Air spindles and small drills

[Bruce Caulley]

Ahoy!

I am quoting a job that has a few thousand 0.3mm holes to drill up to 4mm deep (0.012" and 0.157")

 

I am thinking of using an air spindle, but have been warned that they will be no good for a hole that deep. If only going 2mm deep the supplier reckons it will go all day, but at 4mm deep the TIR of the spindle will start to snap drills.

 

Any advice?

 

Bruce

[Colin Gilchrist]

Stub drill and peck the heck out of it? EDM? Sounds like a tall order...

 

I was just looking at some vacuum work holding from a company called IBAG.

 

They also make high speed spindles, and you can get them as an auxiliary mount to the side of your spindle. They come with separate drives, motors and even have table mount tool changers you can get. You should be looking at 40-80k spindle RPM with the best balance possible.

[Bruce Caulley]

I can get a 90,000rpm spindle with a BT40 back end and TIR of 0.0002" which I personally thought would have been good enough.

 

I think the air spindle supplier was involved with the company that made the sample of the part that I am quoting. They had a nightmare doing it, but looking at the sample I suspect that they got the order of operations wrong and should have drilled the holes earlier in the process. Based on this experience the supplier has told me that he couldn't recommend it.

 

I think he lost his balls on this job and is too scared to get mixed up with it again.

 

Anyone else think this is a tricky, but definately do-able job?

 

Bruce

[DavidB]

Bruce I drill 0.2mm holes using a carbide A3162 X 0.2 drill from Titex at 80000RPM in a jig grinder. My job is in Al, you didn't mention your material to machine?

 

HTH

[Bruce Caulley]

David,

Material is 6061-T6. Your jig grinder probably has a better TIR than an air spindle. How deep are your 0.2mm holes?

 

Bruce

[Bruce Caulley]

Bump!

[DavidB]

2mm deep through hole

[Bruce Caulley]

Thanks Dave.

 

Bruce