ball-barring a 5th axis machine

[Joeyls319]

Morning everyone

 

I got a question on how to ball bar a 5th axis.

 

We got a Haas VF6 with a trunnion on it. We have a Renishaw ball bar. We did the XY palnes but I would really like to do this to the A and B axises as well.

 

Does anyone have any suggestions or is this out of our capabilities with this ballbar?

 

Also, if it is possible, should we correct XY planes before attempting the A & B. I would think so but I'm not sure.

 

Any suggestions or advice would be greatly appreciated.

 

Thanks ahead of time.

 

Joey

[crazy^millman]

If you are going to ball bar then you need a hole different attachment since ball bar is normally tied to fix axis direction and not swivel axis direction. What I have seen people do with 5 axis machine is use a reflector in the spindle and then move the machine tracking it. In your case you need to track the Z axis movement to the A and C axis and really would look at company who has the right equipment to do it.

 

Now does this mean you can not do things no. I would put a precision tooling ball on the 4th axis on the perfect center of C axis(This being the secondary spinning axis). Put a precision indicator with .00005 resolution the indicator needs to be a dial gauge type not a Best Test type but a standard drop type indicator. Now make a loop program that will move the 5 axis movements through a full range of movements but keep the tip of the indicator in contact with the tooling ball. The bigger the sphere the better and it needs to be very precision. Now you can do dwells at places along this movement and have someone record what you see. Now this will show you where the machine is tight and where the machine is sloppy. Now try this at 20, 40, 60, 80, 100, and 120ipm. Now what I would do is create a Excel sheet to put all my data in and record it in 1, 2, 5 , 10 minute intervals. Now use the graphing capabilities in Excel and you have just done a CPK and SPC of the machine. Present this as what you are seeing before the machine is calibrated. Now do it after the machine is calibrated. Now you have a base line in which to compare results. You start seeing problems with the machine you just run this test and now you have results you can compare to that give you an idea where you are having problem and the best way to tackle them.

 

sorry to say this, but look to an OKK, Mazak, Mori, DMG, or one of the machine. I seen a 50 taper 15k OKK go for $239k with almost 40" of travel. Yeah more money, but will run circles around the HAAS. Good luck and hope the information was helpful.

[Hardmill]

Contact tim @ Lasers-Inc .

Perhaps he can point you in the right direction

as to the proper way to accomplish this.

 

 

PEACE

[Joeyls319]

Thanks Crazy and Hardmill

 

Crazy, lots of good info. thanks

 

Joey