Help with cap with flange fixturing

T

twabscs

Aluminum

Joined

May 7, 2012

Location

NW Missouri

• Dec 30, 2020

• #1

Hi All,

Trying to quote a new part, see diagram. I would like to use flat stock to save on material. I have a good mill and lathe with live tooling to drill the holes. My quandary is how I might fixture this on the lathe to turn the diameter as it is has some tight features for o-rings, etc. Once the tight features are completed on the lathe, I'll cut the profile on the mill. Any thoughts on a good way to fixture this. It's only 3/4 thick and is basically a cap with an oring groove.

Thanks

 

Finegrain

Diamond

Joined

Sep 6, 2007

Location

Seattle, Washington

• Dec 30, 2020

• #2

I would do everything except the final ID features in the mill. Then make a fixture with a part-shaped pocket and 2 threaded holes. After the mill work, bolt the part onto the fixture, grab the fixture (make 2 of them so you can swap parts while the lathe is working) with soft jaws, and do the final ID features.

Regards.

Mike

 

T

twabscs

Aluminum

Joined

May 7, 2012

Location

NW Missouri

• Dec 30, 2020

• #3

Alright, thanks. Been going through so many ways to do it. There isn't an ID, just an OD with the groove. It's basically a cap with with a bottom OD w/oring that can be bolted down. I know I didn't show the bottom of the part as need to stay generic. But what you're saying should still work. I'll just need to ensure clearance is there to allow bolting to the fixture. Then come in finish the OD and put in the groove.

 

V

VTM

Hot Rolled

Joined

Jun 8, 2018

• Dec 30, 2020

• #4

Why not do it all on the mill? I see no reason not to. What is the material and what are the tolerances your worried about? I wouldn't go to two machines or fixture It If It wasn't necessary?

 

T

twabscs

Aluminum

Joined

May 7, 2012

Location

NW Missouri

• Dec 30, 2020

• #5

I'll probably try, but I'm more comfortable with these features on the lathe. The radii and groove are +/- a thou. I'm kind of RD for one of my customers. There is another version without the ears and will all be done on lathe, so just going through options.

 

Finegrain

Diamond

Joined

Sep 6, 2007

Location

Seattle, Washington

• Dec 30, 2020

• #6

twabscs said:

There isn't an ID, just an OD with the groove. It's basically a cap with with a bottom OD w/oring that can be bolted down.

Click to expand...

Oh, I see. Well then definitely I would do it all in the mill. +/-.001" is straightforward in the mill unless it's an old knackered POS. Might have fussy surface finish requirements in the O-ring groove but this can be managed in the mill too.

Regards.

Mike

 

V

VTM

Hot Rolled

Joined

Jun 8, 2018

• Dec 30, 2020

• #7

You have an Okuma M560 +/-.001 all day long!! We run a part on our Okuma less stable than what you have there +/-.0002 on an I.D. No problem.

 

T

twabscs

Aluminum

Joined

May 7, 2012

Location

NW Missouri

• Dec 30, 2020

• #8

Well, the mill is one of the best: Okuma M560. I recently did some 14" flanges in 304 and was quite impressed how well it handled the IDs and ODs. Because of the size I HAD to do them on the mill. I'm more of a lathe guy so always tend to go there. Thanks for the confidence, and I'll sharpen my pencil on the quote.

 

V

VTM

Hot Rolled

Joined

Jun 8, 2018

• Dec 30, 2020

• #9

twabscs said:

Well, the mill is one of the best: Okuma M560. I recently did some 14" flanges in 304 and was quite impressed how well it handled the IDs and ODs. Because of the size I HAD to do them on the mill. I'm more of a lathe guy so always tend to go there. Thanks for the confidence, and I'll sharpen my pencil on the quote.

Click to expand...

Yep, you should have no problem holding those tolerances on that machine!! Good Luck

 

B

Booze Daily

Titanium

Joined

Sep 18, 2015

Location

Ohio

• Dec 30, 2020

• #10

Let's see if I understand. The dotted lines are not a trepan, they are a boss with an O-ring groove in it?
How many?
Don't over-complicate it. Make it out of round. Turn and groove on lathe, hold on boss with soft jaws and mill profile and put in holes.

 

T

twabscs

Aluminum

Joined

May 7, 2012

Location

NW Missouri

• Dec 30, 2020

• #11

Yes, it's a boss with oring under the cap. Round material is more expensive than flat. Flat is faster to cut too, thus one of my reasons for thinking about the mill approach. We're mostly a job shop so think 100 quantities. I've been doing this part-time for 10 years, program everything by hand, and am about to go full-time. So you guys will get to entertain more of my semi-machinist questions. Always appreciate your all's help.

 

D

Dan from Oakland

Titanium

Joined

Sep 15, 2005

Location

Oakland, CA

• Dec 30, 2020

• #12

Make it out of material slightly thicker that finished size. Grab the blank on the unused thickness, profile the shape, drill the holes, cut the groove. Flip it over and hold it in soft jaws with profile milled in the jaws and mill off the excess material on the back side.