Eliminating Vibration

[swbca]

1986

When I bought a new 1986 ProStar w/Powerslot the hull radiated a lot of mechanical noise. After adding and aligning the engine to the longer PowerSlot strut which came out slightly later, plus 2 props later (same spec), this structurally elastic boat was incredible quiet and smooth.

 

2021

The new-to-me 2004 ProStar 197-TT is noisier than I expected and has more mechanical vibration throughout the hull than I expected.

 

RESULT - - Can't get a movie with the Ski-Dock Orbit. This is not the fault of the Orbit. My Galaxy S8 phone is completely unusable and my wife's iPhone 8 creates a very low quality video because of vibration. All individual frames from the iPhone are a blur . . somehow this is improved a little during normal playback, but still very poor.

 

But the videos aren't really the problem . . its what to do about the boat ?

Where to start without spending a fortune ? Are new props better than in 1986 for balance ? Is prop balancing better than in 1986 ? Of course it may not be the prop . . . What diagnostics can point to the problem ? Shaft, engine alignment etc.

 

Does this mean anything ? When in reverse, at some moderate throttle levels, the whole hull often goes into an end to end twisting oscillation. I assumed that was normal for this boat but maybe not ?

[MattP]

@swbca The boat is fine.

Use the forward facing camera on the screen side of the. The rear camera uses a rolling shutter to take video and with the vibration creates a video that is unwatchable.

[swbca]

Which phone ? or both ?

[dchristman]

Ironically, the problem is optical image stabilization (OIS). This is a hardware feature of most phones these days and there is no way to disable it through software that I am aware of. The workaround for some phones is to use the selfie camera because that one doesn't have OIS. Unfortunately, newer phones are including OIS in even the selfie cameras. I don't know if this will work on an iPhone 8 or other phones, but here is an interesting solution for the iPhone 7:

[dchristman]

Both of your phones have OIS on the rear camera.

[Zman]

@swbca Back to your priority question of fixing the boat vibration...it sounds like you know all the checks to be made. Checking the shaft alignment at the coupler is fairly simple. Get some feeler gauges, remove the coupler bolts and start with that. Examine your strut for any damage if alignment is way off. Be sure the strut is firmly mounted to the hull, most likely it is. And, being an older boat, you may need a new strut bearing installed if you can feel much play of the shaft in the strut; there should be a little play, very little. Inspect for any prop damage, if in doubt, have a prop shop check it for balance. Check all your engine mounts to be sure they are secure to the engine, and to the boat structure. Lastly, you may need to pull your shaft and check that it is not bent. Even a slight bend can generate a good bit of vibration.

During 4 decades of inboard boat ownership, if I feel vibration in the pylon while underway, that's my cue to check the items above. Alignment is what resolved most issues.

Fix the the vibration before it causes other issues.

Good luck, keep us posted.

[Andre]

GoPro are quite cheap and we get very decent results with a Ski-Doc Orbit.

 

[DW]

@swbca - You can check the shaft with a dial indicator, midshaft and prop tip good areas to verify it's straight. My experience, the CNC cut props tend to be smoother than the cast versions. OJ and Acme offer props to fit your ride. As you found it does not take much to make a prop rough or silky smooth.

[Zman]

+1 on checking for prop runout with a dial indicator, midshaft and near the prop. Maybe you can borrow one from an O'Reilly auto parts store. They have some tools they loan for free (refundable deposit).

[Mastercrafter]

Another vote for go-pro. Smooth as silk. Only hassle is pressing the button between runs as there's no speed-based app to start and stop recording.

 

[dchristman]

@Mastercrafter Wakeye has a function to control Go-Pro.

[ReallyGottaSki]

No i wouldn't be satisfied at all with vibration like that either, and would dive into it.

 

Coupling -

Sounds you are already privy, If angular alignment it out of tolerance, there is also usually resistance to turning the coupler by hand. If there is any difference between parasitics between having the 4 bolts loose vs torqued, its a sign angular alignment is out and can be improved

 

Shaft - as been said, check for runout at multiple places

 

Prop - yes a modern prop is impressive

 

Installation - even a modern prop can give one fits. Consider lap the prop/taper interface with the key absent. mark the shaft where it seats. be certain the prop seats at the same location and not hanging up on the keyway before torqueing the nut

[Vernon Reeve]

The GoPro 8 has voice recognition. So the driver can just say GoPro Start Recording and GoPro Stop Recording. No need to push the buttons anymore:)

[UWSkier]

Google Pixel on Ebay

 

Buy that and get the Wakeye app. Problem solved and with better zoom than an expensive gopro. As others have said, the problem isn't likely your boat. Cell phone camera stabilization is designed for the frequencies of shaky human hands, not a small block Chevy at 3500 RPM.

[Mastercrafter]

@dchristman -- thanks for the heads up. I do have the Wake-eye mount and app, haven't messed with it enough.

 

[swbca]

@MattP You and other pointed out the front side camera works for boat videos. I tried it on my Galaxy S8 and it worked. My only issue . . starting with Galaxy S7 they went to a less wide angle lens on the back side camera than the rest of phone industry. I prefer the less-wide lens. Unfortunately the front camera is still a wider angle so the skier is a very small feature in the videos.

 

Are there any GoPro cameras with a 50mm equivalent focal length?. When watching the televised pro skier events, the cameras in the boat are not an extreme wide angle like the GoPros I have seen. It would be nice to get a normal focal length in our practice videos.

 

There are some newer Galaxy cameras that have optical zoom but I don't think they can run within the app that starts and stops video with boat speed.

 

Thanks for the tip on using the front camera.

[UWSkier]

I'll put the image quality and convenience of my Google Pixel on a Ski-Doc up against action cameras or iPhones any day. The zoom works well right within the Wakeye app (this is 1.8x zoom in the linked video), there's no shake from the pylon, the start-stop from the Wakeye app works great, it has enough battery life for a lot of skiing action, it's cheap, and it automatically uploads videos to the cloud when it gets in wifi range so my buddies/coaches who live 1800 miles away can see them, and it uses the Youtube player right in Google Photos for viewing, which works from any device.

 

You can try more expensive or more cumbersome setups to your heart's content, but I don't think there's anything more economical and convenient than my setup.

 

https://photos.app.goo.gl/8WaMqjAYTBcroTWt6

 

Give it a second to buffer to full 1080p

[swbca]

@UWSkier What model number is your Pixel ? The only thing I am missing that I want is the "normal" focal length, instead of wide angle. Your zoom should take care of that. I always dedicate a phone to sports video, so their aren't Walgreens robo calls coming in when i am using the phone for laptimes on the track or in the boat. I use a second phone as a phone.

[UWSkier]

Mine's similar to the one I linked a few posts up. That one is unlocked. Mine's a Verizon version, but it doesn't matter. It doesn't have a SIM card or a mobile plan.

[swbca]

@UWSkier You use the PixeI phone for your slalom videos. I just bought a Pixel 2 XL on ebay. The rear lens on my old Samsung Galaxy 5 has no problems with vibration on the Ski-Doc . Video from the rear lens of the Pixel is just a blur with Video Stabilization OFF or ON and with no-zoom. Any tips on settings or other ? Are you using the rear lens ? Thanks

[Zman]

How do you get the Samsung S8 to use the front side camera when using the Wakeye app?

[UWSkier]

@swbca Pixel 2 has OIS. Needs to be the original Pixel or Pixel XL.

[swbca]

@Zman I am using a Samsung Galaxy 5 for ski videos. Wakeye automatically uses the rear camera. I just tried to have Wakeye use the front (selfie) camera by setting the phone's built-in Camera app to front. But then Wakeye still used the main (rear) camera. The Samung G5 camera is less wide angle than all newer cameras so the skier is closer without using zoom. The image quality is excellent. The only downside is the video gets choppy when the camera is panning the background fast following the skier across the wake. @UWSkier posted a video from his Pixel and it also is choppy when the skier is crossing the wake.

 

I am curious if newer cameras can keep up with fast panning of the background. But as @Horton says, the old phones are the best because they don't have video stabilization or it can be turned off entirely.

[Zman]

@swbca On my S8 I can turn off video stabilization. Whether it stays off using the Wakeye app, who knows?

I also selected front camera on my phone, but the Wakeye app still only turns on the rear camera.