Internal Downhaul Recommendation

Those that have had both internal and external downhaul, can you provide the pros/cons of each and your recommendation?

What is the purchase of the internal DH? 8:1? 16:1?

The internal DH is 6:1 on the inside then when it comes out of the mast to a block on the sail it doubles it to 12:1.
I used to think that ext would be better (easier to see to make sure nothing is screwed up) but my internal works pretty well.
The internal keeps everything out of the way but it is a pain to replace anything (mast down, base off, trying to get the blocks out of the mast, rerig, get it back in without twisting it, etc).

From what ive heard:
Internal - if something breaks it is a huge PITA to repair or replace. Take that as a grain of salt as I have never dealt with internal. Much more cleaner less lines - less of a snag hazard.

External - I have a NON cascading 8:1 that could be converted to a cascading 16:1. I have not needed to convert to anything more than what I use, which is the 8:1

12:1 I think. Had to remove mine, rerun the line and reinstall. Less than 1 hour total. that was at home, boat in the garage. You'd have to add time for stepping the mast.

Never dealt with external.

I went internal and figured it out how to rig it right in there and I will never look back.

When done right it should provide you with many years of excellent and uninterrupted operation.

I was unluckly once where the line of the outside chaffed itself on a sharp egde on my gooseneck. One I missed whit my file when I build up the mast. It took me 90 minutes to get the mast of the boat, pop the diamond wires out of the spreaders, open up the mast. Stitch a helper line to the system, take the system out, replace the damaged line, close everything up again and step the mast. And I worked in a relaxed fasion.

I didn't feel it was a PITA. I have had no mishaps of any kind since.

Wouter

To disassemble the internal dh: remove the base plate; remove the through bolt from the mast; system drops out of the mast.

Okay and to install ... obviously the reverse ... but how hard is it to get the thru bolt to secure the internal mechanics?

Someone on the main forum said he managed to tape a piece of small line to the bolt as he pulled it out. This would function as a leader line. He could then thread the upper blocks back in easier

Removing it isn't a problem. . . <img src="http://www.catsailor.com/forums/images/graemlins/wink.gif" alt="" />

Trying to remember- it seems there was a short piece of tubing, internally, that the blocks hang from, and the bolt goes through the tubing. So, the problem is aligning the tube and the bolt holes. I think I just used a piece of electrical tape on the end of a batten to slide everything in place, and an ice pick to center the tube and the hole. It really wasn't that big a deal.

Damn! My memory is for [noodle}. Get everything set up: batten taped to tubing, drop the ice pick into the hole in the mast. Carefully slide the tubing into the mast until it contacts the ice pick ( a flash light would come in handy). Then, pull the ice pick out, tap the batten gently and the tubing should be partially aligned in the hole. Then use the point of the ice pick to finish the alignment. Drop in the bolt, secure the mast base and you're done. It is much simpler than it sounds.

I think that was me - certainly that's what I did when I had to do some work on mine. It's pretty straightforward: tape a bit of rope of a similar diameter to the bolt end-to-end with the bolt. Pull it through as you take the bolt out, put a knot in it, and then pull the innards of the system out the end of the mast.

To reassemble, simply pull the rope tight, and slide the bolt back through.

Paul

I like my internal downhaul.
I have run into some trouble with the internal blocks bottoming out on the mast plate and then disassemble is nessecary to correct. What I do now is make sure I have the downhaul line that attaches to the block on the sail pulled
all the way out before attaching to the mast. I also had the internal shackle come unscrewd once. The biggest PITA
I found was getting the screws out of the mast plate, they tend to seize in there so now I lube on reassemble.

Yep, I ended up having replace a set of diamond wires for the same reason. The had just welded themselves to the base plate.

I hate to say this but all these issues have been solved by others already.

Sometimes I find that builders have their own idea's, while the right setup is well known.

A few examples. When employing an alu base plate then use a simple alu blind rivet (not monel). You can buy a simple rivet tang and a score of these cheap alu rivets enclosed for 20 bucks. With some strength you can also rivet 4 and 5 mm monel rivets with this small tangs. One of the better investments for a sailor.

When taking off the base plate just drill off the head of the blind rivet and hammer out the remaining pin with a screwdiver and a hammer. Often one hit is enough. As it is alu on alu you don't get any corroding between the materials that jams up any stainless steel bolts or crews.

Pretty much the diamond wires hold the mast plate to the mast section and the rivet/screw is only hold the plate in place. It is not a heavily loaded items. Been used plain alu rivets for 4 years now and I have no issues what so ever.

Shackles inside the mast, when fitting them secure them with a small wire, glue them or damage the end of the threading. All will prevent the shackles from becoming undone. When you need to take them off later then a simple hand "steel saw" (English ?) is enough to cut through the shackle in about 2 minutes. Shackles are inexpensive and so destroying one every 4 to 5 years is not much of an issue.

Diamond wires, Don't copy the A-cat setup where the terminals are threaded and placed through wholes in the base plata with only two nuts holding it in place. A-cats all use stainless steel base plates and stainless on stainless works, but stainless on alu doesn't, the latter jams up. Also you can't adjust the diamond wire tension on the A-cat setup unless your drop the mast and take off the diamond wires. This is a PITA. It is much better and only 30 bucks more expensive to use the setup as shown in the picture below. Also note the small 4 mm alu blind rivet !





Advantages, I can always replace my diamond wires without much effort and I can even adjust my diamond wire tension with the boat fully rigged. I have done the latter now several times. Just grap a spanner and a smaller screwdriver and turn the turn buckles. By the way, the bottom threaded (stainless) claw does jam up in the alu base plate, but in this case that is what you want. Now it can not turn with the turnbuckle when you adjust the settings. Also it can remain there forever as I can replace the whole diamond wire setup but just unscrewind the turnbuckle housing from the claw. This setup allows continious use of the alu base plate, which is cheaper then the stainless one (I'm told) and adds more to the mast step height then the thin stainless plate. Also this alu casted baseplate doesn't discolour or corrode as stainless. Overall it is a better alternative this way.

Also note the ronstan cleats for the internal downhaul line. ONLY use the RONSTAN cleats here, all others just don't work as well. The line guard of the RONSTAN cleat allows the line to be cleated and uncleated even it the line has an angle in the horizontal plane of 30 to 45 degrees. No other cam cleat has that feature to the same extend. As a result it is not needed to use swiveling cleats.

Notice the small eyestrap ? That is were I tied my downhaul line off using a simple slip knot and a single hitch as security. Very easy to tie and just as easy to untie as it is a slip knot, even when it has experienced very high loads. You must ignore the white-reddish line in the picture. Its use was temporary. An added advantage is that I can pretension my downhaul at a minimal setting using this strap. As such I never reach the end of my downhaul system and I can just uncleat my downhaul when I want it fully off. I just place my slip knot at a different location in the line. No issues anymore with S-hooks straightening or downhaul maxing out. If I have to I can adjust the downhaul pretension on the water. Not during a race, but between races I can. It takes about 30 seconds to untie the slip knot and tie is back at a different pretension setting.

Anybody else notice the simplicity of my mast spanner ? That thing is plain hardware store alu square tubeing that I glued into a V shape and bolted to the base plate using the bolts of the cleats.

And the story continues, but I have to stop now. All these things have been covered on this forum in the past. For as good as all issues, a solution has been found. There is no need to still be hassling with faulty setups.

You know what I need to do sometimes ? Spend a day photographing all the solutions and how they need to be used and place them on the internet.

Wouter

I think I would like the turnbuckle also, but I haven't tried to adjust my diamonds yet. They are set up with the threaded end through the mast plate with a nut on them. I don't see how it would be a problem. Is the mast plate stainless on the blades? Can't say for sure.
I know the Blade manual recommends lubing the nuts on the diamonds due to the "cold welding" issue.
I will post a pic later

The turnbuckles shown use dissimilar metals in the housing and the threads as to prevent cold welding. These are intended to be adjust while under tension and won't seize up. The bare terminal threads and nutts do not have this feature and can seize up. An added issue with the latter can be that the threading is simply ripped of the terminals if the nuts are tightened. The bare threads/nuts setup doesn't have enough revolutions to spread out the load sufficiently. The latter is the main reason I'm told to detach your diamond wires before adjusting them.

I say :"Put a pair of turnbuckles on my boat, I think I can survive the added 150 grams (1/3rd lbs)and 30 bucks in costs"

Remember the saying ;"pennywise, pound foolish"

Wouter

Yeah that's a nice set up for the diamond wires. And yes more photos would be great.

Only trouble is, I now need a drill, hammer, rivets and a rivet gun in order to do maintenance on my downhaul system. Whilst I own all of the above, I certainly don't carry all of them with me.

Paul

I'm always impressed by the amount of stuff some of the guys I sail with bring along to our regattas. Has got me out of a spot a few times.

Me neither, they rest nicely in my toolcase for the time when I plan to do maintainance and then I bring them along. Like I wrote earlier. My downhaul system hasn't required any of these tools since early 2005.

In the past I have used an electic drill with a screw bit to drill off the heads of plain alu rivets (not monel !). These are really soft. A sharp knock on the back of the electric drill was enough to knock them out. I always have a supply of rivets, bolts, shackles and other small stuff like eyes and lines in my small emergency part storage case that travels with the boat. I only had to find a guy with a rivet tang to complete the job and that was not too difficult either in a club with 100 boats in the parking. I used to have a small rivet tang in this storage case as well, but then I tried to pop stainless steel 5 mm rivets with it one time. That WAS a job too large for that little tang.

Honestly these jobs are pretty minor and easily performed. They may well look daunting at first but when done a few times you'll learn they are pretty easy and quick. Blind rivets are a great invention.

Wouter

can someone mock up a diagram of what's going on inside the mast?

I, like DoubleT, didn't seem to get the amount of (max) downhaul I would have expected before not being able to pull anymore DH line.

I am trying to remember what I saw when I looked into the base of the mast recently but I only remember seeing two blocks up top and then the DH line coming in one side of the mast to a block then to the other side. This is diffrent than the int DH on my prev boat.
Sorry, no help. If I had my camera with me then I would have taken pics but it would have been difficult.

Here you are :



Wouter

yep, thats it.
I take it there Is a becket that the other end of the red line is attached to on the block inside the mast to the left

Yes,

Basically it is a three stage cascaded setup.

First stage (blue line) is a 2:1 with a nice soft 5 mm swiftcord line or something. You'll be holding this line in your hand.

The second stage (red line) is a small diameter and very flexible high tension line like 2 mm D12 or 3 mm dyneema. The purchase here is 3:1 making the total internal setup a 6:1

The third stage (green line) is a 2:1 system with a 4 mm dyneema line with a tough outer mantle. This is needed as it does rub against the goose neck or other components a little bit. And it is out in the elements (UV radiation etc).

The internal 6:1 setup followed by the outward 2:1 setup make for a 12:1 setup overall. By using the different line diameters this setup is cheaper and runs more smoothly then any other downhaul setup. This is especially so since most of it is inside the mast and thus well protected from weathering and salt.

Wouter

Thanks Wouter ... and the other end of the blue line comes out the opposite side of the mast.

Good Luck this week at the GC.

[/quote]

I'm interested in building this. The internal crosspiece will carry a huge load. Questions:

1) How far up the mast is the internal crosspiece?
2) Is that crosspiece really "Z" shaped? What is it made of? How thick is the stock material?
3) How is this crosspiece connected to the mast, rivets or a bolt all the way through?
4) The drawing is just a schematic. In reality, could one or two of the internal blocks be a double or MUST they be 2 singles to achieve the cascade effect? First, the 2 on the crossbar could certainly be a double, right? Although only one single is shown for the blue, there must be another that is not shown. Could that be a double? That one might be too close to work as a double, space wise. Hmmm... Wout?

The top blocks can be replaced by a double but the two floating ones must be independent. Think about it: as you pull on the downhaul the blue/red block goes down and the green/red one goes up. If you attach them together, nothing will work.

Why do you think there is another block for the blue line? It's just entering by one side of the mast, going up to the block and down to the other side...

On my Blade the "z" is a stainless steel bolt inserted through a piece of aluminum tubing, inside the mast. It is about 62" from the base plate.

Pictures follow.

another.

another

last one.

The comment about the other end of the red line is still a question. Going back to a Wouter post from 2005 I found this drawing.



I'm guessing that this is NOT what is the photo from THIS thread. PTP's comment above says a lot.
"...there is a becket that the other end of the red line is attached to on the block inside the mast to the left."

This latest setup is simpler and 12 to 1 compared to the old photo I've shown here.

David,

You are showing the diagrams of two cascaded downhaul systems that are on the OUTSIDE of the mast. Often seen on F18's. This is a 2-stage cascaded setup

F16's however predominantly use the internal downhaul system which has a significantly different diagram as it is a 3-stage cascaded setup. See the diagram in my own earlier posting.

Wouter

OK, last question (not!). The green external 2 to 1 exits the mast, goes up and around a block on the tack of the main and down to...what? A clam cleat or an eyestrap on the mast? That would complete the last 2 to 1 cascade, right?

That means there are 3 exit blocks on the mast, two that lead through the mast, into cleats, and on to the sailor's hand and a third for the green to the tack cascade.

So the entire inventory of needed hardware is

1) a double block on the crossbar
2) a single with becket for the green to red
3) a single for the blue internal
4) three through-mast exit blocks
5) two cam cleats
6) stainless bolt and tube for the crossbar.
7) clam cleat or eyestrap for the end of the green.
8) appropriate lines.

Sound about right to you folks? Any of those blocks need to swivel?

Pete, thanks for the 62 inch measurement (1575 mm). I would never have guessed it was so far up the mast!

You're welcome. The next time I pull it apart, I'll take some pictures of the inside.

I used just an eyestrap ti which I tie the green line with a slip knot. Like that it comes off very easily even when alot of downhaul tension is put onto it. Jam or cam cleats tend to let the green line slip or strip the mantle of the core. Eyestrap is best in my opinion. The VWM Blade has a sail hook on the end of the green line that hook into a hole on the base plate.

62 inches sounds like alot but with thsi 12:1 system you can REALLY downhaul your mainsail. I'm getting 5 to 6 inches of downhaul between tensioned and fully tensioned. When the sail is slack it is something like 10 inches. This mains the blue line block needs to travel 60 inches inside the mast. Either that or you need to pretension the setup but repositioning the slip knot in the green line. My setup is just a little too short to go from fully slapck to fully tensioned and so I use this slip knot trick to preset the tension or the conditions I'm expecting. I can even do that easily on the water and have.

Wouter

The way I rigged the downhaul on my Mattia 18HT


I think the advantage of my setup was, that it was easy to install and to get the right lenght of the lines.

But I must admid, that the setup of the Typhoon F16 looks allot cleaner.