Okuma and Fanuc 5 Axis Motion

[cincy k]

So I've read the various topics on Fanuc's WSEC vs TCPC and grasp the concept of how both work beside one thing. When using WSEC for simultaneous motion are you using inverse time feed?

 

From talking with a few Okuma folks it seems they prefer TCPC for simultaneous motion even on a trunnion setup. Based on that, TCPC is an option typically coupled with Super Nurbs and the TCPC control works much the same as Fanuc's. Okuma compares their fixture tracking to Fanuc's WSEC. Does anyone know if it's advantageous for trunnion setups to use inverse time coupled with fixture tracking? 

 

Just throwing some comparisons out there and seeing what kind of info I can get on people's preferences/experiences with the two different controls. Hoping to here from end users of both here.

 

Thanks!

[Guest MTB Technical Services]

I personally prefer to only use TCP on a FANUC controlled Profiler/Gantry (head/head).

With FANUC TCP, the feedrates are G94 (UPM)  as TCP handle the Inverse Time calculation internally.

The XYZ coordinates are table coordinates meaning the CL Tool Tip coordinates.

If you're not using TCP for a head-head machine then your coordinates are the center of rotation of the head rotary axes.

Without TCP you will be using Inverse Time Feed as the machine needs to interpolate both linear and rotary motion simultaneously.

When the tool vector doesn't change between CL points then the feed mode will change to G94 as only linear axes are moving in this situation.

 

Keep in mind with any 5-axis machine that you are limited by the the slowest rotary axis feed.

This situation can be very problematic with larger and heavier work on a dual-rotary trunnion when running TCP as you can reach max velocity

on the slowest rotary almost instantly. Don't cheap out on look-ahead if you want to use TCP on a dual-rotary trunnion.

 

The only advantage I've personally had from TCP on a trunnion is limiting the travel  within the work envelope.

WSEC makes setups easier but also helps with issues of singularity when approaching a horizon.

[Greg Williams]

Okuma use the TCPC function to allow the operator to place the part anyway on the table and run the same program, without TCPC ewe will need to program around the intersection of the 2 rotaries.

Okuma fixture tracking CALL OO88  runs a macro in the background that calculates a new work offset based on the new position and the values of the current work offset, usually the new values are added to H51 or H99. The program then uses this new work offset in place of the original one to continue until CALL OO88 is run again or the end of file is reached. You should make sure you have the super-nurbs for 5 axis option as it is different from the standard super nurbs. Inverse feed is not required with super-nurbs and TCPC

[Mick]

Actually, on the Okuma MU500/P300, it will alarm if inverse feed specified.

 

We don't use inverse time for the Fixture Offset (CALL OO88) at all. Fixture Offset is for 3+2 programming.

 

What post are you using? A Postability or Inhouse Post? I did my own MU500/P300 post, incorporating TCPC and Fixture Offset functions.

[cincy k]

Actually, on the Okuma MU500/P300, it will alarm if inverse feed specified.

 

We don't use inverse time for the Fixture Offset (CALL OO88) at all. Fixture Offset is for 3+2 programming.

 

What post are you using? A Postability or Inhouse Post? I did my own MU500/P300 post, incorporating TCPC and Fixture Offset functions.

 

How are you getting along with your MU500? How much simultaneous work are you doing? How well does TCPC work coupled with M/C? What was you control experience before moving over to Okuma?

[Guest]

So I've read the various topics on Fanuc's WSEC vs TCPC and grasp the concept of how both work beside one thing. When using WSEC for simultaneous motion are you using inverse time feed?

It's not a "vs" situation. They can be used separately or be used in conjunction with one another.

 

Here's where are both similar; they both use #19700 through #19705 to figure out how to apply the calculations. The machines kinematic positions are stored there. THere's other paraameters that define the machine's orientaations, etc... but that's neither here no there.

 

TCPC/TCP is Tool Center Point Control. It's a function that allows you to put the same part program on machines that are dis-similar (i.e. nutating head machine vs. a trunion machine provided they have the same axis configuration - nutating head machine with an A/C axis configuration could run a program that was designed for an A/C trunion machine, etc...). Also, when you change tool lengths, you do not neeed to re-post the program as the TCP function uses the kinematic positions AND the tool length to figure out where it needs to be. An inverse feed program does not have that same functionality without some outside help. Like was stated a bove, your program in UPM and the control calculates the rest.

 

WSEC is Work Setting Error Compensation. It is like Dynamic Fixture Offset with the exception that it is designed to run while doing 3, 3+1, 3+2, or simultaneous 5-Axis work. It works in conjunction with your work offset. So your G54 would be the "perfect" position of your part, not let's say that your fixture is "off" (I know, I know, I know, that NEVER happens ). Wherever and however that fixture/part is off, you put that data in the WSEC Offset table, AND what rotary angles you had the machine at when you figured out that error and voila; your out of position part/fixture is no longer out of position. Sometimes there's more to it that that but, that's the jist.

 

HTH

[gcode]

We're running an Okuma MU-1000 horizontal trunion machine

with parts up to 5000 pounds. The work is almost all 5 axis simultaneous toolpaths

I use G169 dynamic fixture offsetting and CALL OO88 for the 3+2 stuff.

I have one vane fixture that was built .030 off center by a trainee, but parts coming off that fixture

are as good as ones coming off the properly built fixturs

I'm currently using an ICAM post.

This week I'm building a series of parts for Spacex.

The program zero is offset from machine C/L 15" in Z and 6" in Y.

The resulting parts are CMM'ing within tenths.

I've been programming that Okuma for 18 months now and it still never fails to impress me.

It's a truly remarkable machine.

[cincy k]

We're running an Okuma MU-1000 horizontal trunion machine

with parts up to 5000 pounds. The work is almost all 5 axis simultaneous toolpaths

I use G169 dynamic fixture offsetting and CALL OO88 for the 3+2 stuff.

I have one vane fixture that was built .030 off center by a trainee, but parts coming off that fixture

are as good as ones coming off the properly built fixturs

I'm currently using an ICAM post.

This week I'm building a series of parts for Spacex.

The program zero is offset from machine C/L 15" in Z and 6" in Y.

The resulting parts are CMM'ing within tenths.

I've been programming that Okuma for 18 months now and it still never fails to impress me.

It's a truly remarkable machine.

 

 

So for you simultaneous motion with the Okuma are you using TCP?

 

Where there no suitable post from In-house or Postability?

 

What was it like setting up Vericut on the simulation side and being confident in its results?

 

The post, 5 axis ans Vericut would all be new to me just figuring what kind of time is involved from the machine hitting the floor to make parts in a 3+2 configuration for right now and simultaneous stuff down the road.

[gcode]

So for you simultaneous motion with the Okuma are you using TCP?

 

Where there no suitable post from In-house or Postability?

 

What was it like setting up Vericut on the simulation side and being confident in its results?

 

The post, 5 axis ans Vericut would all be new to me just figuring what kind of time is involved from the machine hitting the floor to make parts in a 3+2 configuration for right now and simultaneous stuff down the road.

 

The post outputs tool tip code.

It does not matter where the part is on the table.

G169 handles the 5X tool paths CALL OO88 handles the 3+2

 

I originally bought a post from my dealer.

It worked well enough for 3+2 and simple 5X  tool paths

I use the advanced 5X module for these vanes and the post had trouble with these.

A finish pass on a vane is really just one path rotated 20 times and the post couldn't handle it.

My Vericut machine was still under development and the time.

It was very unsafe, occasionally spinning the C and flipping the A for no reason.

Ron was trying to build an ICAM dealership at the time so I gave ICAM a shot.

The resulting post works well.

[Mick]

How are you getting along with your MU500? How much simultaneous work are you doing? How well does TCPC work coupled with M/C? What was you control experience before moving over to Okuma?

 

I've cut three dies and a ton of sample parts with simultaneous 5 axis. I used the generic 5 axis post, which had been modified for the MU series, but it didn't have TCPC at all, and the fixture offset function wasn't correct. I fixed the fixture offset function, and wrote in the TCPC. We considered purchasing an Inhouse or Postability post, but due the relationship with our reseller going south, we never pursued it further. We're tolerating the post as is, with a longer term view of moving to another CAM system.

 

It works ok, but you have to wary of the approach and retracts. Which is where Vericut comes in really handy. I spent a ton of time creating the Vericut machine model and control, and it handles the TCPC and Fixture Offset function perfectly now.

 

I've used Okuma controls since the OSP2200L (ugh), right through to the P300M so I have been conversant with Okumas since the late eighties. However, I've also got a lot of experience with Fanuc controls as well.

[Mick]

Hey gcode... G169 is TCPC, not Dynamic Fixture Offsetting.

 

Well, that's what the manual says anyway

[Greg Williams]

Both Postability and In-house offer a post for this machine