Question about this rotary table set-up

[darkzero]

John already mentioned it but can you get a NT arbor (or whatever your spindle taper is) for your boring head to eliminate the use of the collet chuck?

Also, can you do the boring in the lathe? Not sure of the size of the table or if I'm missing something that you might have posted before. I've been away from the forum. If you can fit it on your lathe should be much more rigid & quicker to bore out.

 

[NortonDommi]

Ditto for what benmychree said. Don't cut that boring bar!
Although some knock them those el cheapo import boring bar sets are not too bad if you fettle them a bit and they have different sizes in the set.

 

[Janderso]

John already mentioned it but can you get a NT arbor (or whatever your spindle taper is) for your boring head to eliminate the use of the collet chuck?

Good idea, I have the NT30/NMTB 30, taper spindle. I'm sure I have a collett I could put the boring bar in and eliminate the ER40 set up. = maybe more rigid.

 

[Janderso]

Finished, almost.
At least now I have hold down options.
I really enjoyed power tapping with a spiral flute tap.
Made quick work of all those holes.

 

[tjb]

Nice work, Jeff.

Finished, almost.
At least now I have hold down options.
I really enjoyed power tapping with a spiral flute tap.
Made quick work of all those holes.View attachment 325225

 

[darkzero]

Agreed, came out great.

 

[Bob Korves]

I'm sure he still stares at the screen, as we all do ---

My account went away for some unknown reason, and so did I. I am currently working with H-M staff to get set up again with my original account named Bob Korves. In the meantime, I will be using BobKorves. I recently created that user name to post with and for you to find me.

 

[Janderso]

My account went away for some unknown reason, and so did I. I am currently working with H-M staff to get set up again with my original account named Bob Korves. In the meantime, I will be using BobKorves. I recently created that user name to post with and for you to find me.

What ever you call yourself, we are glad you came back!!

 

[Bob Korves]

Both accounts are now combined together as user "Bob Korves" (with the space between Bob and Korves.) Many thanks to vtcnc for setting it up for me...

 

[Jake P]

Hi all,
I hope you are well.
This is a set-up and chatter question.
Over the weekend I made some progress on my rotary table pallet-work table.
I don't have very much experience with boring on my mill.
It's a full size Sharp 3hp knee mill. I locked down X and Y, I used the auto down-feed feature at slow and medium with different cut depths ranging from .025 to .075".
I held it down as sturdy as I could think of. I placed the 2-4-6 blocks inward to reduce chatter. I started out with a 1/2" hole, I am boring to a depth of .500" and I'm going out to 1.625"
This is a 2" Shars boring head. I started out using a Criterion boring bar which I touched up and honed but found it had too much flex as the chatter was bad. I switched to a shorter and thicker bar = same issue.
The boring bar I am using in the picture allowed me to get the job done. The finish was very good.
I had to play around with feeds and speeds as the hole got bigger. I went into back gear around 350 rpm at the end.
My question,
Is there a better way to stiffen up the part?
Is there something wrong with my set-up?
Ideas?
Thank you.

Have a look at Mesa Tools and check out their boring bars. My used mill came with lots of quality tooling and there was one of their 3” (length, 1/2” dia) bars for the Criterion boring head. No chatter at all for me so far.

I ordered their 3” cross hole bar as well. Should be in my mailbox today.