View Full Version : Biggest Part Machined
09-23-2004, 10:38 AM
I've never worked on any really big parts but I would like to hear your experiences. What's the biggest single part you have machined. Length, volume, weight, whatever.
09-23-2004, 11:02 AM
Lathe: 24" dia. 6" thick solid block of Inconel. Was to become a flange of some sort. Did not get to finish it. I had gotten laid off before project was finished. The facility was shut down.
Vertical Mill: Surface milling 96"x6"x1" Zirconium Bar. Chips burn nice! Also some 24"x24"x2" blocks of Tinamel. Same facility.
09-23-2004, 11:27 AM
Coke oven doors and jambs.
These iron castings were up to 22' long.
The jamb has a sealing surface around the inside milled flat and to 125 finish.
The jamb was machined on an Ingersol Planer type mill.
The door was milled on the above machine and drilled on a Carlton NC horizontal drilling machine.
The door had up to a hundred spring plungers to preload the ring.
The sealing ring was welded up and finish machined on the door flat within .002 per 24".
These assemblies were machined on a Gray open sided planer mill.
Sound isolation couplings for atomic submarines.
These were built up of many steel and bonded rubber components.
The main plates were around 84" dia by 4" thick tapered and bored for the bonded pins.
These plates were turned on a King 84" Boring Mill. The pin holes bored on a 5H Devlieg Jig Mill.
There were many other components to these jobs many of which I worked on, some not.
09-23-2004, 11:42 AM
We cast and machined crap spreaders for water treatment plants.
This was a split internal ring gear with bosses on the outside for the spreader arms.
The joint faces for the gear were machined and drilled first. The gear was assembled and the gear ring dia machined on an old Sellers 16' boring mill.
After turning, the bosses were milled and drilled for the sh-it spreader arms to bolt on on that horizontal Carlton drill, or HBM.
The teeth were subcontracted out.
It was big heavy work. The shop was served by three 18 ton cranes with 2 ton aux. hooks.
Someone here can top it though.
09-23-2004, 11:42 AM
Haven't actualy cut on it yet, but I have an old anvil (about 250#) that needs to have its base flattened. ...has diagonal corners that are probably least 1/2" high (or low, depending on your perspective). Pretty wobbly. I may need some help getting it on the B'port table. I can hardly lift it with one hand.
The big problem is - my wife is real small and can't reach up that high. And I'm afraid she might drop it if she tries to step up on a stool. Could chip it or break the horn off, you know.
09-23-2004, 12:01 PM
Kap, I think I put a couple of them in. The ring runs on tracks with loose ball bearings in a groove?
I hate sewage plants. I always smash or mash a finger.. and worry.. It washes off unless you have a cut or other open point of entry.
David Cofer, Of:
Tunnel Hill, North Georgia
09-23-2004, 12:03 PM
No doubt much smaller scale than many of you have done, but about six months after starting my machining career I was charged with making the shafts for tub grinders. Those are those huge shredders that take whole trees in the hopper and send chips out the chute.
The shafts started out 10" dia. and had a few steps and both ends threaded for about a 6" I.D. nut. The tolerance was about +-.003" over the 9-foot length - one pass took about 25 minutes and the lathe was a badly worn out Clausing. The unmachined stock cost over $800 - and I repeat, I had been a machinist for about 6 months.
I never trashed one though. Quite a baptism of fire I think. I still don't know if the management was really stupid or really good at seeing potential.
09-23-2004, 12:05 PM
I didn't personally work on it, but a buddy of mine in Tacoma, Washington machines the tunnel boring machines, such as were used to tunnel under the English Channel. The largest parts were machined on a vertical mill with a table over 12 feet in diameter, and weighed over 40,000 lbs.
I saw him earlier this week and he was working on a valve consisting of three castings that together stood nearly 14 feet tall. One part was bored 57.147 inches in diameter, +/- .030
09-23-2004, 03:14 PM
In one of the History Channel shows about WW2, focusing specifically on the "gear up" to full production, had an all-too-brief snippet of a Sherman tank, nearly complete minus treads, on the table of a vertical lathe. It was doing what appeared to be about 40 rpm, while a stationary single-bit tool cut the seating ring for the turret.
Even though the whole clip probably wasn't two full seconds, it was still interesting to see most of a tank turning like a record player. http://bbs.homeshopmachinist.net//biggrin.gif
09-23-2004, 06:57 PM
I machined on a 6'X6'X4" piece of magnesium a few months ago and also did some work on a big block of aluminum. I dont remember the actual size of the aluminum but when it came into the shop it weighed 350 pounds and when it left it weighed 114 pounds(long weekend). We occasionally do repair work for a large shop and they have some big machines, for example they have a vertical lathe with a 24' foot dia table on it, they also have some really big gear hobs and big two story welder. They make big gears there, mostly for the mining industry. The first time I went there they were assembling a giant gear in the parking lot. It was so big it had been made in 4 pieces.
09-23-2004, 07:15 PM
On the last job, I made several intake plenums for an Indy Car engine. Trying to remember the details after 7 years is tough. I think the block of Alum started out 12" x 12" x 24". Ended up with 1/8" walls all around and something like 80% of the weight in the scrap bin. This could have been fabricated from sheet and welded, but the owner wanted it from solid. I did the job on a Haas VF-4 with a rotary table & tailstock holding what was really just a big sine plate. Being new to CNC, I just wrote programs for each angular set-up, picking up a tooling ball for location each time. This was the first time I used SmartCam for surfacing. Worst thing about it was as soon as the design and programming were finished, my hardrive crashed. No back-ups, owner's son "didn't get around to it". His punishment was he had to help me reprogram it. You can bet he never forgot to back-up again!
09-23-2004, 08:16 PM
Conveyor drums,24x36",about 450lbs.Next would be cable drums 6' x 11',cast steel including left and right grooves,fun for hours.
09-23-2004, 09:54 PM
Making a few changes to a bumper. A little this way and a little that way and it all blends together.
09-24-2004, 01:57 AM
[This message has been edited by John Stevenson (edited 02-10-2006).]
09-24-2004, 06:18 AM
Motorcycle wheel on my 24" Cinncinati lathe.
I was afraid it would unchuck and run through the wall.
David Cofer, Of:
Tunnel Hill, North Georgia
09-24-2004, 06:51 AM
Trunnions for a steel mill cylinder. The cylinder that tilts the ladle of molten steel to pour it into the ingot molds. The ring was 48" in diameter with a 9" diameter trunnion on each side. When that got spinning it created quite a breeze! The lathe was a 54" x 288". Don't remember the maker....The bronze bushings for the trunnions weren't small, either. 15" od x 9" x 15" long.
Assorted large piston rods for hydraulic equipment. 8"+ by 96" long....Lodge and Shipley oil country lathe with a 12" through hole in the spindle and a second chuck on the outboard end.
I also did pedestal binders for steam locomotives. They were about 6" square forgings and were about 4 feet long. Plus assorted other parts. Locomotive drivers on a 90" wheel lathe. You needed the 35 ton crane to pick those up.
Ugh, sewage treatment stuff.....I've made pelletizer parts and hair strainer parts. And repaired the sewage shredder here at work. I needed the hepatitus shot to even work on that...
Kap, you've got most of us beat....
09-24-2004, 08:02 AM
Lessee. Any number of Navy propulsions shaft section. Largest were 55 ft long 26" diameter with 44" flanges 9" thick. 26 ft propellers (doctoring the tapers). Grinding the roller path on an armored 5" 38 cal twin gun mount. Facing a 26 ton shaker table (about 24 ft octagon.) Tons of drydock and hydro-electric pump cases, impellers, inlet rings, volutes, valves, flanges, mounting rings. Acres of fabricated steel machinery foundations - some in place with pertable equipment. Honkin' big crankshafts and steam turbine rotors and cases. Turning circles for big dockyard cranes and once a big green Doug fir log about 40 feet long for a camel to moor subs against (smelled wonderful).
I did a fair amount of portable machine work too. I machined decks for shock mitigated missle storage, struts and stern tubes, sea valve stools, gun and director foundations, steering gear bearing seats (biggest roller bearings I ever saw: 32" ID 54" OD).
Big stuff is what I did for about 20 years and I LIKED it.
09-24-2004, 09:51 AM
I used to make forging dies, some where about 22' long 6' wide and 2' thick, weighing about 100 tons. Setting up would take all day and then some, but then you would make chips for months.
09-24-2004, 11:51 AM
They were long hard setups involving jacks, chains, and malls for tweeking.
The long cuts on the boring mills, and lathes made it worth while.
The mills and HBMs kept you going more.
Used to chalk the parts and use pencil lines in the chalk instead of layout blue for setting up.
Can't hardly see a layout line on a large casting in the dark.
Forrest, we did spindle shafts for subs also including the splines on the ends.
The hob had to be recessed in the floor to allow the shaft to be set up vertically under the crane.
I was in production engineering at that time so didn't actually do that job.
We turned the od an archinedian (spelling?) screw for our branch in Muncy Penn. (Sprout Waldren) that was fabricated from stainless.
This ran in the 36" American Lathe and was 25? some feet long. The screw kept pulling into the tool. I had The operator (Bill) run in reverse so the thread pushed the tool away instead of pulling in.
That was an all weekend event. I ran the King VBM on a HOT gear coupling sleeve, while he ran the lathe.
That 36" American Lathe had a 12" riser block set for the headstock, tailstock, and tool post.
That made it a 60" machine. It took two men 8 hours to raise the lathe.
Those sh-it spreaders were new iron castings and had no poop on them while we worked on them.
I did that work for 15 years and loved it too.
Don't miss it now. Most jobs can be held in one hand here at NASA.
Not something I had anything to do with but pretty amazing.
09-24-2004, 05:36 PM
No personal experience, but the company I work for manufacturers marine propellers. Up to around 25' in diameter, 20 tons, nickel-aluminum bronze. BIG gantry mill.
09-24-2004, 06:00 PM
turning 70+", boring in the lathe 56.3125" and many parts over 1,000 lbs.
I worked in a foundry, the lathe was a king vertical turret lathe, it was 55 tons and top gear was 56 rpm.
It had 2 cross heads and a side head all with power feed and rapid.
It looked like this but one in the picture does not have the side head.
09-24-2004, 07:14 PM
well seams like I lost 3/4 of my pics.Dang it.Here is a long stainless pc.I think it was 38ft long.
The stainless screw is a press shaft.This is a smaller one.Larger one is 55"
sorry for pic size I have tried a few times to reduce it but nothing seems to work.
[This message has been edited by j king (edited 09-24-2004).]
[This message has been edited by j king (edited 09-27-2004).]
09-24-2004, 07:57 PM
Nothing as large as some of yours!!
Got to machine a 1500 pound semi-steel casting that held a 6-foot diameter bull gear. Used a 20-foot bridge mill - the casting looked lost on the bed. It was made to replace one that got broken on a 45-year old, 60-foot tracking antenna. A hardened steel 1-inch dowel pin had dropped into the mesh between the bull gear and drive pinion. Squeezed the dowel pin like a tube of toothpaste and fractured the housing. After machining the housing and mounting a newly made bull gear, I got to go to the Seychelles to install it.
09-24-2004, 09:47 PM
I dunno if i'd have the guts for machining things that huge... not just the fact that if the piece comes off, you're a dead man :P, but also the stress of making a huge part like that into scrap would make me lose 10 years off my life per day.
I bet you don't use a No.4 centre drill when working on parts that big. http://bbs.homeshopmachinist.net//smile.gif
Great stories though. I wish I could get to see things that big being machined someday.
09-25-2004, 08:42 AM
How about the biggest part in the smallest machine?
I machined a groove near the end of a 9-1/2" diameter shaft about 16 feet long using a series II Bridgeport knee mill. http://bbs.homeshopmachinist.net//eek.gif I cheated and used the crane to hold most of the weight.
09-26-2004, 04:45 PM
38 feet has me beat. I used to machine pockets and holes into rock drilling equipment extruded aluminum "runners". 2 - 12 feet pieces welded together, 24 feet long total. Checked the hole locations with a 24 foot template. Layout was a heck of a job...., had to do so just to line up the jig bore. Tolerance, +/- .010 inch. Company "made' 12 foot long caliper sets (in sets from 1 foot on up, 12 calipers 0-1, 1-2, 2-3 like micrometers, only with an anchor point at 'zero" feet).