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Old 03-11-2010, 09:50 PM   #1
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Installing blades

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This is a complete Noob question.

When installing new blades, how can I tell how many shims to use and how to position the shims - On top of the blade? On the bottom of blade? Some on top and some on the bottom? Re: Blade 400 3D.

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Old 03-12-2010, 08:26 AM   #2
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Re: Installing blades

Most of my shim issues were with my early ESKY King II's, which for some reason used a very thick blade root. When trying aftermarket blades I needed to install the shims and did so with them on the bottom. It's not critical, just personal preference.

The reason is centrifugal force when at speed does most of the holding in place. The shims are there more to accurately transfer pitch changes from the grips and prevent the blades from pitch hunting. Basically they keep the blades and grips the same pitch.

The key here is to get a good fit between the blades and grips, allowing the blades to swing but not change pitch. You want to be able to tighten the grip on the blade so that the contact is all along the root, not bending the grip together so only the outer portion is touching the blade root.

The rule of thumb on tightening the grips is to place the blades straight out and roll the heli till the main shaft is horizontal with the blades parallel to the ground. The blades should stay in place until the heli is given a little shake, then they should break loose and fall.

NOTE: I started using beeswax long ago to lube my main gears. Also used it to lube the blade root where it fit into the grip when I saw wear from the grip in the root reinforcement. That helps the blades swing in the grips to find their own "Path" and still allow me to tighten them enough as previously noted.
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Old 03-12-2010, 09:09 AM   #3
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Re: Installing blades

If you have a Vernier caliper it's best to measure the blade root thickness, and the grip gap- subtract the blade thickness from the gap, divide by two- use that amount of shims above and below the blade root. Usually blade roots come in even metric thicknesses ( ie 10mm, 12mm, 14mm) and blade grips are also fixed sizes. Shims are usually standard mm (I have a huge stack all seem to be 1mm or 2mm, some aluminum and some plastic)thicknesses .Try to make sure blades are centered in the grip , not that it would make a huge difference, but the geometry of the design probably is set up with the blade centered.

Last edited by vinver; 03-12-2010 at 09:11 AM. Reason: metric
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Old 03-12-2010, 09:47 AM   #4
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Re: Installing blades

If I have a set of blades that needs a shim, I just throw it on top because its easier to keep the washer in place as I am putting the bolt through. So far I have never needed more than one shim, I just use one shim of the correct thickness as opposed to several shims of lesser thickness.

If the shim is the correct diameter, it shouldn't technically make any difference if you place it below or above as long as both blades are shimmed the same way.
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