BJ Posted October 29, 2003 Report Share Posted October 29, 2003 I'm hearing everybody talk about rope stretch at the helm. Why not use 3/16 rubber covered cable. Any thoughts.. Quote Link to comment Share on other sites More sharing options...
Barry Pyeatt Posted October 29, 2003 Report Share Posted October 29, 2003 Most of the coated cables will break with all the tight flexing that is necessary with the small blocks being used. If you went to the expense of going to aircraft cable you would be fine. But there is a simpler way and that is to just purchase a low stretch rope. I hung a concrete block from a rafter for about a week with the line I planned on using for my steering to "pre-stretch" it. Then I installed it. With the turnbuckle it is plenty tight. The stretching only happens initially. Once you have used it a couple times and tightened it up, it probably won't ever need to be touched again. Using T. Nelson Surbrooks modified steering system makes it very easy and eliminates the thru-hull "U" bolts. You can check it out at: http://surbrook.org/nelson/steering.htm It is becoming pretty widely used because it works well. Quote Link to comment Share on other sites More sharing options...
BJ Posted October 29, 2003 Author Report Share Posted October 29, 2003 Hi Barry, thanks for your quick reply and the good deminstrations. I'm going to install my steering this evening and this will really help. thanks again Quote Link to comment Share on other sites More sharing options...
Dave R1 Posted October 29, 2003 Report Share Posted October 29, 2003 I used cable for mine and haven't had any problems, yet. I did have a hardware store pulley break at the swivel on my first launch. Replaced both with Harken blocks and no more trouble. My original setup had the cable wrapped around a wooden spool on a 3/4" steel shaft. that has been replaced with sprockets and a length of roller chain. Works even smoother, now. Quote Link to comment Share on other sites More sharing options...
Barnacle Jim Posted October 30, 2003 Report Share Posted October 30, 2003 Hi Dave, The suggestion of a sprocket sounds like a good one. Are there any pictures of your set-up? I (and others) might want to try something similar. Quote Link to comment Share on other sites More sharing options...
Dave R1 Posted October 30, 2003 Report Share Posted October 30, 2003 Jim, thanks for the interest. You are probably the only one here who is interested. Unfortunately, I didn't take any pictures of the whole assembly. I'll see if I have any photos of my steering and post them. Here's a description of it, though. Maybe that will help. The steering shaft is a 3/4" steel shaft for a buffing mandrel. This is an assembly with a couple of pillow block style bushings. The shaft has a flat on one end for a pulley and left-hand threads on the other for a nut which would hold a buffing wheel. The thing is designed to run at 1700 RPMs so I figure it can handle the slow speed turning of a steering wheel. It cost me about $12.00. The buffing mandrel with its shaft mounts on a piece of 1x4 that runs between the transom and lazarette. The wheel mounts on the threaded end with a locking collar behind it. I used a commercially made wheel that had a key way in the hub so I cut a keyway in the threaded part of the shaft with a dremel tool and a cut off wheel. took about 5 minutes and I only broke one disk. Originally, I had turned an oak hub tofit the shaft for the steering cable to pass around. This worked well but the stress on the brass threaded inserts I used for the set screws was causing the oak to split. Probably I had put those inserts too close to the ends of the hub. Anyway, I was going to make a new hub but came up with the following instead. I found these sprockets at the local farm supply store that have separate hubs. You buy a hub to fit the shaft and a sprocket to fit the application and weld them together. I got three sprockets that are about 2-3/4" in diameter, one hub with a 3/4" inch hole and two with 1/2" holes. The sprockets and hubs were welded. I made a bracket to hold the two sprockets with 1/2" holes from a couple of pieces of aluminum angle stock so that those sprockets were situated on either side of the steering shaft. The other sprocket was mounted on the shaft. The aluminum angle stock was postioned like two bookends with the sprockets between. There's a clearance notch in both pieces of aluminum to clear the shaft. I bolted them to the 1x4 that supports the buffing mandrel. Now there are three sprockets in a row running athwartships. the center one is locked onto the steering shaft (the hubs have two set screws each), the other two are on 1/2" bolts supported by the aluminum angle stock. I installed a length of roller chain so that it runs over the two outer (idler) sprockets and under the center one. Running the chain this way means that the top of the wheel has the same impact on the rudder as a tiller would. In other words the top of the wheel is pushed to leeward in a tack. As it happened, the diameter of the sprockets at the centerline of the chain was the same as the diameter of my original hub. This made figuring out the needed length of chain easy. I found that my steering wheel turned about 70% of a full revolution from center to stop. I calculated the length of chain wrapped up by that turn and added that to the length required to run through the sprockets. The steering cable is attached to the end of the chain, leads through Harken block on the side and back to the stub tiller. I drilled a hole vertically through the tiller and put a bolt through it. On the underside of the tiller there's a short piece of stainless bar stock that pivots on the bolt and has a turnbuckle on each end. The other ends of the turnbuckles attach to the cables that come from the ends of the chain. I hope that wasn't too hard to understand. I'll see what I can find for you in the way of drawings and stuff. I can see some of the "old timers" turning up their noses at this which is why I didn't really say anything about it before. It might seem complex but it really isn't. It took me almost as long to type this as it did to make it. In any case, it won't break or slip. Quote Link to comment Share on other sites More sharing options...
Dave R1 Posted October 30, 2003 Report Share Posted October 30, 2003 Trying some pictures First, the buffing mandrel/steering shaft In this view the first oak hub is shown. I did a nicer, longer hub before launch but never got a photo of it. Next is a drawing of the latest modification. I didn't bother to draw the sprocket teeth or the individual links in the chain. I had originally done a simpler drawing for myself to show the layout of the required holes and to figure out the required length of chain. I fleshed the drawing out this morning so you could get an idea of what I was trying to describe. Quote Link to comment Share on other sites More sharing options...
Barnacle Jim Posted October 31, 2003 Report Share Posted October 31, 2003 Good morning, Dave, Thanks for the drawing. Yes, I can see what you did. As I understand it, the chain would merely be circular much like the chain on a bicycle? Yet, here's another question: why did you choose the chain mechanism? Is the steering mechanism on larger boats chain driven? Or, was it because you wanted to avoid any possible stretch or slack from a cable or rope? Thanks again for the drawing! Quote Link to comment Share on other sites More sharing options...
Dave R1 Posted October 31, 2003 Report Share Posted October 31, 2003 Jim, the steering assembly is a combination of chain and cable the piece of chain is maybe 16" long. The reason for the chain was two-fold. First was to avoid slipping although I didn't have any problem with that in the previous set up. Second, although I could have easily made another wooden hub or spool to fit on the shaft as I had before, I wanted something that would be easy to install and easy to diassemble for possible service. This includes being able to remove it to do maintenance to the hull inside the lazarette. Centering the rudder and king spoke on the wheel are easy because you just loosen the set screws on the center sprocket, align as needed and retighten the screws. As to other boats using chain in their steering, I don't know of any for a fact but I wouldn't be surprised if some larger boats do. Chain doesn't stretch appreciably and there is always a positive connection between the sprocket and chain. Since my system does include cable, there are turnbuckles to tension them. Quote Link to comment Share on other sites More sharing options...
Dave R1 Posted October 31, 2003 Report Share Posted October 31, 2003 Jim, I did another drawing to hopefully give you a better idea of how my steering looks. Sorry for the lack of clarity. The turnbuckles are located where the labels indicate they've been omitted. In reality, the stub tiller is above the sprocket assembly. Quote Link to comment Share on other sites More sharing options...
Barry Pyeatt Posted October 31, 2003 Report Share Posted October 31, 2003 I think that is a marvelous solution. Very heavy duty for a Weekender and probably a great solution for a Vacationeer. There are several points that I like a lot. First is the direct 1-1 ratio that is achieved. Second no potential for slippage. Third the transition from the chain to a cable and turnbuckles to tension it. A larger center sprocket will increase the amount of movement in the rudder vs. the wheel. It is easily centered. I do have a couple questions on the geometry of the tiller hookup though. With the flat bar across the tiller and the cables hooking up to the bar doesn't it limit the amount of movement in the tiller arm? It would seem to me that the cables would need to be closer to the center line of the tiller arm for it to have a positive movement near the extremes. What did you use for cable and the connections to the chain and tiller arm? How smooth is the wheel movement? I've seen roller chain used on a couple of other (larger boats) but never thought much about it until now. Quote Link to comment Share on other sites More sharing options...
Dave R1 Posted October 31, 2003 Report Share Posted October 31, 2003 Barry, first thanks. I'm glad you see some merit in the design. The flat bar across the tiller pivots on a bolt through the tiller. I haven't noticed any problem with the geometry in that set up though you might be right. Perhaps it would be better to put an eyebolt in place of the pivot bolt and flat bar. Still, it goes easily and the limit of the travel is the tiller hitting the side of the transom opening. The opening was sized according to the plans. I thought about increasing it but the rudder goes over more than far enough to stall as it is. The chain-cable attachment is a thimble and a couple of cable saddle clamps. The same attachment is used for the cable-turnbuckle end. The turnbuckles are attached to the flat bar with quick links. I think after sailing it some next year as is I will probably replace the cable with new pieces and use crimp type clamps. the cable is vinyl-coated small diameter stuff from the hardware store. So far, so good. As to how smooth the movement is. It is very smooth once the sprockets are all aligned. I still want to work out some method for applying some friction somewhere in the system to allow me to release the wheel occassionally. I've got some ideas for a quick release sort of thing but need to fleash out the details. The buffing mandrel that forms the steering shaft came with a small diameter v-belt pulley that is one the aft end of the shaft. I've been thinking I could run a piece of belting around that pulley and around something else that could allow the belt to be quickly tightened to hold the rudder as set. Quote Link to comment Share on other sites More sharing options...
Barry Pyeatt Posted October 31, 2003 Report Share Posted October 31, 2003 I had originally put two eye bolts into the tiller arm with a joiner bedded in the arm but the geometry was fighting me once I got past a straight line from the eye to the blocks on the sides. I only had about 20 degrees of movement that way. I replaced that with one eye at on the end of the tiller arm centered. That eliminated the problem for me. I think as long as the bar pivots that is a great way to do it as well. Once you get to about 30 degrees as you say, the rudder will stall anyway so it is no longer functional. Here is one idea for a steering lock that is a little different than the one I am using as this will squeeze the steering shaft between the locking arm and the rigid base. I think If it is lined with leather it will hold it tightly but still allow it to be rotated freely when the pressure is off of it. I think if you lined it with rubber it might grab too solidly and apply too much friction to move when unlocked. Might be a consideration for your thinking. [attachment over 4 years old deleted by admin] Quote Link to comment Share on other sites More sharing options...
Dave R1 Posted October 31, 2003 Report Share Posted October 31, 2003 That's a good idea. I just need to figure out where to put it. With the hatch in the center of the lazarette there's not a lot of available surface for clamp. BTW, I wanted a hatch there that would have no external hardware. I discovered planing the back layer off a piece of 3/8 lauan made it curve to about the same camber as the deck. I glued some 3/4 x3/4 sticks for and aft near the edges of the hatch and inserted four screw eyes. There are screw eyes also in the stringer at the bottom of the transom. I hook bungee cords in the lower screweyes and then attach them to the eyes on the hatch. They hold the hatch down nice and tight without any hardware showing. I can always pry the hatch up and disconnect the bungees if I need to get in there. Quote Link to comment Share on other sites More sharing options...
Bill Posted November 1, 2003 Report Share Posted November 1, 2003 Dave R1 (and others, looking for ideas...), Just for some good info, ideas and digging, you may want to check out EDSON. They make parts and systems for all sorts of steering mechanisms. Chain and Wire have been used extensively on both power and sail boats. Many large boat (well, 30 plus feet anyway) have moved from tiller to Edson steering as an after market. I should say that for the types of trailerable boats here the cost is pretty prohibitive (in my view). One good thing is that they have all of their catalogs here on line. The ideas are great stuff to get the mind churning..(complete with detailed drawings). For the steering brake you might go to their Traditional catalog here (page eight) and get an idea. : http://www.edsonmarine.com/traditional/pdf/Traditional_Catalog_T1.pdf in a sense, it seems to follow Barrys idea. If you just start out at: http://www.edsonintl.com you can pick right through all the catalogs and ideas you wish (all pdf, so you can zoom right in on the drawings)... :-) I ordered all the catalogs online (free) and received them promptly via snail mail. I personally think a little ingenuity, bike parts, and the local VIP car place and you could come up with a great steering and brake system. The Wright brothers, meet the Stevensons... just a thought..good luck!! Bill Quote Link to comment Share on other sites More sharing options...
Barry Pyeatt Posted November 1, 2003 Report Share Posted November 1, 2003 Very Interesting, Thanks Bill. I just ordered their catalogs too. Quote Link to comment Share on other sites More sharing options...
Bill Posted November 1, 2003 Report Share Posted November 1, 2003 It wouldn't be right if I didn't mention that Ray Frechette Jr., aka. "Beaker" was the one that had originally stirred up the Edson idea. (and has always stirred up quite a few ideas :-) ) We stay in touch here in Maine on some of the larger boat ideas and we had been touching on steering systems, he mentioned he had been digging through the catalogs and nudged me to get them too. (Thanks Ray!) I think that anyone who just wants an idea on how these things work and has a small thirst for ideas and education would enjoy a look... Now heres a question: *(pertaines to "Shaft Mount Brake" on page eight, of the Traditional catalog: The brake plate, and the threaded break leg, are similar to what? That is, I have seen these two parts (or so very similar) used for something else...I can't place it. I know it wasn't on a steering brake system, somewhere, it's close to some other part(s) used on something...sorry to sound vague, but I'm hoping with all our readers, it clicks with someone.... something to do with plumbing? U shaped piece with holes on each end... b. Quote Link to comment Share on other sites More sharing options...
Guest Anonymous Posted November 3, 2003 Report Share Posted November 3, 2003 Hi Bill, Thanks for the tips on the catalogue. I download one or two, and then, sat down. (You had mentioned the high prices, so I wanted to be prepared just in case I might have a weak heart). :wink: Somehow, though, I could not find a single price on any item. Where are the prices, Bill? I'm sure I must be overlooking something. :oops: Quote Link to comment Share on other sites More sharing options...
Barnacle Jim Posted November 3, 2003 Report Share Posted November 3, 2003 Hi Bill, Thanks for the tips on the catalogue. I downloaded one or two, and then, sat down. (You had mentioned the high prices, so I wanted to be prepared just in case I might have a weak heart). :wink: Somehow, though, I could not find a single price on any item. Where are the prices, Bill? I'm sure I must be overlooking something. :oops: One other point for anyone: how do I delete a guest posting? (Maybe Frank can do it?) Quote Link to comment Share on other sites More sharing options...
Barnacle Jim Posted November 3, 2003 Report Share Posted November 3, 2003 Hi Ray, Thanks for the good comments. I'm just glad I was sitting down when I read some of the prices. Actually, I was more interested in some of the parts rather than a complete component, something more along the line of the chain and cable, or the bronze sprockets. Now, as to the advantage or disadvantage of having a wheel aboard Quote Link to comment Share on other sites More sharing options...
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