Fusor V construction - the process long running

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Richard Hull
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Fusor V construction - the process long running

Post by Richard Hull » Tue Jan 14, 2020 1:44 am

This will be a long running and updated postings as replies to show the progression of my work on this effort.

1. The first image is the chamber I plan on using for fusor V.

2. Before construction there is, first, destruction. The second image is the mess created as I tore down the old fusor IV system.
A new coat of paint on the table was much needed. Not seen is the Leybold diff pump. I have already boxed it as my standby pump. I was stunned when I took it apart. It was installed with 60cc of silicon oil in July 2004 and has never been opened or had the oil changed since then. Now, over 15 years later, the oil was as clear as water. The interior and the jet stack were clean, like the day I installed it! Wow! I merely dumped the oil and loaded the pump with acetone and let it sit for overnight, dumped the acetone and wiped every thing down, then stored it away. It took from Saturday to Monday to do all this destruction and storage of the diff pump. The mess remains.

The weather from Friday through Monday has been like an "Indian spring"! January in the 70's!! I used this time to finally get to work on fusor V. The big chill will return soon. In future, the work will be more incremental as the unheated lab is no place to work for extended periods during a cold snap.

3. The last image is a test of just the mechanical pump, my old precision 5 CFM with no change of oil close to the head. 8 microns on an old used pump that was seized up when I bought it 21 years ago at a hamfest for $25.00. I have never opened it up. Not bad and it is obviously good to go. I did change the oil about 8 months ago. More as I advance on the build.

Richard Hull
Attachments
Pix1 - chamber.JPG
Pix2 - destruction.JPG
Pix3 - mech pump.JPG
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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Re: Fusor V construction - the process long running

Post by Dennis P Brown » Tue Jan 14, 2020 5:36 pm

Fusor IV was a great device and provided many people (myself, included) a chance to see a high neutron fusor operate. But I agree its is time to move on and test new ideas so as to enable the continued development of new fusor ideas.

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Richard Hull
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Re: Fusor V construction - the process long running

Post by Richard Hull » Fri Feb 28, 2020 9:00 am

Oh boy what fun! I finally got my $50.00 bottle of turbo oil (100mL) and used the recommened 10cc in a syringe to lubricate the wick for the next 4000 hours of operation. Leaving me with 90 mL of the most expensive oil I have ever bought!

Next, I rigidly mounted the turbo to the experimental table, then placed the 4.5" CF zero length to 2.75 adapter with 4.5" conflat copper seal gasket and tightened it down to spec. I fetched my 2.75 flange to KF 25 adapter so that I might attach my capacitive manometer and check the system now with turbo for leaks and possible more tightening of the 4.5" flange. (Staged system assembly and testing, as recommended in my vacuum FAQ)

Now the tears....I discovered what I though was a deal at the last HEAS as a 4.5 to 2.75 zero length conflat adapter was actually a 4.5 to 3.38 zero length adapter. (it was only 30 bucks). All that work wasted.
I checked my inventory and I have one and only one 3.38 CF to 3/4" compression fitting in my vacuum stock. My bad....

I checked MDC and Duniway and a zero length 4.5 to 2.75 is $102.00. That would totally solve my problem as every thing beyond is 2.75.
In search of saving money, I got to thinking that I could machine out the weld on the 3.38. (I have machined out a number of welds to get a number of goodies in the past.) I would then pull out the nice compression fitting and then bore the 3.38 out to take any needed length of my many " half stub 2.75 fittings I have here. I could then weld this to the 3.38 and have an adapter perfectly "length suited" to my operation. Alas, I have no 3.38 copper gaskets and Duniway forces me to buy a pack of 10 for $23.00....9 of which I might never use!

Simple solution, put out the $102 plus postage and I'm done
Save $79 and pay far less postage, but involve myself in a bit of tear down and build new. I have both the money and time, the lathes, machining ability, TIG welder to do either. Hmmmm. Muddle, muddle, #@$&^*!

3.38 and 4.58 are real oddball sizes, I know. The 3.38 being the less oddball of the two.

Any body out there have a new copper 3.38 gasket to sell, maybe two??

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.

Dan Knapp
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Re: Fusor V construction - the process long running

Post by Dan Knapp » Fri Feb 28, 2020 12:17 pm

Richard, LDS has your needed adapter for $84.00.

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Richard Hull
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Re: Fusor V construction - the process long running

Post by Richard Hull » Fri Feb 28, 2020 10:33 pm

Thanks, I had forgotten about them.

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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Richard Hull
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Re: Fusor V construction - the process long running

Post by Richard Hull » Thu Mar 05, 2020 12:22 am

It was warm here today and I finally was able to hook up and test the Turbo pump for the first time. I received my 4.5-inch to 2.75-inch zero length adapter today and within 1 hour, had it all hooked up to test.
The first job was to pump down the fore-line all through the system. See images below. the long fore-line flex hose was a huge surface area as was the turbo, itself. The TC gauge struggled to hit 100 microns over 35 minutes. I was tightening the 4.5-inch bolts and the 2.75-inch bolts to speed things up, but all to no avail. Probably all water as the TC gauge kept on slowly falling. (A very good sign it is probably water).

After 1.5 hours the system was down to 46 microns by the TC gauge and still creeping down. the TC gauge and the Baratron's digital readout were both within a micron or two of agreement. I decided to turn on the turbo. Wow! What a screamer. as it wound up I heard it go through its short resonance point and then quieted down but still high pitch whine. Long before the rotation gauge got half way up to speed the baratron gauge hit zero and indicated -1.5 microns. I tweaked the calibration pot to have the gauge read 00.00. The TC gauge inched back up to about 100 microns on the fore-line. This showed that the turbo was tearing water out of the system to the mechanical pump.

I let the turbo run for about 20 minutes and the fore-line slowly calmed down to a TC gauge reading of 50 microns. I shut the turbo off and it took about 20- minutes to turn down. As it wound down the baratron still hung at 00.00 microns. and the fore-line remained at 50 microns. As the turbo went deep into its slow down the baratron rose and the TC gauge fell. This is to be expected and the turbo did tear a bit of water out of the system. When the two gauges equalized they would, ultimately, read 33 microns on both gauges but still falling ever so slowly. Still some water in the system and lots of it. I closed the fore-line valve and the TC gauge plunged to about 8 microns, while the baratron pressure rose at the rate of about 1 micron per second and within 1.5 minutes was sitting at 100 microns, (its max high range reading.) I am thinking this is still just water in a monstrous virtual leak in that long flex hose and the turbo body. We will see. However, against the running turbo, water or not, I can hit a minimum of 10e-5 for sure at the turbo head.

All part of my "pump and test" as you go and add components. Slow and easy. No rush, I have already done fusion. Nothing to win. Just another fusor, ho-hum... Doing the same fusion only, hopefully better.

Richard Hull
Attachments
Turbo test 320 (2).JPG
Turbo test 320 (4).JPG
Turbo test 320 (5).JPG
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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Re: Fusor V construction - the process long running

Post by Dennis P Brown » Thu Mar 05, 2020 12:28 pm

Good work! You have my exact same turbo; I say this because after I added turbo bearing oil to my wick, it then took hours of pump down and heating of the unit to get all the water and other stuff out. Maybe your case, maybe not.

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Richard Hull
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Re: Fusor V construction - the process long running

Post by Richard Hull » Wed Mar 18, 2020 11:26 pm

As I shelter in the lab, and the weather moderates, (65 deg. today), I am having plenty of time to putter around and work on a number of projects.

Here are two images.

I finally got the entire line installed and fully tested. Now to continue to machine and mount things as needed to make fusor V a reality.
Newbies please do not follow my example here with the long lengths of flex hose until you get the gauges, gear and experience needed to verify your vacuum sealing technique.

Note the manometer is reading minus as it pulled so low that the diaphragm went negative. This is not recommend. .1 torr =100microns. As this instrument is good for about 4 order of magnitude range.
it reads 10 volts @100 microns, 1 volt at 10 microns, 0.1 volt @ 1 micron and .01 volt @ 10e-4 torr......In theory .001 volt @ 10e-5 torr. To go minus voltage it must go lower. Needless to say, this gauge is kind of worthless below 10e-5 torr

Richard Hull
Attachments
Total line pumped.jpg
HV FusorV.jpg
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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Jim Kovalchick
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Re: Fusor V construction - the process long running

Post by Jim Kovalchick » Thu Mar 19, 2020 12:31 am

Richard,
I'm glad to see you keep making good progress on Fusor V.

A couple thoughts from my electric feedthrough experience:
1. I mounted my feedthrough out the back side because I didnt want 40 kV in my face during operation. There is a drawback though. The weight of the grid tends to sag the stem a little which takes some of the margin to arcing away. I also believe that the grid tries to move to stay in balance with electromechanical forces set by its relative location to the chamber. This causes some visible resonance vibration of the stem that comes and goes depending on voltage and current. I think it is important to center the grid.
2. I did not put alumina on my stem. I have had bad experience with arcing from within the alumina in the past that goes away when I leave the stem bare. I haven't gone past 40 kV in my cross, but my stem has been ok so far.

Jim K

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Richard Hull
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Re: Fusor V construction - the process long running

Post by Richard Hull » Thu Mar 19, 2020 3:29 am

My stem is 1/4 - inch in diameter and is 1.2 inches long. This short stem 1/4 X20 threads into the main stem which is 3/8" diameter steel. My stem hangs vertically against gravity. No sagging there. We will see. There are always teething problems. The weakest stem I have used in any fusor was 1/8" back in the pre-2000 bell jar days. Fusor IV had a 1/4" stem. I just will not use one of lesser diameter.

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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