Aircraft Tire and Wheel Balancing - Using a Postal Scale

[@dalcaptain]

I was at my wits end after wasting 2 hours trying to balance one of my tires. Looking at several internet videos I came upon yours. It made since and was easy to follow. I purchased a postal scale from Office Depot and gave your procedure. I had great joy watching the wheel spin with no low side. Thank you for posting the video. I’ll tell my friends.

[@MartyMitchell92660]

Thanks for your comment and glad to hear you got 'er balanced. Smooth landings.

[@ducaticessna9386]

Man, that is beautiful. Love your work! I'm going to do this with my RV and Cherokee and share with my Experimental building friends. Marty, you are an Aviation Hero!

[@SteveN-zp7jn]

Great idea, build, & execution. Can you add links for the supply list of cones, bearings, shaft, & collars.

[@MartyMitchell92660]

Thank you. I built it over 6 years ago and didn't save my receipts. Sorry, but Google is your friend. Should be easy to match up there. Good luck!

[@ovalwingnut]

I can't believe it! This video was 7 years ago and yet this is the exact Question that was on my midterm test last week! OK, maybe not.. but my mind is still blown. I have never seen anything quite like this. And I can tell you now, I'm a believer and it's all going on my resume :) Seriously, that was dazZling. 500 points awarded. Cheers from So.Ca.USA 3rd House On the Left (but call before you stop by:)

[@MartyMitchell92660]

Wow, I have never received ANY points here on KZbin. Thanks so much! Is it the green one with the white picket fence? I think I know the one!

[@ovalwingnut]

@@MartyMitchell92660 Green house with a white picket fence? Somebody is a Little House on the Prairie fan Actually, that is correct except the picket fence is actually chain link. If you swing by you'll have to let yourself in the gate. My ankle bracelet doesn't receive at that distance But serously, glad after ~7 yrs & Covid "we" are still around to have this virtual conversation. And even "the morning after" I'm still enamored with your Balance-Offset-Ratio-Gravit process aka the "BORG" and can't wait to upsize it to a adult tire (no disrespect). Thank you for the kind words. Live long and prosper Capt Mitchell 🖖

[@MartyMitchell92660]

@@ovalwingnut Be sure to share your "adult size" tire balancer with us. I have a cordless grinder if you need help getting that bracelet off.

[@richardbogert7675]

Marty, nice job and nice video. I have a lot of respect for anyone that designs and builds a tool. Richard Bogert, President, Bogert Aviation Inc.

[@MartyMitchell92660]

Hi Richard. Thanks for checking out my video and for the nice comment. If anyone needs airplane tools, be sure to check out Richard's company at bogertaviation.com/ .

[@rcmerrill1]

For those who don't have any fabrication expertise like me, the Harbor Freight motorcycle wheel balancer works well. Your system is very clever.

[@MartyMitchell92660]

rcmerrill1 Thanks. Yes, I have heard that will work too.

[@jlawrence3659]

Consider rotating hub in tire in attempt to reduce unbalance, thus adding less correction weigh and reducing dynamic unbalance. Also, equal weights on both sides of wheel (as possible) will reduce dynamic unbalance.

[@MartyMitchell92660]

Yes on rotating hub (wheel), no on inside weights. The brake disc takes up that space. Less weight added is much better. This tire/wheel combo was really far out of balance. It would be worth the short amount of time to experiment with different clocking.

[@erwinerwin1245]

If one built the same stand as you did but larger for car tires, would this method also work.

[@Steve-bo6ht]

That's very clever indeed Marty surprised the weight went around the valve as this can sometimes be the heavy side.

[@MartyMitchell92660]

Thanks! I think the tire was pretty old, so who knows what abuse it suffered in the past.

[@KALISARANONTAKUL]

Can I ask you how to measure the remaining imbalance value (g.m) after finishing the static balance process?

[@MartyMitchell92660]

Most owners do not balance these small tires. Once they are statically balanced, they're good enough. Maybe there's a way to do a dynamic balance, but I am not aware of one.

[@zmby322]

yes for sure a very nice well made gravity balancer, but I no tested that your light part of the tire is now the heavy part, because now the light part of the wheel is where you valve stem is, and it went to the bottom, and setting it at a 3:oo it shouldn't have rotated at all if was balanced, how I do it , is just and a small amount of wait on the light side with a little duck tape just to get the right amount that you need , and when you have the right amount of wait on the light side and setting the it at the 3:00 it shouldn't rotate at all, the wheel should not turn at all when it" balanced , I did it like this and haven't had any trouble with it was perfect balanced.

[@MartyMitchell92660]

Hello R Baird. I agree with most of what you said. This tire was extremely out of balance, so was happy to get it close to correct. Worked well on the plane by the way. Once you add weight to the 3 o'clock position, as you stated, you should rotate the tire on the balancer to verify that the bottom is not the heaviest point. You won't know that unless you spin the tire. Also, the bearings aren't perfectly frictionless, so giving the tire a bit of a spin breaks the static friction. The dynamic friction is usually less. I have modified this tool since the video was published. It now measures the correct weight needed directly from the radius where it is attached. Works well!

[@jbroheretoday]

Great vid. Absolutely genius.

[@maircraft4079]

Why not zero the scale with the stick on it? Then you would get a direct reading.

[@oby-1607]

Pretty genius. Good simple fix.

[@MartyMitchell92660]

Thanks you. Glad you like it.

[@user-tv5dt3nm9y]

Quite ingenious, Haas.

[@guysumpthin2974]

The stick idea is unique

[@cableandchain]

dissmount tire turn it half round

[@MartyMitchell92660]

Yes, that would have been a good plan! I have new tires since.

[@nonyabiz9487]

the math formula is cool... i bet this whole concept would work on a car tire just as good. they make aircraft balance stands that are big enough to do car tires.

[@MartyMitchell92660]

I agree that it would work on a car tire but it's hard to beat a dynamic balancer.

[@nonyabiz9487]

@@MartyMitchell92660 oh for sure but those things are expensive

[@MartyMitchell92660]

@@nonyabiz9487 I would imagine they are.

[@johnredfield6715]

Nice technique. Was it by trial and error or do you have the formula for how much more weight to add to compensate for the weight distribution from the center of the light spot of the tire?

[@MartyMitchell92660]

I suppose I could do the math but, no, just trial and error. Since this video was made, I came up with an even better technique, I plan to build a ring that fits inside the rim with a 1" long outward facing post, into a ball joint that transfers the weight required directly to the down rod, then onto the scale. No math, direct reading from the rim with the weights are placed. Thanks for watching and commenting. Marty

[@rv610dave]

@@MartyMitchell92660 If you add a ring to the center with a post aren’t you changing the weight with the post involved? How do you compensate for that?

[@MartyMitchell92660]

@@rv610dave You're right, that would be a problem. So here's what I did instead. I drilled a 1/16" hole thru the axle of the balancer, installed a 6" long rod thru the hole, exactly centered so as to not effect the balance, then turn the axle to the heavy spot, and weigh the force of the rod at the same radius as the rim. Direct reading of the weight required.

[@rv610dave]

@@MartyMitchell92660 Not picturing that, do you have a video of that?

[@MartyMitchell92660]

@@rv610dave www.ocflyingclub.com/IMG_5412.jpg

[@jasonrogers143]

Lord is that all stick on weights by valve stem? Take tire and spin it 180 degrees then do again

[@MartyMitchell92660]

Good idea. The weights were applied to the "factory" lightest place on the tire, but that was when the tire was new. That may have changed with time. Flipping the tire 180 degrees might reduce the amount of weights needed.

[@glennneutrin501]

Yes zero out the scale with the stick

[@glennneutrin501]

Excellent works fantastic

[@MartyMitchell92660]

Thank you.

[@xr500t]

You're just as bad as I am! I will find the longest route to get to my destination as long as it's interesting....and this was! I really liked the rig to mount the tire on.

[@MartyMitchell92660]

Thanks, I know, pretty complicated, Rube Goldberg, but it works.

[@leonardwilson980]

@@MartyMitchell92660 It's just a down sized motorcycle tire / wheel balancer

[@crpth1]

The tool is perfect, but regarding the use of it... Damn! You turn on the "complicometer". LOL :-) Edit: Try to rotate the tire in the wheel it might balance with much less weight

[@MartyMitchell92660]

Complicated? You should see my new rig. Now I have a custom balance arm piercing the axle that I use to measure the needed weight at the correct radius. Direct measurement now. Just put the assemble on and take one measurement. Viola! You're right though, might be a good idea on such an out-of-balance assembly to move things around and look for a better balance to begin with. Thanks, Marty

[@crpth1]

+Marty Mitchell - That sounds good. Any new video about it? I'm always looking for new ideas. I know it's a lot more work but usually I try to determine the heavy "spot" in the individual components (wheel+tube+tire) before assembling them. As a general rule it makes a huge difference in the balance. Be well ;-)

[@MartyMitchell92660]

May make a new video next time I need to balance a tire. Good idea but hard to determine the heavy spot of a tube (other than the usual ways, mark and stem). Cheers!

[@ACommenterOnYouTube]

Harbor Freight sells this machine

[@chuckthebull]

ok this is brilliant! cheers....

[@rv610dave]

Nice, I’m going to use that idea

[@dougpham5449]

good job. I like this idea.

[@babuside1]

oh! Mr. I like that tool, so I prefer to as my final project because I'm student of aircraft maintenance engineering, hence how can help me in that project so as to complete my target of course?

[@paulhogan2389]

Now wait a minute.. Marty you went through all of that.. why not continue on and determine the appropriate area to put the weight. Obviously the placement of the weight is not aligned it's not enough room so how do you determine that. When I was a kid my father's service station we would static balance the tires and that worked great you would lay the tire on there and determined by placing weight to put the bubble in the bullseye. Sometimes there are manufacturer imperfections and all of a sudden you have to put a ton of weight onto the tire to get it to balance out. After you reach a certain point it would best to break the beat of the tire and rotate the tire to a different position in order to use the least of what amount of weight is possible. My thought is this you balance the rim on its own you balance the rubber on its own and you determine in that method the correct location the tire sits on the rim. And with any luck you may not need to use any weight at all. If the room is tremendously out of balance on its own you can put weights on the inside center of the rim. And that would make the rubber position responsible for the balancing. Imagine the manufacturer provided you with a true rim. There you go you have a true rim now you just need a true piece of rubber

[@MartyMitchell92660]

All good suggestions. This was an old used tire with unknown balance issues. Usually, when installing a new tire, you line up the RED DOT on the tire with the valve stem of the tube. The RED DOT indicates the light spot of the tire, so it gets aligned with the heavy spot of the tube/wheel combo. The wheels are balanced nicely as they are small in diameter and uniform in construction, hard to be off much. The tires weigh quite a bit, so that's where all the imbalances come from. When mounting a good brand tire, the balance is usually pretty close. I don't have a method for checking the tire balance alone.

[@muhtesemicatlar6467]

👍

[@Tellekutan]

You must be an engineer. I think you should re-watch your vid and look really hard for introductions-to-error, because there are several. When you're making an attempt to precision-balance a rotating body, especially at high-speed, no assumptions should be made.

[@schnabel69]

Way over thinking that dude. setup is good but expensive. I have used a steel bar to mount the tire with clean dry bearings in place and simply add wt til tire/wheel dont rotate. doesnt need to be that precise for a GA plane that lands at 40-60 mph