Servo throw or travel

[mikemcE]

Boy that's weird.
I need more than that, is that unique ?


Hang up and Drive

[whitrzac]

It's 100% normal. Most servos I've seen only turn 90* at 100% epa.

Some hitecs are programable. I have mine set to turn a full 180* at 100% epa.

[mikemcE]

Wow, totally right , never watched.
I would imagine a longer drag link will solve that , as you don't want a longer arm.


Hang up and Drive

[whitrzac]

Leverage is leverage. Longer arm vs longer knuckle mounting point doesn't matter that much.

[mikemcE]

I was taught the further out from the servos pivot you lose torque, length of the arm doesn't change torque, just throw


Hang up and Drive

[R_2]

Originally Posted by whitrzac

It's 100% normal. Most servos I've seen only turn 90* at 100% epa.

Some hitecs are programable. I have mine set to turn a full 180* at 100% epa.

Same here

Always check your steering setups with power on and moving with your radio.

And one thing has bothered me.. Some people put ridiculously long servo arms on and then limit it with epa.. And by doing that lose half of their servos torque. Short arm - more torque, less speed. Long arm - less torque, more speed.

I always use as short arm as possible (to gain max steering)

[TacoCrawler]

What servo horn is being utilized and what's its arm length beyond the servo's output shaft center point ?

Be sure your TX's steering trim is centered and that the servo horn is attached to the servo
at its center point of travel so it will throw equally in both directions.

Ensure the TX's end point adjustment (EPA) are set to 100% L & R minimally.
Think my GT3-C steering EPA adjusts to 120% L & R at max.
But too much servo throw beyond the physical movement/limitation of the steering linkage can be bad for a servo.

If the servo is buzzing when at full R or L lock... it's probably throwing too far and that resistance will create internal servo heat.
Excessive internal heat can cause damage to the servo.

And so the mechanical steering throw needs be verified/compared before maxing out the EPA setting.
Think I can only max my EPA setting(s) to around 108% L & R.
More then that and the servo will be stressing.
But that throw can be dependent of servo horn's actual arm length.

understanding Dual Rate and Exponential TX settings

^ Exponential has to do with the linearity of the TX's steering wheel in relation to the servo's actual radial movement.
I think setting the Expo nearer to zero is basically a 1:1 ratio.

^ Dual Rate has to do with how much power is supplied to the servo.
Too much and the servo can become jittery in it's radial movement.
Too little and the servo isn't getting enough power and will barely turn.
So I'd set this to max initially and dial it back if need be.
But not so far back that it robs the power the servo requires.

The servo's mfgr's specified torque value is based on the servo's horn arm being approx. 1" from the servo's output shaft center.
A longer servo arm then specified will reduce the servo's actual torque specification/rating.

The steering link and drag link are mechanically pre-determined by most kit/rtr mfgr's.
Increasing/altering the steering's link rod length(s) should not be required.
Using the proper length servo horn is.

However a longer drag link is often preferred over a shorter drag link...
As the longer drag link will generally result with less bind at the ball end
that is attached to the servo's horn when the servo horn turns.
Whereas a shorter drag link can more easily cause bind/restriction there.
But using a longer drag link often requires flipping the servo 180* to allow for that longer drag link.

If for some reason a longer servo horn used then what is suggested by the mfgr is necessary to obtain more steering throw... the servo's specified torque rating will be reduced.

Doing this will reduce he servo's specified torque rating and so a higher torque rated servo may be required for compensation.

Generally a servo horn having a 1" - 1 1/8" over-all length should be fine for the mechanical steering throw utilized with most RC car/truck kits/RTR.
But too much servo horn length /or not enough can become of issue.

Bottom line: a servo generally only turns 45* L & R from center.

So if it's not a faulty TX adjustment... or overly short servo horn causing your issue with reduced steering throw.
I'm not sure what the problem ?

Pictures are worth a thousand words

Guessing at what components/hardware you are using...
doesn't allow for much more then generalized response.