Monofilament Line has Come off the Drum

Monofilament Line has Come off the Drum

The monofilament line is the nylon-looking line that runs from the sail servo drum up and around the bow roller. It looks simple. One track (groove) of the servo drum takes in the line while the other track lets it out. The line runs up and around the bow roller. The moving knot where your mainsheet attaches runs the full length from drum to pulley.

You are highly unlikely to encounter the problem of the line jumping off the drum; there are two ways that can happen – one is that you had the line jump off the drum while in service because it was too loose, or misadjusted ? the other is you had the drum off greasing the servo post, and it got away from you.
It is a bit of a process to get the line back where it should be but if you follow the following steps it should be reasonably straightforward;

Step 1 : Remove the drum from the servo post. Take the screw out of the centre of the drum, and then pull up on the drum and it will slide off the top of the splined servo post. You do not need to remove the bridge over the drum to do this.

Step 2 : Now, untangle the lines – but do not untie the end knots that are in the centre of the drum. When you have the lines straighten out, and all loops on the drum removed, orient the drum so that you are holding the line taut and the drum is right side up. You can identify the bottom of the drum by the splined seat for the servo post. You should now be holding the drum right side up with one line leading forward on each side all the way to the bow roller and no wraps on the drum.

Step 3 : Wind two wraps of the port line clockwise around the bottom track of the drum. Then wrap two turns of the starboard line counter-clockwise around the top track of the drum. Hold the drum so the line stays tight as you are doing this.

Step 4 : Being careful to hold the drum with one finger on each side to keep the line on the drum, hold the drum over the servo post like you were going to install it. If both sides of the line are taut, you are ready to reinstall the drum. If not, take another wrap on one line, or the other, until you position the drum over the servo post.

Step 5 : Now you need to get the knot in the monofilament line (that you attach the mainsheet to) in the right place. Turn on the transmitter and then your boat. Put the left control lever on your transmitter in the full trim position – usually down. Slide the trim tab for that control all the way in the same direction you have just moved the stick (usually down). The winch will turn until it stops at that trim point (full sail trim). Carefully turn the drum in your hand (being careful not to let the monofilament get loose again) until the monofilament knot is just about touching the bow roller housing (12mm at the most).

Step 6 : If you you run out of monofilament on the top drum track before the knot gets to the bow roller housing, simply add a wrap of monofilament counterclockwise on the top track, and unwind one wrap on the bottom track.

Step 7 : Install the drum on the servo post. Note – put a good amount of vaseline in the deck hole around the servo post where it comes through the deck, and a little in the flat space on the deck where the drum will sit before installing drum). The line should be taut when the drum is in place.

Step 8 : Test the travel of the monofilament knot. Using the radio controls, the knot should go from just about touching the bow roller, to just about touching the drum itself. If not, lift drum carefully and turn one way or the other slightly and reinstall until you get the knot travel correct. It is very important that the knot has no way to reach either the bow roller housing or the drum.

Step 9 : When you put the drum on, the lines should be very tight at first. After you run the servo lock to lock a couple of times, the line adjusts itself better on the drum. The line should end up being quite taught, like a base guitar string. Better tight than loose. If it is loose, see instructions below.

Step 10 : Replace the screw in the drum and you are ready to go.
If you are installing a brand new line, then see Replacing the Monofilament Line below for information on installing the new line, tying the end knots, and adjusting the length of the line. Then return here to wind it and adjust it.

Replacing the Monofilament Line

If you need to replace or tighten the monofilament line, or need to tighten it, there are a couple more steps.

Step 1 : Install the monofilament line through the bow roller. If you are installing a new line, tie the knot in the right place (measure from your old line). Then stick one end of the line through the bow roller so that the knot is on the right (starboard) side of the roller. Run the two ends aft to the drum.

Step 2 : With the drum off the servo post, stick the right line into the hole in the top track (from the outside in), and loosely tie a knot in the end. Put the left line through the hole in the bottom track and tie a knot.

Step 3 : From here, follow the steps in ?Monofilament Line has Come off the Drum? above. In step 4), if you adjust the wraps to get the drum close to where it will fit on the servo, but the line is too tight (can’t reach the servo post), you need to adjust the end knots closer to the end of each line. If the line is too loose, and taking another wrap around the drum is too much, then you need to pull the line through the hole more and tie the end knot to shorten the line

Leave a Reply