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, 1:45 am
Poster: Dave Cooper

On Sep 24, 1:45 am, Dave Cooper wrote:

>8" 1/8" thick SS-type 304 hemispheres, $61.70 each from http://www.jgbraun.com/balls.html. (I don't know about the properties of different SS's, maybe one of the more knowledgeable machinist-types could understand if this is suitable)By the way, I also saw the reference to Richard Hull's machinist.
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.

>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.
>Once again, the metals folks can advise me here- I would like to silver solder this big stuff if possible, but I hear the preferred technique is TIG welding, which we don't have the ability to do. I have an acetylene torch and could braze / weld with that, if the steel will braze nicely.

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.

Dave Cooper