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LAN_403

GreySoul

Wed Aug 08 2007, 04:01PM

Registered Member #546 Joined: Fri Feb 23 2007, 11:43PM
Location: Albuquerque, NM
Posts: 239

It's pretty obvious to me....your attempt to make a peanut butter and jelly sandwich somehow took a turn towards copper clad and a digital camera....

What's my prize?

..also...where does the "freakin' laser beam" go?

-Doug

Sulaiman

Wed Aug 08 2007, 04:51PM

Registered Member #162 Joined: Mon Feb 13 2006, 10:25AM
Location: United Kingdom
Posts: 3141

Are the traces mirror-reversed / wrong side exposed?

Capper

Wed Aug 08 2007, 04:58PM

Registered Member #914 Joined: Fri Jul 20 2007, 06:22PM
Location: South Bend, IN
Posts: 85

You etched a negative of your ground plane.

Marko

Wed Aug 08 2007, 05:40PM

Registered Member #89 Joined: Thu Feb 09 2006, 02:40PM
Location: Zadar, Croatia
Posts: 3145

Hey, very cool pics everyone. Is that fusor completely under glass envnelope?

Peter: Does your printer have a ''B & W Halftones'' setting or something similar under quality/toner save setting? Some modes may have it set automatically.

It needed to be set to none/solid otherwise printer messes up the black/white boundaries (obviously bad) and mine also tended to randomly shrink the entire picture for a part of millimeter, enough to cause the infamous top/bottom side mismatch after printing.

When properly set it printed very precisely.

...

Wed Aug 08 2007, 06:05PM

Registered Member #56 Joined: Thu Feb 09 2006, 05:02AM
Location: Southern Califorina, USA
Posts: 2445

Sulaiman got it, I mirrored the wrong side of the board

My printer is configured correctly, it is just a really cheap printer ($300 for a full color laser, including a full set of 'full' 5k page toner cartridges). It feeds the paper at a somewhat random speed, so everything gets stretched/shrunk a few percent at random. Not a problem for normal things, but when you are trying to get the top/bottom to line up to +/- 0.002" it gets to be a major pain.

Capper

Wed Aug 08 2007, 06:12PM

Registered Member #914 Joined: Fri Jul 20 2007, 06:22PM
Location: South Bend, IN
Posts: 85

Marko wrote ...

Hey, very cool pics everyone. Is that fusor completely under glass envnelope?

The fusor grids are under a pyrex bell-jar sandwiched between aluminum sheets. I'll post a picture of the whole assembly after I get home later today. There are some more photos here:

Fusor Link

Reaching

Wed Aug 08 2007, 06:50PM

Registered Member #76 Joined: Thu Feb 09 2006, 10:04AM
Location: Hemer, Germany
Posts: 458

whats about the x-ray emission? I asked the german wikipedia for answers about the fusor.
The x-ray emission is the main radiologic risk. and i dont see any grid to screen the x-rays
Do you use deuterium or so? What psi and voltage on the electrodes.
A bit more info please :)

Hazmatt_(The Underdog)

Wed Aug 08 2007, 07:52PM

Registered Member #135 Joined: Sat Feb 11 2006, 12:06AM
Location: Anywhere is fine
Posts: 1735

well... whatever the case is with your board ... , your connection pads either need to be bigger or the drill hole smaller because mechanical movement will tear them off of the board.
And you need to rethink how you're etching these boards. If you're going to be etching something this sensitive you're going to have to agitate the board or else you will get what you see there, a board that is over etched and under etched.
I have had that problem too from leaving boards in solution, no agitation, solution too cold, or trying to re-use an old solution.

If I had to etch your board I would agitate it in my FeCl3 tank while hot.

Capper

Wed Aug 08 2007, 07:52PM

Registered Member #914 Joined: Fri Jul 20 2007, 06:22PM
Location: South Bend, IN
Posts: 85

Reaching wrote ...

whats about the x-ray emission? I asked the german wikipedia for answers about the fusor.
The x-ray emission is the main radiologic risk. and i dont see any grid to screen the x-rays
Do you use deuterium or so? What psi and voltage on the electrodes.
A bit more info please :)

I don't run the voltage high enough to get x-rays (I'm only running about 450 VDC), and I'm not using any deuterium - so It's not a real fusor making radiation - it's only a "demo fusor" making plasma from trace gas. The guys using deuterium and producing neutrons have stainless steel vacuum chambers and much better vacuum pumps (I can only get down to about 100 microns). If you want to learn more, there's a fusor forum at: Fusor Forum

Scott

...

Wed Aug 08 2007, 11:25PM

Registered Member #56 Joined: Thu Feb 09 2006, 05:02AM
Location: Southern Califorina, USA
Posts: 2445

The etching on the board went fine, it was the transfer that was foobared. I was using PNP transfers, which just don't work for large boards with lots of .008" traces (especially when using uber thick copper). I don't have the pre-etch pics handy (but you can see where I reworked the transfer in the pic of the board etching, black = done by marker), but about a third of the traces were screwed up after the transfer, so I tried to clean them up, but that obviously didn't work to well. The holes for the connectors were the right size, but the library was drawn assuming plated through holes, so the pads were way smaller than they should have been for a homebrew board.

But none of that matters now, I have decided that for the $30 (incl s&h) it will cost to have the board made at batchpcb, it just isn't worth my time. And now I get a solder mask and silk

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