prop balancing

[Slyfox]

I thought I would start a new thread in case this got on a huge discusion. I balanced my prop and found that the vibration 1.3 ips on my rotax was way too much. I spent more time putting the degrees on the hub so that when I started balancing, I could just look up the heavy side of the hub and weight on the opposite side. Made life real easy. I got things down to .73 ips, still have some more to go, just need to find a better weight to use. I figure I'll get some wheel weights and nut and screw to the spinner so no unsightly washers will be showing. Next weekends project.

Advantages are a smoother flying airplane, real smooth and I'm not done yet. There is no more fuel smells and the engine runs great. I figure what was going on is the fuel was moving around in the bowls so much that the needles were opening and flooding the engine. I am real satisfied with the results.

I have the dynavibe if you go here it will explain the procedure. You can get this through aircraft spruce.

steve

[futureflyer]

Steve
We use these products at work for balancing compressor and turbine rotor assemblies ,www.schenck-usa.com/weights_clips.html, incase wou wanted something a little more precise.

Matt

[Slyfox]

actually I'm feeling cheap right now. So I went into my fish supplies and took a spit shot sinker and hammered it flat. Than I will drill a hole in it and install it on the back of the spinner. All that will be showing is a small screw on the outside. When done I will be able to remove the spinner without the worry of loosing the balance. It will also look nice. Also I can take a pair of dikes and modify the weight for a nice balance. thanks for the link anyway.

[TGio]

Steve,
I found a good reference on attaching weight to the spinner and a formula for the amount of weight needed to balance. Have not tried it, but it is FAA accepted. Heres the link: http://www.acessystems.com/downloads/manual-gpb/gpb.pdf

Thomas

[Slyfox]

good find, thank you.

steve

[Caballo]

After many years of inactivity with my Mod.III, (582LC) I am preparing to begin construction again. I ordered a wooden prop with the kit back in 1991. Any pos or cons with this prop (balancing, integrity, etc.)?

Mark
Mod.III (#1050) Kitfox

[SkyPirate]

how did you store it?

[Caballo]

It was stored in my barn for many years, wrapped in plastic sheeting. I have recently located the Mod.III in my garage to begin the building process again.

I would have to park my aircraft in a carport style hanger at the very least, due to the intense sunlight here in southern New Mexico, however.

[SkyPirate]

what will matter is the position the prop was stored in ..layed down flat is best ,..wood props if nicked or not sealed well will attract moisture,..if the prop was standing up ..the moisture will change the balance making the lower blade heavier ..if it was standing up ..take a washable marker and mark the end that was lower ..now find a piece of tube that will fit thru the center hole tight ..set up 2 rails for this tube to set on that are perfectly level,...see if the prop stays or rotates on it's own one way or the other ..if it moves then good chances the prop is not balanced,..this method is a quick way to check ,,not as precise as mounting the prop on a balancer,..which most don't have handy,..there are more precise ways ,..it takes time to build it ,..checking this way first will tell you if a more precise way is needed..this way there is no drag on the tube going thru the prop,..it will rotate freely if the 2 planes it is resting on are perfectly level ,.only a heavier blade will rotate it.

Chase

[Slyfox]

I finally got this thing balanced. I got it down to 0 ISP. Can't get any better than that. How did I do it. Well, I went to the parts store and got me some Wheel weights, the flat ones with sticky on the back side. I ended up with a whole ounce of weights. I have a spinner and so I originally put them in the place it called for using 1/4 piece each time on the outside of the spinner. Finally I got it right down with 4 pieces. Than I removed one at a time and drilled an 1/8 inch hole and put a new weight on the back side and than used a stainless pull rivet and set it in place. All I see now is a rivet and the weight is on the inside. Flies nice and smooth now. I started with an ISP of 1.19, this is actually just under the recommended 1.20 and you need to get the prop worked on. So I was really just inside the allowable to dynamic balance this prop.