drilling and PCB layout

[dave h.]

two questions:

1: when using a drill press, how do you keep a tiny drill bit centered over a tiny copper pad on a PCB, is there a trick to this? or do you just have to be keen-eyed and steady-handed?

2: what programs do you use to make a circuit layout when using a press n peel transfer set up? i used the GIMP and i have mixed feelings, but im used to using photoshop, but i would assume you guys would use something different. and what programs do you use to make schematics that dont look like fried ass?

[R@bbiT]

P-CAD

[Paul Perry (Frostwave)]

So far as 1. is concerned, some people actually etch out the centre of the pad, so ther eis naturally a 'dimple' for the drill to sit in.
Maybe (I havn't tried this) you could try gently tapping a pointed steel pick to make a dimple where the hole goes.
Of course, with a perfect drill press & chuck, the hole just HAS to go where you tell it :wink:

As for drawing circuits, I feel the 'fried ass' look is rather charming.
Hell, some people even do their PCBs freehand! check this work of art by JC Maillet: http://www.lynx.bc.ca/~jc/UnivibeCloneBd.gif

[dpresley58]

Pretty cool artwork, Paul  

I use one of those General scribes to pre-punch the center of pads. A slight tap will get you an indentation deep enough to guide the drill. Then, I drill the pads freehand with a Dremel hooked up to a footpedal that turns it on and off.

Sure, I'd like to grab one of those drill press attachments and probably will soon, but the local Home Despot didn't have one when I went looking the first time so I went with the above method.

AutoCAD is my tool for PCB layout. These are plotted to acetate on the way to the photopositive stock for the boards.

Also, I use one of those OptiVisors for almost all electronics work. It -really- helps me.

[O]

1- When I etch my boards, the etchant automatically eats the center of the pad, so if I was to look at a pad through a magnifying glass, this is what I would see...

(side view)

------------------__----------   <--- copper layer
Fiberglass -----^

2- As far as the layout program, I've been using ExpressPCB for some time now, and so far, I've liked the results. Once you complete your layout, you can edit it using MS Paint. The bottom picture is the output from the Express PCB program, the top picture is the result of what happens when I cut lose with the paintbrush.

[bwanasonic]

2- As far as the layout program, I've been using ExpressPCB for some time now, and so far, I've liked the results. Once you complete your layout, you can edit it using MS Paint. The bottom picture is the output from the Express PCB program, the top picture is the result of what happens when I cut lose with the paintbrush.

In case you haven't tried it, you can achieve the same results within ExpressPCB by varying trace size, using rectangles to fill areas, and arcs for round  corners. And then you can have them make the board for you as well!  :wink: (I hate drilling, and I like double-sided boards).

Kerry M

[O]

In case you haven't tried it, you can achieve the same results within ExpressPCB by varying trace size, using rectangles to fill areas, and arcs for round  corners. And then you can have them make the board for you as well!  :wink: (I hate drilling, and I like double-sided boards).

Kerry M

I tried doing it from within the program, but I got tired of having 4 different clicks of the mouse to get a fatter or thinner tracing. I suck at grafix, so Paint has been my crutch since I learned how to use a computer.

I thought about sending my boards to be made by them, but I think I'm a masochist since I like designing, transferring, etching and drilling.
:shock:

[KORGULL]

dpresley58 wrote:

Sure, I'd like to grab one of those drill press attachments and probably will soon, but the local Home Despot didn't have one when I went looking the first time so I went with the above method

If you can get to a Sears Hardware, check there - that's the only place in my area that had them. Lowes & Home Depot didn't carry that item.

[KevinHart]

For the PCB layout I have been using Eagle 4.1 for a while now. Great as you create the schematic, which is easy as most of the components are in the list. Then switch to the board loayout, place the components and click the button and you get the PCB!  There is a couple of tuourial files that you can download and these get you up to speed really quickly.

[NaBo]

In case you haven't tried it, you can achieve the same results within ExpressPCB by varying trace size, using rectangles to fill areas, and arcs for round  corners. And then you can have them make the board for you as well!  :wink: (I hate drilling, and I like double-sided boards).

Kerry M

I tried doing it from within the program, but I got tired of having 4 different clicks of the mouse to get a fatter or thinner tracing. I suck at grafix, so Paint has been my crutch since I learned how to use a computer.

I thought about sending my boards to be made by them, but I think I'm a masochist since I like designing, transferring, etching and drilling.
:shock:

LOL... thats funny.  I just got into ExpressPCB and was having the same issue with it... those are some REALLY tiny pads for the majority of the components.  I use the .050" traces, and i wanted the thickness of the pad (around the "dimple") to be about the same.  I was so frustrated with not being able to find an option to increase component pad size without ungrouping and regrouping and saving EVERY single component :?

I ended up starting to thicken them up in paint before saying " :x  :x  :x !!!!!!!!  #@$% this!!!  THERE'S GOT TO BE A BETTER WAY!!!"  So then I ended up drawing a nice size circle and pasting it around each hole.  I still thought there must be a better way, but you guys have confirmed it, there isn't!

So I'm wondering... is there a downloadable component library with thicker pads that we could import?  If not... I wonder if people would be interested in collectively compiling one?  Perhaps I'll start a new thread for this.

[dpresley58]

dpresley58 wrote:

Sure, I'd like to grab one of those drill press attachments and probably will soon, but the local Home Despot didn't have one when I went looking the first time so I went with the above method

If you can get to a Sears Hardware, check there - that's the only place in my area that had them. Lowes & Home Depot didn't carry that item.

Why, Thank'ya...    I'll trot by there soon... There's one just down the road from work. Never thought about it as a source.

[Gladmarr]

Hey all, not to hijack the thread, but I'm going to hijack the thread...  What tricks do you guys use to get decent etches for your homemade boards?  I've tried to make my own boards three separate times, and each one turned out almost good enough to use.  I keep losing bits of toner (i've been trying the toner transfer method) from the copper layer, and then my etchant (ferric chloride) eats some of the toner off during the process.  I think we need an in-depth tutorial from some expert on this board.  I don't want to lay out $60 at a shot for boards from ExpressPCB, and I'm tired of waiting a month for boards from Futurlec.

[O]

I think a lot of people use different methods just like they use different programs for their layouts. If everyone was to write a tut on how to transfer, we would probably need a new sub-forum just for that.

I use ExpressPCB and the photo paper method. I've had excellent results and I have probably etched about 5 feet x 2 feet worth of copper board using that method.

[Gladmarr]

Well, O, see I'm not so interested in the program thing, I've got that down.  What I'm getting at is how to make sure the toner really transfers to your copper, and how to keep it on there during the etching process.  I got the modified laminator machine from Pulsar and I still can't get it right.  Am I retarded?  What are the tricks?!?

[O]

What are you using? (paper, printer/copier, pro iron, etc...)

What I do is sand the piece of copper board with 400grit sandpaper in an "X" pattern. Once the board is nice and shiny, I wipe it down with acetone (nail polish remover). I've been wanting to try Naphta (charcoal/lighter fluid), but I'll probably do that on a test board.

Once it's all clean, I pre-heat the board on the iron, copper side-up. I then either place the transfer paper on the board while still on the iron (you need a really steady hand), or I take the board off and set it on a piece of wood and then place the paper on top.

If the copper is scuffed and oil-free, the toner stays on there really well (at least using the stuff I use). If for some reason you lose some toner, just use a sharpie to cover up the spots.

I'm going to be etching a couple of board, so if you want, I can document the whole process...

[RobB]

Leaving the toner on untill after drilling will give you an even deeper "dimple" to centre the drill bit. The extra depth you get from toner + copper makes a difference.  

(side view)
==========_======= <--- Toner layer on top of Copper
Fiberglass----^

Setting the drill press to high speed helps.  
Do you really need your pads to be that small?