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Roger Lee

Wheel and static prop balancer

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Here is a balancer from Harbor Freight that I use, $39.99:

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Roger Kuhn

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We have a Harbor Freight here in Tucson. I'm going to go take a look. Without seeing it my only concern is the sensitivity of the roller bearings on the end. More sensitive is better and if they have a little too much friction, not so good. The bearing insert on the rod will work for Marc wheels with the bearings in and standard round ball bearing, but won't work for the Matco's because they are too narrow and small. I typically don't leave the bearings in the Matco's for a balance. You would need larger inserts.

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You can't leave the Matco bearings in because they are tapered roller bearings. You would need larger inserts because the bearings must be out.

 

Why?

 

If you look at my photo or video in the other thread, I use my balancer snugged down onto the wheel bearings - it seems to make no difference as the bearings in the balancer have so much less resistance than the wheel bearings. They seem to add no additional play, so they seem to have no effect one way or another.

 

Anyway, works for me!

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The Harbor Freight unit worked on the Matco's for me. Don 't recall whether bearings were in wheel or not. Regarding the friction issue that Roger mentioned, the wheel rotated on the spindles very easily and always came back to the same spot. Not sure if an even lower friction unit would have a practical impact on the balance of the wheel. Remember, weights are typically 1/4 ounce and I don't think the balance will be more sensitive than that. I'm balancing clunky wheels/tires here, not the prop (which I ALWAYS have electronically/dynamically balanced.) Roger Kuhn

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The Harbor Freight balancer Rogerck shows here is the one I referred to where we discussed Andy's worn out tires. This worked well for my Matco wheels and also worked for the Marc front wheel. The supplied tapered cones which support the wheel hub fit a range of hub diameters. Vibration free taxi, takeoffs and roll-outs after landings now that wheels are balanced. It should work out with a prop after one roughs in the balance to a point where the prop is at the stage where it is searching a few degrees one way or the other. As rogerck points though, the prop should be dynamically "system" balanced on the plane to get good results. I had thiis done and it makes a difference. Don't forget to bring your 20% coupon if you buy at HF. This balancer is a good deal.

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I picked up the Harbor Freight balancer at lunch today...for $40 it's hard to go wrong, especially since they have a return policy and I'll be doing my balancing on Saturday.

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Most of the new composite props are not like the old wood, solid carbon fiber or metal props. These composite props are so close most prop Mfg's like Sensenich only recommend a dynamic balance. That is on the plane running up near cruise power.

 

 

As far as the wheel balancer part,

If the inserts on the Harbor Freight balance will fit into the wheels and the roller bearings on the rod ends are good then this will work without any issue. I just haven't seen one. I typically don't leave the Matco wheel tapered bearings in only because I want a good seating surface and if you don't push in hard enough to seat them and it has a tiny wobble it will throw the balance off. I use two different inserts depending on what tire and bearings I have to deal with.

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Use real lead 1/4 oz weights and not the non lead version from Harbor Freight. Once you decide where you want the weight mark it with a marker and then clean the wheel whit some lacquer thinner 3 times with a clean rag. Once you stick the weights down mash them down well so the adhesive strip adheres well and there are no air bubbles. If you do this right they will not fly off. Failure to clean well is the number one cause to lose weights.

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I had a long time pilot/builder ask me what is accepted practice for wheel balancing? I can't imagine that stick on weights meet FAA standards. Is there any direction from FD for this? I haven't seen one. Not from Matco or Desser either.

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There isn't any. Usually when I get a wheel in that I have put weights on I have to pry them off and they don't come easy. They use them on motorcycle s and cars and other fast spinning tires. They seem to work there just fine too. The tire shops told me most stick on weights that come off are due to poor cleaning and install.

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Dresser sells stick on weights. No info online on their use.

Here is a fairly long, quite technical Goodyear publication on aircraft tires, weighted heavily to large planes but still interesting to "breeze" through.

It does use a mark to align tire and tube. Yellow.

 

http://www.goodyearaviation.com/resources/pdf/aircraftmanual.pdf

Note that Dresser makes a tire balancer for <$400, McFarlane makes a different type for under $200. http://www.mcfarlane-aviation.com/Products/?PartNumber=TOOL108&

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This is an interesting issue, it seems to have been missed by LSA, but I don't find it in CFRs either. Legitimately I don't think you can do this on an SLSA without approval from the manufacturer, can you?

 

I'm sorry I got this going in two places, but I'll ask the same question here as I have elsewhere - Does FD balance tires before the plane is delivered to the dealer?

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I'm interested in the A&P mechanics comments on this, but until contradicted, I'd be fine with the authority in 43.13

 

§ 43.13 Performance rules (general).

 

(a) Each person performing maintenance, alteration, or preventive maintenance on an aircraft, engine, propeller, or appliance shall use the methods, techniques, and practices prescribed in the current manufacturer's maintenance manual or Instructions for Continued Airworthiness prepared by its manufacturer, or other methods, techniques, and practices acceptable to the Administrator, except as noted in § 43.16. He shall use the tools, equipment, and test apparatus necessary to assure completion of the work in accordance with accepted industry practices. If special equipment or test apparatus is recommended by the manufacturer involved, he must use that equipment or apparatus or its equivalent acceptable to the Administrator.

 

(B) Each person maintaining or altering, or performing preventive maintenance, shall do that work in such a manner and use materials of such a quality, that the condition of the aircraft, airframe, aircraft engine, propeller, or appliance worked on will be at least equal to its original or properly altered condition (with regard to aerodynamic function, structural strength, resistance to vibration and deterioration, and other qualities affecting airworthiness).

 

Dresser, Goodyear and MacFarlane all say to balance tires and tell how. I'd accept following their practices as being adequate.

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Does this mean that I can keep my wheel weights and still plan on taxiing in my CT without fear of loosening my fillings in my teeth? :wacko:

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Stick on weights are acceptable for aircraft tires. Here is a Desser link and a few more. If you search the web you'll see they use stick-on weights for aircraft tires. They should be applied to the flat spot on the tire rim. Centrifugal force and the adhesive will hold them there.

 

http://www.desser.com/store/products/BALANCE-TAPE-ON-WEIGHTS-PACKAGE-10-STICKS-9902.html

 

http://www.aircraftspruce.com/catalog/lgpages/matcoweightbalance.php?clickkey=18403

 

http://www.littleflyers.com/airwheel.htm

 

http://www.amazon.com/Aircraft-Tool-Supply-Balancing-Weights/dp/B005VRA4SU

 

http://www.skygeek.com/stick-on-wheel-balance-weights-20-pack.html

 

 

 

Hopefully that will be enough files to look at. I was getting tired. There are tons of pages that describe using stick on weights for aircraft tires. It's all about technique. Place the weights on an inner flat spot, clean the spot at least 3 times with lacquer thinner and then press the weights hard against the metal wheel to get all air out from under the adhesive and set the adhesive firmly against the metal. When it comes time to replace the tires and if applied right you'll have to pry the old weights off. No use making something hard out of something easy.

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You misunderstand my basic question Roger. ( I probably should not have mentioned the remote possibility of them coming loose.) I am wondering about the authority to do the work. Jim may have the answer, but this is SLSA, and the standard are different.

It would be interesting to hear FD's take on this.

 

And, no one has answered the question about whether FD balances tires from the factory.

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I tried to balance my wheels today with the Harbor Freight balancer. I say "try" because it was literally impossible. Even with 3+ ounces of weight the tire would not balance or even significantly change balance. I took the rod and wheel off the stand and turned it by hand. There was a significant, bordering on extreme, amount of wobble, meaning the wheel was not turning true on the shaft.

 

On the off chance I had a warped wheel or bearing, I pulled the other wheel, and got identical results. I'm not sure if it is the shaft or the bearing cones, but something in that setup is way out of true. I'm returning mine tomorrow. Not sure if I just got a lemon or not, but I no longer trust the contraption and will be buying a higher quality balancer in the future. Caveat emptor.

 

I'm running my tires unbalanced for now (as they came from the factory, it can't be the end of the world). When I get a better tool and have some time to mess with it I will revisit the balance issue.

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Thanks Doug. I also looked at the cones, and they might be slightly out of round as well. Maybe I'll see if I have a rod around that is straight to use and see if it does any better.

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Andy,

Go to McMaster or grainier and get a hardened and ground shaft. You will never have to worry about this again. The steel from lowes and Home Depot is not what I would consider acceptable for this application.

 

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I have the same unit shown by Roger on the first post in this thread. It is a quality unit. For weights I tried to buy some 1/4oz stick ons from Les Schwab (a west coast tire chain) but they didn't know how to do a transaction that small so they just gave me a bunch :)

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