this might sound a bit anal but here goes
i'm building a uv lightbox for pcbs
i have the tubes, scavenged hf electric ballasts and fittings, some old greenhouse glass which i hope isn't restrictive to uva, some kitchen foil for covering the insides and enough ply to make a box.
the question i have:
is there a good way to work out the spacing of the tubes to avoid hot and cold spots?
I have tried toner transfer before and it was pretty much a week of my life i will never get back so i'm trying to get this as perfect as possible so i don't end up killing myself.
also make me jealous with some home etched boards if you want
Really, the only quick and easy way is to use an engineer with extensive knowledge of the lights you're using. The long and tedious way is to try it with the lights evenly spaced, then try to burn a test pcb with that set up. If you're not happy with it move the lights closer together and add a light or move them farther apart and subtract one.
>>917294
>some old greenhouse glass which i hope isn't restrictive to uva
The vast majority of common glass is restrictive to UVA.
I probably lost a week of my life trying toner transfer too. Then I gave it one last shot using a different printer and all of a sudden it worked beautifully. I quickly learned that the brand of printer and toner is the single largest variable in the equation.
Brother is a definite no. Most Dells seem to work well. HP tends to work too. Use the absolute cheapest photo paper you can find, the cheaper the better. Always print high quality, and if there is a special setting in the driver like 'make blacks blacker' then turn it on.
tl;dr toner transfer does work, using the right printer.
>>917426
But it's not common glass.
OP said it was greenhouse glass, which should not be UV restrictive.
>>917432
i tried every single printer and photocopier i had access to, even asked friends to print it out at work. spent a fcking fortune buying different types of paper that i still have the rest of somewhere that will never be used.
i tried different irons and settings and an old laminator that i got for free that was supposed to be broken but just had 5 sheets of a4 lost inside it
i must just be clumsy or retarded cleaning the paper off because the tracks just wouldn't stick
i cleaned the boards with ipa, ethanol?, some pcb rubber thing, steel wool, some acidy stuff.
im fucking done with it.
good for you though anon well done.
>>917432
>Brother is a definite no
Motherfuck. Not even for coarse PCBs? I don't need high tolerance, I just need a whole bunch of very simple boards with a handful of components each.
What sort of toner should I look for? Is it like a specific formula?
>>917660
Fine or course makes no difference. The toner isn't going to stick. Best bet is to get a bunch of steel wool and clean the copper really really well. Then get print outs from different people using different peinters. Dell is the best I have found so far.
Just try with one print out, and if it doesn't work, clean the board again and try with a different print out.
