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Building the Victoria - Radio

[Editors Notes last updated January, 2004 ]

Using a Standard Servo

by Hal Slentz-Whalen  (Written 1998 or 1999 or so)

I like the standard winch (Futaba 3303-without bearings) [Ed Note: I've never found a Futaba 3303 referenced anywhere, so I don't know what Hal was referring to, the standard servo (not winch) is called a Futaba 3003] because it is fast (full out to close hauled speed, S-125 [Ed Note: Now discontinued] was twice as slow), and initial purchase is about 1/4 the cost. Has enough torque to hold in the sails close hauled into a breeze that will lay the boat over...but not pull out the sheets. I have seen this happen (a strong breeze pull the winch servo arm out), however, on batteries just about to quit ...which leads me to my first point.

BATTERY PACK VOLTAGE ON-BOARD = TORQUE OR WINCH STRENGTH.
Therefore, Use alkaline AA batteries (even the cheap "Price Club" generics put out 1.6 volts new). I have observed an almost insane desire in one club I've raced against to use RECHARGEABLE batteries for their on-board radio receiver / servo battery pack. Those RECHARGEABLE (nickel/cadmium) do not put out...voltage is low to start with and rapidly dies out. ALKALINES ARE KING...they start strong and hold their voltage for a long time (I've sailed hours on 4 AA batteries in the boat--the hand held transmitter batteries last four times as long). [Ed note: this was written before the advent of 6v NiMh RX rechargeable packs which now  offer much greater staying power than Alkalines and cut annual battery costs tremendously]

I've used my Hobbico Digital Voltmeter for these readings and have estimated that the voltage range of alkaline batteries in the 4-battery on-board pack will stack up against nicads pretty much like this (THIS IS NOT SCIENTIFIC BUT ACTUALLY JUST MY ESTIMATES--NOT REALLY READY FOR "CONSUMERS REPORT", JUST A QUICK RESPONSE TO YOUR QUESTION):

Alkalines:

1. Duration period 0-60 minutes @ 6.4 volts-6.0 volts
2. Duration period 61-120 mins @ 6.0 volts-5.8 volts
3. Duration period 121-180 mins @ 5.8 volts-5.6 volts
4. Duration period 181-240 mins @ 5.6 volts-5.4 volts

Note: advertised 1.5 volt batteries actually are 1.6 volts. The above voltage is the product of 4 batteries "in series" = adding together the voltages
 

Ni-Cads:

1. Duration period 0-15 minutes @ 6.0 volts-5.8 volts
2. Duration period 16-30 mins @ 5.8 volts-5.6 volts
3. Duration period 31-45 mins @ 5.6 volts-5.4 volts
4. Duration period 46-60 mins @ 5.4 volts-5.0 volts

Note: advertised 1.5 volt batteries actually are 1.2 volts (OR LESS EVEN NEW). The above voltage is the product of 4 batteries "in series" = adding together the voltages) [Ed: note: many folks use 5 cell packs now]

It is my contention that (even forgetting the ease of not messing with all the recharging ritual) alkalines immediately give superior performance to nicads which make the Standard Winch totally useable and even tactically the quicker beast (even putting cost aside). As to cost...NICADS can run $15-$25 for four rechargeables (which over the months due to "Memory" get weaker and weaker)....compared to buying up to 80, repeat 80, double "A" alkalines at Price Club for $16. Let's see 80 divided by 4 batteries per load in the boat = 20 reloads or about 80 hours of sailing!!! THAT'S VALUE WITHOUT THE FUSS OF RECHARGING. Don't get me wrong...I still use rechargeables in the R/C electric cars...

[Ed note: Prices have changed, a 1650 mAh 6 v 5 cell pack now costs about $20 and mine have lasted over 2 years charged with a standard wall transformer type R/C Charger]

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Sail Servo Wiring

by Bill Petynia

Here's something we learned from our CR-914 experience and I am using with the Victoria.

Adding a jumper wire between the battery (+) lead and the sail servo will increase the sail servo power since it does not experience the loss going through the receiver. I also added a jumper between the black leads, but it probably isn't necessary. When using a 6-volt battery, the sail servo torque will be increased nearly 30%. Unfortunately, with a 4.8-volt battery the increase is only about 10%.

These values are for a Futaba S-3801 sail servo. I am using a Futaba S-125 [Ed Note: Now discontinued] in the Victoria but have not measured the increase for the S-125. I will do so, but would expect similar increases.

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Selecting a Radio/Servo

from VRC Forum

Brad Meilink:

I have ordered a Futaba 2VR 2 Channel/ with S3003/S125 Servos from Tower Hobbies to go with the TT Victoria purchased as a Christmas present. Trouble is that the radio set is back ordered until who knows when! I'd like to get started with the assembly of the boat but, right now I am waiting on the radio and servos before proceeding.
Any suggestions for an alternative set up? (Also, Tower now shows the S125 servo as DISCONTINUED)

 

Steve:

Get the Futaba Radio with the standard servos, 2-S3003, and buy one of their TS-65 servos $29.95 for your sail servo. It works just fine in my Victoria. Check out the how-to section of the Victoria web site for information on servo wiring and running rigging, I make a six inch arm servo arm, and run the mainsheet from one end and the jib from the other end, worked great and much less friction than the Kit set-up. I drilled holes every half inch so I can match the travel to the sails.

 

A.J. Moritz:

The radio package you have ordered is the ideal one to go with. Particularly for package price you get when you purchase the complete package.
Steve has made an excellent recommendation. Still another alternative is to check with your area hobby store. Most hobby stores can get other routings (distributors) for the same radio package you have currently on order. If that doesn't pan out, you buy a std 2 channel out of their stock, for computability issues, I would stay away from Airtronics brand. There is a great servo that works as well as the Futaba S125 [Ed Note: Now discontinued]. Its the Cirrus CS-80, its just a little smaller than the S125 but it has virtually the same performance at about 1/2 the price (29.00). For a rudder servo, any equivalent to Futaba 3003 (S-148) will work fine.
The control arm in the VRC HOW TO will work with the Cirrus horn or the TS-65 that Steve recommended.
What ever servo/winch you select, make darn sure you tighten the center horn screw as tight as you get it or it will strip out the mounting horn male insert on the servo.

 

David Goebel:

Brad, I only have 6 Hitec 2 channel systems and I'm very happy with all of them. I'm using them on my Victoria, my Soling 1m, R/C Laser, Marblehead and 3 other boats. They've worked great for me in all cases. I recommend the Hitec 615mg servo or the Cirrus CS-80 they work just great.

 

Tom Causin:

I was in the local Hobby shop today and found a NEW Futaba 3802 servo. Tower has it for $59.95. It is smaller than the S125 [Ed Note: Now discontinued] and a little faster and has a higher torque rating!. Check out TowerHobbies. They have the info on the new servo (Futaba's site has NOT been updated as of 7/21. Futaba is back in the game. Other servos of note are the Cirrus CS-80 which cost much less

 

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Here's a list as of Sep 2002 that Carl Vogt compiled

Cirrus

CS-80MG PRO These servos have not one but three metal gears that really take a beating in the dirt! The output gear is supported by dual ball-bearings for precise control and efficiency. SPECS: 1.60 x 1.49 x 0.79 2.01oz ( 57g) .25 sec/60 deg 130 oz/in (9.4 Kg/cm) Ball Bearings

Tower Hobby

TS-65 This is the Standard High Torque Servo from Tower Hobbies SPECS: Torque: 77 oz. in. Dimensions: 1.6"x 0.8" x 1.5" Weight: 1.73 oz. Connector: JR/Hitec Plug Speed: .16 sec @60 degrees

TS-80 TS-70 Super-Torque Metal-Geared Ball Bearing Servo SPECS: 4.8 Volts 6 Volts SPECS: Speed: 0.24 Sec 0.20 Sec Output Torque: 106.7oz/in (7.7kg-cm) 133.3 oz/in (9.6kg-cm) Weight: 2.11 oz (60g) Length: 1.59" (40mm) Width: 0.77" (20mm) Height: 1.48" (38mm) Signal Pulse: Positive Pulse Control 1520us Neutral.

FMA Direct

PS905MBB The FMA Direct PS905MBB is a heavy duty, metal geared, dual ball-bearing servo suitable for use in large airplanes, cars, and boats requiring high torque and the impact resistance of metal gears. This is a standard mounting size servo with nearly the same dimensions as the FMA standard S300 series but with a beefed-up case and over 305% more torque.

Specifications: Dimensions - 1.59"L X 1.59"H X 0.79"W; Weight is 3.0 Oz; Torque is 110.0 In. - Oz. @ 4.8 V and 135 in-oz @ 6V; Transit time for 90 degrees is 0.34 sec @ 4.8V and 0.27 sec @ 6.0V; Mounting is by four-point shock mount. Double ball bearing output.

Futaba

S3802 This is a High Torque, Arm-Type Sail Servo with a Metal Output Gear for Sailboat Applications. This S3802 is the replacement for the S125 servo

SPECS: Length: 1.73" Width: 0.91" Height: 1.69" Weight: 2.54 ounces Sail Arm Length: 125mm Torque: 122.1 oz/in @ 4.8V - 153 oz/in @ 6V Transit Time: .70 sec/60° @ 4.8V - .55 sec/60°@ 6V

S3003 The Futaba S3003 Standard Servo that replaces the S148 servo. This basic servo is used in cars, boats, or where standard servos are used

SPECS: Speed: 0.23sec/60 degrees at 4.8V Torque: 44.4 oz/in (3.2kg/cm) at 4.8V Size: 1.59"L x 0.78"W x 1.42"H (40.4x19.8x36mm) w/o output shaft Weight: 1.31 oz (37.2g) Connector: "J" type with approx. 5" lead

Transmitter Modification

from VRC Forum

sgood@gte.net

Can the springs that hold the sticks on the Futaba 2ER transmitter be removed to provide a more of a "free form" movement?
If so, I would appreciate your preferences on which stick(s) to modify.

A.J. Moritz

It's very easy! Open the transmitter casing, usually the back of the radio will have the battery compartment enclosed and there will be a couple of wires attached to the battery compartment area and the circuit board on the front half of the radio. Separate the 2 half's enough so you can gain have access to inside the front half.

Locate the sail servo (winch) control stick. There will be a small spring attached to small arms that keeps the stick in a neutral position. Remove the spring, don't worry about the arms if they seem to flop around or even detach from the stick-casing mechanism. After the spring is removed, the stick will have free action. Put the radio back together. When the stick is all the way towards you (down) that will be your close haul position (sails all the way in).

David Goebel

I believe Futaba offers the same ratchet plate for the throttle servo stick (which would probably work on the rudder servo stick too) that Hitec does. These ratchet plates are added per the manufacturer's guidance and allow the stick to be set in a position and not move.  I've tried a Futaba without the ratchet plate and it's pretty fluid movement.
Most folks I hear from leave the horizontal stick as a spring loaded self centering rudder stick, and put a ratchet on the vertical moving "Throttle" or sail control stick.
Here's some pictures of Hitec radios with the ratchet:
 
Old Hitec Challenger radio:

Newer Hitec Ranger IIz:

Tom Causin:

If you look at the Tower Hobbies Radio section, you will find "tech notes" attached to the description of the transmitter. Under the description, you will find a part # that you can go through tower or take to your Hobby Shop to get the correct part. I've done it to the HiTec transmitters and I know Futaba makes one as well. don't just remove the spring you will regret it! Your local Hobby shop will get it for you!!

Rick Moynahan:

Okay Tom, I give? Why would you regret taking the spring out of the transmitter for the sail control?

Patrick

I think Tom's comment regarding the spring was intended to encourage sailors to modify to a ratcheted system which most radio makers provide. The gives improved control over the sail servo as it is less likely to move off of your setting by accident.

Another problem related to this is that the coarse adjust control moves when the trim tab is adjusted if there is no ratchet on the stick.

Tom Causin:

Awesome pickup Rick! At least SOMEONE reads inside the lines. I could have added that the spring keeps tension on the stick. Without that tension you cant give your thumb a rest (as stupid as that sounds) it also provides the ratchet clip some pressure to help it function. The sail control stick doesn't become mushy!! Just little points.

 

But, I've gone to the trouble of putting them in my xmitters and I've sailed boats without them. It does make a difference. The next time your in the shop or on an order sheet from tower, plunk down a couple of bucks and get two sets (one for the guy who didn't get them! ).

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Remote Receiver Switch

from VRC Forum

Jim

A 1/16 in. brass rod with a short 90 deg bend inserted into the predrilled hole in the Futaba switch, lead straight out the inboard hole on the port side of the cockpit bulkhead with a bead glued on the end is makes a good remote switch.

Mike Duggan

Hi everyone, Here is what I have done to solve this irritating switch issue. I have removed the manual switch from the battery line and installed a micro miniature reed switch commonly used in the household alarm business. I have epoxied this to the bilge (centerline)(they are environmentally sealed) I use Tony Pardinas' stand and have sewn the magnet into the underside of the seat canvas directly below the spot in the hull where the reed switch is located when the ship is in the stand. The reed switch I have used is a normally open contact in the presence of a magnet. So when I set the ship in the stand the magnet trips the reed and opens the battery line effectively shutting off the receiver. No drilling holes in the hull, no complicated manual wiring, and most important; no opening the hatch. If anyone is interested I would be happy to post the details (part information and ordering info along with a diagram).

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