K&B Head Dampeners

[BruceW]

Besides the new tail blades, I also picked up a set of Extreme 3D (orange is the hardest) K&B head dampeners from EspritModel. The medium hard Mikado dampeners have been fine IMO on the Logo500, are still in great shape, but I just wanted to try the K&B just to see if there is a difference.

Installation was very easy and I did not even use soapy water as suggested. One key thing I found is to first slide the dampeners onto both ends of the feathering shaft before inserting them into the head block. It would be too hard to push the shaft through otherwise. Also, don't try to use the plastic washer spacers that are normally used with the o-rings. It will make the gap too tight. The rounded part of the dampener goes in toward the head block. When pushing the dampener in to be seated, I also found the plastic washer spacers came in useful to help push them in since the material is a little soft.

As mentioned in the tail blade thread, the weather sucks right now so there won't be any flight reports for several days. As you can see from the pictures, these dampeners fit the Logo head block perfectly.

[Mathias]

I just bought two set of these myself.

First I bought extra hard dampeners #3092 and K&B tail blades. Now I have bought Radix 92mm and K&B dampeners. - I haven't had it airborne yet. :o

I am suffering of upgrade sickness... :(

[zguy]

Interested to know how these work for you. One question, without the plastic washer/spacer will the dampener drag on the grip bearing?

[BruceW]

The radial bearing in the grip near the dampener barely touches it and the grips feel very smooth on the bench. When flying, the centrifugal force will keep the grips away from head so I don't expect any friction on the bearing.

[OICU812]

I had no Idea they made these for the Logos wow!!! Cool, something else to try!
:smokin:

[OICU812]

So you have no ring between the damper and the grip bearing??? That does not seem right though.... there has to be something there...

[BruceW]

I tried the ring but it was so tight that the grips were notchy and tough to move. Fairly sure the dampeners were seated all the way into the head block. As you can see from the picture there isn't really any slop on either side.

Also, I did some hovering with punch outs in the driveway tonight (between storms) and the blade tracking and balance were perfect. I'll need to wait till its clear enough to try some hard cyclic maneuvers to see the real difference.

More to come.

[BruceW]

I am suffering of upgrade sickness... :(

Welcome to the club.:wink: I was thinking the same thing when I picked up all this stuff. Oh ya, I also got another EVOlite 6S 5360. Maybe I should have made a New Year's resolution to cut back on helicopter stuff.

[OICU812]

So could you sand these dampers down a mm on each side to allow for the ring spacers? I would want that load directly around the spindle to the inner race of that bearing. Imho of course but that seems odd they did not allow room for that spacer, it is important to direct the disc load.

[BruceW]

The material seems firm enough to sand down without gumming up so its worth a try but I'll fly them the way they are now before attempting a mod. Maybe I'll take the head back apart and double check the seating. So far after my test flight the grips are still perfectly centered in the head block.

[OICU812]

No worries Bruce, not trying to bust yer ballz dude, but,,, I would definetely sand them though and get it to where there is zero notchiness and you were able to use the stock ring.

[th3tick]

Trying to clear one thing up...

These aren't "made for" the Logo, are they? You're just using the ones they made for the T-Rex 600, right?

John

[BruceW]

The label on the package (first picture) says Logo 500 / 600 but I'm sure that just helps it sell.:wink:

[th3tick]

The label on the package (first picture) says Logo 500 / 600 but I'm sure that just helps it sell.:wink:

I should have looked at all the pictures :DOH

[BruceW]

No worries Bruce, not trying to bust yer ballz dude, but,,, I would definetely sand them though and get it to where there is zero notchiness and you were able to use the stock ring.

I know what your saying and it was my first concern also but figure I should try it this way first since most people won't go to the trouble of sanding it down. The main thing I do want to do is double check the seating though and I'm about 90% its all the way in. Before I installed the feathering shaft, I pushed it in for testing but I think the featuring shaft spreads out the material and makes it harder to squeeze in further.

[BruceW]

One thing I just noticed on the Espritmodel site is that the dampeners are only for flybar style heads.

http://www.espritmodel.com/index.asp?PageAction=VIEWPROD&ProdID=7021

[OICU812]

Yea one thing I can say about Mikado dampers that I can not say for many others is that they truly are very good. I have only had one pair yet between blowing up a model where I "had to" change them. A 600 rex for example you're lucky to get 50 flights tops, while on the Logos you can get many, many more out of a set.

[BobbySmith]

Hey guys i have alot of flights wiht these in a stock head they work really well iam fixing to try them in a flybarless head with 1 o ring

Bruce did you face the round side inwards? they should fit fine with the plastic spacer

[BruceW]

Hey Bobby,

Yes I did put the rounded side inward but maybe I did need that soapy water mix to squeeze them further. With the plastic rings, it was definitely too tight so there must be something wrong if its working for you. I'll look at it again tonight. I also want to measure the hole depth then I'll know.

[BruceW]

Spent some time last night sanding down the dampeners to make them fit in the head block and make space for the plastic spacer rings. Out of the package, these K&B dampeners are not the right width for the Logo head block and I measured them and the head block parts accurately to make sure. Either the dampeners came out of the mold wrong for me or something else is wrong if others get them to work.

The original insertion of the dampeners was correct, so they would not go further into the head block. The problem here is the dampeners are 6.60mm out of the package and I had to sand them down to 5.82mm +/-0.05mm to make a perfect 1mm spacing for the ring on each side. Basically they should be inserted so they are recessed into the head block by 0.25mm from the outer edge. Mine were obviously protruding before sanding.

Here is a diagram (not to scale) with the critical dimensions before sanding on the top and dimensions after sanding on the bottom. It worked out so there is a perfect 1mm gap on each side between the radial bearing in the grip and the dampener. There is just a little bit of notchyness in the bearing but if I lightly pull the grips outward they run smooth.

Today I flew with the dampeners in place and they performed well. Tic-tocs seem a bit more crisp and cyclic reaction went up a little bit also. Since I changed the tail blades, there might be some issues with the gain on the gyro that I still need to play with so I'll report more after dialing that in.

Overall, these dampeners are very firm and I'll see how well they age after many more flights. The original Mikado o-rings still looked new after 30 flights.

http://www.helifreak.com/attachment.php?attachmentid=37071&stc=1&d=1201659326

[Mathias]

Bruce, you might had a problem fitting them because that the original spacers are 1mm. - The two that comes with the Extra Hard Dampeners #3092 are about 0,5mm. Maybe Bobby were using the Extra Hard Dampeners #3092 before switching over to K&B Dampeners..?

Just a theory...

[BruceW]

That could be. I have the medium hard dampeners and the stock ones that came with the kit and both of those have the 1mm plastic rings. Oh well, the sanding seemed to work well and was worth the experiment.

Last night I checked the grips for play/friction and there is no notchiness (3 flights yesterday). They are very smooth and the K&B dampeners seem to work well at 5.82mm with the 1mm rings. After a few more flights I'll report any other findings.