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Old Apr 09, 2012, 12:23 PM
RCHN #150
Rickn816's Avatar
Lawrenceville, GA
Joined Nov 2007
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Originally Posted by jamesppp View Post
Rick,
As far as the tail is concerned, everything is new other than the tail case itself . I do have the "upgrade" carbon tail assy which is the open case type. The new tail shaft is the "hardened' model Mikado offers for twice the price of the standard.

I replaced the main shaft with the "hardened" shaft they offer as well as the main gear. I did not replace the main bearings here
I don't think I accomplished anything replacing the main rotor parts. The FBL head is brand new Mikado stuff.
I flew it yesterday evening and it flies great and no cutoff on the SL. As long as the vibes don't cut off the SL I'm good with it
I can remount the SK directly under the main shfaft ising a piece of light ply or aluminum if want to move it. Bench runs with tail blades only show much less vibration here as the back shelf is a bit cramped for the S K.
If I don't get any shutdowns I will leave it as is I think. > 3.5 isn't too bad for a heli with this much airtime on it I wouldnt think
You are good.

Rick
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Old Apr 09, 2012, 12:25 PM
RCHN #150
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Lawrenceville, GA
Joined Nov 2007
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Originally Posted by Xrayted View Post
What is your SK unit mounted to James? I used the Zeal gel using two split pieces under the edges of a metal plate and then used standard thin double sided tape to hold the unit on the metal plate. It made a huge difference over the supplied gyro foam tape.

http://www.readyheli.com/search.asp?keyword=Zeal+tape
I have good results with 3M thin tape, metal plate, and 3M thin tape. On my T500 I put it on the bottom plate. On my Furion, there is a platform ahead of the main shaft.

Rick
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Old Apr 09, 2012, 01:07 PM
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Originally Posted by Rickn816 View Post
I have good results with 3M thin tape, metal plate, and 3M thin tape. On my T500 I put it on the bottom plate. On my Furion, there is a platform ahead of the main shaft.

Rick
I have a Go Pro mounted to my 500 and I tell you I have learned more than I ever wanted to know about isolating things from vibration

I discovered that what will work for one person may have no effect or possibly make things worse for another depending on the frequency of the vibrations. I had just always assumed what worked for one would work for another, but this camera thing really opened my eyes.

I tried at least 10 different mounting options, all of which worked great for others but failed for me despite my heli being smooth as silk before discovering that I could use the battery to stop the vibes. I now have my camera mount sitting on a metal plate on top of Zeal tape and another plate that quickly straps on top of the battery when I want to film. It works wonders! The dense battery changes the frequency of the vibes to one that the Zeal tape can block out much better.

Bottom line........I found out it takes a lot of experimenting and just because something works for one doesn't mean it will for anyone else
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Old Apr 09, 2012, 01:16 PM
RCHN #150
Rickn816's Avatar
Lawrenceville, GA
Joined Nov 2007
5,995 Posts
Quote:
Originally Posted by Xrayted View Post
I have a Go Pro mounted to my 500 and I tell you I have learned more than I ever wanted to know about isolating things from vibration

I discovered that what will work for one person may have no effect or possibly make things worse for another depending on the frequency of the vibrations. I had just always assumed what worked for one would work for another, but this camera thing really opened my eyes.

I tried at least 10 different mounting options, all of which worked great for others but failed for me despite my heli being smooth as silk before discovering that I could use the battery to stop the vibes. I now have my camera mount sitting on a metal plate on top of Zeal tape and another plate that quickly straps on top of the battery when I want to film. It works wonders! The dense battery changes the frequency of the vibes to one that the Zeal tape can block out much better.

Bottom line........I found out it takes a lot of experimenting and just because something works for one doesn't mean it will for anyone else
Yes, Sir. One size does not fit all.

Thanks.

Rick
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Old Apr 09, 2012, 04:13 PM
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Quote:
Originally Posted by Xrayted View Post
What is your SK unit mounted to James? I used the Zeal gel using two split pieces under the edges of a metal plate and then used standard thin double sided tape to hold the unit on the metal plate. It made a huge difference over the supplied gyro foam tape.

http://www.readyheli.com/search.asp?keyword=Zeal+tape
Xrayted, I used the Sekisui foam included with the Sk uniton the bottom 4 corners , then the metal plate and the thin white foam and then the Sk unit. I mounted all of that on the small back tray of my Logo.I mounted it "by the book" as shown in the Sk manual

I first used the Sekisui foam tape that came in a HR Parkmite kit I bought and I loved it. It worked great on my tail gyros.

If I have any problems I am going to mount it directly below the main shaft. I will have to fab up a plate to fit between the battery mounting tabs in the frame.
I will find my piece of Zeal and try it . There are barely any perceptable vibes there
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Old Apr 09, 2012, 05:17 PM
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Originally Posted by jamesppp View Post
Xrayted, I used the Sekisui foam included with the Sk uniton the bottom 4 corners , then the metal plate and the thin white foam and then the Sk unit. I mounted all of that on the small back tray of my Logo.I mounted it "by the book" as shown in the Sk manual

I first used the Sekisui foam tape that came in a HR Parkmite kit I bought and I loved it. It worked great on my tail gyros.

If I have any problems I am going to mount it directly below the main shaft. I will have to fab up a plate to fit between the battery mounting tabs in the frame.
I will find my piece of Zeal and try it . There are barely any perceptable vibes there
Sounds like you have done about as much as you possibly can. Mine was much worse inside the frame under the main shaft for some reason. I installed an ally KDE mount in the factory RX mounting location and it worked much better as far as having access to to the unit and being able to slip it in after getting the wires plugged in. I also have my servo wires covered and isolated from the frame en route to the unit as you can see in my pic. Not sure if it's really helping me, but I had read of others that were having issues with vibes being transferred into the unit through the cables.
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Old Apr 09, 2012, 05:51 PM
RCHN #150
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Lawrenceville, GA
Joined Nov 2007
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Quote:
Originally Posted by Xrayted View Post
Sounds like you have done about as much as you possibly can. Mine was much worse inside the frame under the main shaft for some reason. I installed an ally KDE mount in the factory RX mounting location and it worked much better as far as having access to to the unit and being able to slip it in after getting the wires plugged in. I also have my servo wires covered and isolated from the frame en route to the unit as you can see in my pic. Not sure if it's really helping me, but I had read of others that were having issues with vibes being transferred into the unit through the cables.
I use the bus on my Furion.

Rick
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Old Apr 09, 2012, 09:36 PM
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Originally Posted by GetToDaChopper View Post
ya that's cool, but of course they have none in stock....


grimbeaver

you might want to look carefully at the blade grip bearings, screws and washers, sometimes the bearing aren't pressed in (seated inside) all the way or they might just be bad, when the outside grip bearing starts to go bad it no longer holds the blade grip the same distance from the centerline of the tail shaft causing an imbalance in the tail rotor assy and the same go's for bearings that aren't pressed in all the way, or even screws and washers that are not the same weight in the rotating tail assy can cause a imbalance in a tail rotor that is rotating at approximately 12,000 RPM's.

when something is turning as fast as the tail rotor (approximately 12,000 RPM's) it only takes a small fraction of a gram on one side more than the other on a tail assy with little mass to start with to cause some big vibrations........


oh and in case you somehow see this jimmy, a tail rotor can also cause up and down vibrations with a 720, it's actually easier for a out of balance tail rotor to swing a heli up and down ver pulling the mass of the hole heli fore-aft, one more thing to consider is something out of whack with the main rotor blades like tracking or blades that aren't lifting the same for whatever reason can cause up & down vibs.

you just have to remember that vibration that is caused by a out of balance condition (and excluding the shock type) is just accelerations that are oscillating back & forth, up & down, left & right or in what ever plain the oscillation happens to be in......
HK metal blade grips looked questionable. Was planning on getting a new belt and reducing the tension on the belt but LHS was willing to part with their TT upgrade kit for a good price since it had been sitting on the shelf for quite a while. So got that and new tail rotor holder and tail pitch assembly. So whole new tail to try, hopefully the wind will die down tomorrow so I can try it.
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Old Apr 09, 2012, 10:57 PM
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are you installing the hole TT tail assy or just the rotor assy, please let me know how it gos after you fly it, ok ?
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Old Apr 09, 2012, 11:17 PM
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Originally Posted by GetToDaChopper View Post
are you installing the hole TT tail assy or just the rotor assy, please let me know how it gos after you fly it, ok ?
Got the upgrade kit so new boom, tail assembly, aka the works. Plus bought new blade grips and pitch. Basically the entire rear of the heli is new except stabilizer, tail control arm and boom brace.
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Old Apr 09, 2012, 11:59 PM
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Hey for those of you who would like to know more about the new SK540s gyro sensors i came across this info......

Quote:
The fusion of two streams of gyro data while implementing some filtering can theoretically provide the flybarless system with highly accurate angle data, which leads to a very “locked in” and “flies like on rails” feeling.

Looking at the size of the unit I think that it is using two modern 3-axis ITG-3200 gyro chips, and a 32-bit main CPU. There is no room in this small box for two pairs of old style Nintendo Wii IDG-500/ISZ-500 chips, which are used in today`s FBL systems like Mikado V-Bar Blueline /Mini V-Bar (which are becoming outdated and obsolete now).
if true here are the features of that chip !

•Digital-output X-, Y-, and Z-Axis angular rate sensors (gyros) on one integrated circuit with a sensitivity of 14 LSBs per /sec and a full-scale range of 2000/sec
•Three integrated 16-bit ADCs provide simultaneous sampling of gyros while requiring no external multiplexer
•Digitally-programmable low-pass filter
•Fast Mode IC (400kHz) serial interface
•Low 6.5mA operating current for long battery life
•Wide VDD supply voltage range of 2.1V to 3.6V
•Flexible VLOGIC reference voltage allows for IC interface voltages from 1.71V to VDD
•Standby current: 5A
•Smallest and thinnest package for portable devices (4x4x0.9mm QFN)
•Turn on time: 50ms
•Digital-output temperature sensor
•Factory calibrated scale factor
•On-chip temperature sensor
•10,000 g shock tolerant
•On-chip timing generator clock frequency is accurate to +/-2% over full temperature range
•MEMS structure hermetically sealed and bonded at wafer level
•RoHS and Green compliant

2000/sec ! wow that would kick futaba's butt !
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Old Apr 10, 2012, 05:44 AM
RCHN #150
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Lawrenceville, GA
Joined Nov 2007
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Quote:
Originally Posted by grimbeaver View Post
HK metal blade grips looked questionable. Was planning on getting a new belt and reducing the tension on the belt but LHS was willing to part with their TT upgrade kit for a good price since it had been sitting on the shelf for quite a while. So got that and new tail rotor holder and tail pitch assembly. So whole new tail to try, hopefully the wind will die down tomorrow so I can try it.
I found with the Align TT system, you need really good bearings. My LHS heli guy uses two bearings for the shaft in the tube - he says it reduces vibrations. They are spaced at "inequal" thirds, the closest being forward.

The other problem with the Align system is if your tail blades touch dirt, chances are you will lose a tooth or two on the drive gears. That is a PITA - I just finished another rebuild there.

I went TT because of the reports of static buildup with the belt - now I wish I had used the belt . . .

Rick
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Old Apr 10, 2012, 08:07 AM
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Originally Posted by Rickn816 View Post
I found with the Align TT system, you need really good bearings. My LHS heli guy uses two bearings for the shaft in the tube - he says it reduces vibrations. They are spaced at "inequal" thirds, the closest being forward.

The other problem with the Align system is if your tail blades touch dirt, chances are you will lose a tooth or two on the drive gears. That is a PITA - I just finished another rebuild there.

I went TT because of the reports of static buildup with the belt - now I wish I had used the belt . . .

Rick
Well one of my other issues was that the metal tail casing that comes with the HK500 does not have the pin which sticks into the boom and it is poorly designed to where you can't get it super tight so it slowly (or sometimes quickly) twists on you. So the upgrade should be solving multiple problems for me. Touching the ground is exactly why I went with the belt initially, however I've gotten pretty good at landing.

Also the HK pitch assembly had more wiggle to it then the Align so I replaced that. The HK metal tail blade grips were also not the best. If I tightened down the grips fully you would not be able to twist them because something was off by just a bit. I'm quickly realizing why HK doesn't sell any FBL heli kits yet. They would have to greatly increase the quality of the parts.

Also multiple people suggested that I needed to get my belt loosened up and for that I would have had to shorten the boom and that really did not sound like fun. Maybe if I had a benchtop sander that I more easily have gotten a straight edge.

Unfortunately looks like I might have to wait till tomorrow yet to try out the changes. The wind has been just wicked this spring in the midwest.
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Old Apr 10, 2012, 09:03 AM
RCHN #150
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Lawrenceville, GA
Joined Nov 2007
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Originally Posted by grimbeaver View Post
Well one of my other issues was that the metal tail casing that comes with the HK500 does not have the pin which sticks into the boom and it is poorly designed to where you can't get it super tight so it slowly (or sometimes quickly) twists on you. So the upgrade should be solving multiple problems for me. Touching the ground is exactly why I went with the belt initially, however I've gotten pretty good at landing.

Also the HK pitch assembly had more wiggle to it then the Align so I replaced that. The HK metal tail blade grips were also not the best. If I tightened down the grips fully you would not be able to twist them because something was off by just a bit. I'm quickly realizing why HK doesn't sell any FBL heli kits yet. They would have to greatly increase the quality of the parts.

Also multiple people suggested that I needed to get my belt loosened up and for that I would have had to shorten the boom and that really did not sound like fun. Maybe if I had a benchtop sander that I more easily have gotten a straight edge.

Unfortunately looks like I might have to wait till tomorrow yet to try out the changes. The wind has been just wicked this spring in the midwest.
I got in a couple of flights this morning. In addition to my SK unit acting totally weird, I need to rebuild my tail grips and replace the bearings. Some fun. And no crashes.

Rick
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Old Apr 10, 2012, 09:24 AM
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i always like the "no crashs" part.....
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