Best location to mount VBar sensor on Whiplash?

[jhamel]

I decided to change my FBL setup to the Silver Line VBar. I would think that the most logical place to mount the sensor is on the gyro mounting plate. However, I recently had a discussion with a MA representative who advised me that the boom CF plate is a better option to mount the sensor as it has lower levels of vibration. Apparently, the gyro plate vibrations are suboptimal for even the vibration-insensitive Sliver Line VBar.

I have not seen a Whiplash setup with the sensor on that rear plate.

Does anyone have experience with different mounting locations for the VBar sensor?

[itbvolks]

Working on a similar setup so in for the good timing.


I don't have anything to add but curious why the move from the SK720?

[Seasick78]

I use a CGY750 on a Whip gasser with the sensor mounted in the front. No bad vibration issues for me. I've had wobble issues that were related to adjusting the 750, but as far as I can tell there hasn't been any vibe issues per-se.

Again- that's with a gasser (much higher vibes than most anything else).

Josh

[Doug Darby]

My silverline sensor is on the front plate and the logs on my Gasser are very clean.
My personal thought was the front would be better as the rear plate is attached to a block with rotating gears and a gear mesh.
But I have no reason to believe it won't work on the rear.
Let us know how it works out.

[itbvolks]

Honestly, looking at the design this morning - I have to agree. I would think mounted on the rear carbon boom plate would be an area more prone to vibration harmonics due to a couple reasons.

Gears within the tail drive assembly as well as resonance due to the TT.


Not sure it matters but I would think the big mass of frame and motor/main shaft mounts might help dampen the vibs better up front.....????

[jhamel]

Originally Posted by itbvolks

I don't have anything to add but curious why the move from the SK720?

The decision to not use the SK-720 was made for me; the SK-720 displays a sensor error on the SK-LCD and the LED flashes red even before take off. I updated to the latest 3.12 firmware, and still have issues with the SK-720. I sent it to Skookum for repair. I did not want be grounded for the next few weeks while waiting for the SK-720, so I figured I would give the latest VBar a try.

BTW, the Skookum was reading vibes in the 3.0 range when mounted on the Whiplash front gyro plate. However, since the SK-720 requires special mounting padding, I do not know how those sensed vibrations apply to the VBar which will be more hard mounted.

Assuming that I am happy with the VBar, the SK-720 and accompanying power bus will go on the For Sale section whenever I get it back from Skookum.

[jhamel]

Originally Posted by Doug Darby

My silverline sensor is on the front plate and the logs on my Gasser are very clean.
My personal thought was the front would be better as the rear plate is attached to a block with rotating gears and a gear mesh.

Originally Posted by itbvolks

Honestly, looking at the design this morning - I have to agree. I would think mounted on the rear carbon boom plate would be an area more prone to vibration harmonics due to a couple reasons.

Gears within the tail drive assembly as well as resonance due to the TT.

Initially, I was not even considering mounting the sensor anywhere but on the specifically designed front gyro plate. MA even went through the trouble of using Delrin as opposed to the regular metal mounts in an attempt to reduce and optimize gyro vibrations. Were in not for the fact that the MA engineer specifically mentioned that the rear plate works better for the gyro than the front gyro plate, I would not even be discussing this issue. It would certainly make it more convenient to mount the sensor on the front gyro plate. Mounting the sensor on the back would require a servo wire extension and additional servo wire ties. Mounting the sensor on the front would make the wiring more neat.

It is very reassuring that all of you seem to have good sensor performance when mounted on the front gyro plate. Still, when one of the helicopter designers advices to mount the sensor on the back, this advice is hard to ignore.

BTW, any special mounting tape that I should use with the VBar sensor? Does the kit come with mounting tape? Will the readily available 3M 4011 or 411 mounting tape, single or double layer work fine since the Silver Line sensor is vibration resistant?

[Doug Darby]

The VBar silverline sensor comes with mounting tape and mine is hard mounted using that tape to the front plate and flys like a dream...
Mount her up and have fun....

[Seasick78]

My CGY750 sensor is also hard mounted.

[JamesK]

I've been running a Blue-line sensor mounted on the gyro plate with one piece of Futaba tape without issue.