how to make this type of variable width traces in KiCad ?
i have tried with changing width of individual trace but its not looking good. This is made by me. but with constant trace width.
I am not sure what you mean by ânot looking goodâ. I am not digging into any details but your variable trace photo looks perfectly OK to me.
I generally like to make my traces as fat as will easily fit. I will often vary the width to allow fitting through tight spaces where necessary. The pcb fabricators do not provide a price discount for etching more copper. Unless you are doing high voltage or controlled impedance, fatter traces are at least mildly advantageous because they tend to reduce stray inductance and are more mechanically robust. For example I tend to use a 0.75 to 1 mm wide trace for connecting an 0603 chip where there is space to do that. Of course the priority is to use wider traces where current is higher.
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I have use ânot looking goodâ term when i change width of individual traces like V+ and V- , I have attached photo how its look like, I want to replicate exactly this pcb as shown in photo. I am new to pcb designing so i have not knowledge of impedance, min width as per current requirement, multilayer pcb and its calculation. but i am learning.
BTW thank you for your reply.
What does the board do? It will require a lot of work to duplicate the layout as shown and it may not be worth the effort if you donât need high current traces.
I got the circuit from the broke trimmer, it was attached to 4v DC motor with micro B usb and rechargeable li-ion battery . so i think those traces might needed. im not going to manufacture the pcb. just to improve my skill ,i am doing this.
I know when designing my bench power supply I resorted to using zones. You can just put down lots of âdotsâ to get the outline you need. This might be painful but thatâs the closest you can get short of trying to do some kind of photo import. I havenât tried that sort of thing and Iâm not sure if it would be easier than making the zones.
how to put dots, i tried to find but cant find it. sorry for being naĂŻve.
I get some similar result when ânecking downâ traces.
I think that is a very good idea, but I do not see any significant problem with the variable widths shown in the last photo. I agree that it looks a bit strange cosmetically. But given your described function, I see no functional problem.
However:
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The trace where it joins the resistor could be as wide as (or almost as wide as) the resistor pad. You would not need to vary the trace width as much as you did.
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It might look better if you make more and smaller steps in the trace width. Such as 20% or 25% at a time.
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Many designers try to avoid 90 degree bends in traces because it provides a point where the trace is more likely to peel away from the substrate.
I have been engineering since 1975. Once in my life I encountered a crosstalk issue which was caused by capacitance between traces. This design had low current and (I think) 40V transients near an amplifier input. The best fix was to somewhat reroute one of them, but in theory thinner traces might have helped. At all other times, layout inductance is the adversary and wider traces are advantageous.
thank you sir, Ill reroute my pcb. but still how to add dots in pcb layout.
Thank you for the reply and suggestion. I did by creating trace frame as **hermit sir ** told and then add two more traces to fill it. Thank you 
now i have to do this in whole circuit 
Perhaps @hermit can elaborate on his idea for âdotsâ. My idea is to temporarily use a layer such as F Fab to draw graphic lines as a guide for drawing the zones. Then those lines can be deleted when the zones are complete. In KiCad version 5.99 you get selection filters which make it easy to select (then delete) the desired item without disturbing other items.
Sorry. That was clumsy. I should have said mouse clicks.
Yes I was thinking about it. If I were to do it with zones I am not sure that drawing guidelines (as I had proposed) would be so necessary. KiCadâs tool for drawing zones is reasonably good. But still I think that some minor tweaks to the varied track widths as @do_b had shown would be my first option.
I understand where you are coming from. Smart approachâŚwhen you donât understand the circuit do not make any changes
what you show in your post with variable trace width is perfectly fine for your duplication. If you look at what Iâve sketched below, removal of the rounded corners will make it look like the original board. The added âbumpâ at trace angles or width changes will not make any difference.
@BobZ , I have tried to use do with the zones but kicad does not consider those zones as net and make hatched line around it. how to solve this ? any idea.
@JohnRob, thank you for your reply. but how to remove those round corner ? i dont have any idea how to do that. could you please give more explanation or give me any article regarding this. Thank you. and no sir. Im just engineering student. this project is to sharpen my skill. i am not duplicating anything or manufacturing it.
The exact details will vary with the version of KiCad. But if you get a right click context menu for the zone, you need to fix two variables.
One of the variables is to specify the net to which the zone is connected. I like to give many of my nets meaningful net names using local labels (in the schematic) because the KiCad assigned names tend to not be helpful (such as R17 pin 1)⌠I do not pay attention to which pin is which in a resistor but KiCad (with most EDA programs) seems to care.
The other variable is âthermal reliefâ connections to pads. You should uncheck that if you want solid connections. This may make some soldering more difficult (more heat required) but it is what I generally do.
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Sometimes its easier to use simple zone outlines and use a keep out zone to get the fancy shapes
