Hi, I am building a cruiser with a very narrow stern. I am planning on using a remote servo and a sliding tube (from model plane aeroleron) but the stern is so narrow that I am afraid the throw arm on the rudder won't have any space at all (and therefor no torque) I am considering a pulley system now, but I have never used one, and I am afraid the rudder will slip and get out of alignment. I want to keep the remote servo setup otherwise the servo will obstruct the stern cannon. Any ideas, comments, or even insane proposals?
The Verite is the same ... a very narrow pointy stern. I ended up using a model airplane wheel pant anchor as a control arm. It is very short ... perfect for those tight rudder shaft spaces. The one I picked up was for 5/32 wire, but a short length of brass tubing worked well as a sleeve aroumnd the rudder shaft. By the way, a solid pushrod would be better than the sliding nylon or cable in a tube setup. If the push tube comes loose, it will flex and take away rudder travel. Even if it is anchored solidly, the sliding tube type control has built in slop that may make it hard to keep a neutral rudder while going straight.
what you might want to consider is a timing belt or gear option. a timing belt will not slip as it's a belt with teeth that fit into grooves on the pulley. on rudder, you have to make certain you can get enough tension on the belt to keep it tight, which you can not always get if you mount the pulley to a servo (I've had this problem). Now if you use a pulley system to get the linkage back far enough that you can put a servo with gears, that is easy to get enough tension on the belt. You might want to look at the "karlsruhe refit" thread, I think there may be pictures of the servo in that ships stern, if not, ping me and I will post some
I hate push arms, they near get enough throw in one direction. What ship are you building, this helps as there might be one done out there already. I've always used gears, even in narrow sterns you can get a small gear on the rudder post and a larger gear farther back with a push rod to a servo. See: http://www.portpolarbear.com/reports/Inside%20the%20FN%20Montcalm.htm http://www.portpolarbear.com/reports/Inside%20the%20USS%20Minneapolis.htm
It's the USS Detroit CL8. I've used gears before, but only for twin rudders. Same setup as described here, except that it turned two rudders. I don't know why I didn't make the mental leap. I think I will try it.
Solid pushrods work well in the right circumstances and with a good angle between the servo and rudder arm. Sometimes, rudder travel limiting stops need to be installed to prevent the rudder from over rotating and jamming the rudder. Best is two short pushrods, one on each side of the rudder. My Richelieu has a double pushrod setup that has never failed. If it is strong enough for a 30% sized acrobatic gas powered aircraft, then it is good enough for our ships.
How far along are you on it, and where are the pic's. We dont see many pictures of cruisers being made.
I have the hull put together with the deck and caprail in place (in this case it's not a real caprail, just solid wood down to 3/8). It still needs sanding. Also, I made the hull with a flat bottom, so I have to turn it over and attach the the rounded bottom (ie the bottom of the ribs) and then fill in the space with balsa. No pics yet. I am still a newbie with wooden hulls and my 'workmanship' is best hidden behind a nice layer of paint. Once the hull is sanded. I will post some pictures.
you can set up a couple of Battlers Connection small gears in series to get you out to a wider section of the hull then a large BC gear on the servo.
I bet it still looks better than what I have done. I made a pair of Oi's, and finally after may tries to get it to all to go together, just dumped them both into the trash can.
Just the ribs, keel, and subdeck. Nothing wanted to fit together right. Wasted some time, but decided to purchase after that, lol.
I have had my share of ummm....sub-optimal results. This one might end up as one of them. But so far so good. There are a few mistakes, but nothing (so far) that I can sand out.
