Etchable pancace coil


Could this be acceptable coil symbol as a schematic part?
For me this would be ideal, although it is not a standard symbol for a coil. But if you use both a solenoid and a pancake in the same project then I is clear at one glance who is who and more important what is connected to the inner winding and what to the outer winding.

And if someone can scrutinise the xml that would be nice too.





just wondering…
is there also an option to make a silkscreen for the bottom?

say i want to indicate 1 header should be on top
the other at the bottom of the PCB
Or both at the bottom in this case


Silkscreens can be top and bottom; In your core parts, PCB view, you can insert text or image on either side of the board. You can draw any image you would like in Inkscape, save it as .svg, and insert on to the board.


a few more questions:
What is the correct layer name for the silkscreen layers top and bottom?
google points me to this page but it doesn’t explain anything about the silkscreen for the bottom.

EDIT: silkscreen0 seems to be the bottom silkscreen layer

Is there a spec file that covers all the files, and all their respective layers and other name tags?

i see
when do i use who The wiki doesn’t seem to cover them all (just like it does not seem to mention a second silkscreen layer by name)

How to use metric and imperial mixed in one file. (without going insane)
I noticed that Frizing Inkscape Illustrator (and also Corel) all seem to do things a little bit different. And are not 100% compatible with eachother.
This specially comes to light when you change a Imperial to a Metric value.
Then the trace width always gets messed up.

The thing is this, I calculate and draw my coils in metric, since I don’t know how to do this in imperial.
Though Fritzing seems to prefer Imperial. Is that correct? I see more and more EE stuf moving to Metric (1mm and 2mm pitch headers for instance)
So what will the future require? Metric seems to be more universal.

Since all of this is still beta i’m not expecting it to be complete, though i find it difficult to get my head around all of the details when i can’t seem to find the actual info about the detail that i try to figure out. :slight_smile:
So if this info is listed somewhere that would be a great help.
A table or a cheat sheet style 1 page document that covers all the tags is what i have in mind. If really non exists then i’ll give it a try to start one.


Ok here is what i got so far

PancakeInductor.fzpz (11.8 KB)

i have a weird ratsnest line showing up that i cant figure out where it comes from.
the breadboard view is a bit weird, how can that be done better?
the pcb view has a large squre around the center pin that was smaller when i designed it.
any idea why this happened?

please give me some feedback



Your two connectors IDs in your PCB view need to be labeled connector0pin and connector1pin and need to be inside the imbedded layers copper0 and copper1. If your coil is on the bottom only side then it should be in in the copper0 layer only, (see below).

 <g id="copper0">
    <g id="copper1">
       <circle id="connector0pin" />
       <circle id="connector1pin" />
    <line id="coil-1" />
    <path id="coil-0" /> 

Bauteile Editor kann nicht mit separaten Kupfer0 und Kupfer 1 Ebenen umgehen
HopeRF RFM69HCW ISM Transceiver
I want to include some latching DTDP relays... but oh dear

Hm not sure what happened, the connector id’s got lost somehow.

Thanks, it slowly starting to come together in my mind


I started from scratch over and over again to get rid of all overhead and get a grip on the basics.

now i have this part:

part_40t_02mm_447OD_pancacke.fzpz (13.1 KB)

but it doesn’t want to load. and i don’t see why
also it would have been nice if fritzien could tell me why it does not load instead of just telling me “Unable to load part from …” If it knows it can’t load it then any clue would be welcome
eventually a checklist?
so that you know what is ok and doesn’t need to be changed. and also what is the actual showstopper.
But if that is possible i have to leave that to the devs…


Hi uaneme,

To start with, your fzp has one copper layer call “copper”, should have copper0 and copper1…

<pcbView> <layers image="pcb/40t_02mm_447OD_pancacke_pcb.svg"> <layer layerId="copper"/> <layer layerId="silkscreen"/> </layers> </pcbView>

and your pcb.svg, “copper0 and copper1” are not embedded. I didn’t look any further then that.

Back to the old drawing board…



Thanks Steve,
it’s hard to keep track of everything, and I didn’t realise that the copper layers MUST always be embedded.

Is there another way to try and open a part in the part editor then dragging and dropping it into fritzing?
Fritzing itself is very intuitive, but the parts editor for some reason is not intuitive at all. To copy a part then edit it and change it into a new part? I don’t get it. I’ve spend quiet some time to figure out what is expected from me and i just don’t seem to get it.

I hope there soon will be a way to create a .fzp in the parts editor from scratch. I’m not sure how others experience it, but to me it is confusing to copy some part and then figure out what goes where

Anyhow i fixed the embedded copper layer and this time i used inductor.fzp as my guide
I have to say that i’m not too sure if what i’m doing is correct. I just copy the inductor and fill in my values, but i feel like I don’t know what i’m doing.

this time I also included the prefix (seems i overlooked that too)
and i also included a spice tag
but still no joy

I guess i’m looking for an even more basic way to get started with the parts editor.

part_40t_02mm_447OD_pancacke.fzpz (13.2 KB)
this is the latest version i have made


You have a top and bottom coil. Are you using two coils now? Is the top and bottom the same?


Yes i now have top and bottom coils (more copper, 2 parallel coils)

but yes top and bottom are the same in this case, i’m also thinking of making the 2 seperate but then i need an extra hole in the center. So for now i first need a part that Fritzing can agree with, the next phase will be getting a few variations on the theme, then fabricate a few and see how usefull they actually are.

Ultimately i would want bigger coils (7cm across and even bigger) but for now i’lll try to stay within the 5x5 cm footprint that my favorite fabhouse offers for very cheap. So i need to do some consessions.
Since the 5x5 offer is dual layer i’d better make use of it and therefore make 2 parallel coils.

But the first 4 i’ll etch DIY on singlesided copper. (so i’m in a constant battle with my own thoughts on this project)



for some reason I could not get this svg file to upload. Try it out, see what happens.


It looks to me like you are working off the back-end of Fritzing, you don’t have all of those long crazy moduleID numbers for file names. By using the Load Image in the Parts Editor it will resolve several issues; first it error checks, if you do not have proper copper layers it will tell you, if you do not have the appropriate font it will correct them for you. You can also check your connector pins to see if they are checked. It will let you know if you have any unconnected pins. When you assign a pin with select graphics it will change your pinID to the appropriate pin number in your svg. It will also add the “gorn” necessary for flipping and rotating or whatever it is for. Technically, the Parts Editor will rewrite you svg to the Fritzing format.

The way I do it… I will start with a part that is close, usually a generic connector, either pins or pads. These have fairly clean files and the pins are numbered 0 through whatever… keep it simple. I then will create a master file by cleaning up all the meta data, gorns and transform matrix or whatever, if left in, these can sometimes cause a problem when loading the image back into Fritzing. Inkscape of CorelDraw will generate the Transform Matrix when exporting as .svg and Fritzing will create the gorns where ever needed. Some of the old Fritzing files have a lot of garbage in them that Fritzing does not need or use, there is no reason to have it in there… just makes them harder to read. From then on, all my editing is done in the master file and I don’t export anymore files for that project from Fritzing. I use NotePad++ to view and edit the Fritzing files, the results of my master files, and the fzp. My master files are all cleaned up and everything is grouped and labeled for ease of editing.

It is really, truly easy once you understand it…:grinning:


First of all thanks once again

Thats how i started off, but once i could not load my file into fritzing i started adding all that stuff to figure out if that was causing the issue

But at this point I just don’t have a clue what is stopping the show
did i make a silly typo?

Maybe i’m just stubborn to start from scratch. but even when i use the inductor from fritzing core as base to work from, fritzing refuses to load it
And yea, the SVG stuff is now falling into place in my mind, and i hope to get the same understanding about the parts file.

And also when resusing parts to create new parts then I just don’t have a clue what is no longer needed. I try to make my parts as clean as possible, and therefore i name everything that i made, and wherever is see a generated id then i try to figure out what it is.

I’m now pretty much sure that my SVG’s are correct when it comes to graphics and id’s
However the connector stuff i can’t be sure of as long a s my part doesn’t load.

I will try again to use the parts editor and let that do all the ‘magic’ stuff.

Your help is very valuable, though my mind is still feeling a bit like a ball in a pinball machine, and yes i realise that i’m the one who is making it more difficult then it is. I just took one wrong turn into a dead end street :smiley:

This is really an issue that you want to sit next to someone and look at it together, without the internet inbetween
as a shortcut to that AHA moment.

Ok i’m back into the machine…


Trust me, I did not learn this overnight… I played around with it for several days just to see what works and what don’t work. I think the best way to see how files should be written is to create a connector from the Generic Connector Parts. These are generated in the PartFactory on the fly.


hehehe can imagine!!

i’m now wondering if i should have left out the connector id’s when i made the SVG’s

If the parts editor can create those then that would save inkscape time
I think i have to working now but it looks like something is messed up with the positioning. So i’ll investigate that first


getting dangerously close!!!

The breadboard view misbehaves and i don’t see what is causing this

and a few cosmetic issues,

  • grid alignment in schematic view
  • mixed metric / imperial stuff, not an issue with this part but i see that this will be a major headache for another idea i have. This imperial stuff is needs an exorsist…

Pancake Inductor.fzpz (14.6 KB)

main question:

(why do the ratsnest lines pick the upper left corner in the breadboard view?)

BTW it would help if fritzing would display a red + or something at the origin in the PCB view so that a critical mechanical part can be positioned at an exact spot


It doesn’t work that way… The PartFactory only creates generic parts, “connectors, resistors, etc.”. It won’t create connector Id’s into your custom parts. What you can use it for is to create a two pin connector, open that into InkScape, past your coil in the svg then drag your connectors around where you want them. work on one view at a time, when one view works properly then work on the next view.


Ok then i need to wrap my mind around this one more time and see how i can make it nicer.

Still the breadboard ratsnest issue i can’t see what that happens?

Do i need special id’s there for the ratsnest stuff? Or is it caused by ‘flexible pins’ or something?why do they get connected to the upper left corner and not to the connector pins. Ir did something happen when i imported the SVG into the breadboard view?