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Servo

PostPosted: Sun Nov 02, 2003 8:56 pm
by Skip Quinn
Could someone tell me what I need for a rudder servo. Is a Hitec 303 strong and fast enough? Thanks Skip

Skip

PostPosted: Mon Nov 03, 2003 6:00 pm
by Capt. Flak
I use a Futaba 3802 sail servo. I originally did this by accendent. I missunderstood some advise I was given and purchased the servo for both my jib trim and rudder. The advise was not intended for the rudder. What happened is that my rudder is slow compared to most everyone else. It takes about 1.1 seconds for it to travel from center to hard over. Or about 2.2 seconds to go from full right to full left. I find this to be great for me. It prevents fumble fingers and the boat reacts more like the full size boat. If you are turning your rudder any faster, you are probably putting the breaks on. The torque is more than enough and I might be adding a tad more weight than other servos. But this was one mistake that has turned out to be a good one.

I have won over a few people to the idea as well and they have made the switch to the 3802. Their sailing has improved.

A fast rudder servo is not always a good idea. High torque however is always good if you ask me.

Joe Walter #24

PostPosted: Mon Nov 03, 2003 8:47 pm
by Skip Quinn
Thanks Joe. Skip

Skip

PostPosted: Fri Nov 07, 2003 2:46 am
by Rick West
Skip, the move in the last year has been to servos with over 100 torque. Such servos will reduce, if not illiminate a spinout downwind in a stiff breeze. if you make this move, be sure to read the Phantom series for the scoop on input voltages on the system.

When you get one running, you will like it a bunch.

PostPosted: Fri Nov 07, 2003 7:48 pm
by Skip Quinn
Thanks for the advice Rick. Skip[8D]

Skip

PostPosted: Fri Dec 19, 2003 8:07 am
by lee krusienski
I use a Futaba S9202 wich is rated at 70 inch/ounces at 6V. It is very fast and responsive and strong enough for all conditions. It costs around $55

PostPosted: Sat Dec 20, 2003 10:16 pm
by Rick West
I agree with you Lee. The 9202 works well for the rudder. The Hitec 645 is fine too.

PostPosted: Fri Feb 27, 2004 2:53 pm
by Tom Causin
I found the FMADirect servo ps705MBB
It has 106 in./oz of torque. Its $28.95
FMA is hi quality
It look to be good for Jib trim as well as Rudder



https://www.fmadirect.com/site/Detail.h ... &section=8

Tom Causin
Ashburn Model Yacht Club

PostPosted: Fri Feb 27, 2004 8:22 pm
by Skip Quinn
Thanks Tom. I'll check it out. Skip

Skip

PostPosted: Fri Feb 27, 2004 8:44 pm
by Doug Wotring
try www.servohut.com

they carry GWS servos I got a bunch for club members at 11.50 each 11in/oz at 6v

PostPosted: Mon Mar 01, 2004 3:46 pm
by gcobley
Looks like there is a remaining disagreement in this thread, so I think I should stir it up a bit ;-)
Fast versus slow rudder servo/winch?
Fast would be needed to prevent "spin out" (broaching?) in heavy air downwind (see Rick's post)
Slow would force you to sail smoothly and avoid the rudder as a brake (Joe's Post)

My strategy is a fast servo with a switch to reduce the throw for light airs which makes it effectively a little bit slower also. Avoiding the rudder brake is mostly about a light touch though.

Gerry

PostPosted: Tue Mar 02, 2004 1:19 pm
by MichaelJ2K
A radio capable of either dual rates or expotential mixing can also work. Set the dual rate to approximately 1/2 to 3/4 of the total throw. Or, set expo to keep the rudder movement slow with small stick movements. Moving the stick to the extreme allows the servo to speed up to control rounding up in a broach. FYI, I'm using an old Futaba S-28 on rudder. It works just fine.

PostPosted: Wed Mar 03, 2004 5:17 pm
by Capt. Flak
Gerry,

The slow rudder with the sail servo I use has no problem keeping up with broaches. If your rocking and rolling down wind, it is the size of the rudder and the torque behind it that will make the difference. Since the rudder has a maximum size and most everyone uses that, it comes down to torque. If you use a small servo with little torque, you will find yourself out of control a lot.

The slow speed of my rudder is not so slow that it can't deal with emergencies when needed. And I think it helps keep you under control in those cases better as well.





Joe Walter #24