[craneman32]

I recently purchased some fibreglass blades. They are yellow and black. Maybe someone has had the same problem? The blades are quite a bit thinner then the Grip. I put a rubber washer in to fill the gap. < 1/8". It tightened up nicely. I know it sounds like a horrible mod. Will it work? Is there a better way? Or are there blades useless?

[rotormonkey13]

The rubber might wear, but it's certainly not unheard of to use metal shims for exactly that purpose.

[bartman]

Hi
I went thru the same thing when I put trex carbons on my blade. The trex blades are thinner at the root. You need to make up four spacers. I would not recomend rubber as the blades need to pivot in the grips. Also make up four spacers. One under and one over the blade to keep it centered in the grip. I cut up an old bank card. I drilled the center holes for a bolt the same size as the blade grip bolt. I then bolted them all together and mounted it in a drill. I then spun up the drill and held it square up against some sandpaper. I was left with four equally sized and more importantly equal weight spacers.I am pretty shure you can buy them but I hate to spend money if I dont have to.

[Phil Noel]

Originally Posted by craneman32

I recently purchased some fibreglass blades. They are yellow and black. Maybe someone has had the same problem? The blades are quite a bit thinner then the Grip. I put a rubber washer in to fill the gap. < 1/8". It tightened up nicely. I know it sounds like a horrible mod. Will it work? Is there a better way? Or are there blades useless?

The first manufacturer to use yellow and black was Rotor Tech. They initially used this colour combination one some of their FAI flyers over 10 years ago. In time, they adopted these colours, in different patterns, on the other blades they produce.The different patterns are to tell what type of blade they are FAI/FBL or 3D.

Of course, being a top blade manufacturer, many cheap blade manufacturers have now started to use these colours, and some even copy the same patterns. As you did not say what brand yours are, they could be from a number of different brands.

Generally speaking, you will want the transfer of energy from the blade to the grip to be as positive as possible, so offhand I would say you should find some spacer washers made of metal.

Also to consider, is that if this root area is too thin and/or not adequately reinforced on the inside (very common among cheap blades), then you risk throwing a blade in flight - not a nice site to behold, as the heli almost explodes (expensive damage ensues and all the saving go out the window) due to the instant imbalance and the thrown blade becomes a dangerous projectile.

[craneman32]

A friend owns a machine shop! He made me 2 little aluminum shims. They are a great fit. However I should have made 4 so I could put one on top and one on the bottom of the balde. I put one on each side on the bottom side of the blade. I spooled it up and it works fine but these blades are horribly out of balance. There is a 1 inch differance in height while spinning. What is the best way to fix that problem?

[Max]

In those circumstances, use a metal washer. Rubber washers will cause the blade to flex in the grip making your pitch change unexpectedly

[craneman32]

sorry you misunderstood. I filled the gap with an aluminum shim. I suppose my new problem would be a new topic. One of the blades, while spinning, is higher than the other. Balance I suspect. How do I correct it properly.

[Max]

Originally Posted by craneman32

sorry you misunderstood. I filled the gap with an aluminum shim. I suppose my new problem would be a new topic. One of the blades, while spinning, is higher than the other. Balance I suspect. How do I correct it properly.

Funny. Your first post mentions a rubber washer... Nevermind... I'm glad you got that sorted.

On to the next problem!!!

This problem you describe above is called "tracking", and it is common. You need to adjust the linkages on either the higher blade to DECREASE its pitch to lower it, or INCREASE the pitch by turning the ball link on the low blade. Depending on how far of your tracking is, it might be just 1 turn of the linkage or several.

Make sure you have a way of telling which blade is which. Most use 2 different color trim tape on the tips of the blades (ie I put red on one blade and blue on the other)
Then when hovering at eye level, you can see which color is the high blade and which color is the low blade. Adjust accordingly until both blades are in line

[rotormonkey13]

What I usually do is mark a blade grip with a sharpie or something. Then adjust the links on only that grip. After adjusting, test fly it. If it's worse, adjust the other way. If it's better but not perfect, give it one more turn and repeat as necessary.

That way I don't have to put silly colored tape on my blades or keep it in my field box.

[rotormonkey13]

Oh and FYI. Balance is a separate issue. Tracking problems as you describe are caused but the pitch of one blade being different than the pitch of the other. Balance problems would manifest as a vibration. For example your skids might look like a blur while you fly. That'd be a balance issue.