Fanuc Robot and Controller ?'s

Looking at getting a used Fanuc S420 robot arm in the not so distant future. From what I have read so far they seem not too difficult to implement. I am trying to learn what I can about the controllers. The RH and RJ controllers and robot arm seem to be in my price range. The RJ2 and RJ3 are too pricey for my budget and use. This will be my first robot arm and am concerned about how easy/difficult any potential repairs and replacement parts will be on older controls. Since I have not been around robot arms before I am not familiar with the fine differences between each of the controllers.

I machine a lot of aluminum parts that need to be polished. I am looking at mounting a big motor to the arm to go around and polish a bunch of parts mounted on a table. Do these controls have a cutter comp. type feature as on cnc mills? As your finishing wheels start to wear down you can change a number and the robot will compensate for a tighter path? Any other features that might be handy for my application?

Any input appreciated.

"Truth is not determined by the number of people who believe in it."

Looking at getting a used Fanuc S420 robot arm in the not so distant future. From what I have read so far they seem not too difficult to implement. I am trying to learn what I can about the controllers. The RH and RJ controllers and robot arm seem to be in my price range. The RJ2 and RJ3 are too pricey for my budget and use. This will be my first robot arm and am concerned about how easy/difficult any potential repairs and replacement parts will be on older controls. Since I have not been around robot arms before I am not familiar with the fine differences between each of the controllers.

I machine a lot of aluminum parts that need to be polished. I am looking at mounting a big motor to the arm to go around and polish a bunch of parts mounted on a table. Do these controls have a cutter comp. type feature as on cnc mills? As your finishing wheels start to wear down you can change a number and the robot will compensate for a tighter path? Any other features that might be handy for my application?

Any input appreciated.

"Truth is not determined by the number of people who believe in it."

I don't think there's a compensation because it would be very difficult to implement in 3D space.

However, the robot program is just a line by line listing of a number of end effector points (really robot positions).

The easy thing is to use the teach pendant, and step thru the program, and tweak each point.

Be very very very careful around robots, and pay attention to the servo disconnect when working on the tooling or use the teach pendant when you are near them (usually a deadman switch that must be held in a center position...fully released or squeezed fully closed and all motion stops) They have no idea you or anyone else is there and are typically designed for rapid accelerations and thus have powerful servomotors. In other words they will put you in the hospital...or worse...

Perimeter fencing/guarding and a light screen for protecting the load/unload operator station is highly desirable in keeping people and robots separated.

I don't think there's a compensation because it would be very difficult to implement in 3D space.

However, the robot program is just a line by line listing of a number of end effector points (really robot positions).

The easy thing is to use the teach pendant, and step thru the program, and tweak each point.

Be very very very careful around robots, and pay attention to the servo disconnect when working on the tooling or use the teach pendant when you are near them (usually a deadman switch that must be held in a center position...fully released or squeezed fully closed and all motion stops) They have no idea you or anyone else is there and are typically designed for rapid accelerations and thus have powerful servomotors. In other words they will put you in the hospital...or worse...

Perimeter fencing/guarding and a light screen for protecting the load/unload operator station is highly desirable in keeping people and robots separated.

We use fanucs at work, I cannot remember model off hand, the learning curve on them is steep...some of our guys went to a class in Detroit on them to program them..I can say from working with ours that they are very precise.

The wiring loom on them is one thing to look over good, and make sure they have not been pressure washed.....if your looking at used ones and they are powered up wiggle the wire that goes into the teach pendant real good....it is coomon for them to go bad so the control will show a chain fault usually if there is a wire in there that is touch and go.

Most of ours run thousands and thousands of cycles a shift with generally few problems...ours are rated at roughly 300 lbs as I recall...they work in an environment where they get coolant and water on them...and they survive it well.

we currently have (12) running counting mentally...and in 4 years maybe 1-2 servo motors have worn out....preventive maint. has been faithfully performed on them their whole lives. The typicall faiulures have been due to breakage in the wires to the sensors in the end of arm tooling that tell the bot if the gripper is open or closed...when these break and short they will blow a fuse.

I sure hope you are going to build a guarded cell to run yours in because they will smash a human to bits and not even care...simple minded brutes they are .

I would say just offhand from what I have seen that you would save money to have the thing setup by a wizard with them...they can make it look childishly simple to program one and teach it. Then play with yours in off production times to learn it well yourself.

The co. I work for used a co. called "Rexcon" out of the Metro Detroit area and what they did for us is pretty sophisticated, to the point that when fortune 500 compant reps come on a tour they see things they were told were impossible...done every day literally thousands of times.

We use the vison system, and it is simply amazing is all I can say, it can ID a part, set X,Y, and Z postion (2 camera binocular setup actually ON the robot) and rotation...and the robot will pick the part up within .001". One camera not on the robot is simpler, probably far cheaper, and will allow X, Y and rotation to be set for each visually aquired part.

We use fanucs at work, I cannot remember model off hand, the learning curve on them is steep...some of our guys went to a class in Detroit on them to program them..I can say from working with ours that they are very precise.

The wiring loom on them is one thing to look over good, and make sure they have not been pressure washed.....if your looking at used ones and they are powered up wiggle the wire that goes into the teach pendant real good....it is coomon for them to go bad so the control will show a chain fault usually if there is a wire in there that is touch and go.

Most of ours run thousands and thousands of cycles a shift with generally few problems...ours are rated at roughly 300 lbs as I recall...they work in an environment where they get coolant and water on them...and they survive it well.

we currently have (12) running counting mentally...and in 4 years maybe 1-2 servo motors have worn out....preventive maint. has been faithfully performed on them their whole lives. The typicall faiulures have been due to breakage in the wires to the sensors in the end of arm tooling that tell the bot if the gripper is open or closed...when these break and short they will blow a fuse.

I sure hope you are going to build a guarded cell to run yours in because they will smash a human to bits and not even care...simple minded brutes they are .

I would say just offhand from what I have seen that you would save money to have the thing setup by a wizard with them...they can make it look childishly simple to program one and teach it. Then play with yours in off production times to learn it well yourself.

The co. I work for used a co. called "Rexcon" out of the Metro Detroit area and what they did for us is pretty sophisticated, to the point that when fortune 500 compant reps come on a tour they see things they were told were impossible...done every day literally thousands of times.

We use the vison system, and it is simply amazing is all I can say, it can ID a part, set X,Y, and Z postion (2 camera binocular setup actually ON the robot) and rotation...and the robot will pick the part up within .001". One camera not on the robot is simpler, probably far cheaper, and will allow X, Y and rotation to be set for each visually aquired part.

I would really try and get at least an RJ2.

The learning curve is steep. Like said it may have alot of faults becuase used. Would be best if you could find someone close that could help you for a few hours.

Becareful they are very dangerous.

I would really try and get at least an RJ2.

The learning curve is steep. Like said it may have alot of faults becuase used. Would be best if you could find someone close that could help you for a few hours.

Becareful they are very dangerous.

In thinking about this, unless the parts are very large, I would think it would be better to have the polishing equip be mounted stationary, and hold the part in the robot, you could then have lots of different polishing, blowoff, etc. stations without having to keep changing the tool on the robot. The polishing station would also be easier to move closer to the center of the robots world to compensate for wheel wear.....maybe

Fanuc at one time had some simulation software for robots, not sure if they still do or not...would be worth checking into, might give you some food for thought.


Bill

In thinking about this, unless the parts are very large, I would think it would be better to have the polishing equip be mounted stationary, and hold the part in the robot, you could then have lots of different polishing, blowoff, etc. stations without having to keep changing the tool on the robot. The polishing station would also be easier to move closer to the center of the robots world to compensate for wheel wear.....maybe

Fanuc at one time had some simulation software for robots, not sure if they still do or not...would be worth checking into, might give you some food for thought.


Bill