Stainless steel 304 shell cutting

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Dan Faust
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Stainless steel 304 shell cutting

Post by Dan Faust »

Is there a sufficient way for cutting stainless steel 304 holes that are 2" in diameter?

http://www.sharpeproducts.com/store/hemispheres

The holes are intended to be ducts for various operations including:

Vacuum, leybold d16a-max 3x10e-3 Torr, with a vacuum gauge near chamber duct

Voltage, variable transformer connects to rectifier that transmits AC into DC, wires connect to conductive source that sends voltage into the inner grid, detectors use voltage duct for readings

Viewing, temperature resistant glass, so you don't get your face burned and so vacuum isn't compromised

Maintenance for fixing grids and leaks

Deuterium needle valve inlet port with gas regulator, 1 sccm at beginning

Tungsten wired inner grid
Cooper wired outer grid

Volume of my chamber (EDIT): 799.88 in³

Basic, yet somewhat informative let out of my design

Ever Fusor has flaws

X Ray and neutron detectors would be operational near main power source

My vacuum pump reaches max vacuum at 3x10e-³
Last edited by Dan Faust on Wed Aug 03, 2016 1:01 pm, edited 1 time in total.
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Jerry Biehler
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Re: Stainless steel 304 shell cutting

Post by Jerry Biehler »

These: https://drillsandcutters.com/2-carbide- ... oCP27w_wcB

They cut cleanly, i had to cut a bunch of 1-1/2" hole in the bell riser of my large system for more conflat ports and use one of these, it was 3/16" stainless. You want a big 1/2" drill to drive these with a handle and good cutting fluid.

ImageIMG_4159 by Jerry Biehler, on Flickr

ImageIMG_4160 by Jerry Biehler, on Flickr

ImageIMG_4164 by Jerry Biehler, on Flickr
Jim Stead
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Re: Stainless steel 304 shell cutting

Post by Jim Stead »

Jerry, did you do that welding yourself? Which brand/model machine did you use?
Jerry Biehler
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Re: Stainless steel 304 shell cutting

Post by Jerry Biehler »

Jim Stead wrote:Jerry, did you do that welding yourself? Which brand/model machine did you use?
Yes, I do my own welding, Thermal Arc 300GTSW
Dan Faust
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Re: Stainless steel 304 shell cutting

Post by Dan Faust »

Jerry
You my friend are amazing
Thank you
I have to look into this
Thank you
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Rich Feldman
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Re: Stainless steel 304 shell cutting

Post by Rich Feldman »

Dan,
If you need only a few holes, I bet a hole saw from the hardware store could suffice.
What worked for me, trepanning through 3/4 inches of mild steel, were Bosch (?) "bi-metal" saws. Turning at 120 rpm, with plenty of oil, frequent backing out for chip removal, and frequent breaks for forced-air workpiece cooling to catch up. I would consult a speeds and feeds reference before trying the same on stainless steel.
Story and pictures here: viewtopic.php?f=15&t=8600&p=61411#p61411

I see that your hemisphere vendor has a laser cutting service. You might ask them for a quote on making your 2" holes.

Nice work there, Jerry.
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Zan_Chaudhry
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Re: Stainless steel 304 shell cutting

Post by Zan_Chaudhry »

Hi Dan,
I had a lot of trouble with the same thing, and I had to make a lot of holes (one of them through 1/2 in. thick SS 316). What I used were 1 1/2" carbide tipped hole saws, very similar to what Jerry mentioned. I got mine from Amazon though, and the company sells 2" as well. You could take a look at those if you wanted (You'll probably get them faster, and might save on shipping, if you're a Prime member, but otherwise I don't think there'll be much of a difference.) And like Rich and Jerry said, the cutting fluid is VERY important. And those are really nice welds, Jerry. I've been trying to get decent at TIG, but I think that the only thing that works is practice... Lots of it...(Sigh)https://www.amazon.com/gp/product/B0002 ... 41VXAZ6MAE
Dan Faust
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Re: Stainless steel 304 shell cutting

Post by Dan Faust »

I have noticed that must fusioneers suggest a lower rpm.
Is this because of chipping or over heating the drill?
I know some of drill presses are built for very high duty work but stainless steel is one tough cookie when it comes to cutting
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Richard Hull
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Re: Stainless steel 304 shell cutting

Post by Richard Hull »

In my old fusor DVD I showed my effort at doing all the processes as I constructed fusor III from scratch. (1999) I used my mill to turn the rings and drill holes into the hemispheres and I also showed the TIG welding process I used in putting on ports. The zero length ports for the camera and HV insulator, I had to inlet cut on my lathe for fusor IV. It helps to have all the right tools.

Yes, TIG takes practice, but it remains the easiest and one of the cleanest of all welding techniques provided you plan and setup the work prior to picking up the handle of the welder to strike the arc.

When cutting obstinate or traditionally difficult metals, It is all about speed control and drill/tool and metal type. A good machinist or a careful neophyte will read up in this before plunging into a cut. Poorly thoughout cutting can ruin the tool or drill and work harden the piece being cut. SS can cut like butter with the application of considered preparation.

Richard Hull
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Dan Faust
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Re: Stainless steel 304 shell cutting

Post by Dan Faust »

Richard,
I have never been an engineer nor a carpenter or anything in a field that constructs things but I have seen that the TIG can work wonders for beginners

Is your DVD available for purchase anywhere?
I think that will be tremendous help with my lack of knowledge with welding equipment

-Dan
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Richard Hull
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Re: Stainless steel 304 shell cutting

Post by Richard Hull »

Sorry Dan. I stopped selling them a few years back. The work was dated and so I stopped offering 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
The more complex the idea put forward by the poor amateur, the more likely it will never see embodiment
Dan Faust
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Re: Stainless steel 304 shell cutting

Post by Dan Faust »

Thanks though,
I will look for tutorials online for the TIG
I found that harbor Freight has incredible deals relating to some welding and drilling accessories but I think I might go to a local welding shop to get some of the work done there
My parents don't own any welding equipment and it will get very expensive if I purchase the welding and drilling equipment along with the vacuum, variable transformer, and other things
I'm committed but it will take a while because I do not have an income that is sufficient
$30 a week won't cut it
Dumpster diving next!
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Rich Feldman
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Re: Stainless steel 304 shell cutting

Post by Rich Feldman »

>> I have noticed that must fusioneers suggest a lower rpm.
>> Is this because of chipping or over heating the drill?
>> I know some of drill presses are built for very high duty work but stainless steel is one tough cookie when it comes to cutting.

The answer isn't simple. As Richard H cautioned, efficient cutting of tough metals depends on the tooth speed and feed rate or pressure being appropriate -- not too fast or too slow, too aggressive or too timid. The tradeoffs between tool cost & tool lifetime, surface finish, time per part, spindle horsepower, etc. have evolved for centuries. Millions of machinists have learned to recognize when something is working properly and when it's not. Revolutions do happen, on rare occasions as well as per minute.

I think you would learn a lot by studying this chart and its list of DO's and DONT's.
http://www.fairburyfastener.com/holesaw_speed_chart.htm
One of many found in seconds using this thing called the Internet.
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Jerry Biehler
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Re: Stainless steel 304 shell cutting

Post by Jerry Biehler »

Cutting materials have recommended surface speeds that they perform best at. High speed steel is a lot lower than carbide so you need to go much slower or you will burn up the tips. With the carbide cutters you can usually max out the speed of a standard 1/2" drill without worrying about killing the tips from that. What can kill the tips on those is jamming.

Stainless is not too big of a deal, you just need to make sure you are always cutting, if you allow the cutter to rub the metal and not cut the stainless will work harden and then you are in trouble. Not so bad to deal with if carbide but high speed steel or carbon steel cutter will be dulled instantly.

Tig is pretty easy especially with the inverter welders. I used to teach it. Also used to work at Airgas repairing welding and plasma equipment. Vacuum welds are pretty simple, they are single pass fusion welds. You can tack on the outside to hold in place while welding. If you are doing welds where you are welding thin metals like tubing to heavy stuff like flanges it gets a bit more complicated since you need to concentrate the heat on the heavy section.
Dan Faust
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Re: Stainless steel 304 shell cutting

Post by Dan Faust »

Awesome everyone
slower rpm along with patience and a little bit of drilling knowledge
I consider this thread closed
Unless that's improbable because Administrators don't have time to close forums
Or maybe....
Live long and prosper-Vulcans (Star trek)
Not knowing our end should never discourage us from achieving more
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