Fixturing For Welding Large Spheres
I try do that as well. I find that doing that beats having them show up in my cube yelling about some screw up. I have done some rather silly things, usually at the end of the day a long way from lunch. In te case of the elbow I was overruled by something that in the end was sort of pointless as we had a 1000 lb lift over the elbow and as it turned out never had to move the elbow anyway.drmike wrote:I think you are right on - NASA has lots of huge chambers that pull down to 10^-8 or better. At some point the outer wall doesn't matter, it's the inner coil size that matters. If a tank has the shape of a cylinder it should be fine. Easier to maintain too.
JC - yikes! I guess some people have to learn things the hard way.
I would always go the machine shop and ask for the best way to build things. Once the guys understood what I was trying to do, they always came up with great ways to make it. I think just understanding the tools in the machine shop are a really important factor in designing anything.
And here's the monster itselfJccarlton wrote:I try do that as well. I find that doing that beats having them show up in my cube yelling about some screw up. I have done some rather silly things, usually at the end of the day a long way from lunch. In te case of the elbow I was overruled by something that in the end was sort of pointless as we had a 1000 lb lift over the elbow and as it turned out never had to move the elbow anyway.drmike wrote:I think you are right on - NASA has lots of huge chambers that pull down to 10^-8 or better. At some point the outer wall doesn't matter, it's the inner coil size that matters. If a tank has the shape of a cylinder it should be fine. Easier to maintain too.
JC - yikes! I guess some people have to learn things the hard way.
I would always go the machine shop and ask for the best way to build things. Once the guys understood what I was trying to do, they always came up with great ways to make it. I think just understanding the tools in the machine shop are a really important factor in designing anything.
http://www1.jlab.org/ul/jpix/med/FEL_11.jpg
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johnshearing
- Posts: 7
- Joined: Fri Oct 17, 2008 1:32 am
- Location: New York
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Hi All,
This is my first post in this forum.
The following link shows a method for making huge spherical vacuum chambers without the need for a fixture. Specially shaped plates with compound contours are not required either. Regular sheet stock can be used.
http://www.justodians.org/SphericalVacu ... custat.htm
The patent application is released to public domain.
Hope someone finds this useful
Best John
This is my first post in this forum.
The following link shows a method for making huge spherical vacuum chambers without the need for a fixture. Specially shaped plates with compound contours are not required either. Regular sheet stock can be used.
http://www.justodians.org/SphericalVacu ... custat.htm
The patent application is released to public domain.
Hope someone finds this useful
Best John
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Orionblade
- Posts: 9
- Joined: Sat Dec 13, 2008 6:59 am
ZOMG!
I live not far from Jlab. Feel free to PM me with the name of the idiot deciding to use aluminum and I'll be happy to charge him a very large consulting fee the next time he wants to build something improperly.
Ugh.
Not to mention the difficulty with outgassing because aluminum (specifically the surface oxide) has such a high porosity and it picks up cutting fluid residues. Never try welding an aluminum oil pan, for example. ZOMG! The oil appears to miraculously flow through apparently solid metal. It's actually got billions of pinholes because the aluminum outgasses during the weld process.
Totally been there and done that, and know some folks that worked on the FEL, and the CLAS detector.
As far as large spherical chambers, there's a few ways to do it.
1. Build a polyhedron (OUT OF STAINLESS!!!) and be happy that it's big and round-ish.
2. Build a press and stamp out 1/8 sphere sections, with flanges, and weld it up
3. Build a polyhedron out of stainless, fill it with water, and set off about 2 ounces of the high explosive of your choice within it. (Assuming you want a 10m chamber) This will result in a spherically symmetrical detonation wave that will cause your tank to do the same thing that the fuel tanks for the space shuttle do. *BOOM* sphere!
4. Build a big cylinder/cube/who cares as long as it supports itself, and within said tank, build a spherical chamber from wire mesh.
Or you can always get a few hundred tons of stainless and machine out the insides so it's a big sphere. Not reccomended for those with less than infinite money
Ugh.
Not to mention the difficulty with outgassing because aluminum (specifically the surface oxide) has such a high porosity and it picks up cutting fluid residues. Never try welding an aluminum oil pan, for example. ZOMG! The oil appears to miraculously flow through apparently solid metal. It's actually got billions of pinholes because the aluminum outgasses during the weld process.
Totally been there and done that, and know some folks that worked on the FEL, and the CLAS detector.
As far as large spherical chambers, there's a few ways to do it.
1. Build a polyhedron (OUT OF STAINLESS!!!) and be happy that it's big and round-ish.
2. Build a press and stamp out 1/8 sphere sections, with flanges, and weld it up
3. Build a polyhedron out of stainless, fill it with water, and set off about 2 ounces of the high explosive of your choice within it. (Assuming you want a 10m chamber) This will result in a spherically symmetrical detonation wave that will cause your tank to do the same thing that the fuel tanks for the space shuttle do. *BOOM* sphere!
4. Build a big cylinder/cube/who cares as long as it supports itself, and within said tank, build a spherical chamber from wire mesh.
Or you can always get a few hundred tons of stainless and machine out the insides so it's a big sphere. Not reccomended for those with less than infinite money
When you have a Cray II for a brain, you wish your body had more clock cycles available...