Fusion Message Board

In this space, visitors are invited to post any comments, questions, or skeptical observations about Philo T. Farnsworth's contributions to the field of Nuclear Fusion research.

Subject: Re: Parts ideas...comments please!
Date: Sep 24, 8:29 am
Poster: Carl Willis

On Sep 24, 8:29 am, Carl Willis wrote:

>304 SS is a common alloy and is reasonably machinable. Use of carbide tools is highly recommended.
>RE: The URL for the spheres - tried it but >message says it either moved or is down.

I just found that R&B Wagner is another online "architectural metals" company that has exactly the same price for 11 ga. stainless hemispheres, plus they may be able to do some limited machining on the parts (cut holes where I want.)www.rbwagner.com It turns out that most vacuum steel that I have seen since I posted the question is 304, so I feel reassured that it is a good choice.

>>These will need a 10" conflat flange each. >Lesker lists these at ~$240 each, so I will have >to scrounge / beg to stay within personal >budget. If anybody has them surplus or used, >that would be helpful. I doubt we have the >resources to cut out the holes from the blanks >on something that big.

>You might consider your local High School or >Junior/ Community College or Tech School. >These almost certainly have metal lathes large >enough for your needs....probably need a 11" or >12" swing for the 10" flanges. Cutting out the >centers is relatively easy ...just takes a >little time.

Dave, I'm still a little confused about how to do it. We have a lathe, just no chucks that will get around the flange, so the problem is how to get it centered and secure on the lathe. I may have circumvented the problem for now, though- I just found some 10" conflat flanges that have an 8" bore for $50! I like that price...

>You CAN silver solder or braze stainless, but I >believe you have already gotten the best >advice... TIG weld. Depending on your >location, you probably have a vacuum equipment >fab shop in the vicinity. It will cost a >little money, but they can do the job quickly >and throw in a Helium Leak Test as a routine >check. Most likely well worth the money.

Wow- a helium check- now that would be nice. Thanks Dave, I'll see what turns up in the "yellow pages."