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[old shrimper]

hi guys
i need a recommendation for a servo about 20 mm high   ( brand part # ) the one i ordered is way to high its about 50mm
has to handle a rudder 55 m x 30m with a  60m prop and 540 MFA on 6.1 using 6V
thanks bob

[colin]

Probably a silly answer but can you mount it on side and still link up.


Colin

[old shrimper]

i could but it looks messy, i wanted to re sees it through the aft lower deck in the center  but the keel comes up to high in that section to be able use the  servo i have
if i move it to next section the control arm becomes about 6" long ( not sure that's a good idea ?)  in the pic its hard to due to glare of the 2 pack resin , but in foreground is the deck with the rudder tube  then there is a slot cut in bulk head
and the deck continues  on the other side ALL this is closed over  for ever when its finished
if i go to next section i still have to cut about 10 m out of the keel to get it lower enough for the control arm to line up
can you link me to some pic of the servo fitted in some models ?

http://i1266.photobucket.com/albums/jj529/atomicmaloo/MODEL%20BOAT%20PIC/DSC00957_zpsfc515992.jpg

http://i1266.photobucket.com/albums/jj529/atomicmaloo/MODEL%20BOAT%20PIC/DSC00956_zps62aa067e.jpg

[colin-d]

Hi Bob,
 
you want to be looking for Low Profile Servos..... there are quite a few out there on the market, usually a bit more expensive that the normal servos..
 
i used one of these on my SS Furie build... (BlueBird BMS-706MG)
 
hope this helps..

[RAAArtyGunner]

 
 
Bob,
 
Is it possible to cut out portion, say rectangular shape, of the cross member near the rudder.
It would need to be large enough, to allow lining up with your servo and rudder, as per Colin's photo

[AlanT]

I know your problem well just having come up against it during my Lindberg Fletcher Destroyer build, which has a very low stern area. I also don't like to lie the servo down, prefering the upright position.
 
I always like to use HiTec Servos, and as well as their standard servo they do an excellent Micro Servo which is 20mm high. There are other cheaper Micro Servo's around, especially on Ebay but I've never had a great deal of success with them.
 
Available almost anywhere. This is the code for it :- HS430BH HV Mini Sero Ref: 4504 You will find this code probably relates to a large model shop in Poole.
 
Regards
 
Alan

[colin-d]

the HS430BH is a High voltage servo.... 6v-7.4v  not the normal 4.8v-6v
 

Micro Servo which is 20mm high

the dimentions are not realy that much smaller, Size in Millimetres -(L.W.H) 40.60 x 19.80 x 36.60 (high)
 
most Low Profile servos are about 20-25mm High..
 

[inertia]

I suggest mounting a standard servo as close as you can and then routing the connection to the tiller arm via a flexible tube-inside-a-tube arrangement. Aircraft modellers call them "snakes". Example of these is here http://www.slecuk.com/catalogue/Snakes.html
You'll not require a connection to both sides of the tiller arm; one will be enough with a slow model like this will be.
Suit yourself, but I'd give up on hunting for a servo that low in profile if I were you.
DM

[AlanT]

Sorry wrong link selected....This is the Servo I used:-Hitec 55. Cost around £10 -
Alan

[malcolmfrary]

To move a large rudder I would not consider using any sort of Mini or Micro servo.  Low profile types with the right spec seem OK, but are likely to cost.  If the servo is to be mounted out of sight, it doesn't matter which way it is facing, all that really matters is that movement of the stick gives a corresponding movement of the rudder.  Using a snake is good, or a  rigid rod (a shark trace wire can be stiffened using a splint).  6" is no problem for the shark trace - I've had that arrangement on yachts for years.

[old shrimper]

hi guys i need some info on this set up as you can see the clives bind up before the servo gets to it switch off point ( i think anyway ) there is enough rudder movement about 35% do do the job but will it burn out out or damage the servo not being able to go the full travel
thanks for any help cheers Bob

[hdserv]

use a ball joint
 ball screws onto servo arm cup for the ball onto push rod

[malcolmfrary]

The redneck engineering answer is to provide clearance by filing away the offending bit of arm at each end. 
Personally, I've never bothered with a clevis, putting a Z bend in the wire has always done the job OK.  My rudder links are usually two part - the rudder one overshoots the servo and is supported by the servo arm, the servo link goes forward and is connected to the rudder link using a "choc bloc" electric connector.  Simple, robust, reliable and allows for easy tracking adjustment.  Probably comes from my habit of making my own tiller arms from the brass bits of dead mains plugs.

[sailorboy61]

Use a linkage stopper on the servo arm so the tiller rod sits above and doesn't foul?
 

[old shrimper]

can you guys link me to some pics of a   Z BEND , A mini BALL JOINT ,( and were to by them ) and a LINKAGE STOPPER ?
is it possible to reset the micro switch in the servo to stop it going as far ?


as yet i don't have the raido TX / RX can i just connect the  +   6v to  one of the 3 wires on the servo lead and the -  to one of the other 3 wires to make it work ?
thanks Bob

[Tug-Kenny RIP]

It's not really a good idea to connect a servo direct to a battery. There may be a chance it's fully charged to over 6 volts and the servos are designed to run at less than 6 volts. Also worth noting is the fact that a direct voltage will drive the servo motor continuously against it end stop !!!

Another thing which is not normally possible is to adjust the set stop to reduce travel.  All in all, you are damaging the servo.

A  "Z"  bend is merely a bend in the linkage wire in the shape of a "Z".  This allows the wire to bend if it is obstructed in any way.

Hope this is helpful

Ken

[old shrimper]

hi Kenny
thanks for the heads up on the servo i will get a TX/RX set before i try it out
 
will the ESC drop the voltage from 12 v to the correct voltage for the servo ?


i will make up a Z bend linkage to morrow i have plenty  of 2m rods
cheers Bob

[black magic racing]

http://cgi.ebay.co.uk/ws/eBayISAPI.dll?ViewItem&item=370760924561
here are the ball joints you are looking for

[inertia]

If your setting-up procedure so far hasn't involved powering up the servo then I think you are worrying unduly. All servos can be made to move that far simply by turning the output arm by hand, but under power they rarely move over 45 degrees each way (often less than that). Buy the radio and see how far the servo moves before you convince yourself there is actually a problem. BTW no modern servo contains a microswitch; they are a little more sophisticated than that! Connecting them directly to a battery as you suggest will not prompt any movement at all. That's what the third wire is for - you don't need to know anything further, just don't do it.
Ball joints are always a good idea in that there is absolutely no backlash (slop) in the linkage and you can take off almost 180 degrees of drive before the servo arm overlocks.
Many speed controllers are equipped with BEC (Battery Eliminator Circuity). This takes the voltage from the main motor drive battery and reduces it to a safe level to operate the receiver and servos etc. Just make sure that you buy this type. Personally I prefer to use a separate battery pack for the receiver wherever possible.
DM

[malcolmfrary]

The Z bend in my case is a shape in the end of the wire linkage to go through the tiller arm, which I usually get from filing and drilling a bit of brasswork from a dead 13 amp mains plug (too tight to actually buy "proper" model stuff).  Slop is minimal, and I have never had a problem.  The wire from my tiller arm is usually set to overshoot the servo arm - another similar wire goes from the servo arm and connects to the tiller wire using an electric choc bloc connector.  Simple, self supporting and allows for easy adjustment.  However, you have your clevises, they are designed to work, just stick with them.
When you get the radio, a good idea would be to not have the servo arm fitted initially.  Turn it all on, let the servo find its centre position, then fit the arm.

will the ESC drop the voltage from 12 v to the correct voltage for the servo ?

If the ESC has a label saying "BEC", yes.  Powering up a servo without a valid signal will cause it to twitch a bit, and if repeated will eventually cause the servo to get to the end of its travel, probably way beyond where it will ever go in service.  Yet another reason why the TX should be switched on before the RX.

[old shrimper]

HI GUYS thanks for info so far
this is a page shot of the controller im getting for $40 with RX unit they have good reviews on rc forums http://www.ultimaterc.com/forums/showthread.php?t=117089
where it says E POINT ( END POSITION ) is that the steering limit so you can adjust the amount of rudder / wheels movement
and what is expertenchel  (EXP ) do we use it ?
need some coaching here , i have no idea what im getting in to
has any one USED one of these ??

[AlisterL]

EXP on a radio refers to an exponential rate of movement. Rather than being truly proportional with the movement of the sticks (or wheel and trigger) on the transmitter, with EXP enabled the rate of change of movement of the arm increases the further you move. In theory it give you more precise control on smaller movements I guess.

[old shrimper]

 hi mate
thanks for that info its not something i would use i guess ? i wont small rudder movement with large amount of wheel

[black magic racing]

hi.i use these on all my power boats,they are great,it has a small switch on the handle where you can adjust the amount of movement on the rudder servo when going,great for setting up at speed,it also has trim adjustment,end adjustment and more,

[old shrimper]

hi mate
good to here they are OK can i call on you for some set up advice when it gets here ?
cheers Bob