[Tips and Tricks] PCB routing

Post by **modman** » 12 Aug 2008, 11:54

I would like to start making my own layouts. What's the best way to go about it?
Do you use computer program? Do you use auto-routing or do you draw the tracks manually? What are the factors involved in optimal component placement?

thanks for sharing your thoughts and experiences

mike_a · Post by **mike_a** » 12 Aug 2008, 21:40

I'm also just starting to learn this, so I don't have any tips yet

However, I've bought RG's book on PCB layout (through smallbear), and I highly recommend it.
It's oriented towards stompbox layouts so you won't get lost.

Anyway, that's my 0.02$, but I would also like to hear any other tips from the pro's as well

.

puppiesonacid · Post by **puppiesonacid** » 13 Aug 2008, 10:47

The specific tips and tricks I would like to have more in depth answers/knowledge about is how to get proper scaling for components layouts. I would hate to waste time, effort and money because I couldn't get it right within a couple try's. Having an FSB.org approved "way" of doing things would be great.

Thanks again for making this forum a valuable resource for DIY musicians,

puppiesonacid.

danielzink · Post by **danielzink** » 14 Aug 2008, 00:48

While not a "pro" by any stretch of the imagination - I have successfully laid out and etched plenty of my own effects boards.
I've tried pretty much all of the normal PCB layout programs. And I've settled on the DIYLayout Creator program:

http://www.storm-software.co.yu/diy/ind ... t=software

As far as component spacing etc., once you've got you circuit laid out - you have a "render PNP" option. That'll output a gif file that I print out on regular paper. Then I take that printout to my bench and take a regular safety pin and punch out the pad holes and actually test fit components. I've got it down to a science at this point as I know how many "dots" to place the pads apart for 5mm lead spacing as well as how many dots for normal resistor spacing vs making a compact board and having the resistors "stand up" etc.

HTH

Dan

asfastasdark · Post by **asfastasdark** » 27 Aug 2008, 21:44

Danielzink, thanks for referring me to that. I'd been looking for that program for quite a while and just downloaded it, and it's so much fun to use!

marshmellow · Post by **marshmellow** » 28 Aug 2008, 09:18

I would really consider using something more sophisticated like Eagle, Target, Altium Designer, Splan, whatever... They are much more comfortable to use and have one main advantage: your layout WILL WORK. You don't have the chance to produce one that is not working if you use the tools the right way.

Personally I like Eagle because it is free, easy to use (also for beginners) and not to overloaded with functions I don't need (compared to some CAD guy that is going to route a multi layer mainboard for a computer).

As far as auto routers are concerned... Once you've used one you will probably not use it again. It may sound simple but you need much more layout experience to work successfully with auto routers to get predictable results. Also most auto routers won't do component placement for you, only trace routing.

Component placement isn't that critical with your average booster. I would just start laying out a PCB for some TS or a even simpler circuit to get started with the software you choose and gain some experience. For Eagle there are also tutorials available on their website.

RnFR · Post by **RnFR** » 28 Aug 2008, 13:17

i've been trying to use eagle lately and have been having a good go at it. gaussmarkov.com has been a big help, as well as instructables from make magazine. one thing that i can figure out though is how to widen traces. anyone know how to do this?

marshmellow · Post by **marshmellow** » 28 Aug 2008, 14:34

When you select 'route' you got a width setting, that determines how wide the trace is going to be.

For an already existing trace type 'change width' (or 'ch wi', you can always shorten if there is only one possibility for Eagle to understand), choose the value you want and click the trace. In the latest Eagle version you can also do this by right clicking the trace, go to properties and type in the value.

RnFR · Post by **RnFR** » 03 Oct 2008, 04:19

thanks- i'll give that a try. i've been slacking on my Eagle studies lately, but i have been doing some layouts in DIYLC. and although DIYLC is a great program, i really feel like i should be concentrating on learning Eagle more. hopefully i'll get back to it soon, but DIYLC is just so easy to work with if you want to just whip out a vero layout quick. i have yet to find any "render PCB" function in DIYLC though- anyone know anything more about this?

here is a PCB layout for a dirty boost/overdrive that i have been working on.

RLBJR65 · Post by **RLBJR65** » 09 Oct 2008, 12:13

RnFR wrote:i have yet to find any "render PCB" function in DIYLC though- anyone know anything more about this?

If you are using the old windows version it says "Render PNP".
I've never had much luck getting it to print right though so I render the image, open with MS paint, then reduce it by 50%. I always want to fill in the pcb anyway so as to leave as much copper as I can (saves on etchant) so for me it's no big deal.

I have not used the new version much so I'm not sure about it.

I like DIYLC. It's so simple! No long lists of parts to sort through etc. The parts are in my bin, I know what size they are so I can adjust spacing as needed. If in doubt the pad spacing is the same as most perf boards so you can easily check the spacing you need for the components you already have.

jimosity · Post by **jimosity** » 11 Oct 2008, 04:28

I assumed that Eagle was WAY over my head only a few weeks ago; then I watched these videos:
http://tangentsoft.net/elec/movies/
(Specifically starting about video #7 and on...)

Now I can whip thru it with no problems at all and I've even laid out my own boards, etched them and have them built within days of watching those videos for the first time.

One thing that really helped a lot was also reading (as already stated) the Eagle info on the Gaussmarkov site. Plus - he's got a package of libraries that have almost all of the parts you need when building pedals.
I removed all of the stock Eagle parts libraries and am only using his part libraries and it's awesome.

I'm so glad I spent the time to really sit down and learn to use Eagle, there's much more that I can do with it as opposed to some of the others.

johanwastaken · Post by **johanwastaken** » 13 Oct 2008, 22:01

I am making 9-10 or so units of a pedal which means that maybe it's finally the time to start building pedals with PCBs instead of perfboards. I made a layout in Eagle, does this seem fine or is there anything you would change? This is the first time I've made a layout so it's very possible that I've made some beginner mistakes.

The pots need to be where they are as they will be PC mounted.

With the silkscreen layer (yep, it's a tubescreamer-like pedal):

I am going to order the PCBs from a fab house and the clearances are well within their limit.

madbean · Post by **madbean** » 14 Oct 2008, 02:47

It's a nice layout...a schem would be helpful, and the ground plane is a bit distracting for me.

If you are PCB mounting the pots, won't you need to have their lugs oriented the same way with the volume and drive? Or are you going to bend the pins around? Also, I don't see a pulldown resistor.

johanwastaken · Post by **johanwastaken** » 14 Oct 2008, 21:47

madbean wrote:It's a nice layout...a schem would be helpful, and the ground plane is a bit distracting for me.

If you are PCB mounting the pots, won't you need to have their lugs oriented the same way with the volume and drive? Or are you going to bend the pins around? Also, I don't see a pulldown resistor.

Okay, thank you.

Here is the schematic:

I've been told that a ground pour is a good idea. I think I will keep it (is there a reason not to?) but here is a picture without the ground pour so that it's easier to see:

As you can see, I've changed the layout somewhat. I've added a reverse polarity protection diode. I think the alignment is weird atm but I will take care of that later. There are also two capacitors in series in the feedback loop. The reason for this is that I haven't been able to find suitable 51pf caps so I'm running two 100pf caps in series instead.

And yeah, about the pots. I am not sure yet in what way they will be oriented but I have ordered some different pots and then I will try out what works best for me. But it's an easy fix if I need to reverse them later.

Is it okay to run the LED as I did in the layout (from the 4.5v-bias instead of 9v)? That makes things a lot easier for me. And if you're wondering how the LED will be activated, the idea is that I want everything mounted on the PCB so I will run wires from the L1 and L2 pads to the footswitch and when the effect is on, those two are connected together which will make the LED turn on.

Dirk_Hendrik · Post by **Dirk_Hendrik** » 17 Oct 2008, 16:56

Do yourself a favour since you have enough boardspace. Make the pads bigger. It will make drilling easier, soldering easier, and reliability higher.

And thanks for helping to save the planet with that groundplane!

Dirk_Hendrik · Post by **Dirk_Hendrik** » 17 Oct 2008, 16:58

You might want to add a 1Meg depop resistor at the input

borislavgajic · Post by **borislavgajic** » 18 Oct 2008, 08:56

I do not like trace going to secound legg of IC.....becouse of angle ......I always make 90` traces,and then I go into curves........

....And I agree with all comments before
It looks nice...keep going

boris

Solidhex · Post by **Solidhex** » 18 Oct 2008, 18:49

Yo

The area of layouts I'd like to learn more about is placing components and routing wires to avoid hum or any parasitic capacitance. I'm really good with the "tetris" and common sense goes a long way with layouts but I'd love to see an extended list of rules for stuff like that.
R.G. Keen wasn't able to get into specifics in the book lest he lose the easy to understand aspect. Great book by the way. It was exactly what I needed.
I actually did the layout on Guassmarkov's for the Zonk machine shortly after reading that book... http://gaussmarkov.net/wordpress/circuits/zonk-machine/ you can use is for the Maestro Fz-1/1-a and Tonebender MkI. That site was a HUGE help in using the Eagle layout program.

---Brad

johanwastaken · Post by **johanwastaken** » 18 Oct 2008, 23:10

Dirk_Hendrik wrote:Do yourself a favour since you have enough boardspace. Make the pads bigger. It will make drilling easier, soldering easier, and reliability higher.

And thanks for helping to save the planet with that groundplane!

I'm not making the board so drilling is not an issue but I will make the pads bigger

Dirk_Hendrik wrote:You might want to add a 1Meg depop resistor at the input

Yep, I will. I'm not sure though if I want it on the board or between the switch and the jack.

borislavgajic wrote:I do not like trace going to secound legg of IC.....becouse of angle ......I always make 90` traces,and then I go into curves........

....And I agree with all comments before
It looks nice...keep going

boris

Thank you!

How would you do that trace? It kinda has to be angled or it'll collide with the traces next to it.

RnFR · Post by **RnFR** » 23 Oct 2008, 17:57

recently found this book in the google library. haven't given it a good look yet, but i thought i'd share anyway.

looks like it should have some good info!

http://books.google.com/books?id=SoA4ko ... r#PPA40,M1