Rudder Servos

[Ian Dowlman 1Participant @iandowlman1]

I have bought servos for two boats which operate successfully, and give a rudder movement of 30 degrees-ish each way. Both were purchased on advice, one from a model shop and one from an on line supplier, but over the phone.

However I recently needed a small servo for a limited headroom and purchased this from another local model shop. When I got it home I found that it had a 180 degree rotation. I can't see how I'm going to get this to work with a rudder.

Looking at several on line suppliers, the amount of throw (or rotation) in degrees on the servos seems to be seldom mentioned. Is this then something which we should specify on purchase, or is the amount of throw on the servo adjustable?

Some general advice would be appreciated so I can purchase exactly what I need.

Ian

[Ian Dowlman 1Participant @iandowlman1]

[Malcolm FraryParticipant @malcolmfrary95515]

The throw is generally dependent on the transmitter, but obviously some servos are designed to respond differently. "Standard" servos are generally in the 30-something to 40-something degrees area with a range of transmitters, anything that responds differently usually has this shouted in its advertising to attract those who want this difference.

Some transmitters have the facility to adjust the travel end points. There is a plug-in device called a "Servomorph" which allows the end points to be adjusted in hardware in the boat. While modifying the board in a servo is sort of possible, it really is the sort of thing where if you have to ask, the answer is "probably not". Even more if it is a space restricted servo, because extra resistors have to be inserted.

[Dave MilbournParticipant @davemilbourn48782]

Ian

I have used and can recommend both this servo and its supplier. **LINK** Malcolm's guidance is bang-on, with the proviso that any "specialist" servo such as 180° retract, sail-winch or continuous rotation will normally be flagged as such. If your local model shop doesn't know the difference then don't shop there.
Any idiot can sell a boxed item without having the first idea what's inside it and it rather sounds like you've found one of those! If I were you I'd take it back and ask for a refund.

Dave M

[Ian Dowlman 1Participant @iandowlman1]

Malcolm and Dave

Thanks for the advice.

I will certainly be less naive when buying servos again. I'll admit that although I explained what I wanted, and why, I was served by someone who looked about 14 and should have been more careful.

Dave, I purchased the coupling you suggested and it looks like a good bit of kit. The stretch Nomad is underway and I am going to take pictures of progress so I can submit them to the Forum as the project progresses.

Ian

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