Metal Removal

[gcode]

The estimating department was light on a quote for one of the vanes we build and management is whining.
so I put some numbers together to put this part in perspective

It starts as a piece of 8" thick flame cut A36 steel plate Ø57.75 OD x 9.75 ID weighing 5720 pounds

The finished part weighs 2735 pounds

There are a total of 6 operations, 4 VTL ops and two 5 axis mill operations, one rough and one finish

Here is the break down

Stock blank                              5720   -1580 lbs   2 VTL roughing ops
Mill roughing blank                 4140
Mill roughing complete           2860   -1280 lbs
Finished part                            2735   -125 lbs   2 finish lathe  1 finish mill 

Total stock removed                 2985 pounds

There is nothing exceptional about this part, it's just another day at the office.
This is just the first time I've broken one down by weight like this.

I didn't know it, but Mastercam can give you the volume of STL files now, so I am able to calculate the weight
of the stock models between operations... I thought that was pretty cool.

Back in the day I used to program these parts without STL's or stock models because V8, V9 and early X versions
would catch fire and burn to the ground trying to crunch STL's of these parts.

[Newbeeee™]

Just checking - Sales fucked up the price, and Management are pressurising you?
Gotit.

[gcode]

Just checking - Sales fucked up the price, and Management are pressurising you?
Gotit.

like I said
Just another day at the office 

[Kyle F]

Here I am thinking I'm so cool taking my 168lb piece of aluminum down to 8lbs hahaha.
That's some wild #'s, hard to even imagine a 5k lb piece sitting on my table!!!!

[JakeL]

hard to even imagine a 5k lb piece sitting on breaking thru my table!!!!

Fixed that for you 

+1 to the insanity of gcode's projects, really cool to hear about.

[Kyle F]

Fixed that for you 

+1 to the insanity of gcode's projects, really cool to hear about.

The MAM has a max weight of 660, we CRASHING through 

[CNCAppsJames]

In his back building they have a 90t overhead crane... there's been a few projects I heard about where they needed forklift assist on that 90t crane.  

[Aaron]

I'm working on a part that made me think of you, G.   I'm starting with an (already turned) blank of A36 that's #3216, and after the first roughing op it's #1908.  This is half of a rotor that'll be pinned together to be finished and then bolted to a diaphragm wall. 

I managed to get 'em down to a bit less than 9 hours to do that, so 1308/11 = 118 lb/hr.

That'll do pig.

[gcode]

I'm working on a part that made me think of you, G.   I'm starting with an (already turned) blank of A36 that's #3216, and after the first roughing op it's #1908.  This is half of a rotor that'll be pinned together to be finished and then bolted to a diaphragm wall. 

I managed to get 'em down to a bit less than 9 hours to do that, so 1308/11 = 118 lb/hr.

That'll do pig.

Sounds like you're building  the same type of parts I am
a vane and a diaphragm, bolted and pined together to make a closed impeller.
What kind of machine are you roughing it on? 

[Aaron]

Sounds like you're building  the same type of parts I am
a vane and a diaphragm, bolted and pined together to make a closed impeller.
What kind of machine are you roughing it on? 

They've got some big toys, but due to them being occupied, we're on the "small" Okuma MCR-A5C dual-column VMC.

[gcode]

They've got some big toys, but due to them being occupied, we're on the "small" Okuma MCR-A5C dual-column VMC.

We do one series of parts that is too big for our Okuma 5X machines. They are about Ø75"x 12" and we rough them on our old Cincinnati 5X gantry mill. I'm not getting near the MRR that Arron's Okuma is, and the machine is down 20 minutes of every hour for chip removal.

[Jeff]

the machine is down 20 minutes of every hour
for chip removal.

Did ICE deport your Mexican chip shovelers? 

[gcode]

Did ICE deport your Mexican chip shovelers? 

No, everyone at our shop is legal.
It's just hard nasty work and the shape of the part makes it a large bowl
full of chips. If you don't keep the chips out, it will wreck the inserts
recutting chips.

[Aaron]

Yeah, I'm lucky here that these are the half-discs, makes chip removal better.  It would have been nice to do it on a horizontal boring mill like originally planned, but we're fighting gravity a bit.    They did rig up a big air gun pointing right at the bottom of the cutter, which was huge for insert life.

What we did drill out the lowest point between the vanes w/ a 2.9" drill, then, plunge rough a 2.5" slot from that hole outwards to the inside (since it's a shorter distance), then going back to that initial hole working out to the outer rim.

After that, I worked with their Kennametal rep to find a 2" Kennametal shoulder mill w/ .6 DOC inserts, but I'm doing 3-4 depths of Opti (1"ish-1.5" deep for each "section").  I'm stepping down the DOC from .3 down to .2 for each depth section.  That seems to be the right combo of material removal and small enough chips that the air blast can get 'em out of the way.   By doing the smallest step down at the very bottom of the vanes, it seems to be evacing the chips nicely.

I don't know how much manual intervention they're doing between passes, though, I'm not onsite but they say it's going really well.   They were planning on doing 22-25 hours of roughing for the bigger pieces (76"x38"x7"), but we got it done in ~9, so they're pretty happy.   They have 11 parts to do total, each having two halves, so that'll be 22(parts)x13(hours) = at least 286 hours of roughing time saved.

[gcode]

That Okuma is a powerful machine!
I mostly use Ingersoll 1/2" button cutters and mid feed face mills for roughing