Dampening options

[vitek]

I was digging through my parts bin and found a set of single and double-dot head dampeners. I realized that I haven't really experimented much with my dampening.

I have run what is basically the recommended settings for a while now... two zero dot dampners, a #0329 and a #0332 shim, the c-clip, then a #0331. [http://ronlund.com/extreme/head.jpg]

I'm going to try putting a two dot on the outside for a little while, and then maybe replacing the #0329 with a #0331. I'm currently running MAH 690s, but may be switching to SAB 680s shortly. This is on an OS70 powered extreme.

Just trying to find out what might work well without having to try all twenty seven dampening permutations.

Travis

[WillJames]

Are they the 2 yellow dot ones or the 2 white dot ones. The 2 yellow dot are MUCH softer than the 2 white dot ones.

[DavidH]

No dot = 70 durometer
1 yellow dot= 50 durometer
2 yellow dot= 60 durometer
1 white dot= 80 durometer
2 white dot = 90 durometer

The 70 durometer is the standard oring that comes with the majority of the MA rotor heads.

David

[bighands3d]

What I used on my setup that worked well for me with a set of 700 V's and a WC61
was the one set of stock orings and one set of the 2white dot. white dot on out side. If you have and xtreme then you have the cliped spindle. this will probably give the fell your looking for without make the head to stiff. If you have a none cliped head axle than use three shims with the same setup.

[vitek]

The ones I've got are single and double white dot. Any one else mess with the dampening? DavidH?

[DavidH]

Yes I have used an 70 duro inboard and and 80 duro outboard on each side.
I used a 1mm shim and .5 mm shim on each side with that combo. Cyclics are quick and predictable. With this combo have to run the headspeed 1550 or more to keep the mast bumping from happening. Below 1550 the heli will oscilate.

David

[conrod]

Mast bumping?? is this the same thing as making the heli oscilate??

[vitek]

Yup.

DavidH, do you happen to know the P/N for the 80 and 90 duro dampners?

Travis

[DavidH]

120-75 Head Dampener Shim Kit

Kit contains 4 X 80 Durometer
4 X 90 Durometer
2 x 1mm shims
2 x .5 mm shims
2 x .25 mm shims

That is the only way I have seen those dampeners. I don't know the individual part numbers for them. Contact ChrisS thru here, he is at MA and can tell you the part numbers for the 80 and 90 duro damperners.

David

[cdrking]

Travis,

Did you try a few different combos? I purchased a kit from Rick's that has two regular o-rings and two 70s and two 80s.

Don't know what I should try. Also anyone have any good tricks for removing the spindle without marring it? I have been removing one spindle bolt then remove the spindle with one grip on it. Then I use two pieces of oak to clamp it together.

Any better way?

Jeff

[WillJames]

From what I have seen. dampening depends on the blades you fly and your style of flying. From what I have seen and heard in the Extreme, you should run harder dampening with the MAH blades and softer dampeners with V's.

[DavidH]

Jeff,
Here is the way I remove the bolts from the blade axle. I take a hex wrench and stick into each bolt on each end. Then I loosen the bolt. Of course only one breaks free <G>. I then unscrew the one that breaks free and take the grip off on that end. I then take my cordless drill that has a 3/8 keyless chuck on it. I slip the chuck onto the exposed end of the blade axle. I then tighten the chuck by hand as tight as I can. I then hold the chuck and turn the allen wrench that is in the bolt in the other end of axle. The bolt will break loose and I unscrew it and take the other grip off. I then loosen the chuck from the axle. I have used this method for couple of years and have not marred the blade axle anytime.

David

[WillJames]

Cool tip David!! Thank you!! :)

Now that is what I'm talking about!!

[conrod]

hmmm...good idea David. I use a vise to hold my axle at the center.

[DavidH]

Yeah if you want to take the axle out of the head. Holding in the middle with pliers is fine. But sometimes I just take the grips off to grease the thrust bearings. So no need to take the clips that hold the axle off and remove the axle. So this allows me a quick way to remove both bolts with no problem.

David

[conrod]

This was with the old style..no clips. Haven't crashed the new style yet so will convert to Drill chuck method. Thanks for posting. :)

[DavidH]

Haven't crashed the new style yet so will convert to Drill chuck method

So you only grease the thrust bearings after a crash ? <G>


David

[conrod]

yeah. :)

[WillJames]

Do you use the synthetic hydrogen grease on the thrust bearings David, or what do you recommend? I need to do my Extreme.

Thanks in advance for the tips!! :)

[cdrking]

And how often do you grease the thrust bearings?

Dampening: I just tried the 80 durometers on the outside and the 70 durometers on the inside with the regular shimming (0329 and 0332).

David, do you think there's a big difference running the 80s on the outside versus the inside?

It flew awesome, tracked perfect and really felt crisp through all maneuvers. I am going to stick to this setup for a while and see how it holds up.

Jeff

[DavidH]

Jeff,
I grease the thrust bearings about every 20-25 flights. I don't know if it makes a big difference using the harder duro dampener on the outside. It is just something I started doing when MA came out with the different durometers. My personal opinion is it gives a little better control having the harder durometer on the outside. Nothing scienitific about it, just my experience.

David

[cdrking]

David,

In the Fury manual it says to put the thin shim 0329 on toward the dampers. Does it really matter if this shim or the 0332 is next to the damper?

It seems like the thin shim is cutting into the damper after a few flights causing it to look frayed. I wonder if I can just put the thicker shim next to the damper. This shim doesn't have such a sharp edge.

Jeff

[DavidH]

Jeff,

On the C-clip axle if I remember correctly it says put the tapered washer next to the orings. I use to do that and the orings would fray and wear quickly.
Now I put the thicker shim next to the orings, then the thinner shim if I am using more than one shim and then the tapered washer. Since assembling the system in the above fashion the dampeners last longer. A few other of the MA Team pilots assemble the shims and washer in this fashion also. Don't know if this has been amended in the instructions.

Will I use Valvoline wheel bearing grease on the thrust bearings. I wanted grease that would stick as long as possible to the thrust bearings. Using the wheel bearing grease, only time I see grease on the blade roots is the first flight after I grease them. After I wipe that off the blades I never see it on the roots again till next time I regrease the thrust bearings. There is always some in the bearings when I regrease them.

David

[WillJames]

Sweet!! Thank you David!! I have a tube of the valvoline in my grease gun right now from doing my trailer bearings before the VA event!!

[Russ McC]

Not trying to contradict David, just a different take on head maintenance. For me I never lube the thrust bearings between crashes, sometimes as many as 400 to 500 flights, I have never had a thrust bearing go bad and they look about the same after 400+ flights as they do after 10.

As for Dampers I just use the standard ones with the tapered washer one thin and one thick shim. Don’t grease the dampers!! I also use the silicone tube in the center of the spindle, even on the Tempest. For me Dampers are also a non maintenance issue. :)