Chinese Spindles

[Ricardoco]

Hi

For what it is worth I think that drilling a hole down the centre may be a very bad idea. Think about it, the Chinese are very good at making things down to a price so their design is not going to be conservative, that's for sure. Therefore, the diameter of the shaft will have been minimised in diameter and material specification to do the job and no more. Removing some of this material will weaken the structure I am sure.

If you want to do it anyway and can't drill or bore it because the material is hard, you can always get is spark eroded ....maybe.

Still think it is not a good idea though.....sorry

The picture below is of an ER11 water cooled spindle with a hollow center and looks as though it is meaty enough, so i would assume that an ER20 model would be larger, the problem is some come with hollow shafts and some dont, it seems you take pot luck. I have sent a few mails to see if i can stipulate hollow shaft ER20 collet. we will see how that pans out, but they are not as fragile as you may imagine as the pic shows.. unfortunatly ER11 is a little limiting for my project.. Spark erroding wow but then im not sure where i would get that done..