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.
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
Wouter Hijink Formula 16 NED 243 (one-off; homebuild) The Netherlands
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
Re: Internal Downhaul Recommendation
[Re: tback]
#112256 07/23/0704:29 AM07/23/0704:29 AM
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?
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.
Re: Internal Downhaul Recommendation
[Re: PTP]
#112257 07/23/0705:45 AM07/23/0705:45 AM
Someone on the main forum said he managed to tape a piece of small line to the bolt as he pulled it out.
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
Re: Internal Downhaul Recommendation
[Re: tback]
#112258 07/23/0706:46 AM07/23/0706:46 AM
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.
Re: Internal Downhaul Recommendation
[Re: ]
#112259 07/23/0707:04 AM07/23/0707:04 AM
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
Last edited by Wouter; 07/23/0709:03 AM.
Re: Internal Downhaul Recommendation
[Re: Wouter]
#112261 07/23/0708:44 AM07/23/0708:44 AM
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
Last edited by PTP; 07/23/0708:45 AM.
Re: Internal Downhaul Recommendation
[Re: PTP]
#112262 07/23/0708:54 AM07/23/0708:54 AM
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
Last edited by Wouter; 07/23/0708:56 AM.
Wouter Hijink Formula 16 NED 243 (one-off; homebuild) The Netherlands
Re: Internal Downhaul Recommendation
[Re: Wouter]
#112263 07/23/0710:15 AM07/23/0710:15 AM
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.
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.
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
Wouter Hijink Formula 16 NED 243 (one-off; homebuild) The Netherlands
Re: Internal Downhaul Recommendation
[Re: Wouter]
#112267 08/09/0708:35 AM08/09/0708:35 AM