# axis 5 override speed

• Is there a way that i can set an override speed to one individual axis on a Fanuc in fully automatic, namely axis 5? The reason for this is we have a fault on axis 5 which is causing a vibration thro the arm of the robot. If i jog axis 5 manually below 25% speed the vibration stops. We are currently awaiting an engineer to investigate the problem so if there is a setting or line of text to help me override axis 5 to keep me running it would be hugely appreciated. Thanks.

• Think about what want to have: an override for just one axis!?

How should that work? In every movement all axis move coordinated. Linear move: they are moved in a way that the tcp moves along a linear path.

Joint move: They move in a way that every axis reach the target position at the same time. Now think once again about the question for an override for a single axis. It doesn't make sense to have an override for one single axis. The movement can't be realized without coordinated axis velocities.

• There is a speed limit for each axis, but I'm not sure if you can modify it with a system variable.

Is this set globally somwhere?

• Even with an speed limit for only one axis... your overall speed will be lower on the other 5 axis.

You are working with an 6 axis machine, J movements make all axis start and finish at the same time, the axis who has the lower speed is like a "master" and every other axis syncronice the speed to match it and finish the movement at the same time. You will never see an axis finish his movement and others still moving if 2 or more axis are used. Movements are blended with cnt but even that way this will never happen.

Linear movements are more tricky because the motion planner moves the axis at different speeds in order to get a linear path.

So even if you find a way to limit the 5th axis speed, you will gain nothing. Just run at a 25% override or change speeds where robot gives a collision error, this is not something that I can recommend you because things will get more damaged, but we all know that sometimes you cannot afford to stop the machine while getting replacements.

• Even with an speed limit for only one axis... your overall speed will be lower on the other 5 axis.

This much I understand wholly. However, I have an application (4-axis robot) that runs the same motion command for many different PRs, some of which are up to 180deg different from each other

At the placement position where J4's rotation is most similar to the pick position, J4 doesn't need to spin as quickly to arrive at the destination at the same time as the other joints.

However, rotate the J4 position180deg for the placement, it now has to spin quicker to arrive at the destination along with the rest of the joints.

I can slow down the programmed motion, but it would slow down the motion for the "easy" rotation as well. I basically would love for J4 to be the limiter/Speed clamp for that specific motion command, rather than programmed speed being lowered for all moves.

• In the move instruction, specify the move time, not speed.

This will automatically apply the necessary linear and rotation speeds.