Haas VM spindle speeds

[chipman]

We have a few of these machines, VM3 to VM6, they have 12,000 rpm spindles and we run lots of smaller cutters less than 1/16 in diameter.

 

Some of the operators claim that anything above 7,000 rpm will make the machine move/float.

 

What do some of you do to help alleviate that problem. External chiller?

 

And yes I understand that it is a Haas...so you know the drill.

[Thee Dragracer1951]

We have two VM2's

They both have spindles that move around with temp. I warm them up in themorning, and if I have to do anything closer than a couple thou in Z it's a total crap shoot.

Which is pretty strange to me. My 2000 mini is very accurate.

These VM's are a 2011 and a 2012.

Another thing they do is if I move the Z by .0001, it won't more for a couple tree clicks. Then it'll move a half thou.

[Prodoggg]

We have a VM3 and don't have any problems running at high RPM. The coolant is used to cool the head and flows around the casting before coming out of the nozzle. Make sure you have plenty of coolant flowing around the head and it is not being restricted by a valve. If we don't need all the coolant flow on the part we will direct one or two lines off the table with full flow and one on the part. Also make sure your tool holders are balanced, check for tool run out, should be less than .0003 on small tools. We use shrink fit holders and have good luck. Hope this helps.

[chipman]

We have two VM2's, I warm them up in themorning, and if I have to do anything closer than a couple thou in Z it's a total crap shoot.

 

How much fluctuation do you see?

 

So I am guessing that you work around the fact that it floats?

 

The coolant is used to cool the head and flows around the casting before coming out of the nozzle.

 

I did read this somewhere and I had one of the guys on the floor try it, he said it did not make any difference. Are we doing something wrong?

 

We have the Rego-fix power grip tool holders, they alone are rated to 3μm runout, So I believe that runout of the tool holder alone would not be an issue.

We don't have a balancer and the only way for us to check runout would be in the machine. But it might be wise for us to send out a tool mounted in a holder to check runout to eliminate the possibility.

 

It just kills productivity to run 1/32 ball endmill at 7k rpm.

[mkd]

if your bread and butter is using tiny cutters i'd suggest using either a air driven head or a planetary speeder head.

want 40,000RPM? no problem.

 

why burn up any machine when there is a better, faster way?

[chipman]

if your bread and butter is using tiny cutters i'd suggest using either a air driven head or a planetary speeder head.

want 40,000RPM? no problem.

 

why burn up any machine when there is a better, faster way?

 

40k would be sweet!!!

 

I looked into the air driven and the boss and owner were worried about the air consumption and it sounding like a jig grinder.

I could not get them to give me permission for even the guy to come demo the unit.

 

We have a speeder head, And it has worked but also heats up quickly and grows. So the depths were inconsistent. When I was on the floor I was using it to semi with. But now It's sitting in the box seized up.

 

RPMS should have been one of the biggest deciding factors when purchasing these machines,

But upper management did not consult with others, So we are stuck with what we have.

 

If this place was mine...

[mkd]

if you guys are using a piston compressor currently, i would not consider the air driven option as well.

 

like anything money is the bottom line. if you can show them more RPM will save X-amount of time and money AND it would earn back the investment for all the cutters that need it then it should be a no brainer.

 

As far as thermal growth and longevity, you get what you pay for. A forum member promotes Kiaser attachments. some have internal coolant passages. Others will need splash-cooling.

(http://www.emasterca...showtopic=75589)

 

lead a horse to water....

[Joe788]

Chipman, if possible, can you do semifinishing at 12,000rpm for awhile before the final finishing? I have a few different buddies with SS and VM machines with that 12k spindle. They seem pretty happy as long as you keep it cooking at high RPM so it's not growing and shrinking.

[Robert Ouellette]

I have a 2010 vm-6 and no problems at all. I see .0001" - .0003" after a full day of running flat out. but I run it with full coolant flow all the time too. on aluminum parts I can run a full week of parts and not change a single offset and not see more than .0002" over the week. have you had HAAS come in and adjust the thermal comp?

[chipman]

I have a 2010 vm-6 and no problems at all. I see .0001" - .0003" after a full day of running flat out. but I run it with full coolant flow all the time too. on aluminum parts I can run a full week of parts and not change a single offset and not see more than .0002" over the week. have you had HAAS come in and adjust the thermal comp?

 

 

Can you expand on the thermal comp.

What is it that they might actually do?

[socaled]

Electronic Thermal Compensation (ETC)

 

This powerful software feature – standard on Haas machine tools – uses a proprietary algorithm to compensate for the expansion and contraction (due to heating and cooling) of each linear axis. The ETC algorithm utilizes a model of the lead screw, and estimates heating of the screw based on the distance traveled and the torque applied to the motor. Heat is represented by a thermal coefficient of expansion, and the axis distance is multiplied by the coefficient to get the amount of correction needed. A real-time clock allows monitoring of in-motion time as well as non-motion time (e.g., lunch, breaks) and compensates accordingly. Our testing shows about a 4 to 1 reduction in the error associated with average lead screw growth. A series of parameters allows this feature to be implemented on each axis of various models, with some room for fine-tuning. Keep in mind that ETC does not correct for: thermal growth due to changes in ambient temperature; growth due to part expansion; or growth due to spindle expansion/retraction.

 

Cut & Pasted from http://www.haascnc.com/techfo_programming.asp#gsc.tab=0