Mounting FBL controller on 550SX

[crashjack]

I'm working on mounting my Ikon FBL on my new 550SX. Unfortunately, the Ikon has to be mounted a certain way, which includes strapping the controller down, for the Self-Level feature to operate properly and reliably. From an access and wiring perspective, the best place to mount is on the flat area behind/below the anti rotation bracket, mounting behind or next to the elevator servo. Unfortunately, this is a lousy place for a strap as the strap has to run all the way down to the tail servo "compartment", and then has to be done in a way to where it doesn't interfere with the tail servo arm. Even without the Ikon having to be strapped down, I have to believe that most folks aren't relying on just Velcro or two-way tape to secure their FBL without some sort of extra protection (e.g. some sort of strap). Any suggestions?

[alexf1852]

I don't use self-leveling. So I just use the provided mounting tape.

If you take the time to dynamically balance the tail, then you shouldn't need to strap it down.

[hemp]

Originally Posted by crashjack

I have to believe that most folks aren't relying on just Velcro or two-way tape to secure their FBL without some sort of extra protection (e.g. some sort of strap).

Most FBL units prefer not to be strapped down. VBar gyro tape does an excellent job of securing the unit while providing vibration damping. You can buy it separately here. Everyone has their own favorite tape, but nothing has beat the VBar gyro tape for me.

Try without strapping it down first. If the self-level works then you're set. If it has issues then I can talk you through how to implement "The Milton Mod" with your 550sx, but it will require some drilling, zeal gel tape, fuel tubing, and a long skinny zip-tie. A bit of work, but virtually guaranteed to eliminate vibration problems.

[Andy from Sandy]

If you get the right type of double sided tape, like an automotive one the holding power will be akin to gluing it on with epoxy. It will also ensure the unit doesn't move in hard stops.

If a Logo has a vibration that affects a FBL unit then fix it is my motto. The model should fly that smoothly that you can go a whole flight and not see a single raised vibration in the log on a v-bar.

I have never seen the need to strap down a sensor.

We have a couple of people using the Spirit and Bavarian Demons at my club and they are not strapped down. The bail-out on them works fine.

[crashjack]

I'm kind of surprised that a lot of folks don't strap down. My fear would be that if the controller did come loose and started flopping around, it would result in one seriously out-of-control heli.

The Milton Mod is what I'm doing. I wanted to start that way right off the bat. I've just read too many horror stories, and I'm so nervous flying anyway, I would rather not have something else to worry about. I've already got the gel pad, fuel line tubing, skinny cable ties, etc. I just need to mount the Ikon.

Regarding the Ikon, unlike some of the other FBL controllers with bailout, the Ikon uses accelerometers for self-leveling, which are apparently sensitive to vibrations. The most reliable way to eliminate vibrations is to mount the Ikon on a gel pad, and then strap down with a cable tie, running the cable tie through fuel line tubing to where the tubing is the only thing making contact with the Ikon (the cable tie itself should never touch the unit). This creates a dampening effect, which is supposed to eliminate vibration issues.

[Retired2011]

Strapping the sensor down will only induce more vibrations to the sensor, think about it...you're defeating the purpose of the gel pad by transferring vibs through the zip tie.

As Andy said, if the heli has vibrations bad enough to affect the FBL sensor...
FIX THE VIBRATION.

[hemp]

Originally Posted by crashjack

if the controller did come loose and started flopping around

It just doesn't happen. These components are extremely light. As long as you don't try to re-use the double-sided tape, it'll stay put.

Originally Posted by crashjack

The Milton Mod is what I'm doing. I just need to mount the Ikon.

Then you just need to drill a hole through the frame below the upper tray, but above the tail boom holder. There's plenty of room in there. It's easier if you have the frames apart, of course, but it can be done. You'll need a bit larger in diameter than the zip tie and long enough to reach through so it's straight. Once the hole is drilled tape one end of the long zip tie to it and pull the bit back out. Voila. (If pulling the bit out with tape on it doesn't work, you can run a skinny piece of metal through and use that to guide the zip tie, whatever works.)

Originally Posted by crashjack

unlike some of the other FBL controllers with bailout, the Ikon uses accelerometers for self-leveling

To my knowledge, that is how all of them do self leveling. And thus, they're all sensitive to vibrations. But a properly working Logo will not vibrate that badly as suggested by AfS so it really shouldn't be needed.

Originally Posted by Old Hippie

Strapping the sensor down will only induce more vibrations to the sensor, think about it...you're defeating the purpose of the gel pad by transferring vibs through the zip tie.

That is incorrect. Read the thread on the Milton mod that I linked earlier - that was all hashed out years ago, back when nitro was a thing.

[maarset]

Watch mr Mel's spectrum analyzer video. He straps down a black mini vbar on a logo 400 and you can see a reduction in vibs

[Roger_Salmon]

Originally Posted by maarset

Watch mr Mel's spectrum analyzer video. He straps down a black mini vbar on a logo 400 and you can see a reduction in vibs

Doesn't this imply that the mounting tape is still too flexible and that the tiedown is eliminating it. It would be interesting to compare mounting with a more rigid tape.

[jbobb1]

You might consider this:
http://www.helidirect.com/lynx-omicr...er-p-24408.hdx

I use it on my 2 of my X3's and my Gob 500. It has survived several crashes on the X3. Self level is working correctly also, once you get it tweaked!

[crashjack]

Originally Posted by jbobb1

You might consider this:
http://www.helidirect.com/lynx-omicr...er-p-24408.hdx

I've got a gel pad. However, my understanding is that no gel pad is sticky enough to be trusted to hold an FBL controller. Plus, the dampening effect is more pronounced when the FBL is strapped down, and the fuel line tubing also adds to the dampening effect (from what I read).

Regarding drilling, do you drill between the two frame screws holding the boom clamp, which means drilling through the top of the boom clamp (the same part the screws are passing through)? This is the only way I see getting under the plate. I don't see any room between the top of the boom clamp and the plate. It might look that way from the outside of the frame, but the outside of the frame actually extends about 1/8" above the plate. Take that 1/8" away and allow for the plate, and you are pretty much into the top of the boom clamp where the frame screws are passing through.

[jbobb1]

The Omicron pad has a nice adhesive on both sides and it seems to be a bit more stiff. It's nothing like the typical gel pad. I don't strap mine down, you just have to make sure your surfaces are clean.
I previously had my iKon mounted on my Gob using the Milton Mod method....Align PU gel pad, fuel line and zip tie. After a routine maintenance I decided to remount the iKon because I've had good results on my X3.

[hemp]

Originally Posted by crashjack

Regarding drilling, do you drill between the two frame screws holding the boom clamp, which means drilling through the top of the boom clamp

Yep, exactly. Like I said, much easier to do with the frames apart, but it can be done. I would remove the boom though in case you miss low.

[crashjack]

Got it drilled. It wasn't a big deal. I just took a ruler and marked a spot in line with the two frame screws. Tip: Once you drill through the first side of the frame, you can feel the boom clamp with the bit such that you can feel your way to drilling into the top flat part and not accidently drilling into the rounded part that fits around the boom. Unfortunately, I didn't realize this until I had already drilled through the clamp but luckily, I drilled through the top anyway.

My biggest problem was that my bit wasn't really long enough, and I didn't want to guess at the placement of the hole on the other side.. I had to pull the bit out of the chuck to where there was only 1 - 2 mm of the bit clamped down. This gave me just enough length to where I made a small hole on the other side, creating a mark I was able to drill through after flipping the heli and properly seating the bit. The hole on the other side was slightly off due to the insecure bit and then drilling back the other way into the small hole. However, I was able to get my cable tie through all three holes without having to poke something else through, taping the tie to it, and pulling the tie back through.

[taosgraveyard]

Quote
To my knowledge, that is how all of them do self leveling. And thus, they're all sensitive to vibrations.

End quote

This I think was in response to a comment about ikon using accelerometers

Of the two FBL units that have, in my opinion, the most reliable rescue feature, The Bavarian Demon 3SX does not have accelerometers. Instead it has great firmware. It's rescue reliability is not prone to problems caused by vibrations as the others

[hemp]

Originally Posted by taosgraveyard

The Bavarian Demon 3SX does not have accelerometers.

I think you're right, I had forgotten that fact. It probably is less sensitive (as evidenced by their claim to support nitro & turbine models, though I've never tried it.) Co-pilot II likely has the most reliable rescue feature in the single-rotor world with its infrared optical stabilization, but very few people are running it since FBL took over.

In any case, regardless of the unit if you're having trouble related to vibration then you can either do something like the Milton Mod or try to eliminate the vibes. Or both.