HiTec Electronics Upgrade for Nirvana
What you get
This is a new radio system from Hitec featuring many components that we have used for years, but with new technology in the transmitter. This transmitter only uses 6 AA cells, and yet has the power of the previous 8 cell unit.
Top from Left to Right - Receiver (red), Battery holder & switch harness, steer servo (red horn), sail servo (white horn). Bottom L to R - Transmitter, Antenna, Bag of horns & mount screws for servos.
Note: This battery holder is plugged into the switch harness so it can be unplugged for charging or service. The switch is heavier duty.
The receiver is packed in a stronger protective box. The sail servo is metal geared and has the same power as the standard MT servo. The sail servo arm that comes with Nirvana fits this servo but should be modified during installation to provide a stronger hub. Everything fits into the standard Nirvana compartment with one minor modification.
Tools and materials needed: #1 Phillips head screwdriver, X-acto knife, Sanding block, 100 grit sandpaper (1 sheet), CA glue, Drill motor and drill bits (1/16"- 3/16"), Dremel tool (optional).
Remove MT electronics - You will be replacing every electrical component in the Nirvana, so start by removing all components from the boat. Keep all servo mounting screws and leave the sail servo arm with the sheets run through the roller.
Modifications - There are a couple of modifications to the compartment that are best done at this time.
2) Switch mount - Cut installation hole on left side of upper platform for Switch. See instructions below. Note in photo above, the new switch holes are drilled (old ones in lower left corner).
3) Antenna Hole - Drill a 1/16" antenna exit hole in the back wall of the compartment in line with the inner edge of the cockpit seat bench and 3/8" down from the lip of the compartment. See photo below.
Note drill sticking through antenna hole on the right. It is drilled in line with the inner face of he cockpit seat, and 3/8" down from the lip of the compartment.
Install the switch - Temporarily sit the sail servo in place, and then take the "on-off" plate off the switch and lay on the platform to the left of the sail servo - location as shown in photo. Mark the holes and the opening with a pencil.
Drill screw holes with 5/32" bit. Drill each end of the center cut-out with a 3/16" bit to remove the majority of the cut-out. Then use X-acto knife or small file to square the hole. (Squaring not done yet in photo above)
Install the switch from the bottom with the small pigtail (red fitting) facing the center of the boat. While holding the switch in place, put the "On-Off" plate on top of the platform with "On" to the left. Install the screws.
Battery Holder support - Install a 1/4" piece of foam, or other material, to elevate the battery holder above the compartment floor. The support piece can be glued to the floor with rubber cement or CA glue. The support should be no larger than the size of the battery holder and positioned so the right end aligned with the right side of the opening for the battery holder. Do not install the battery holder at this time.
Install Servos - No modifications need to be made to the servo mounts. Remove the horns from the servos. Note that the screw in the steering servo (red horn) is a coarser thread than the one in the sail servo. It is important that you remember which is which when you come to reinstalling the servo arms later in these instructions.
Using the screws from the original servo mounts, install the two servos with the spline posts mounted to the left (see picture). Do not install the servo arms at this point.
Install Receiver - Before installing the receiver, thread the antenna wire though the hole drilled in "Modifications" step above from the inside out. Then plug in the two-wire plug coming from the left side of the switch into the "Bat" socket with the black wire to the right. ("Right" when reading information on the face of the receiver) Install the wire coming from the Sail Servo into the "Ch 1" socket (black wire right), and the wire from the steering servo into the "Ch 2" socket (black wire right).
Now turn receiver upside down with the wire sockets to the front and down. Tuck all the wires down into the cut-out. Insert the bottom right rear edge of the receiver just to the left of the steering servo mount feet and rotate the receiver flat wedging it between the steering servo and the side wall. (See finished picture below) The receiver will go down flat but will probably pop up when released. Make sure all wires are down into the lower section of the compartment and not caught under the receiver.
While pushing the receiver flat into position, draw a line along the left wall of the compartment at the top of the receiver. Remove the receiver and drill a small hole at a sharp down angle so that when it goes through the wall of the compartment it will be below the caulk joint with the side deck of the boat. Hole size depends on the screw you have to use. Reinstall the receiver and run a small retainer screw down into this hole to hold the receiver firmly down in place.
Photo above shows drilling receiver retainer screw hole at steep angle so hole will exit below deck.
Photo above shows retainer screw in place.
Boat Batteries - mount four batteries in the battery holder. Plug the battery holder into the plug leading to the switch. Install the battery holder with the wires underneath, but not directly under the holder and make sure that the plug is kept up near the top of the holder to keep it well out of the bilge. Make sure the switch is "Off".
Photo above shows battery holder in place with red switch plug remaining up high so it does not get wet in bilge.
Transmitter - Note that the left lever on the front, used for sail control, is spring loaded to center. You must remove the spring on the lever housing inside. Unscrew all six screws in the back of the transmitter and open case carefully. Identify the spring on the left stick mechanism and remove with a pair of tweezers. Close case and replace screws.
Open battery compartment. There are two plastic "shunts" to the left of the battery case. The lower one is marked "Ch 2". Pull the Ch 2 shunt off and reinstall on the right two wire prongs. Install 6 batteries in the compartment and check to see that the red light goes on when you turn the switch on.
With the transmitter switch on, turn on the boat switch and check for operation. Turn boat off and then the transmitter off in that order and proceed.
Install Servo arms (horns) - In the accessory pack in the radio kit you will find a black arm. Drill out the 3d hole from the end with a 5/32" bit. Remove the old steering arm from the steering wire, and thread the steering wire into the enlarged hole on the new arm from the top. Do not install on servo yet.
Sail Servo Arm modification - You can do this step without removing the sheets from the roller at the end of the arm. Remove the bottom hub socket and springs from the sail servo arm. Then grind off the inner well, and the side walls that housed the springs leaving the round hub section of the arm the same thickness as the rest of the arm. In photo below, Right is before, Left is after grinding.
Take the white circular horn that was on the sail servo and temporarily install from the top down through the hole in the arm hub. This is not a tight fit, but not to worry. While holding the parts together examine inner well and old spring stops to make sure they are cut down lower than the white hub socket. If not, when the arm is installed, these sections will contact the top of the servo and bind up.
Once the bottom has been modified, sand the top of the arm in the round area where the white horn will be glued. Sand the white horn where it will contact the arm. Using CA glue, glue the horn into place with the spline hub facing down. When dry, choose a hole in the horn that is most in line with roller on the arm and drill all the way through and install one screw for extra strength. Grind off end of screw where it comes out the bottom. Do not install arm on servo at this time.
Install servo Arms - Turn on the transmitter and then the boat. Move the left (sail) lever on the transmitter all the way down, and the fine tune slider all the way down.
Line Shield - I highly recommend the installation of a shield under the sail servo arm and above everything else in the compartment. See photo below of one made from a plyable cutting board (thin plastic sheet). Cut it out so it fits close to the compartment wall all the way around, and cut out so it will slip around the shaft of the sail servo. Trimming with scissors will allow it to fit firmly in place. This installation will protect the sheets from becoming entangled in the items below, and also baffles any water entry off to the sides.
Photo above shows plastic shield in place. Slip in from rear, note cut-out around the sail servo arm. This picture also shows a different sail servo arm modification using a trimmed red servo horn.
Antenna Mount - My recommended antenna mount requires that you reinstall the backstay so that it is tied to the stern fitting on the boat with the hook and tension bowsie at the top (hooks into masthead fitting). So you will, in effect, be reinstalling the backstay upside down. Read the rest of this section before actually reinstalling the backstay.
The antenna exits the electronics compartment at the front end of the left seat board. Take a little slack in the wire as it exits the compartment and then tuck the antenna under the edge of the seat board all the way to the back end. From there thread the antenna through the hole in the backstay deck fitting as shown below.
Picture shows red antenna wire exiting from under edge of seat boards then over to backstay deck fitting.
The best way to attach the end of the antenna along the backstay is by using a bowsie (like the one that adjusts the length of the backstay). However, to use this fitting, you need to thread onto the backstay before tying to the stern deck fitting. Then thread the end of the antenna through the 3d hole, and tie a simple knot. When the bowsie is moved along the backstay to tension the antenna, it will stay put.