Poll

Would you buy:

mfd hardware
14 (28%)
panel elements and gauges
13 (26%)
entire cockpit mockups
6 (12%)
motion simulators
2 (4%)
dope for snuffy
15 (30%)

Total Members Voted: 29

Voting closed: June 01, 2012, 01:09:35 am

Author Topic: OSHW and Freespace. Would you buy parts for building an fs cockpit simulator.  (Read 12672 times)

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Offline Nuke

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Re: OSHW and Freespace. Would you buy parts for building an fs cockpit simulator.
progress!



having some issues with brightness and contrast right now. the issue with contrast is it takes some time for my code to load the shift register with the value of the next digit and during this time the previous display's digit is visible. its not a very big amount of time in relation to the time the actual digit is visible, but its enough to affect readability. my solution to the problem was to lower the resistance values for the current limiters, from 470 to 180 ohms. the value i actually want is 250, but with the 470s the displays were dim, and now their to bright, and the contrast issue is the same. ive inserted a "blanking" delay at the end of an output cycle, where i turn off all the displays for a set length of time. it doesnt really work all that much. ultimately i figure the problem with the contrast is actually a problem with the arduino ide. its just too slow. you waste hundreds on ns of time just setting one of the pins values (times multiple pins), thus pissing away precious microseconds. the solution will be to talk to the registers directly. i knew at some point i would need to come up with tighter code, so this is not a major issue.

another odd bug with my code, which left me scratching my head was that for some reason it wouldnt let me output values from an array over a typical for loop, but it would let me output the value from the loop counter, and thats what you see. you may also notice the beer, fiy thats my 5th one, so i better stop tweaking before i burn out my displays.

*edit: reasons not to code drunk*
nested loops end up in places that a couple of ifs should have been used
variable names are indecipherable gibberish
comments are 80% swear words complaining about why the code underneath it doesnt work
you #define entire lines of code
you forget important idiot proofing (your microcontroller wont tell you when it segfaults)
you also forget that your target mcu cant multiply

anyway i got the serial interface somewhat working. though im not happy with my packet format, which was designed for simplicity (and my blood alcohol level when i designed it). i decided to make the entire command a single byte, so i wouldn't need to go through the trouble of finding sync. the first nibble was the opcode and the second nibble was the parameters for that code. of 16 possible op codes 0-9 were used to write a hex value to to a specific digit. the other 6 were debugging codes, to do things like dump all 10 display values in raw mode, or dump the font, 2 more to allow you to set and clear decimal points, and 2 more to read a single digit in hex and raw. so a lot of redundancy there.

anyway this is somewhat cumbersome. im actually thinking of using a text format. ascii is only 7 bit, and i can use the 8th bit for sync, just set it for the first byte and look for a byte > 127. the opcodes can just use a single character, and this gives me like 96 possible codes (minus control characters, which id rather not use). the downside here is it would be very slow. say i want to write f in hex to digit 5. i would do W5F. i could also do simd codes: like WAA55F00C666 (W is the write hex command, A is the parameter, for write all, followed by the values to be written, lol). writing raw values would just take 2 characters to represent their values in hex, and read commands would be very short. if your controlling this in lua this would be a really easy and intuitive way to do things. but this device will sit attatched to anomain mcu, and micro controllers aren't so good at text processing.

my other option is to use a binary format, that can be sorted out with bitwise operations. i can keep my sync bit, and use the remaining 7 bits to store opcodes/data. i can drop to 3-bit opcodes instead of 4 (i dont need as many because i can allocate as many additional bytes for data as needed), and this gives me an entire nibble for parameters. all the read all commands would be one byte commands with no additional bytes. there would be 4 read commands, for raw/hex/text, and another to read the decimal point flags. the read commands all have complementary write commands. the difference is that additional bytes would follow the command for the data. hex and text modes only need include another byte. raw mode and decimal point mods require 8 and 10 bits respectively, since the 8th bit is for sync, these need 2 data bytes. so all commands are less than 3 bytes. the 4-bit parameters also allow for expansion. values 0-9 index individual displays, where a is the all command, and in the case of write commands would require additional data bytes, and probibly some formatting to save space. other values can be used for settings, like brightness and contrast. so i rather like this idea.

ultimately i intend to use an i2c interface for this. i2c is a lot easier do deal with. it has all its sync data build in, and its designed with an address-register-data format. you can also write to a series of registers by sending additional data bytes. reading is a little bit more trouble, you need to send a address-register to the device, then you can receive bytes back starting from that register, and you can also receive a series of bytes in this way, with the register incrementing by one for each. it makes using a uart seem archaic. for now im going to be using a serial interface. i will try to do some interface with freespace though serial. im going to use a proxy script like i did before. freespace will talk to it over tcp/ip loopback, but ultimately will talk to the arduino over serial. id use my ethernet shield, but the library im using only supports tcp server. so i couldnt use my existing udp code, where my proxy script just needs a little modification. so i will use that for my initial testing.
« Last Edit: May 07, 2012, 09:34:14 pm by Nuke »
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Offline ABetterWay

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Re: OSHW and Freespace. Would you buy parts for building an fs cockpit simulator.
Have you played with any of the LED driver chips?  Like the MAX7219 (http://www.maxim-ic.com/datasheet/index.mvp/id/1339).  Seems like it might be easier and it apparently handles the brightness. I don't think I have seen one that can do 10 digits yet.  The MAX7219 can handle up to 8 7 segment leds.  When I start fooling around with these things, I am going to give this chip a shot.


 

Offline Nuke

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Re: OSHW and Freespace. Would you buy parts for building an fs cockpit simulator.
that looks like a nice chip. would save a lot of time. do they have one with an i2c interface? if they did you could use it on the bus without a microcontroller and save on your part count. 3-wire is ok i guess, you could implement it side by side with an mcu, say you need a display with input controls, mcu would let you deal with input in addition to output on the same mcu. ive mostly been using 7400 series because you can source the parts for next to nothing. there are also bcd and hex display drivers as well, i looked at some of those, but these limit the number of digits you can display. i kinda wanted an interchangeable font, and some of these single chip solutions kinda restrict what you can display.

my hex format doesn't have a facility for a - sign for displaying negative numbers (i probibly wont use this mode for displaying game data), the raw format of course lets you output anything the display can draw. the text mode is the "easy method" but require more complicated translation code. internally i store everything in a 10 byte array where each byte is a raw mode character. when reading to or writing to the array, there are several translate functions and usually some mapping info. bargraphs are another matter though. i will want driver chips for those.
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Offline Al-Rik

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Re: OSHW and Freespace. Would you buy parts for building an fs cockpit simulator.

there are two routes to take for this:

route a:

run an application on the computer that renders the graphics to an auxiliary video output from your video card. output to a small lcd monitor (like those composite review camera monitors you get for $20-$30 on ebay). these displays would be modded to also contain an array of command buttons and possibly other controls, like knobs/rotory encoders. you need a video card with composite out (unless i can source a monitor with vga/hdmi interface), and probibly a usb connection for the buttons.

pros: better graphics, cheap, more configurable
cons: more cables (usb/composite/probibly power), dependant on cost and availability of non oshw lcd screens, requires video port on your video card (and theyre starting to phase out composite/svideo/vga, for new standards like hdmi)

Well, I would like to use route a... sort of ;)

17" or 19" 4:3 TFTs are nowadays cheap to get on the second hand market, and many gamers have them still with all the other old hardware in the cellar or loft - sometimes next to an old an obsolete Pentium IV or Athlon 64 PC.

DLP Projector becoming cheaper every year,  and Thrustmaster sells those shiny little fake MFDs for little money.

And that is my plan:
At the moment I have an old Athlon X2 with 4 GB Ram and Onboard GFX in my living room, mainly as music server. It's connected to an old, wall mounted 19" TFT.
In the long term I will add Full HD DLP Projector for watching DVDs and Blue Rays in the living room.

While I will it not use for every day gaming, I would like to use the Projector for Freespace, Wing Commander Saga and Diaspora on the big screen.
I will create a least small mock up cockpit with 2 of those fake MFDs from Thrustmaster.
One Left, One right an maybe an old 19" TFT in the middle, connected via VGA or DVI Cable to the second connector on my Gaming PC.

The MFDs I will connect via USB and binded to keys with JoyToKey.
 
I would like to use the middle 19" TFT for Radar, Target View, Weapon & Shields and all other HUD Gauges that are not part of Freespace Target Reticle.
(In normal Games it would use it for Teamspeak, ;) )

At the moment I use also a double TFT set up, a big 28" full HD for the game an old 19" TFT for Teamspeak.

 

Offline Nuke

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Re: OSHW and Freespace. Would you buy parts for building an fs cockpit simulator.
some "progress" though i dont really think it can be classified as "progress" so much as stumbling around in the darkness.

anyway where i left off i was making a small modification to my design that routs that pin for the interrupt header to the output enable pin of the shift register, to give me the ability to completely cut off the leds from the rest of the board, only costing me a header i was probibly never gonna use anyway. the design change was done, and layout updated. i was waiting for my toner transfer paper to arrive, after failing horrifically to produce my own. so a couple days ago i printed out the pattern on the transfer paper. one other thing i needed was to aquire a drill press. because i needed to punch some precision drilled holes to align the two transfer sheets. not having the cash to dish out on tools i just built one out of legos, using 1 modded lego and a dremel:



this was built last night, legos are a serious time sink, i finished up mostly in 4 hours. but i didnt like something with the gear box, the worm drive was mounted on one side of a pair of rack and pinion gears, and the weight of the dremel was enough to flex the axel, and this caused the dremel to lean to one side while it was being raised and the other while lowered, i found this annying, took the whole thing apart, and put the worm drive in the center of the axel instead so that it would flex evenly. this added another 3 hours to the build, but i ended up with a fairly functional and accurate drill press. its only downside is i rushed the base design, and so the work area isnt all that big. and the work area clearance is less than ideal. i also used studless parts for the rails, i could have probibly used bricks for it like i did everything else but it would have been much larger and more complicated. of course i only wanted something that could do this one small job. a lot of the contraption blocks my view so i just hooked up an led board from a dead flashlight to a battery with a potentiometer, letting me dial up the leds to a brightness which would not burn out the leds. i used a pot because i was too lazy to do math to figure out the voltage drop and how much current limiting resistance id need.

so yesteray after i printed out the layout to the transfer paper, i expirimented with ways to cut pcbs. first thing i tried was a pair of scissors, this worked but only for small cuts and it did warp the pcb somewhat. i then tried the score and break method, at first it didnt seem like it would work, but then i deepened the scoring, cut the metal on the other side, and it broke with with a rough edge, the coper in that area bent slightly, but i used some heavy grit sandpaper to clean it up. so it looks like this will be what i will do from now on.

onward i used a plain paper print of the bottom layer to dimple the pcb in the areas where the alignment holes were, for this job a hammer and a small finishing nail was sufficient. i was thinking of just drilling through the paper, which in retrospect may have come up with more accurate results, but the dimple method worked fine. i also regretted not having finer drill bits on hand. something half as big could have made my alignment holes lign up better. i simply drilled into the dimple and then cleaned up the burrs with an engraving bit. i then re-polished it, and gave it an alcohol bath to remove any impurities.



so i use some pins i found in moms craft box through the holes in the board to align the top and bottom sheets, i then secured the edges with tape. removed the pins, put some paper above and below and put the iron on as high as it would go. not to self, in the future use masking tape, it doesnt liquify when ironed. it seemed tob e going smoothly at this point. this is the pcb while cooling down:



thats a boring picture. but then i peel the stransfer paper off and i get this mess. i think i ****ed up in the ironing stage, after hours of work i wanted to go do something else and i may have rushed through the ironing process. also im not sure i did it right either, probibly didnt apply enough pressure or enough heat, or for long enough. what i got looked like this:



this is completely unusable. but i did learn some things. my alignment process is ok, but it could use some work. i need to get some smaller drill bits, some epic solvents, and a roll of masking tape. i have no idea whether my cleaning precautions were sufficient or not but the board was fairly clean and im pretty sure this is critical to success. transfer paper didnt seem to be of very good quality at all. i had expected more of it to transfer. more pressure more heat, more time, and some other things. not all is lost. i just have to scrub and re-polish the board, give it another alcohol bath, get rid of all the sticky gunk, and i wont have to do the alignment process again or cut anymore pcb. i may improve my drill press but i will keep it in one piece for now. so only thing im out here is one sheet of transfer paper, and maybe a couple ounces of rubbing alcohol. will maybe try again later/tomorrow/next month.
« Last Edit: June 05, 2012, 10:40:30 pm by Nuke »
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Re: OSHW and Freespace. Would you buy parts for building an fs cockpit simulator.
You built it out of Lego. Boss.

 

Offline Nuke

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Re: OSHW and Freespace. Would you buy parts for building an fs cockpit simulator.
meh, i cleaned the board and tried it again, with more heat, more time on heat, more pressure, more cleaning, and the results still aren't much better. im going to have to attribute this to either bad toner or piss poor transfer paper (which i got from a chinese dude on ebay). i managed to double the dpi by printing it as a 1-bit bitmap @ 1200 dpi (this is probibly the upper limit for this old printer that im using, it just barely fits in the printer's memory), this resulted in a darker, more solid print, even on the slick transfer sheet. i gave it an entire 3 minutes of heat on each sidewith considerable downforce, followed by a 30 minute cooldown and 5 minutes in the freezer. i did do some alignment checks with a ruler and everything was within 1/16th of where it should have been. id have liked 1/32 but this is still within tolerance. but over 50% of the traces are broken, and all my sharpies are too blunted for a fixup. i may have to do a re-design with fatter traces and pads, which will not be fun, as i will probibly need to re-cut a larger pcb, unless by some miracle i can keep it all within the same bounds. fml. i guess il try some more expensive transfer paper from a more reputable source, and maybe see about re-filling the toner cartridge, possibly make it darker. i went through the whole process in highschool and it wasnt this much of a pain in the ass to get the toner to stick to the ****ing board.
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Offline jr2

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Re: OSHW and Freespace. Would you buy parts for building an fs cockpit simulator.
What was the Chinese dude's rating?

 

Offline Nuke

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Re: OSHW and Freespace. Would you buy parts for building an fs cockpit simulator.
it was actually fairly good. thing is if somone screws you your out a buck or two, but though buy spam you kind learn who the good retailers are. just dont buy anyghin in the $30+ range, because thats where you get screwed, i bought a soldering station and got trashed before it got here, it works, just some case damage, but not only did they insult me with a 10% refund which i did not revieve, they also hijacked my email and started sending spam in my name. they got into big trouble for that.
« Last Edit: June 06, 2012, 09:16:23 am by Nuke »
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Offline Nuke

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Re: OSHW and Freespace. Would you buy parts for building an fs cockpit simulator.
yay i did it!

after a while of thinking what i was doing wrong 2 things immediately stapped out at me. the first was that perhaps i was not using enough toner. dispite the print dialog not having any darkness settings, i did find that the printer had a default toner setting of 3 and printed at medium. i changed these settings in the printer to 5 and dark, respectively. the result was a much darker print. the other thing, was uneven heating. my alignment meathod was about 50% of the problem. the pins caused the paper to bow in the middile, and i had just taped both ends. this time, i took the 2 pins that lined up the best and taped down the paper there on both sides. once taped i pulled all the pins and visually aligned the remaining holes.this allowed me to tape down the ends with the paper stretched tightly across the surface. i then visually confirmed that i could see light through the alignment holes. i then folded a peice of paper in half, and stuck the board and transfer sheets in between. i also decided i would use a more strict ironing protocol. i applied heat and preasure for a full 30 in 3 passes, for a whole 1.5 minutes a side. the first pass i just covered the entire board with the iron and pressed down really hard. i then turned the board 90 degrees and did a slow spweeping pass. and the 3rd pass i did at a 45 degree angle. i did this to both sides. i then gave it a full 30 minute cool down, and 2 minutes in the freezer. resulting in:


for comparison heres the first attempt


i then used my meatloaf pan (dont tell the others i used this for etching, they would have a fit). peroxide and vinegar, with a little salt for taste (i mean to make it cut faster). it turned out to take a cup each, but i did it in 4 batches of 1 cup each (half a cup each). the lego device in the picture is another tool i designed just for this project, you stick a peice of steel wool (i used a spent sos pad) on the end, and it applies rotation with one of the older model lego gearmotors. essentially a better way to polish the copper clad boards. it was super effective. i dont know if i can attribute it to my success or not. i would have used my dremel if it wasnt now a fixture in my lego drill press (and a pita to remove).



it took 4 baches of my home made etchant which was super-effective, all be it slow. it takes a few minutes for the reaction to start up. i presume it needs an amount of copper in the solution t really start cutting. then any salt added to the surface will cause foaming. you could keep adding salt to facilitate the cutting. eventually the liquid gets saturated with copper and wont etch anymore. i then neutralized it with baking powder (yea your supposed to use baking soda, but they both have sodium bicarbonate in them, i wasnt sure how much to use, so i just shook a little in and it fizzed for awhile, then i rinsed it down the sink with cold water).



aftersome more polishing to remove the toner, and a spray down with orange oil to remove the tape remenants, followed by soap-water bath, followed by an alcohol bath, followed by a rinse in cold water. i get this:



a close inspection did reveal a few bad traces, bot those can be soldier or wire bridged. im pretty pleased with the way it turned out. especially the spot on alignment. light shines right through all the vias, without excessive shadow over. next task will be to find a drill bit small enough to drill the holes. i will likely need several. but all mine are somewhat huge. the alignment holes pretty much ate the entire pad, and thats my smallest bit. but im sure i can scrounge up a few bucks.
« Last Edit: June 12, 2012, 02:37:10 am by Nuke »
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Offline z64555

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Re: OSHW and Freespace. Would you buy parts for building an fs cockpit simulator.
:applauds:  :yes:
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Offline pecenipicek

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Re: OSHW and Freespace. Would you buy parts for building an fs cockpit simulator.
nuke, you are my hero :D
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to heal my heart and drown my woe!
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Offline Al-Rik

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Re: OSHW and Freespace. Would you buy parts for building an fs cockpit simulator.
i then used my meatloaf pan (dont tell the others i used this for etching, they would have a fit). peroxide and vinegar, with a little salt for taste (i mean to make it cut faster). it turned out to take a cup each, but i did it in 4 batches of 1 cup each (half a cup each). the lego device in the picture is another tool i designed just for this project, you stick a peice of steel wool (i used a spent sos pad) on the end, and it applies rotation with one of the older model lego gearmotors. essentially a better way to polish the copper clad boards. it was super effective. i dont know if i can attribute it to my success or not. i would have used my dremel if it wasnt now a fixture in my lego drill press (and a pita to remove).

it took 4 baches of my home made etchant which was super-effective, all be it slow. it takes a few minutes for the reaction to start up. i presume it needs an amount of copper in the solution t really start cutting. then any salt added to the surface will cause foaming. you could keep adding salt to facilitate the cutting. eventually the liquid gets saturated with copper and wont etch anymore. i then neutralized it with baking powder (yea your supposed to use baking soda, but they both have sodium bicarbonate in them, i wasnt sure how much to use, so i just shook a little in and it fizzed for awhile, then i rinsed it down the sink with cold water).

aftersome more polishing to remove the toner, and a spray down with orange oil to remove the tape remenants, followed by soap-water bath, followed by an alcohol bath, followed by a rinse in cold water. i get this:

a close inspection did reveal a few bad traces, bot those can be soldier or wire bridged. im pretty pleased with the way it turned out. especially the spot on alignment. light shines right through all the vias, without excessive shadow over. next task will be to find a drill bit small enough to drill the holes. i will likely need several. but all mine are somewhat huge. the alignment holes pretty much ate the entire pad, and thats my smallest bit. but im sure i can scrounge up a few bucks.
The etched PCB is of amazing Quality  :yes:

You are right with the effect of Copper in the etching solution. Professional PCB producers use Copperchloride and Hydrochloric acid as etching solution (please don't try it at home, it produces a lot of dangerous fumes ). It's a good idea to keep a little bit of an old etching solution and add it to a new one to start the process quicker.
Heating the solution up to 40° Celsius and slightly moving the PCB will also make the process quicker, and a quicker etching leads normally to a better quality.

If you neutralize the etching solution with bicarbonate add it until nothing  fizzles any more. If it's still blue, then there is still Copper in the solution. You can also check the pH Value with a Litmus paper, it should be around 6 to 7.
With enough Bicarbonate a green or blue salt deposits,  that's a mixture of  Copper acetate and Copper carbonate. Let it dry and put it in the trash can, it's not very dangerous.
Calcium hydroxide or Calcium carbonate are better neutralizing agents and removes copper better. Calcium hydroxid won't fizzle, but the solution will heat up, so you have to add it carefully. 

Bicarbonate with a little water and Scotch-Brite (or a new sponge) is also a very effective way to clean the cooper surface of the PCB before transferring the layout.
Use deionized or distilled water as last rinse, if you can get it cheap use it to make up the etch.
Take a look on the behaviour of the water on the PCB when you lift it out of the rinse: there should be for at least 30 seconds a homogeneous film of water on the whole surface, without any dry spots.
A blow-dryer set on cold air is the best way to dry it.

Also try to use Isopropanol instead of normal alcohol. It has a higher purity, smells less awful and is a better solvent for most dyes.
And avoid fingerprints on the PCB at all costs during any stages. Never touch it without gloves.  Fingerprints are in professional PCB Production Plants one of the most common sources of trouble.

And regarding drilling the vias:
Good Luck ! ;)

 

Offline Nuke

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Re: OSHW and Freespace. Would you buy parts for building an fs cockpit simulator.
i used ferric chloride before, and if they carried it over at radio shack like theyre supposed to, id use that. i kind of am limited to what kind of chemicals i can get though. mainly because i live in a small town on an island in alaska. post office will not ship chemicals, shipping companies will, but only ground shipping, and they always gouge on alaska way more than the postal service. so with hazmat fees you could spend upwards of $50 to ship a few ounces of powdered etchant. this recipe is one i saw on hack a day, and you can get everything at your typical grocery store. there are quite a few methods to etch pcbs, and im just using the most cost effective for me. i saw an interesting mix of high purity peroxide and muriatic acid that can etch a pcb in seconds. the fact that the process im using is really slow makes it easy to maintain control of the whole process, so you dont get overetching or undercutting, like you do with fast etching methods.

il try heating the solution next time. it should absorb more copper at temperature. i did apply considerable agitation, i just tilted the pan back and fourth. i considered building agitator machine out of legos, but because i didnt know what to expect from the process, decided against it for the first attempt. which is good because i know that 2 axis agitation is necessary,  and it is also necessary to elevate the double sided boards so both sides get equal flow.

my process is far from perfect, but its what i can do with practically no budget.



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Offline z64555

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Re: OSHW and Freespace. Would you buy parts for building an fs cockpit simulator.
If they have pools up in your area, try taking a look in the pool cleaning chemicals to see if they have some muriatic acid. The hydrogen peroxide is what really speeds up the etching process for the acid, thanks to the extra O2, and it also helps revitalize old etching solution. Not entirely sure, but you may be able to use peroxide for the ferric chloride, too.
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Offline Nuke

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Re: OSHW and Freespace. Would you buy parts for building an fs cockpit simulator.
i could probibly get better peroxide at the pharmacy. the stuff i have is only 6%, and the acidity of the vinegar is only 5%. im sure i could find stronger in town if i looked for it. like cleaning grade vinegar. only pool in town is at the only high school in town. being an indoor pool, probibly doesn't need the same level of chem-foo of an outdoor pool. i dont think they would part with their chemicals though, considering how expensive they are to ship in.
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Offline Nuke

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Re: OSHW and Freespace. Would you buy parts for building an fs cockpit simulator.
wile still unable to procure the required drill bits (#71 seems to be the optimal size) i went through my dremel stuff and found a tiny engraving bit i use for cutting traces while circuit bending (the one on the left). it is also very small in relation to the pcb hole size. i tested it last night, after some slight modifications to the drill press. it stuff goes right through the fiberglass substrate and makes mostly clean holes, so i figure i can use this to punch the vias, though it is likely too small for some of the component pins, like the 3 ics (unless i use sockets).

the test i did kinda illustrates how piss poor the visibility of the work area on the drillpress is, dispite the lighting system (which now has an articulated mount). aside from that it seems my holes are less well aligned that i thought they were. or perhaps this bit has trouble staying centered. perhaps a higher rpm is needed. it was 3 am when i did the test and i turned it to the lowest setting to avoid disturbing the neighbors.

i was actually reading up on several techniques to connect vias, several used copper foil, some involved complex electroplating techniques. what i may just do is take a piece of solid copper wire and solder it to both sides. im gonna spend some time working on the vias, im gonna leave the component holes alone for now, because those will require more precision. so i guess i got some work to do.

*edit*

i drilled all the vias, but none of the part holes, i may start connecting vias tonight if im bored. this will allow thorough trace continuity testing of the board, before i start populating it with actual parts.

*edit again*

so my method for connecting the vias is crude ugly and time consuming but effective. ive probibly connected a third of them, but im too tired to use a soldering iron without burning myself or setting the house on fire. il post some photos in a day or two when i finish the job. this board is more of a test of prototyping techniques than anything. if i ever decide to mass produce anything il just use a fab house to get professional grade stuffs. i should at least get a somewhat functional numeric display out of this. granted i just got a character lcd in the mail that can provide better output. meh.
« Last Edit: June 14, 2012, 05:43:59 am by Nuke »
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Offline z64555

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Re: OSHW and Freespace. Would you buy parts for building an fs cockpit simulator.
What's wrong with bridging the two sides of the via with a blob of solder? Tin one side with a fairly big blob that covers the hole, flip over, do the same on the other.

If the board's thin enough, and the holes are small enough, the two solder blobs will fuse when you tin the other side of the board, thereby making a connection.

Edit: Wait, I take that back. That wouldn't work. Sorry. Try heating one side of the hole with the iron and stick the solder through the other side. Little bit more tricky :(
« Last Edit: June 14, 2012, 08:14:03 pm by z64555 »
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Offline Nuke

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Re: OSHW and Freespace. Would you buy parts for building an fs cockpit simulator.
well i kinda connected a **** ton of vias today, not all of them but a majority. i accidentally pulled up 2 traces though, one of which has a rather ugly jumper wire on it, and the other with a bare wire bent into the shape of the original trace and soldered down. all this was because one trace was bad, and after several attempts to solder ridge it i attempted to put a bare wire down. it worked, but then other solder joints kept bridging to it, and it an attempt to undo the problem, pulled the whoe entire trace off. this ripped off a neiboring trace, resulting in 2 jumpers, fml. fortunately its on the backside of the board, so it wont interfere with parts on the top. **** like this always happens in the proto phase. now i got 2 of the bus lines crossed somewhere, and i got to fix that.
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Offline Al-Rik

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Re: OSHW and Freespace. Would you buy parts for building an fs cockpit simulator.
i could probibly get better peroxide at the pharmacy. the stuff i have is only 6%, and the acidity of the vinegar is only 5%. im sure i could find stronger in town if i looked for it. like cleaning grade vinegar. only pool in town is at the only high school in town. being an indoor pool, probibly doesn't need the same level of chem-foo of an outdoor pool. i dont think they would part with their chemicals though, considering how expensive they are to ship in.
I'm not quite sure if you will get a higher grade peroxide at the pharmacy. Higher grades are more dangerous and a potential chemical for the home grow terrorist, so don't wonder if the pharmacist ask at lot of questions. ;)

Be careful with the muriatic acid. It's just an other name for hydrochloric acid. It won't burn your flesh or cook your eyeball like high grade sulphuric acid does, but it produces a lot of dangerous fumes.
Always ware safety goggles & gloves and work outside of your house. Also keep a lot of water in reach, so you can rinse it off immediately.   

If you want to use muriatic acid try this, the only thing i'm not approving is the using of a booze bottle to store the etching solution. At least add some stickers with the symbols for corrosive and the name of the stuff that is inside  ;)
http://www.instructables.com/id/Stop-using-Ferric-Chloride-etchant!--A-better-etc/?ALLSTEPS

Quote
il try heating the solution next time. it should absorb more copper at temperature. i did apply considerable agitation, i just tilted the pan back and fourth. i considered building agitator machine out of legos, but because i didnt know what to expect from the process, decided against it for the first attempt. which is good because i know that 2 axis agitation is necessary,  and it is also necessary to elevate the double sided boards so both sides get equal flow.
Try to etch it vertically, tupperware has some useful boxes for that kind of work.
Also try to get a pump to blow air inside the etching solution via a L-shaped tube on the ground.
Together with a little movement of the PCB this should be working like here:
http://www.conrad.de/ce/de/product/530328/SPEZIAL-AeTZMASCHINE-TYP-2030/2512150&ref=list