How To Counter Bore?

[wrustle]

(06-04-2013, 06:59 PM)EdK Wrote:

(06-04-2013, 06:43 PM)f350ca Wrote: Could you not counter bore it with a regular left had tool bit (one that cuts toward the headstock) Do as a facing cut from the center out. You have a hole to start in.

I might be able to with a small enough tool. I'll see if I have one small enough to do the job. Otherwise I'll just grind one out of a blank.

Thanks,
Ed

Ok, I'm lost now.....I thought that was what you were intending all along.

Start in the center and feed out. That's what the ground EM's are used for I posted pictures of.

Take your .250" blank or EM and grind back all but one flute a quarter inch or so (you're only going .050" deep) and grind an angle on the front by eye....(nothing fussy) enough to get the point in the hole and feed out by hand to your 1" dia. (look at the close up picture I posted)

After your first pass is established to a measured dia., the remaining passes will be done in a flash.

Later,
Russ

[EdK]

(06-04-2013, 07:08 PM)wrustle Wrote: Ok, I'm lost now.....I thought that was what you were intending all along.

Later,
Russ

Russ,

Yes, that was the intention all along. I was just asking for advise on what tool to use. I have a number of suggestions now and since I'm lazy I'll look for the easiest way to get it done. I need more experience taking videos so I'll attempt a video of me butchering the work piece. To be continued....

Ed

[TomG]

Sorry Ed, I didn't realize it was a 1" dia. counterbore. I would definitely just grind a facing tool out of a lathe bit and go to town. Or, if you have an old end mill, do as Russ suggested and make one out of that.

Tom

[PixMan]

I've used the end mill thing Russ showed, still have it in my box....somewhere.

I've also added a few Micro100 (brand) solid carbide boring bars to my tooling library just for things like that.

You shouldn't fear breaking the one you have, just take facing out cuts of just .003" to .005" per pass.

[EdK]

(06-04-2013, 11:49 PM)PixMan Wrote: I've also added a few Micro100 (brand) solid carbide boring bars to my tooling library just for things like that.

That's exactly what I have. The tiny one in the picture and one about twice that size.

Ed

[Mayhem]

(06-04-2013, 06:17 PM)EdK Wrote: ...The material is 1018 CRS direct from our friend Russ. Any thoughts?...

Yes - you should have had Russ machine it before posting it to you

[wrustle]

(06-05-2013, 06:03 AM)Mayhem Wrote:

(06-04-2013, 06:17 PM)EdK Wrote: ...The material is 1018 CRS direct from our friend Russ. Any thoughts?...

Yes - you should have had Russ machine it before posting it to you

Hahahaha......hindsight is always 20/20 they say!

[stevec]

(06-04-2013, 06:17 PM)EdK Wrote: I vaguely remembered that I had bought a couple of small solid carbide boring bars off of ebay some time ago. Surprisingly I was able to find them in quick order.

I was gonna offer my 2 cents but after reading that, I decided I can't offer any help a tall!

[dallen]

Ed I have a boring bar you can borrow here's a picture of it I think its small enough to do what your wanting to do.

[EdK]

(06-05-2013, 03:35 PM)dallen Wrote: Ed I have a boring bar you can borrow here's a picture of it I think its small enough to do what your wanting to do.