Fanuc Robodrill AlphaT10C -- Retrofit -- Help

Theres a (unresolved) thread on this forum about the same problem

www.linuxcnc.org/index.php/italian/forum...integration?start=30

So they are not simple analog drives. I believe (but do not know for sure) that they take 3 phase PWM and return position and current in a serial link

Here a little more info:

www.cnczone.com/forums/fanuc/161101-fanu...pin_definitions.html

So no fancy digital current data, just analog phase currents, so I guess the encoder is connected to the controller separately

(I am assuming this is the same interface)

also how fast do you want the machine to be, as these robodrills do fly around fast i don't know the model but i guess its a 30m/min machine at least?

just linuxcnc does not have any jerk limiting in its motion planner as such currently if you use this machine for production im sure you brought the robodrill to drill holes and fast

Ive been working on a lot of Robodrills lately, as we provide service on them. Robo's are Fanucs baby and they guard how the machines work closely. This can be pulled off,but in the end, you would be way ahead to fix the Fanuc 16.PCW is correct in that the encoders go strait to the drives then out to the control. The original control has several parameters that control the drives.That being said,if you pursue this you have the following obsticals to overcome.


If this machine has absolute encoders,you will have to figure out how to decode them.All the RB's ive worked on do.
These machines dont have limit/home switches.
The tool changer is cam operated and uses the spindle motor to index the turret as a c axis,which I beleive is driven by a dual x axis drive.Ill check on thurs.

As RobH pointed out,these machines move FAST,the accell and decel ramps are quick. Im not sure the EMC will pull this off.One of the weaker points of EMC seems to be the PID loop (my experience) and I dont know if you can tune the Fanuc drives(assuming you can get them to work) good enuff to move that quick and smooth.

Im not saying it cant be done,but in the end, if you actually use this machine to make money, you would be way ahead to bend over and pay Fanuc. The amount of production gained at only $20 hour would pay to get the 16m working.

All of this being said, I am intrigued by getting digital fanuc drives to work with the the EMC.We have several Fanuc drives and motors laying around ,Ill give Mesa a call and see what they recommend to get started on this and see if I can contribute to the cause.

The EMC is a powerful tool,but it does have its limitations.I think this is one of them as are dual path lathes.The emc seems to shine on older equipment that is not super hi speed.Im sure it can be made to do anything with enuff effort......

Looking at the motor labels, I don't think this has serial encoders, but probably the
older encoder which has traditional quadrature plus index output. I have a converter
that will generate traditional commutation (Hall) signals, but if you use the BLDC
component, you probably don't need this, you can just use the quadrature and
index signals as is. If it DOES have serial encoders, I have a converter for
those that provides quadrature plus index and commutation.

Many brushless drives are made to take whatever proprietary encoder output
their motors give and send plain quadrature plus index to the CNC control, and
these Fanuc drives may do the same.

Jon

Robh Wrote

also how fast do you want the machine to be, as these robodrills do fly around fast i don't know the model but i guess its a 30m/min machine at least?

just linuxcnc does not have any jerk limiting in its motion planner as such currently if you use this machine for production im sure you brought the robodrill to drill holes and fast

Well, its a wrong machine in wrong persons hand. i am a tool maker by profession (Plastic Injection, compression, press tools)

30m/min! Max i have run it on is 6 to 8m/min Rapid, max spindle rpm i used is 3500

Dont ask why i bought Robo drill!

JR1050 wrote:

One of the weaker points of EMC seems to be the PID loop (my experience) and I dont know if you can tune the Fanuc drives(assuming you can get them to work) good enuff to move that quick and smooth.

i dont think the PID is the issue here and it has been tweaked abit more also just lately which might help with faster accelerating machines.

I think he would get the motors tuned just fine with a very good close follow,
im guessing 1500rpm motors, 20mm screw pitch?
or 15mm pitch 2000rpm motors?

my concern was more the bang bang effect linuxcnc would have on machine with its straight line ramps as there is no damping untill some smart person can write some jerk limiting code.

Hello !

My apologies for this late response! As I mentioned before, I could not understand what you guys are talking. ( I am not from electronics background) Now things are a bit clear.

Here is what seems logical to me.

Simply remove the entire fanuc controller along with the ATC. I dont want to work hard for fanuc, thats not the whole purpose. I just want to start my machine to do simple 3D work for Dies and moulds. I know this is'nt heroic, but is practical.

Please help me with the hardware i will require for the retrofit.

Here is what i need.

1) Servo motors ( as per your suggestions) X and y axis stall torque is 3 N-m, And Z is 6 N-m along with brake. The Z axis does not have a counter weight. (Max rapid required is 300in/m) (Screw Pitch is 5mm)

Encoders -- Accuracy required is +/- 0.01 mm

2) Spindle Motor direct coupled 4000 Rpm should be fine. ( current motor is servo 8000rpm, 7KW)

3) Drives for the servo.

4) breakout board

5) motion control board

6) Input --- MPG pendent , Auto zero - XYZ, cycle start , cycle stop, feed hold, limit switches + - home, e stop, feed override, spindle speed over ride, Power Switch.

Thank you

Prashant