Model Boat Mayhem

The Shipyard ( Dry Dock ): Builds & Questions => Navy - Military - Battleships: => Topic started by: goBulawayo on July 19, 2017, 10:09:09 pm

Title: Old RAF style launch - help needed re adding a rudder
Post by: goBulawayo on July 19, 2017, 10:09:09 pm
Hi All, I picked up this old RAF style launch many years ago and recently started working on it again with a plan to build it as a pleasure cruiser - when originally built it was steered by the engines, I now wish to add a rudder and have no idea how I might add it as the rear of the deck gets in the way - Any ideas from anyone please? I had thought of adding it to the stern but that would not look very nice.

Many thanks in advance Wayne

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Title: Re: Old RAF style launch - help needed re adding a rudder
Post by: Tug-Kenny RIP on July 19, 2017, 10:19:35 pm

It shouldn't be to difficult.  You can get a complete rudder kit from the model shop.  Choose the right size.

 You will need to drill out a hole up though the hull, to come out under the deck and epoxy it in firmly leaving enough room for the tiller arm to be connected and  linked to a servo.

Hope this helps

ken
Title: Re: Old RAF style launch - help needed re adding a rudder
Post by: goBulawayo on July 20, 2017, 05:53:58 am
Thanks Ken, I did have a think about this before, the gap under the rear is quite small but I suppose can be worked and the rudder would need to be amost in line with the prop posts to allow the servo arm a bit of movement- I suppose it not being behind the props wouldn't be too much of an issue?

Wayne
Title: Re: Old RAF style launch - help needed re adding a rudder
Post by: Nordlys on July 20, 2017, 08:31:05 am
In my experience the Rudder should be immediately behind and inline with the propellor for best results.
I cant see it working too well if not.
Nordlys
Title: Re: Old RAF style launch - help needed re adding a rudder
Post by: dougal99 on July 20, 2017, 07:29:43 pm
If you are using twin props with one rudder you will get better steering if your props turn inward forcing water over the prop. turning outwardwould move the water away from the rudder. Two rudders would be best of course.
Title: Re: Old RAF style launch - help needed re adding a rudder
Post by: goBulawayo on August 08, 2017, 06:54:21 pm
So I tried one central rudder between the props and no go so I have cut down some old offset hinges to mount on the transom with some new rudders, waiting for them to arrive now

Wayne
Title: Re: Old RAF style launch - help needed re adding a rudder
Post by: Perkasaman2 on August 08, 2017, 07:12:41 pm
It might be easier to cut a neat rectangular hole in the rear deck above the site of the rudder(s) and make installation and connection to a servo  a lot easier. Finally make a close fitting hatch to cover the opening after framing the new deck opening.
Title: Re: Old RAF style launch - help needed re adding a rudder
Post by: goBulawayo on August 08, 2017, 07:24:15 pm
Putting a rudder under the hull just did not work, hence the transom mounted rudders directly which will be directly behind the props

Wayne
Title: Re: Old RAF style launch - help needed re adding a rudder
Post by: tonyH on August 08, 2017, 08:38:05 pm
If you can sort out the access hatch, one of the simplest hinges of the MTB type (as the photo) are from the inserts from electrical connectors, the 'chocolate block' variety.
The small one suits a 3mm rudder post and the next one up should do for 4mm.
I've used them a few times and the best way I've found is to solder a brass bolt into one of the cable-clamping screwholes, cut the head off the bolt, stick them through the hole in the transom and fix them in place, after making sure that the rudder post is free turning. You can actually make up the whole thing, rudder, hinges and lever before you fit them to the hull.

Have fun

Tony