Need Help!- Fast boring

[Xenomorph]

I need to bore a 1" +/-.001 hole about 8 inches deep. Can someone please recommend a tool to do this in Aluminum and feeds and speeds? I need to do this as fast as possible. I need to be able to bore this at 32 inches a minute.

[ctate2000]

There are some very good 8D drills on the market today. Mitsubishi and OSG come to mind first. They are both capable of drilling the hole and holding that tolerance. I suspect you can get close to your 32 IPM requirement with them. Quick guess would be 500 SFM and .015 IPR yeilding 26 IPM. Being aluminum you can probably go faster. CNC machining center with through coolant will be required and alignment will be critical.

[ctate2000]

Oh yeah....get your wallet out they are very proud of these drills. One inch drill capable of 8D will be several bills.

[Glacern]

Originally Posted by ctate2000 CNC machining center with through coolant will be required and alignment will be critical.

Good info, plus extra emphasis on the high pressure thru-spindle coolant in order to hit that tolerance at that speed.

[Xenomorph]

What kind of finish would I expect from these drills? I need a 32 or better.

[big_mak]

Why you need to go so fast?

The manufacturers claim these tolerances, but they are only attainable pretty much in laboratory conditions. It's pretty tough to have all your parameters in check to get those results. Look at Mapal Tools they may have a reamer that can help you out there.

[Xenomorph]

In order to meet the production demands

[ctate2000]

Big,

I disagree, I use these drills everyday on aerospace parts. We machine everything from cast aluminum to hard steels. Recently we drilled aluminum with a .250 12D from OSG and it was between .250 and .249. We used a .281 and went 10D in 52100 bearing steel, again .250-.249. The first hole was on a VMC the second on a 12 year old CNC lathe. The only time you have trouble is when the machine is not aligned correctly or you do not follow the manufacturer's instructions.

Xeno,
I would call and ask about surface finish. Visualy, we have very good surface finishes but I have not measured them. In aluminum it may be possible but 32 MIF is tough with any drill. You may consider a PCD drill with burnish margins.
Mapal produces tools that are self supporting with burnish pads. Plan to break a $1000 bill on a tool from Mapal.