Boring a Deep Hole

[EdK]

I need to bore a 1.5" hole in some 6061 aluminum. It'll be a through-bore that will be 5" deep. What's the best way to accomplish this task? The aluminum will be a rectangular piece.

Thanks,
Ed

[stevec]

Ed, if I couldn't get 5"+ from my quill on my mill I'd set it up in my 4 jaw on the lathe. Oops! you didn.t mention the length.

[f350ca]

Yep the lathe would be my choice.

[wrustle]

What kind of tolerance are we talking about here?

[TomG]

Yes, the lathe and a boring bar would be your best bet for a hole that deep.

Tom

[PixMan]

I agree....lathe is best and especially if you have a taper attachment to correct for any taper you may get. How big of a boring bar do you have and how big of one can your machine hold? I've got a beautiful, never yet used solid carbide 5/8" bar and a steel 1" bar that I'd be happy to ship out for you to use. I could have one of these in the USPS Priority Mail tomorrow for you to have probably by Saturday.

Pick one and it can be on it's way in the morning!


That 3/4" one in the middle with the 55º insert has a minimum bore of 1.250" if that one appeals to you. The 1" one (second from bottom) uses a CNMG43x insert and has a 1.260" minimum bore. The 5/8" solid carbide one that uses old TPG221 inserts (just above the 55º one) has a minimum bore of .812".

The bottom one is a 1-1/2" bar that wouldn't fit without a VEERY oversize bore resulting!

[Mayhem]

Now that is just mean, showing that picture and then saying "pick one"

Seriously, that is a generous offer and one of the reason I like this place and the folk who inhabit it.

[big job]

(07-16-2013, 06:23 PM)EdK Wrote: I need to bore a 1.5" hole in some 6061 aluminum. It'll be a through-bore that will be 5" deep. What's the best way to accomplish this task? The aluminum will be a rectangular piece.

Here goes my stupidity, 1.500 X 5" deep? Best way, on a mill. Sure on a lathe, but what if there are 5 more holes to bore. Guess Im just not seeing this. Only thing Im seeing is a hole 4.50" x 12" deep, do it all the time common boring head & common boring bar. And if you run out of quill just
raise the knee.. carefully..

[EdK]

Oops! I guess I didn't provide enough information. I've attached a drawing that should help.
I would also rather do it in the lathe but how would one hold such a long piece in the 4-jaw without risk of the thing flying off requiring me to use my clean pair of underwear that I was reserving for my parting adventures?

As far as tolerances go, I can make the piece that will be a light press fit into the bore fit the size the bore ends up as long as the bore has little to no taper.

Ed

   

[EdK]

(07-16-2013, 09:16 PM)PixMan Wrote: I agree....lathe is best and especially if you have a taper attachment to correct for any taper you may get. How big of a boring bar do you have and how big of one can your machine hold? I've got a beautiful, never yet used solid carbide 5/8" bar and a steel 1" bar that I'd be happy to ship out for you to use. I could have one of these in the USPS Priority Mail tomorrow for you to have probably by Saturday.

Pick one and it can be on it's way in the morning!

That 3/4" one in the middle with the 55º insert has a minimum bore of 1.250" if that one appeals to you. The 1" one (second from bottom) uses a CNMG43x insert and has a 1.260" minimum bore. The 5/8" solid carbide one that uses old TPG221 inserts (just above the 55º one) has a minimum bore of .812".

The bottom one is a 1-1/2" bar that wouldn't fit without a VEERY oversize bore resulting!

Wow! Thanks for the offer Ken and I may take you up on it since I have nothing even close to the size of boring bar I'll need to do this. But let's hold off for now until I get it all figured out. I'm in the planning stages for a future project right now. I think my boring bar holder is sized for a 3/4" shank but I'll have to check to be sure.

Thanks again.

Ed