Model Boat Mayhem

Technical, Techniques, Hints, and Tips => Other Technical Questions... => Topic started by: iantype-r on February 23, 2014, 09:26:53 pm

Title: Rudder play
Post by: iantype-r on February 23, 2014, 09:26:53 pm



Hello all, I have the same setup as pictured below. The brass wire makes some play in the rudders. I don't like this and want to eliminate it, can anyone give me some ideas.
(http://img.photobucket.com/albums/v474/iantype-r/6baa86df1ea849b58fbde8c3d038e7c7_zpsb4aa9a37.jpg)




I have seen these, but I'm assuming once they are bolted to the arms they would lock, I need the top to turn as the rudder moves,
http://www.sourcingmap.com/pcs-linkage-rod-connectors-servo-horn-rc-car-plane-buggy-parts-p-427913.html?currency=GBP&utm_source=google&utm_medium=froogle&utm_campaign=ukfroogle&gclid=CLbq05qX47wCFQUewwod6iMABg
Title: Re: Rudder play
Post by: tobyker on February 23, 2014, 10:08:03 pm
You will get play in those as the brass wires are too flexible and will bow when they are in compression. If you don't want to go to the complexity of double (push-pull) linkages, I would get some fine tube and slip it over the brass wires - or just cut the bent ends off the wires and solder them into the ends of the tubes. The bowing will start in the middle of the links so you should be ok with the finer gauge wire at the ends.
Title: Re: Rudder play
Post by: Colin Bishop on February 23, 2014, 10:16:07 pm
As Tobyker says, slip some close fitting brass tube over the wire which will make it much more rigid.

Colin
Title: Re: Rudder play
Post by: Skimmer Fan on February 23, 2014, 10:30:01 pm
I have used something similar from my local R/C model shop sells aeroplane spares. I also used stronger larger stainless steel rods.
I used two nuts, the first one I tightened up until it was just giving me movement then tightend another nut up to the first nut using it as a locknut. I also put a small amount of Loctight thread lock in the second nut. Seems to work ok for me.
Title: Re: Rudder play
Post by: NFMike on February 23, 2014, 11:39:55 pm
(http://www.sol.me.uk/boats/ahtshull/photos/steering1.JPG)


The black plastic ends have metal globes in them that are bolted to the various arms/wheel. No play.
Title: Re: Rudder play
Post by: malcolmfrary on February 24, 2014, 01:51:43 pm
http://www.shgmodels.com/acatalog/2013cat.pdf
Page 29, lots of ball link options.
Title: Re: Rudder play
Post by: Martin (Admin) on February 24, 2014, 02:22:11 pm

Many RC servo links need much stronger links than you would think!    O0
Title: Re: Rudder play
Post by: nemesis on February 24, 2014, 02:27:53 pm
Hi, Well, that is my parallelogram theory up the spout, nemesis
Title: Re: Rudder play
Post by: boat captain on February 24, 2014, 02:56:14 pm
I was told and read somewhere you should not use metal to metal connections on servos as they can cause interference to the receiver.

Joe
Title: Re: Rudder play
Post by: iantype-r on February 24, 2014, 03:27:33 pm
Many thanks for all the replies, I will have read when I get home,

Thanks

Ian
Title: Re: Rudder play
Post by: malcolmfrary on February 25, 2014, 09:21:50 am
Hi, Well, that is my parallelogram theory up the spout, nemesis
If plague's picture is being referred to, I see 2 separate parallelograms, one for each rudder.
Quote
I was told and read somewhere you should not use metal to metal connections on servos as they can cause interference to the receiver.
Joe
That was probably prop shafts.
Title: Re: Rudder play
Post by: inertia on February 25, 2014, 09:55:58 am
I was told and read somewhere you should not use metal to metal connections on servos as they can cause interference to the receiver.

Joe

FM receivers are said to be somewhat prone to interference from metal-to-metal electrical "noise" (such as the type of pushrod connection shown in the original post), but PCM receivers are fine. It's good practice to use plastic cup and brass ball links for pushrod to tiller connections as there is absolutely no slop at all in them.
DM
Title: Re: Rudder play
Post by: davidm1945 on February 25, 2014, 10:22:23 pm
As Tobyker says, slip some close fitting brass tube over the wire which will make it much more rigid.

Colin


I used the U shaped rib from a broken umbrella, cut to length and crimped in several places over the control rod, it won't bend now!


Dave