Angle head weight and duration on spindle

[yaji63]

I' am using an angle head which 11 Kg's of weight and i have a job for which i need to keep this angle head on the machine spindle for a weeks time (or probably 2 weeks continuously) . Workpiece is Aluminium 6061 T651.

The spindle will be running at 3,000 RPM. Operation is drilling for 30%, 35% of the time rough milling with a 10mm endmill and 35% finish milling with 10mm endmill again.

The spindle is 12,000 RPM Fanuc direct drive design.

I would like to know if anyone knows the limit with regards to duration for a 11 Kg angle head clamped on the spindle continuously without taking it off. My worry is about the draw bar being able to hold this weight for days on end along with any effect on the spindle bearings (in case).

Is anyone out here doing any similar application where a heavy angle head stays on the spindle for days on end ?

Thanks a ton in advance for anyone who can throw some light on this issue

PS: Programming has not been an issue as i developed a VBA app for converting 3 axis programs to angle head (switching axis movement from Z to X or Y including circular interpolation) after some help on the program conversion issues in some of the other posts in here.

[Geof]

I don't think you need worry. 11kg is about 25lbs and drawbar tensions are in the region of 2000lbs so the angle head is not likely to pull the drawbar down.

The spindle bearings at the bottom are a pair of angular contact back to back and preloaded. This bearing assembly can taken many pounds of upwards end load when pushing a large drill in so it will be able to take a similar end load down. It is not at all likely that 25lbs down is going to be anywhere near what they can take.

[yaji63]

I don't think you need worry. 11kg is about 25lbs and drawbar tensions are in the region of 2000lbs so the angle head is not likely to pull the drawbar down.

The spindle bearings at the bottom are a pair of angular contact back to back and preloaded. This bearing assembly can taken many pounds of upwards end load when pushing a large drill in so it will be able to take a similar end load down. It is not at all likely that 25lbs down is going to be anywhere near what they can take.

Thanks for the info Geof. I was worried about the duration because most of the times i have seen an angle head being used for a couple of hours only and not for days on end and i did not want anything to happen to my spindle or draw bar.

[stevo1]

I am with Geof. I had production setup on 12 vertical machining centers that used all RAH's that were about 50lbs each. These machines were set with 6 of these heads each and toolchanged them thru the cycle for years. There was start up years that these machines ran 24/7. We also had another machine that exclusively ran a RAH that was about 60lbs and the only time it was taken out of the spindle was for a setup with the probe about 3 times a week for no longer then 20min each time, otherwise the RAH ran 24/7.

Stevo