Demo fusor progress

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Finley Blaine
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Joined: Tue Jun 11, 2019 8:49 pm
Real name: Finley Blaine

Demo fusor progress

Post by Finley Blaine » Mon Sep 23, 2019 9:47 pm

Hi everyone, this is going to be long as I have done a lot since the last update on the design.

Starting from the beginning,
I made a basic wood frame that has space for future extra components.
IMG_20190820_130643.jpg
Then installed some components, including the mechanical pump, diffusion pump and its associated valve, vacuum gauges, and a water cooling loop
IMG_20190923_220623.jpg
The water cooling loop can be more clearly seen here. It uses a transmission oil cooling radiator (generic chinese) and a shaded pole water pump off ebay.
IMG_20190923_220631.jpg
I built the power supply mostly according to the design, perhaps slightly anticipating the complexity of the wiring. The reason for its complexity is on the left there is a large DPDT switch that changes the output between a straight rectifier and capacitor (10kv 10ma) and a voltage doubler circuit (20kv 5ma). The second pole is for switching the meter's position of the resistor ladder at the top, as I have a 10kv electrostatic meter. Certainly overkill for the demo fusor, but too late, I've already finished it.
IMG_20190829_232031.jpg
With me and my Father's recent purchase of a mill, I can now make a couple of design changes and work to a much higher tolerance on some operations. I also no longer have to try and get time on the school's mill.
Being machined in the image is the outer wall of the chamber, the flats for flanges are being cleaned up after I spent 7 hours on the school mill two months ago cutting them out using and endmill with a tooth missing.
IMG_20190920_215007.jpg
Here is one of the flanges I have been working on, This adapts whatever one off standard I made up to KF for the vacuum gauges.
IMG_20190922_124630.jpg
I am currently working on a diy high voltage feedthrough, using porcelain and PTFE (I heard it's low outgassing) so we'll see how that goes.
After that the other plates associated with the chamber need to be bored and mounted, then there's not much work until a test.

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Richard Hull
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Re: Demo fusor progress

Post by Richard Hull » Tue Sep 24, 2019 3:31 am

Milling machines pay for themselves very quickly when viewed against taking your stuff to a machine shop. This assumes you have the work for it to payoff. Part of the payoff is acquiring a new skill set. Each new skill set pushes you along to gain more hands-on experience, saving money all the time.

Nice build and a super demo build.

Richard Hull
Progress may have been a good thing once, but it just went on too long. - Yogi Berra
Fusion is the energy of the future....and it always will be
Retired now...Doing only what I want and not what I should...every day is a saturday.

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Dennis P Brown
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Location: Glen Arm, MD

Re: Demo fusor progress

Post by Dennis P Brown » Wed Sep 25, 2019 12:18 pm

Impressive high voltage supply but like a real fusor supply, yours is also very lethal. Also, wood isn't really a very good material to encase high voltage systems - its water content can cause corona issues. Good machine work. Milling is, for me, fun. Lathe's are generally just a hassle.

Finley Blaine
Posts: 14
Joined: Tue Jun 11, 2019 8:49 pm
Real name: Finley Blaine

Re: Demo fusor progress

Post by Finley Blaine » Wed Sep 25, 2019 4:33 pm

Thanks Dennis, I was careful to make sure that all high voltage touches plastic (I have no idea what type, I just had some 12mm black sheet lying around). There is quite a noticeable airflow coming off the switch, however I believe that is due to the geometry and polarity of the switch ionising the air and not due to the wood. Please correct me if i'm wrong, but it appears to work exactly the same as an atmospheric ion drive.
I agree that Lathes are rather tedious to use. I have to make quite a lot of complex parts on the lathe that are a single piece, as I don't have a tig welder. I have a 300mm mini lathe I got cheap off ebay a few years back. The new mill makes it look like a toy in comparison. mills are more fun.

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Richard Hull
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Re: Demo fusor progress

Post by Richard Hull » Wed Sep 25, 2019 5:39 pm

My general experience in my lab is that I use one of my 4 lathes on a basis of 5 trips to be saved by a lathe to only one at the mill. Mills are for odd shaped pieces needing liner cuts, circular, accurate off-center boring, etc. Lathes are for round stock and precise center boring. Hex stock can be easily handled as can squared stock in four jaw chucks for cam boring or odd lobed items on a lathe. I try and use the best tool for the job that requires the least effort. I tend to do a lot of threading and round or hex work. This is handled best by the lathe. The mill is used for slotting, dovetailing and odd cutouts in boxes, etc. For me, I could not get along without both my South Bend K-9 lathe and my chi-com mill. Nothing beats the right tool for the job and having that tool at hand.

Richard Hull
Progress may have been a good thing once, but it just went on too long. - Yogi Berra
Fusion is the energy of the future....and it always will be
Retired now...Doing only what I want and not what I should...every day is a saturday.

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