Hospital Hop...how to stop it?

[Doby]

Wait wait wait.. i get it I get it i get it...

Andy.. play this game the way you see fit.. I can tell you now however.. Im not the kind that’s going to comment on how your designs for Proboat work. Its just tacky and not all that professional.. especially when you work for a company (Horzion) that makes products that are in direct competition with ours. Im not going to do that to your boats.. but again its your head.. do as you please.

ROCK ON UL-1 Drivers.. lets get some heat wins.

Grimracer

So Andy works for ProBoat?

If true, it would be nice to know who is affiliated with what company so any advice/ comments can be weighed appropriately.

[Grimracer]

....ummmm.....back to my questions at the end of post #23 please. And can ya show me what you mean about the turn fin setting with a pic or drawing.

Thanks


(I didn't know Andy is affiliated with Pro Boats)

Youz guz need to duke it out with your products on the field of battle...not this thread please!

lets see here.. if this works on this old dog..... sorry about the ugly pic.. its just to get the point across.

Grim

[Capt. Crash]

...that is a big help.....now one more time....where exactly should the CG be with the boat buttoned up and ready to terrorize the pond.

Crash

[Capt. Crash]

Mike,

That's so the bottom of the rudder doesn't become a planing surface, right??

That's a mighty small planing surface! I'd think it might have more to do with turbulence created there.

[Bill-SOCAL]

So Andy works for ProBoat?

If true, it would be nice to know who is affiliated with what company so any advice/ comments can be weighed appropriately.

Well in the interest of full disclosure then, I am a member of Team Futaba (Air) as a Field Representative. I am not paid, receive no other compensation and pay for everything I get (but I do get a decent discount). I do get free service (hardly ever need it ) and a free Team Shirt each year. Sadly some think that we Team members will compromise our integrity for the sake of that free shirt.

Oh well. Like my signature says on another forum - "Ignore me - I get a free shirt!!"

[Grimracer]

Capt.

Setting the CG at 3 to 3 1/4" back from the sponson backs will get you very close. Typically on a good race boat the CG is around the center of the back of the turn fin. One of the reasons my turn fin design is swept.. allows better turning on a wider CG range.

The bottom of the rudder can make lift.. more then you think.. also remember to sharpen the rudder.. (lift lift lift)


Grim

[Darin Jordan]

The bottom of the rudder can make lift.. more then you think.. also remember to sharpen the rudder.. (lift lift lift)


Grim

Thanks Mike... that's what I thought... I recall reading that in an article on making Monos work (I think by John Finch??? )...

[Capt. Crash]

Lot's of good stuff in here to help me and the lurkers out there....you know who you are!


Thanks again everyone.

[detox]

Mike, Good info concerning prop, turn fin, COG, and rudder sharpening .............THANKS!

While sharpening the rudder you will notice water intake hole plugged at bottom of rudder (red arrow) with what looks like epoxy. Be sure to plug this area again using epoxy (JB Weld) if port is exposed after sharpening. I removed red area of turn fin only.

[Jeff Wohlt]

Some of the Chine walk can be attributed to flat sponson design with too much angle. You may be getting your walk from the light front end and the motor/blade torque as the front is light it will try and twist the boat to the right then it reacts after hitting water and then the reaction occurs...left side hits and pushes it back up. No doubt this is a faster design than a low angle sponson but handling will be the issue in certain water conditions. You are packing a lot of air in that hull riding high in the front but the tail also rides pretty high so I doubt that the hull is not exiting the air.

Are you running the 3 blade prop?

As Grim noted...that strut angle is waaaaay off but that will push the nose down and make the sponsons run wet. You have to have a certain amount of area that is in contact with the water. Should be fine on smooth water but waves or other boat wash will make it hard to handle.

[AndyKunz]

So Andy works for ProBoat?

If true, it would be nice to know who is affiliated with what company so any advice/ comments can be weighed appropriately.

No, I work for Spektrum supporting aircraft stuff almost exclusively. I own a Miss Elam and hope to get it on the water as soon as it melts.

For the record, I also told Mike at the IHobby show that it's a really nice looking boat and I would like to have one. He might think I'm dissing him, but I'm not. I just happen to come from a different school of Sport/Scale hydroplane design.

Andy

[Capt. Crash]

Are you running the 3 blade prop?

Yes...that's all I've run. The stock prop and setup did not do the Chine Walk...the 40X52/3 and stock setup (7/8" depth) does and so does the 40X57/3 @ 1"strut depth. I've not tried the setup I took the picture of (1 1/16" depth)...it was next on my agenda. I may have try it just to see how she runs.

Thanks for the explanation on the reason for the Walk...that makes sense to me.

[Capt. Crash]

Some of the Chine walk can be attributed to flat sponson design with too much angle. You may be getting your walk from the light front end and the motor/blade torque as the front is light it will try and twist the boat to the right then it reacts after hitting water and then the reaction occurs...left side hits and pushes it back up.

I just checked my Center of Gravity and it appears I was tail heavy. I'm sure the 3 oz GPS isn't helping by being aft. I moved it up between the batteries and slid the packs all the way forward and I am just about balanced right. I wish the ESC wires were just a little longer. I have to lay the connectors on top of my GPS window...that's why I went AFT in the first place. I may move the ESC forward a little to fix this. My 5250s only weigh in @ 241 grams each so the movement of things forward should help compensate.

[LuckyDuc]

Good stuff gents! Like Capt said... When possible, please post illustrations/pics for us noobs. It helps us visualize the advice better.

[LuckyDuc]

BTW I really appreciate the info on the location for the C of G range.

[Jeff Wohlt]

All I know to weigh about Andy's info is his past boat experience... many years, creating a nice UL1 hull for the LSH class, electronic excellence, One of the best ESCs ever made for brushed motors, Flying and building planes, designing an adapter for plane ESC to pistol adapter so we can use other ESCs.

Besides that....he seems to be almost normal!!

I still have one original UL left I may build with the New UL1 motor/ESC and prop and see how she does. I won't claim it will be as fast because of sponson design but it handles rough racing waters well....at least mine did and I also put ride pads on it. Gotta finish to get any points!! Wish I could make one out of glass...guess I could.

[Capt. Crash]

Would someone tell me what the scale of these boats are...1:32?

[Bill-SOCAL]

A typical hydro is about 30 feet long. The UL-1 is a little over 2 feet (27 inches). So pretty close to about 1/12th scale give or take a little.

30 feet = 360 inches

360/27 = 13.33

[Capt. Crash]

Wow...I a was a little off! Of course that happens when ya get old....I went the wrong way when comparing to some of my other boats....

Thanks

Got me some new hyroplane friendly buoys made up last night and am ready to rock Saturday.

[Grimracer]

Capt..

The buoys we use are made by Kershaw floatation in FL.

They are 12” foam spheres that one cuts in half. The great thing about these buoys is that they are firm but not hard. They lay flat on the water.. The boat does more glancing then hitting.. you have to hit them dead straight on to damage anything and truth is I have only ever broke a outrigger on one of these as they have a tendency to launch the boat…not grab it.. Any of this make since?

I have never seen this type of buoy at a FE race and I have always wondered why? Anybody help.. Maybe I am missing something?

Anywho…

ROCK ON

Grim

O yea.. one more thing.. the club paints the buoys.. the reason this is done as when struck it leaves a paint witness on the boat.. great info if needed for the CD.. Just make sure you clean it off before the next race..

[Bill-SOCAL]

Which brings me to the dumbest rule in all of NAMBA, that brushing a buoy is the same as cutting it.

Maybe the solution is to make them absolutely solid so if you hit one you sink!!! Touching it ends the race for you anyhow in most instances since you lose a full lap (another thing I do not understand, why not a points penalty, but ONE FULL LAP!! - WOW)

[Fluid]

The one lap penalty was originally to keep drivers more focused and paying attention to the position of their boat on the course. With only a 50-point penalty some racers would cut a buoy to win too. While I prefer the 50 point penalty I'll abide by the sponsoring body at each race.

Bill, I do not know where you found the NAMBA "rule" that brushing a buoy is the same as cutting it. Here is what the rule book says:

DRIVING RULES AND REGULATIONS: D.3.a.
"A one lap penalty will be assessed when a boat cuts inside a course marker or
when the boat jumps over or makes an obvious hit on a buoy. No penalty will
be assessed for a boat that touches a buoy on the outside causing no damage
or displacement.'

You are not alone in ignorance of this rule. I remember an out-of-town racer who was assessed a lap penalty at an FE Nationals because a local turn marshal "heard" his boat hit a buoy....he did not see it but the CD still allowed the penalty - after the end of the heat! Now THAT was BS.....



.

[Bill-SOCAL]

Every NAMBA race I have ever been to, including the 2008 FE NATS used that as the rule. A touch is the same as a cut. I think that kicker is the interpretation of "displacement". People see that as meaning if the buoy is seen to move, even bobble in place, then it violates the rule and gets the one-lap penalty.

This contradiction in this is apparent, saying that the buoy was brushed but not displaced is the same thing as saying you can touch it as long as it doesn't appear that you have touched it.

I guess I need to look closer at the book and challenge that rule the next time. I guess we will need clarification on what constitutes "displacing" the buoy. To me that means moving it out of its location, not just making it bobble in place. Your wake displaces the buoy as well. See, the devil is in the details.

Jay wrote:

You are not alone in ignorance of this rule.

Sadly nearly every racer in my District shares my ignorance. Or at least shares my inability to distinguish between a touch and something more.

FWIW I just sent off an email to AL Waters (NAMBA President) asking about this. Basically where is the line between touching/brushing and "displacement"?

[AndyKunz]

It's at the discretion of the CD.

Andy

[Bill-SOCAL]

Andy is correct. As I said, I sent an email to Al Waters, the President of NAMBA. Here is his response.

Bill,
You are reading the NAMBA rules. Here is one for you. D19 rule since 1991 is
no brushing or touching.

You typed................
************************************************** **************
Every race I have been to interprets this rule to mean that if you touch
a buoy then you have displaced it thus you get the penalty.
************************************************** *********************

Not true.......if you have displaced a buoy then you have touched it. You
have it backwards. Displaced means that it is in a different location than
its original location. It is then up to the CD to determine if it was done
by the boat or the boat wake. Buoy penalties are no different than jump
starts.........it s discretionary call by the CD.

If you don't want to get called for a jump start, don't be so close to the
start line.....................If you don't want to get called for a buoy
penalty, don't get too close to the buoys.........

Thanks, Al

Al missed that I was asking about the general NAMBA rules. Here in District 19 Jay, we have this rule:

3-91 Brushing or touching of buoys will result in a lap penalty.

So in my District we follow the most restrictive possible interpretation of it. hence my earlier statement that I have never been to a NAMBA race that does not use the you touch it you get a penalty rule.

[Doug Smock]

Tough crowd Bill!!

[Ub Hauled]

I was thinking about "the hop"...
Tony's UL did the same thing in the beginning,
looking back I believe it was a combination of factors...
first it was a little lose and started flying and then the first sponsons
would take off and land hard rebounding and throwing the hull to the other side
and so the hop started, violently like described earlier. The reason
it started bouncing side to side like that and get worst, is because the
turn fin would hit the water at an angle and push the hull
up to the other side again and then the vicious cycle would start
over and over again... if you can keep her nose down this dance
probably would not happen.

just my shot at it...

[properchopper]

We'll see how Darin's G-10 ride-pad addition affects things Sunday [early]. I agree with Jeff that torque reaction has a large contribution to the dance ; the three blade 40/57/3 should help as I evidenced last Sunday ; also the stock driveshaft has a lot of windup/rebound so I'm running a stiffer Octura
.150 which has far less of this.

[LuckyDuc]

Being a noob to FE boats I have a question... I've been flying helis for quite some time now. Has anyone incorporated a gyro and 'elevator' to assist with keeping the hull stable on the water? If so, how has it been successfully applied?

[Ub Hauled]

the response times are not fast enough... it has been thought of though.

Tony, I'll be there...