what cnc: fanuc heidenhain or siemens? 4

[pascual]

My company wants to buy a CNC machine. We have an ofer for a Cincinnati CFV 1050 with 3 options:
1/ Siemens Sinumerik 810D, or
2/ GE Fanuc 18i-MB, or
3/ Heidenhain iTNC 530
I don't know the diferences among them to take a decisition. We are mold makers.

what do you think would be better?

thnxs in advance,

 

[EdDanzer]

It will depend on what country you are in, what type of CAM software you use, and if you consider resale value. Some CAM software post processors for the Siemens, or Heidenhain may not be available, or cost more, or be an additional cost.

 

[pascual]

I live in Spain, and the post processor it's not a problem since I use Pro/e and haave the possibility to create one for myself.

The problem I have is that I am not able to determine what kind of control would be better.

 

[EdDanzer]

Better in this case will be more subjective the actual. All the controls are good. The Fanuc will typically cost more, but may have better resale value. What other controls do you have in your shop? The ability to standardize will reduce training, programming, and maintenance costs.
You did not describe the type of work you would be doing, that may have an impact on the decision.
Do you have an opinion on Fagor?

 

[pascual]

The cost will be the same for the three. The ofer is the Cincinnati machine with one of these three for the same price.

I have a Fagor control 8050 but I'm limited. When I try to work by point postprocessed tape, the feedrate is limited to 2500 mm/sg aprox. The 8050 has very little go-ahead procesing. Anyway the ISO code it's not relevant since the postprocessor takes care of it. We don't program directly the CNC.

About the type of work. We are mold makers, from miniaturized piezes (toys, collection trains,...) to small automovilistic components (molds as long as 550 milimeters).
We machine cavities, cores,... everything in CNC.

 

[EdDanzer]

Your best choice would probably be the Fanuc. Feed rate can be limited by the drive package more than the control with newer controls designs. Check with Cincinnati to see if the feed rates are the same for all controls. The only way to know how the control will actually perform is to do a test cut with both controls with a program that requires fast block speed and see which one looks and measures the best.

 

[koruma]

Hi Pascual, I see you are well versed in these CNC matters,maybe you can help me... where can I find technical info about the NUM 720F?

 

[aamoroso]

FANUC

 

[laundry]

fanuc is regarded as the rolls of controllers ex cnc eng.

 

[cadcamguy]

Seeing that you are in Spain... I would take a look at

http://www.soraluce.com/soraluce/DesktopDefault.aspx?tabIndex=1&tabId=219&portalId=1&leftmenuid=686

I have heard good things about them, your support more than likely will be better... they would more than likely be willing to deal on price

Maybe the new rev of cinnci's are better, we have had some older models and I'm not real fond of them.

As far as a post... you have ProE... I take you have Pro/Man so you should be able to tweak a post fairly easily

3 axis.. Fanuc..... more than 3 .. you might consider the others... but that model is 3 axis... but you are in Europe... I just feel Fanuc ..nickle and dimes you to death for memory,options...etc

 

[debco99]

I have any information you may need on the Num 720 if you want to get in touch with me

Regards

 

[koruma]

Thanks a lot debco99, I have a problem with a 720F, the speed reference of channel z is always set to +10Volts,and due to this, I can't initialize the machine, I checked the D/A converter and the opamp that drives this output, these are OK...in you opinion, which could be the problem??

 

[debco99]

Hello Koruma......Assuming your reference to the Z channel is the Z axis and the speed reference is always at +10 volts.
As soon as you power up is there a fault displayed?
Double check all the parameters to make sure they are correct.
Give me some idea how you checked the D/A converter to make the conclusion it's ok.
What type of servo drives does the machine tool use? just curious.
Does the control show a large ampount of lag <following error> as soon as its turned on?

More info and suggestions to follow

Regards

 

[koruma]

Thanks for your reply, debco.
Initially there is no error message in the display, the first thing I do is to select the manual mode to check if there is movement in the 3 axis, the axis x and y move normally, but the motor of axis z start to oscillate as soon as I supply power to the motors, when I checked the output of speed references in the NUM 720, I have 0 volts on axis x and y, and 10 volts in axis z.
I dismantled the num and extracted the DA converter and its associated opamp, I tested this components in a protoboard, and they work Ok, since all the outputs share a common bus, I assumed that the DA conv was the fault...
Now I'm thinking that maybe I have a software problem..What do you think?

 

[EdDanzer]

Try swapping the encoder wire directions.

 

[debco99]

What type of feedback does the machine use?

The fact that the machine is oscillating tells me the problem is in the position feedback.

If possible swap the encoder's or feeback between axis.

I'm assuming the machine was running and this is a failure and not the result of the machine being moved and a possible wiring error.

Are you using Num servo drives with resolver feedback?? There is a procedure for setting up the resolvers depending on the type used.

Are they Num motors as well??

Regards

 

[koruma]

One more thing:
If I disconnect the power to the z axis motor, the display registers an increasing error in the z axis.
I tested the servo driver-motor-tachogenerator set by disconnecting the speed reference from the cnc and applying a variable DC voltage to the speed reference of the servo drive, the motor responds ok, it does not oscillate, and it runs faster on higher voltage, and slower on lower voltages, if I reverse the voltage, the motor runs backwards.
The motor is not a num one, and the servodrive is a minimaestro. The speed feedback is supplied by a tacho generator wich is part of the motor.
I tested the encoder by manually moving the axis, and it register the forward and backwards movements.

 

[debco99]

You are on the right track, even with no encoders connected or motors you should have a lag of zero until you push the Z axis jog button.

When I test a control with no motors or drives I just set the parameter that controls the amount of following error allowed before a fault display. This allows me to test all the jog functions I have written to the plc.

Have you verified all the paramters are correct?

Do you have a way of getting into the plc software?

You need to figure out a way by swapping cables to make the Z axis into the Y or X, swap feedback and speed reference from the control, Im sure this would work to only prove you have a hardware problem in the cnc.

You can also contact Num direct @630-505-7722 tell them Dave B. sent you.

Let me know if I can be of further help

Regards

 

[koruma]

Just one more question, debco, the manual mode programs are on the plc or the cnc?
The plc's backup battery was discharged, I assumed that this was not relevant...
Where can I get detailed info about the Num (diagrams, software, utilities,etc).
THANKS A LOT FOR YOUR HELP!!!!!

 

[debco99]

Everything is done in the PLC, so it really sounds as the plc program is corrupt and you need to verify this somehow.

Did you call up the parameter page??

You need to validate all of this before anything can be done

Regards