Mounting 600 grams of Aluminium around a spindle of a CNC machine

[khalchris]

I am trying to mount a circular clamping brackets made of aluminium around a drilling CNC machine spindle , the total weight of the clamping brackets is around 600 grams,I will perform some drilling tests but I am worried that the centrifugal forces made adding this weight on the spindle will cause a lot of vibration and out of axis rotations and hence the drilled holes will be very poor

I was wondering if anyone have tried to mount something on the rotating spindle before or anything similar to what I am planning to do.

Thank you all

 

[ornerynorsk]

It all depends on if it is a balanced or an unbalanced load. You will have a greater starting load, but the spindle will have more inertia, as well.

It is better to have enough ideas for some of them to be wrong, than to be always right by having no ideas at all.

 

[Tmoose]

I'd include a dense circular pattern of drilled and tapped holes for setscrews to be used as trim balance weights.

http://www.singahobby.com/files/images/Vess-100CC-Propeller-Balance-Ring.jpg

Axially drilled holes are considered safer than radially drilled holes.
If the OD and faces run very true ( 0.0001 inch or so) to the ID, and the corresponding spindle diameter runs very true a homogenous part would have pretty good balance. Assymetrical modifications and features to provide clamping (slots, tapped holes, screws/bolts) will be a bigger source of unbalance.

 

[Screwman1]

Good idea Moose. I remember in the VERY early days of hard drives (12" platters!) that CDC used radial Nylock setscrews as balance weights. They could get a rough balance by putting one or more into selected radial holes and then by screwing then in or out of the holes they could dial in a precise balance.