 1/2oz weights from Harbor Freight. Whatever adhesive they use, its really good.. hasn't shown any signs of loosening up yet.

I know its not the best solution..there is centrifugal force at play.. but it hasn't been a problem so far (yet).

https://www.harborfreight.com/1-4-quarter-oz-wheel-weights-67225.html
 
You must log in or register to reply here.
Back
Top