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Old Sep 14, 2007, 08:38 AM
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DanL's Avatar
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HH -
You could key the rudder shaft sector gear so that the rudder shaft slides in and out of it. The small gear to big gear issue will be a problem unless you get really tough gears in really solid bearings. Otherwise the large forces will degrade the components. But, moving on to another possible approach...
Dump the current approach totally.
Extend the shaft to go up into the tiller. Extend with another shaft held in place by an over-sleeve - all soldered together. The slightest play is greatly magnified in rudder travel.
Then make an operating tiller. Attach a pinned tiller to the head of the shaft. You have that big hatch with great access - rig a below deck relay mount to pull two lines. The lines go up thru the deck and fairleads near the bulwarks and to the tiller. They pull the tiller right/left.
For appearance, use clear monofilament. Attach the helmsman to the helm, not the deck, and he will move back/forth with the tiller.
Mechanically, this approach works great on my brig, with very little rudder play. I have long control lines - yours will be much shorter, so your "tightness" of the whole system will be better than mine.
If this doesn't work for you, let me know. I'll try for strike three and then stop.... : )
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Old Sep 14, 2007, 10:14 AM
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Dan...

...I don't see the sector gear working due to space restriction. I had not thought about using the tiller like it is supposed to be used. If I can come up with a hardened tiller that is strong enough to handle the forces exerted by the lines pulled by the servo and figure a way to make it slip over the top of the rudder shaft it might work. My shaft does not extrude above deck any more though. That means the tiller (head?) will need to extend below deck to reach over the rudder shaft. I still have to use the rudder assembly block because the only thing holding the rudder to the ship is that tube piece the rudder shaft slips through that is part of it…unless I fabricate a new piece to replace it. And screw it to the deck like the rudder assembly block.

I was planning to move my static tiller forward and patch over the transom cutout (looks). I won’t be able to do this if I have to actually use the tiller.

Philip…does the prototype have as much play in the rudder as mine, and is it a performance problem for your ship? What’s the chances of a retrofit upgrade to a better rudder shaft and getting rid of both of the brass gear shafts for tighter tolerances and better wear?

Capt. Slick
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Old Sep 14, 2007, 11:39 AM
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HH -
OK, here's my third swing at it...
Involves a working tiller - with very easy mods and realistic looking operation and will fit the space and take care of the tiller-in-the-transom issue.
No time to type right now - can we talk tonight/this weekend? PM me your number if interested.
I'll try to sketch the details tonight....
Thanks,
Dan
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Old Sep 14, 2007, 12:53 PM
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Hey...I'm all ears!

No hurry...throw the idea at me anytime.

Thanks Dan

Capt. Slick
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Old Sep 14, 2007, 01:34 PM
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Pull-pull systems work fine with rc plane's rudders and elevators. I made my Curtis Jenny pull pull using Spectra (no stretch) fishing line. Or, Dubro has a kit. Running your rudder using a below-deck bell crank that extends athwartships across both sides of the rudder post would be similar to my plane's system. I don't know if you have enough room for that type of bell crank, though. If you run lines to the tiller itself, be aware that you can run into geometry problems, same as when you run lines to the yards. Solvable, but might take some experimenting. DanL seems to have figured it out, so get some photos of his design :-).
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Old Sep 14, 2007, 05:46 PM
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HH -
I may be out of ideas after this one...
Sketch shows concept.
1. Remove all existing gear/belt drive.
2. Add arm to servo long enough to get 30 deg rudder deflection (tiller L is determining factor)
3. Add extension to rudder shaft just a tad above flush with deck.
4. Key top of shaft to accept a short flat bar that will extend forward to provide a base for a new "false" rudder shaft. This gets the shaft away from being buried in the transom. The bar is flat to the deck, with a slight clearance above deck. Drill and tap top of shaft extension for a lockdown screw to hold the forward extension plate in place.
5. Attach a false rudder shaft as shown to provide an attachment for the tiller head.
6. Key and pin/setscrew the tiller head to the new false shaft. I pinned my tiller with a thru bolt from the back
7. Arrange a pull-pull system as shown. About one to two inches of bungee on each side gives flex to the control llines and acts as a "servo shock protector" should the rudder get bumped.
8. Use hook-to-eyebolt attachment of line to tiller - allows easy removal and disconnect during transport.
9. Place fairlead such that line/angle of pull is most straight/direct at the max angle of travel of the tiller and you won't have any geometry probs.
Sketch is attached. I'll post pics of the brig later this PM.
Note - my tiller is hand shaped from a little scrap of oak. I drilled it out and inserted a piece of piano wire with slo set CA to stiffen/strengthen it, but probably not even necessary. Also have some wire wrapped around it -see pic later- for reinforcement, but again probably overkill.

Hope this is useful... Strike three, single, home-run???? We'll see..
Always fun! MGD time.
Dan
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Old Sep 14, 2007, 09:51 PM
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HH - rudder/tiller system pics.
The double line coming off the block on the tiller goes thru the fairlead disguised by the block attached over it. Those lines go forward to the servo arm.
The other lines to the ships wheel, etc are dummy lines.
A delrin square with a hole in it to match the size and angle of the rudder shaft serves as a snug bearing for the rudder shaft.
There is almost no play at all in the rudder in either direction. It doesn't always self center on the bench (off by a few mm's.), but the water always centers it under actual operation.
No probs with the system while sailing.
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Old Sep 17, 2007, 10:17 AM
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Need help with possible Prince artifacts aquisition.

See this thread in dock talk:

http://www.rcgroups.com/forums/showthread.php?t=743984

Capt. Slick
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Old Sep 17, 2007, 10:23 AM
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Dan

Man you have done such a beautiful job on your ship...I could never approach that quality.

Thanks for all the time you took on this trying to help me. You are very much appreciated! At this point I just need to ponder all the possibilities. I think I need to try sailing my ship again with adjustments to the sheets before I attempt to correct the rudder problems. Until I hear from Philip on this I'm not sure I really need to do anything with it. I don't know that it is really causing me any problems. Wish the Prince had the same design as the Brig.

Capt. Slick
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Old Sep 17, 2007, 11:55 AM
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Rudder play

Hoghappy - you should have negligible rudder play. The amount you are talking, 2" at the distal end of movement, without any servo movement would almost certainly prevent you from tacking.

Our Prince has sailed for about 60 hours total and has negligible play.

I am pretty busy at work here, since I have just got back from two weeks vacation, but when I have a chance I will comment on the postings.
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Old Sep 22, 2007, 09:40 AM
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The Prince sailing

sailing!
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Old Sep 22, 2007, 06:49 PM
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Nice !
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Old Sep 23, 2007, 07:30 PM
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Hoghappy Rudder play

Sounds like you have ascertained that you have a wear problem on the spur gear rudder shaft where the aluminum transfer pinion engages it.

This is a replaceable part, but I cannot see any wear on ours at all!

Could the rudder servo block be cracked (visible only under strain?) where the extension part of the block that penetrates the stern joins onto the main part?
I could check this out for you at no charge if you sent the assembly back to me, but if it needs replacing or repairing I would have to charge you.
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Old Sep 23, 2007, 07:40 PM
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Gerald K

Congratulations on your launch!

I am expecting to see some pictures of your ship sailing in a bit of wind soon....

A builder on the US East coast has just launched his HMS Surprise (number 18) and I will post the picture he sent me on the 18 gun brig-of-war web forum soon.
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Old Sep 24, 2007, 08:34 AM
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Gerald...excellent...I can't wait to see some action shots! It was too windy (15-20 mph) here this weekend to sail the Prince, but I had fun with the sailboats until I knocked one over and bent the rudder shaft and broke the servo gears.

Philip...when I pulled the rudder gear for inspection it did show some wear, but not as much as I expected considering the play. I got the same amount of play when I slid the shaft up and down. That tells me that it may not be the gears. A cracked block may be the problem although I don't understand how that would effect the gear contact. I will pull the rudder assembly again and apply pressure while observing for a crack. If it is cracked I may be able to strengthen/repair with thin CA. That stuff will wick into almost anything that is absorbant and harden it like a rock. If that doesn't work I may take you up on your offer to repair the assembly...thanks.

Capt. Slick
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