Model Boat Mayhem
Technical, Techniques, Hints, and Tips => Engineering Techniques and Materials. => Topic started by: durhambargeman on February 17, 2007, 04:35:36 pm
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Hello All, Is it possible to control a rudder by push rods from a servo, with the connections at the rudder end being under the water out of sight? If so, would water enter the hull through the holes containing the push rods? Would the servo have to be higher so that the push rods were at an angle, and if so, how much of an angle? Hope someone can assist as I do not want the connections on view if possible. Thanks, Ray
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Ray
It sounds as if your best solution would be to use a "snake" pushrod, as used extensively by model aircraft builders. This is a flexible plastic tube approx 3mm in diameter which slides back and forth inside another, close-fitting plastic tube. The outer tube is fixed to the hull (usually with epoxy glue) while a threaded rod is fitted to each end of the inner tube. One is connected to the servo and the other to the tiller arm. Avoid any sharp bends in the snake or you'll introduce too much friction in the system. You will also need to ensure that the inside end of the outer tube is above the level of the waterline, although I doubt if you would ever completely eliminate the ingress of water because of the slight capilary action between the tubes.Your model shop should understand what I mean by a "snake"; if they don't then they are totally DUMB and shouldn't be in the trade!
Works for me - suit yourself, and good luck!
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Hi Ray,
Some of the power lads us a rubber type bellows when
thy fit the power out drives. see your local model shop.
Good luck,
John. POLL
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Thanks for the advice fellers. Perhaps I should have mentioned that I am building a Thames sailing barge, so the rudder is quite big, but I will have a word with my local model shop and see what they have, cheers. Ray
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Here are a couple of snake type rods used in a Revel U-boat. Obviously they are internal but the sleeves could penetrate the hull and be packed with waterproof grease to give a seal.
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Is it steered with a tiller, or by wheel?. If by wheel, it should be possible to reproduce the ropes/chains to the rudder head and drive it in a scale manner. I'm working on a similar system for my Torpedo Boat at the moment. It isn't easy, but I've nearly cracked it!
Rick
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Halcyon
A system that although not invisible but none the less authentic looking, is to use the outer tubes of the snake.
If you put a yoke on the rudder, it can be controlled with cords to the servo arm (push pull) via the snake tubes through the transom........works for me and virtually no chance of water ingress.
John C
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If it is a Thames barge then there is no need to hide the linkage as it is in view on the full size as on mine. One thing I did have to do was add a perspex extension on the bottom of the rudder extending forward of the pintle so as to make a semi balanced rudder and take the strain off the servo.
MikeK
(http://i86.photobucket.com/albums/k116/ChilliK/P2180015.jpg)
(http://i86.photobucket.com/albums/k116/ChilliK/P2180014.jpg)
(http://i86.photobucket.com/albums/k116/ChilliK/P2180013.jpg)
(http://i86.photobucket.com/albums/k116/ChilliK/P2180016.jpg)
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Mike K
Can we see more of the model please.
I am trying to do a ship of about 1880-1930 at the moment and am looking for inspriration for deck fittings, weathering etc.
Would be grateful
TT
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'TT',
There are a number of ways to hide the push rod(s). Those 'ways' depend a lot on your imagination. If they are below water then I'd certainly try to provide some way of sealing out water (or at least most of it!). That 'snake tube' thingy seems like one good way of doing that. Is it possible to make the model's rudder control like the 'real' ones? If the 'real' rudder control line(s) were visible, why not? If they were under water too, then why not? (And since I have no idea how it was 'really' done, those were 'real' questions.)
- 'Doc
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'TT',
...And since I have no idea how it was 'really' done, those were 'real' questions.
- 'Doc
Hi Doc
I am really interested in the other detailing on the boat. Some of the deck fittings etc. :)
I never doubted that those were 'real' questions, and so I am confused by your response ???
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TT
Substitute "full-size" for "real" in Doc's note and it makes better reading.............well, it did for me!
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'TT',
The basic idea was to duplicate how the rudder controls exited the hull on the 'real' boat. If that isn't practical (no idea if it would be or not), then do whatever you can think of to make it sort of look 'right'. If someone says it isn't how 'they' really did it, just tell them that -you- did it 'right' and that -they- did it wrong. Works for me! Not sure if -they- believe me, or just don't want anything more to do with 'that' kind of idiot...
- 'Doc
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Mike K
Can we see more of the model please.
I am trying to do a ship of about 1880-1930 at the moment and am looking for inspriration for deck fittings, weathering etc.
Would be grateful
TT
The barge has been through 3 house moves, a long session as an ornament on shelf (albeit a bloody big ornament !) and now resides in the shed waiting for my promise of 'I must put the barge in the water one of these days' With this in mind you must realise that any weathering has come as a product of neglect - certainly not skill ;D ;D. If it stays dry I'll rig it up and get a couple of pictures for you
MikeK
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Doc
Now I see where you are coming from. :-[
thanks FLJ for pointing my in the right direction.
Mike
More Photos
That would be brilliant
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Brilliant thanks mike
;D 8)
You can never have too many ;) :D ;D
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Hi Mike
They were perfect before
Now they are tiny? and juse a link that you follow to tinydom ??? ??? ???
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Hi Mike
They were perfect before
Now they are tiny? and juse a link that you follow to tinydom ??? ??? ???
Nil desperandum as they say. I'll take them off again so it's not wasting space and go away and keep trying 'til it works.
MikeK
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testing
(http://i86.photobucket.com/albums/k116/ChilliK/barges/P2190017.jpg)
That worked ok lets try more !
(http://i86.photobucket.com/albums/k116/ChilliK/barges/P2190019.jpg)
(http://i86.photobucket.com/albums/k116/ChilliK/barges/P2190020.jpg)
(http://i86.photobucket.com/albums/k116/ChilliK/barges/P2190021.jpg)
(http://i86.photobucket.com/albums/k116/ChilliK/barges/P2190022.jpg)
(http://i86.photobucket.com/albums/k116/ChilliK/barges/P2190023.jpg)
(http://i86.photobucket.com/albums/k116/ChilliK/barges/P2190025.jpg)
(http://i86.photobucket.com/albums/k116/ChilliK/barges/P2190027.jpg)
Lets see how this works
MikeK
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Success !! The only difference was the batteries in the camera went flat during transfer, surely it wasn't that.
Won't write all the blurb again except to mention that the only bought bits were the lee/halyard winches and the sheet blocks on the mainsail and bits like chains and sidelights. There is another three or four similar shots if you want me to put them on, TT. I believe we are limited to 8 per posting so I didn't go daft.
MikeK
PS I see that you are asking about flotation for your model elsewhere. On the barge I carved bits of polystyrene tiles and packed them in all accessable corners. The hatches are held down on their coamings by an elastic band secured to two screw hooks on inner keel and hatch underside, with enough stretch to get a hand under and unhook when access required
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Mike,
How the @#$$ did you get that thing through the door, much less on a shelf?
- 'Doc
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Mike,
How the @#$$ did you get that thing through the door, much less on a shelf?
- 'Doc
hi Doc - we build big doors in Geordieland ;D ;D (Texan type joke ;) ;))
All is not what it seems - obviously the false keel and rudder extension come off, giving a flat bottom to sit on. Then all the masts, bowsprit etc are collapsable as in the full size barge. Usually I only tilt the bowsprit up vertical and drop the main topmast down to cross tree level and that is enough. Going beyond that is a bit of a palaver. The only thing to suffer was the house flag which was on a staff above the maintopmast and not allowed for betwixt shelf and ceiling ! (The ceiling won !!) I stuck in on the mizzen instead, which will probably annoy the purists ;D ;D
MikeK
PS How dare you call my pride and joy a 'thing' - miffed I most certainly am !! (joking) ;D ;D
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Another Barge in the North East?
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A couple of close ups
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Now you've shown me up - very nice indeed. Is it the fibreglass hull model ?? You are still on your own (?) in the North East, 'cos I've moved deep south now to bring light to the southerners ;D ;D
MikeK
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God help the southerners 8) 8)
Not realy meant but couldn't resist it
Cheers
Bob B
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What a shame! I sail at Saltwell park Gateshead.Its a Tony Williams hull the rest of the boat including fittings is scratch.As my first sailling boat I was very impressed by its handling properties.
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BobB - Yes my son that's what I'm here for ;D ;D
MCR, I used to belong to the South Shields MBC, but I was the only barge in town so to speak, so I always raced yachts and old 'Will' hardly saw the water. It's the same now I'm "darn sarf" my club focuses on yacht racing so the barge is still on a promise !!
My model is the result of gridding and scaling up a 1:48 plan for a static one to 1:24 plank on frame, then during building MB mag. did an article on, I assume, the Tony Williams model along with the white metal fitting kits for the winches.
Originally I made up a rig with threaded rod, saddle and micro switches under the aft cuddy that powered an electric motor to turn the rod, which turned the (unbalanced) rudder and also the ships wheel. Looked realistic but was so slow the handling in a good wind was frightening, with concrete round the sides and all :o :o
MikeK
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Both very nice boats gents. :)
Thanks for posting. :)
OOPS
::) ::)
Looks like we hijacked the rudder thread
Sorry everyone. :-[
There is very little action in the scale sail forum.
Maybe we could spice it up a bit.
My next Q will be over there.
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Ditto, sorry Ray for wandering off a bit, but there was some bits about steering eh ? ;D ;D
MikeK