What makes a mono act unpredictable coming out of a corner?

[Sean Bowf]

What makes a mono act unpredictable coming out of a corner?

Is this just tied to the hull?? Is there a common hardware adjustment that solves this problem?? Would a hook in the hull cause this??

This is NOT in reference to my boat...but been thinking about a boat another club member has.

Sean

 

[CMBrunner]

What makes a mono act unpredictable coming out of a corner?
Is this just tied to the hull?? Is there a common hardware adjustment that solves this problem?? Would a hook in the hull cause this??

This is NOT in reference to my boat...but been thinking about a boat another club member has.

Sean

The driver !!! :lol:

Not to be funny (OK, maybe a little).

Could you describe the problem a little better and with what kind of hull ?

 

[mark voorhies]

What makes a mono act unpredictable coming out of a corner?
Is this just tied to the hull?? Is there a common hardware adjustment that solves this problem?? Would a hook in the hull cause this??

This is NOT in reference to my boat...but been thinking about a boat another club member has.

Sean

The driver !!! :lol:

Not to be funny (OK, maybe a little).

Could you describe the problem a little better and with what kind of hull ?

I'll give you the top 4, but more info. would help. ( In my opinion)

1) driver

2) improper radio set-up

3) too little torque, in. oz. on steer servo.

4) rudder placement, depth

Been guilty of all four above,

and certain ones have helped.

 

[Sean Bowf]

I think it was an arrowshark hull, but would not swear to that. I am just trying to learn here, not trying to give any type of boat a black eye or anything.

It is a gas hull, and the owner said it might dart off when coming out of the turn (not sure which direction, never really noticed it during the races). He got the hull second hand, and I am not sure how closely the setup resembles any instructions that come with the hull (if any do).

I do know that I saw a delta force for sale (I am told the arrowshark is a knockoff of the DF) that had a long rudder bracket on it. I was told that this was an ideal setup for that hull (think it was a .21, but not sure). I noticed that most gas hulls I saw this weekend (to include the one in question) had the rudder's leading edge in front of the prop, and pretty sure, in front of the drive dog. But I have zero gas experience, so this might be exactly where it is supposed to be.

Sean

 

[waltr]

Another thought could be too much negative trim.

That can also cause it to bow steer by forcing the nose down.

 

[Ed Knudsen]

WOW ! What makes a Mono unpredictable? Over 20 years of building and racing mono's and "stuff" still happens I don't understand LOL. Darting out in the turns could be the nose of the boat burying to deep in the water. Marks comments are right on. Heres a couple more. You might want to look at the rudder blade angle as related to the bottom of the hull. Kicking it back will raise the bow in the turns, kicking it in towards the transom will push the nose down in the turns. Also with your transmitter, if it has this feature, slow down the steering servo speed rate to about 40/50%. Anyway "Arrowshark" is a Seducer somewhat look alike sold under different names = Prestwich,Delta Force,Lynx etc. Chinese.

You say "Gas" but then mention it could be a ".21". Won't be a .21 if it's gas. Anyway if you Google "Arrowshark boat" you will be able to get a ton of info,pics etc. Here's one site that shows a build sequence for the Arrowshark Flying Dragon

http://www.extcustoms.com/arrowshark.html

Even if the boat your asking about is not an Arrowshark a lot of this info would be applicable. I also suggest you register with Jims boat dock. Lots of gas help to be found there.

Hope this helps.

Ed

 

[Sean Bowf]

You say "Gas" but then mention it could be a ".21". Won't be a .21 if it's gas.

The comment about the .21 was me wondering if all of their hulls should be set up the same. In short, the .21 I saw had a very long rudder bracket, the gas hull had a very short one. So I was wondering what the affects of this were (longer and shorter rudder bracket)...and wondering if I am comparing apples to oranges by thinking that the hulls by the same company should be set up similar...even though one is a small nitro hull, and the other is a large gas hull.

In short, I was wondering if a short rudder bracket (rudder close to the hull) could cause the hull to be unpredictable coming out of the turns, or if I am grasping at straws.

Sean

 

[NAMBA860]

defenitly check the oz. rating of the servo. i wouldnt run anything under 100 oz. of torque

 

[TomMoorehouse]

unpredictable?
is the driver female?

ha ha good one Donkey.... we don't have any females on the forum that might be offended :angry:

I have banned people after they make 10 non constructive posts in a row before.... that pisses me off.

remember kindergarden rules.... if you don't have anything nice to say don't say anything at all.

 

[bzubee]

Check out the March issue of the IMPBA Roostertail and then look for Junes issue and Septembe's issue we are re-publishing John Finches past Mono set up articles and the articles tell all sorts of very good mono set up tips and what they do to help control monos.

www.impba.net

Bill Zuber

IMPBA President

 

[Joe Warren]

What makes a mono act unpredictable coming out of a corner?
Is this just tied to the hull?? Is there a common hardware adjustment that solves this problem?? Would a hook in the hull cause this??

This is NOT in reference to my boat...but been thinking about a boat another club member has.

Sean

BAD SERVO, The hardest work a servo has to do is Straighten the boat out after a turn. this is where you will see one fail 1st....... Low Battery voltage.(1 dead cell in pak) Servo torque Goes Up/down with battery voltage, Must use a cycle charger to find a bad cell or voltage meter. Loose fitting radio box in hull, or linkage to rudder not snug, Bent Rudder blade????? Wrong prop will also wet the hull up too much & Over load a Servo in the turns... Look @ IT CLOSELY, You will find the problem.

 

[BigChuck]

If IT is an ARROWSHARK!!!!

1. Bottom Not level

2. Trim Tabs are not level!!!

3. Trim Tabs themselves are not a level surface.!!

4. Plus everything else that has been said.

 

[Harald1966]

It is definitively not the (male) driver, Sean

The servo is an expensive Futaba with lots of torque. Speed is set to 15% on turn and 100% on return.

Have been playing with trim tabs settings but did not fin a perfect match.

This problem occures in low speed, so by increasing the speed in the corners the boat is still OK for racing.

The hull is a Arrow Shark with a (huge) 5/16 inch deep concave depression (hook) on one side and is straight on the other side. I have checked with other Arrow Shark drivers and they tell me that their hulls are straight, so I guess I have been unlucky this time.

This is a cheap hull and I am not going spend much time fixing it. I will buy another hull instead (A/C Razor).

A longer rudder bracket could maybe help, but the next owner have to figure it out...

Thank you for your input guys!

 

[Joe Warren]

It is definitively not the (male) driver, Sean The servo is an expensive Futaba with lots of torque. Speed is set to 15% on turn and 100% on return.

Have been playing with trim tabs settings but did not fin a perfect match.

This problem occures in low speed, so by increasing the speed in the corners the boat is still OK for racing.

The hull is a Arrow Shark with a (huge) 5/16 inch deep concave depression (hook) on one side and is straight on the other side. I have checked with other Arrow Shark drivers and they tell me that their hulls are straight, so I guess I have been unlucky this time.

This is a cheap hull and I am not going spend much time fixing it. I will buy another hull instead (A/C Razor).

A longer rudder bracket could maybe help, but the next owner have to figure it out...

Thank you for your input guys!

BONDO.... Will fix it.

 

[Harald1966]

BONDO.... Will fix it.

What do you mean???

 

[racerred]

Lay some bondo in the hook on the boat and make it like the other side just lay enough so it is very smooth.

 

[Sean Bowf]

Lay some bondo in the hook on the boat and make it like the other side just lay enough so it is very smooth.

Would the imbalance mess up the handling of the boat?? I mean, wouldn't it make one side of the boat heavier than the other??

Sean

 

[steelpad]

the weight of the bondo is not that high and we in holland use it too (maybe a different brand)

it will only helps the hull handle better in this case, and if the weight is pulling, well, just add 5 or 10 gr of lead in the other side of the hull to give it a stait line again.. but i think that will not be nessesery.

polyester filler is lightweight, of you are scared of it, you can take non drip epoxy gleu aswell(24 hours) only that will be much more work..

 

[Ron Olson]

Lots of things. It could be the the CG is too far forward also making it spin out coming out of the turns.

Yes, we do have a female or 3 in here. Misshydro, Cathy Preusse and the woman that has Twiggy the Water-skiing Squirrel but the last 2 aren't on here often.

 

[Harald1966]

OK, the problem is that this hook is so huge, deep and long, so it will cover the lists (don't remember the English word) under the hull. The way to fix it is first to cut loose the rails inside the hull before straighten the hull and epoxy it together, then use bondo. In other words, to much work for a cheap hull.