Vision Craft testing questions

[Joey Jones]

Howdy Tunnel experts!

So, I went out to my ultra-secret testing slough this evening for a few runs. Matter of fact, this is the first time I've run the boat this year. I finally got the chance to run this Sholund prop that I bought last year. Man-alive, let me tell you....that is where it is! Thank you Mark!!!

I'll get some video up on Monday (not enough bandwidth here at home), but it was the best it's ran so far. Granted, I haven't run much. Anyway, I'm having a few issues that I'm hoping one, or some of y'all would recognize and give me some pointers with.

The first 2 runs were great. Well, it ran great, the pilot was shaking so bad it was hard to keep focused. On the 3rd run, I noticed that the boat would kinda "skip out" while on plane. It did this so bad on the last straight-a-way, that it leaped out of the water and rolled. I've hit fish here last year, and the damned Gar were jumping again today....

Am I hitting something subsurface, or do I need to start looking at motor height/trim etc? The first 2 runs were perfect (minus the driver). I hate to blame fish on my ignorance in setup, or driving. Also, keep in mind this entire setup is brand new. I'm just past 1/2 gallon of fuel. Call it about 10 runs on this boat.

I put cotton balls in the "free space" of my radio box. They were dry, so I don't think I'm shorting the electronics, or glitching. I'm running 2.4 (Airtronics).

I'm going back out tomorrow, not changing anything. I hate to waste fuel/time and my sanity chasing an easily fixable issue. Maybe I'm hitting stuff...I dunno...ideas? Thanks!!

-Joey

edited for grammer

 

[Matt Minassian]

If your lower unit was hitting things in the water, the boat wouldn't skip out of the water, it would nose dive into the water.

Without seeing a video it is hard to say and I am by no means an expert, extremely far from it. But if the butt end is coming out of the water and it's kind of doing what we would call a chine walk in mono terms but meaning it's rocking back and forth while it hops would of the water, I would see about possibly lowering the motor a tad to keep the rear end in the water.

I am sure the more seasoned professionals will chime in with some better knowledge.

Matt

 

[Joey Jones]

If your lower unit was hitting things in the water, the boat wouldn't skip out of the water, it would nose dive into the water.

Thanks Matt! When I say "skip out", I don't mean it was coming out of the water...the boat would "skip" (RPM would bump up for a split second), and the transom would kind of lift and go either right or left....it wasn't predictable, and was just a "hop". The last time, yes..the boat came totally out of the water. Which makes me think I'm hitting something. But, I hate to use that excuse (again).

If I am hitting something, great, that is preventable (sort of!). If this is a known setup issue, then that is something that I'd like to know.

-Joey

 

[boatwreck77]

shawns on vacation.. so ill answer.. drop the motor a 1/16 or add a ounce or so behind the radio box.. should help settle the boat

 

[Andy Greene]

Take Jeff's advice and try and get us some video so we can relate better to what your saying and what the boat is doing -

Your in good hands btw- Jeff / Shawn and the rest of the fools that love this game will make sure your taken care of and

The Vision boys take care of their own

 

[Joey Jones]

**** I love this hobby.

 

[RonShaw]

If your lower unit was hitting things in the water, the boat wouldn't skip out of the water, it would nose dive into the water.

Without seeing a video it is hard to say and I am by no means an expert, extremely far from it. But if the butt end is coming out of the water and it's kind of doing what we would call a chine walk in mono terms but meaning it's rocking back and forth while it hops would of the water, I would see about possibly lowering the motor a tad to keep the rear end in the water.

I am sure the more seasoned professionals will chime in with some better knowledge.

Matt

Great advice Matt. You are spot on!!

 

[Andy Greene]

**** I love this hobby.

Thats what is all about Joey , Hope you can make it south one day.

Enjoy the ride, you know the rest of the advice

 

[Beau Parsons]

Joey,

Just a thought have you checked the C.G., and what prop are you running? I finally got my new Vision setup last weekend and man she is fast as hell.

Beau

 

[Joey Jones]

Joey,

Just a thought have you checked the C.G., and what prop are you running? I finally got my new Vision setup last weekend and man she is fast as hell.

Beau

Hey Beau! Hope all is well! Glad to hear you got the new boat completed.

I have checked the GC...long time ago. It was very near on what Shawn posted somewhere waaay back. The prop is new; I got it last year. It's whatever Mark Sholund suggests for this boat and motor combo. It freaking rips, I'll tell you that!

I was running some prop (440 maybe?) from offshore electrics. I had the motor real rich, just breaking it in...taking it easy. After that I started slowly leaning it. I put this prop on at the end of last summer..never got the chance to run it until today. I'm more than excited!

-Joey

 

[Joey Jones]

Ok, I did get a little of "squirreliness" on video. This was the end of the first run. I got scared (I was already shaking), and brought it in. However, you can see, the boat appears to be in good trim when it's hooked up.

At the end, it kinda sounded like it's wanting to leave the water.....wind? Motor height/trim?

This is not the behavior I described above, like I felt as thought I was hitting something. Still no video of that.

Ok, I'm not sure what changed..I've embedded Youtube videos to my posts before, but **** if I can figure it out now. Here's the direct link, with my apologies....

http://www.youtube.com/watch?v=SosspFgXbSw&feature=youtu.be

-Joey

Edit: Sorry about the angle and generally crappy video. GoPro's aren't really known for their stellar videography of RC stuff.

 

[Andy Greene]

Hard to really tell with that short a video , but it looked like a darn good starting point to me Joey.

Keep us posted.

Andy

 

[Joey Jones]

Hard to really tell with that short a video , but it looked like a darn good starting point to me Joey.

Keep us posted.

Andy

Thanks Andy...Yeah, I know. I can only do small videos from my connection at home. I'll get a longer one posted later this week...the University has Excellent bandwidth

. I really just wanted to show that "looseness" at the end there. I'm going back in my memory bank, reliving the few runs I made yesterday. I think Jeff may be on to something with lowering the motor. I'm likely going to try that.

It was dead calm when I was running yesterday, too. So, it's entirely possible that a small breath of air got to me, and lifted it. I won't rule that out, but I don't see any "cat's paws" on the water indicating a breeze. At any rate, I'm on the bloody edge of flying it. I think making it a bit more stable can't hurt. At least for a few tanks of fuel, until I get a better idea..

Anyway, I'll play around with my video editor too...I might can export a higher quality video. I'm new a video editing too....can you believe that!?!?!?

-Joey

 

[RonShaw]

Joey,

Make a setup board out of a flat piece of cabinet grade 3/4" ply for now, by cutting a slot large enough for your lower unit to clear. Slide the hull on the setup board with the lower in the slot. Lift the front of the hull until the rear of the sponsons touch the plywood, and tell me where the prop shaft assy is in relation to the top of the ply as well, (same plane as bottom of sponsons). I'm thinking your setup is high causing you to "blow out" the rear of the boat. Remember also, tunnels need a little ripple on the water to free up the hull. I have seen some strange acting tunnels over the years on perfectly flat water!!!...

Good luck.

 

[Joey Jones]

Joey,

Make a setup board out of a flat piece of cabinet grade 3/4" ply for now, by cutting a slot large enough for your lower unit to clear. Slide the hull on the setup board with the lower in the slot. Lift the front of the hull until the rear of the sponsons touch the plywood, and tell me where the prop shaft assy is in relation to the top of the ply as well, (same plane as bottom of sponsons). I'm thinking your setup is high causing you to "blow out" the rear of the boat. Remember also, tunnels need a little ripple on the water to free up the hull. I have seen some strange acting tunnels over the years on perfectly flat water!!!...

Good luck.

Wait a minute!! You may be on to something here Ron...

So, I made a setup board last summer. I grabbed it out of the garage, and as my luck would have it, it's warped. I'm out of wood too. No worries...there are benefits to being single...I used my kitchen table. It looks like the propshaft assy is about 1/8" above the sponson bottoms.

Also, something new hit me while I was looking at this. Something didn't look right...the motor looked to have a few degrees of positive trim. I have a digital pitch gauge for my helicopters where the sensor unit and display is magnetically attached to the part that clamps to the blades. So, it makes it easy to just use the sensor part for all kinds of other things...like this. Turns out, my lower was trimmed positive. I'm back to 0 degrees with respect to the sponson bottoms now. I think that I read somewhere that Shawn said that is what you want (maybe I'm making stuff up, who knows).

Long story short, yes...Ron, you're right that my setup (trim anyway) was high. Although, I also want to say that having the propshaft assy 1/8" above the sponson bottoms is the correct height for a Vision Craft?

Thank you Mr. Shaw. Got me to looking at something that I probably should have long ago...especially after Jeff's insight to lower the motor. He was right too, it appears!! Many thanks to all! I still have to go run it to verify, but I'm feeling a lot more confidant now.

-Joey

 

[boatwreck77]

looks to me your in the ball park I run mine 3/16 above the bottom I would leave the hight and lower the trim to 1 or 2 deg.. this is my base setup and I will add weight to trim the boat

 

[boatwreck77]

also if its slick calm they can be difficult to trim and set... better to have a tight boat in testing.. it will sure get loose in heat racing traffic....

 

[Joey Jones]

Awesome, thanks again Jeff. I appreciate you sharing your setup info. Storms are moving in, so I had to go pull the boat (not the Vision!) out of the water. Oh well...I'll get back to testing next weekend hopefully.

-Joey

 

[Rene Danner]

Also try 1 1/2 oz of weight on the Cg. And 3/16th up on the bullet and neutral on the lower.

 

[Kris Flynn]

I had to go about 1/8" to bottom of bullet and 1

.5deg Neg with our Sport Vision (Mongar V2 os and 40x52/3). Just couldnt keep it on the water.

It is a mod boat build (heavier) but maybe I should add another 2oz just behind radiobox so its easier for my wife to drive