Model Boat Mayhem

The Shipyard ( Dry Dock ): Builds & Questions => Working Vessels => Topic started by: meechingman on May 19, 2019, 10:33:23 pm

Title: Becker rudder issues
Post by: meechingman on May 19, 2019, 10:33:23 pm
My tug 'Denton' , an ex Smit Nederland, has the stock Becker rudders.
My problem is this: If I use a little too much helm, the linkage pin circled in the photo comes out of its swivel mount and I then have no control over the rudders at all. They just waggle and I have to drive the tug back to shore as best I can.
The previous owner tried to stop this by installing a mechanical linkage from the rudder control arm, connected to a rod that slid back and forth, with a couple of stops on it to restrict its movement, shown in the second photo. This didn't work well and it would either jam or slip.
So, in the menu of my transmitter (Futaba T6EXP) I set a maximum throw for the rudders, but I still occasionally lose control with the pins coming out.
Anyone else had this issue? Any solutions?
Title: Re: Becker rudder issues
Post by: Taranis on May 19, 2019, 10:42:53 pm
Billings have produced a new brass rudder but not released a price and have to contact a stockist to order
Have a look on their Facebook group


The rudder has a revised linkage
Title: Re: Becker rudder issues
Post by: Taranis on May 19, 2019, 11:15:06 pm

Subtle but effective change

https://www.facebook.com/billingboats/videos/345642986229478/ (https://www.facebook.com/billingboats/videos/345642986229478/)
Title: Re: Becker rudder issues
Post by: mudway on May 20, 2019, 12:27:44 am
This guy does them in different sizes too.


https://www.ebay.com.au/itm/Model-Boat-Becker-Rudder-small/173599800089?hash=item286b5abb19:g:tzAAAOSwd4tTuSA0&frcectupt=true (https://www.ebay.com.au/itm/Model-Boat-Becker-Rudder-small/173599800089?hash=item286b5abb19:g:tzAAAOSwd4tTuSA0&frcectupt=true)

Title: Re: Becker rudder issues
Post by: Umi_Ryuzuki on May 20, 2019, 04:52:11 am
That appears to be a huge rudder arm.A shorter rudder arm and a change up in the linkage could solve the problem.

Title: Re: Becker rudder issues
Post by: tugboyben on May 20, 2019, 06:28:12 am
Morning
Umi is right linkage on your servo  is very long




The servo arm is very long i would think that is your problem too
Move Both rudder linkage's more to the centre of the servo please keep us posted


Jason
Title: Re: Becker rudder issues
Post by: meechingman on May 20, 2019, 06:24:28 pm
It seems that this is a common issue and is regarded as a design flaw in the rudder.


Changing the rudder arm and linkage would indeed lessen the rudder throw. I can do the same thing electronically (as have others) by setting the End Point Adjustments on the transmitter. I've done so, in fact, but will probably have to restrict the movement still further.


I was hoping for a solution like the modified rudder shown, that would allow the rudder to be put hard over. As Billing don't seem to sell that revised rudder, and modifying it as shown is waaaaay beyond my skills, looks like I'll have to settle for less throw. :(


However, she does turn sharply when required and I do have a bow thruster to nudge her if necessary.
Title: Re: Becker rudder issues
Post by: JimG on May 20, 2019, 07:45:17 pm
IIRC on my Smit the Becker rudder could be put to around 45 degree, the rear was then at 90 degrees. I doubt that much more rudder than this would be needed, it turned well as it is.I would think that any more rudder movement would start to produce rudder stall and be less effective.
Jim
Title: Re: Becker rudder issues
Post by: meechingman on May 20, 2019, 07:50:03 pm
Pretty sure my pins pop out before then.


I think for the moment, I'll limit the rudder throw via the transmitter, and then wait for Billing to start selling the revised rudders.


Then it will be rudders off, shafts out for a greasing and reassembly with the new bits.
Title: Re: Becker rudder issues
Post by: Taranis on May 20, 2019, 08:00:00 pm
Pretty sure that modification could be done retrospectively without difficulty
Title: Re: Becker rudder issues
Post by: meechingman on May 20, 2019, 08:44:26 pm
Alas, my modelling skills aren't up to doing that kind of work, and RSI doesn't help. :(

Title: Re: Becker rudder issues
Post by: meechingman on May 30, 2019, 10:01:05 pm
Just to update the thread, I'll wait for the revised version of the rudder to go on sale.


But whilst checking the settings on the transmitter before limiting the rudder throw, I came across a good example of 'user error' (my excuse is that the manual isn't explicit enough!  ok2  ) I thought I had set the max throw at 30% but what I hadn't realised is that you can set port and starboard throws separately. So while starboard throw was at 30% and that should be quite safe, port throw was still at 100% and that's why I kept loosing the links on the rudders!


I've now set both to 30% and I'll see how things go when I get her back on the water.
Title: Re: Becker rudder issues
Post by: Taranis on May 30, 2019, 10:02:19 pm
Nice result  :-))
Title: Re: Becker rudder issues
Post by: JimG on May 31, 2019, 12:55:15 pm
Just to update the thread, I'll wait for the revised version of the rudder to go on sale.

I've now set both to 30% and I'll see how things go when I get her back on the water.
You will still be better if you reduce the throws mechanically, by moving the links closer to the center on the servo arm. Most people assume that the servo is free to move to any position in its arc when in fact it is moving through a set of discrete steps,the number depending on the transmitters digital encoder. What you are doing is reducing the total number of steps the servo sees for the full movement of the stick, in your case only 30% of the normal amount. While this may not have too much effect on steering it is bad practice, older radios have less steps than the more expensive newer sets and may give a more jerky movement. It is always best to reduce the need for lower rates or need for rudder trim if possible.
Jim
Title: Re: Becker rudder issues
Post by: dodes on June 18, 2019, 02:36:56 pm
My  smit tug runs perfect and turns in her own length. The rudder has a maximum of about 30 degrees. Full size ships have a max of 35 degrees after that it becomes a brake.