### What are end points?

I'm very new to quads and I have been flipping my newly built quad a few times already. When trying to fly for the first time, should I be more concerned about the POTs on my KKboard, or the end points of my transmitter? And my second question is, what is the difference between the end points and dual rates?

#### Replies

• End points are the initial settings in the radio that you program to give the desired maximum travel of each servo or channel.

Dual rates switches then gives you the ability to choose between what could be described as 'virtual end-points". Say you set your end points on channel 1 to 100% each end. Then you go ahead and set up two dual rate values of 100% and 70% on that channel on an Aux switch on the radio. this means that when you select the 100% dual rate setting you'll get 100% of the endpoint travel you set, and when selecting the 70% setting you'll get 70% of the end point travel.

Real life example. I'll use a fixed wing model as an example.

Say the Elevator is supposed to have 25Deg up/down for aerobatics and 12.5deg for normal flight. You could set your end points so that 25Deg both directions is achieved.

Now due to linearity errors introduced by the linkages you may end up with numbers like 125% for up and 110% for down. However, you would have set your initial maximum travel, slight differences in these numbers are not really a problem, big differences can highlight mechanical setup issues.

Now you then go ahead and set up two rates on a dual rate switch. One at 100% and one at 50%. You then get full travel aerobatic mode when you select 100% and the easy normal flying setup of reduced elevator when you select the 50% setting which will drop the elevator maximum travel to 12.5%

Now you could equate this to the pitch channel on your quad or whatever. Seems that in most cases you leave the end points as they are, say 100% and you teach in our case, the APM what those limits are.

Then, (and correct me is I get the flight mode wrong), when in stabilize mode full travel of the pitch stick will result in the quad pitching to a maximum angle say 40 deg, moving the stick halfway back  it would angle itself to 20deg. So you can see by using dual rates that you can add in a switch that you can use to limit the pitch and roll of the quad. A dual rate switch could be sued to limit the pitch/roll maximum angle.

But hey, that's just the start, wait till someone tries to explain exponential :-)

• Moderator

End points relate to how far a servo would travel and rates speed up how fast things happen. You might find some KK board folks around here but in general we are all about Ardupilot here

• Hi Gary, thanks for replying, I know this is an Ardupilot forum, but you guys have been the best community for helping me out! Other sites are not reliable so I appreciate the information.

Can I just ask, when it comes to stick sensitivity, am I to adjust the dual rates before the end points? Your help is greatly appreciated!

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