Hi,
I’m all done my Schematic and PCB Layout. I’m ready to send off for getting my board made, but I just had a quick question. I have some fab and assembly notes that i want to send off. It’s just some text guidelines and a simple crude dimension drawing of board thickness. Should I put these on the drawings layer? or the comments layer? A quick answer to this would be very helpful.
Thanks.
Hi,
In my experience, those questions have to be spoken directly with the manufacturer, as each one wants the information in their own way.
Some may want an email, some a pdf with the instructions, some have a web site with a questionaire…
I usually contact the manufacturer and ask him the details.
About a year or two ago there was some extensive discussion on the Forum about how people used the different layers. The Footprint Library Conventions document (KLC) gives you moderate insight into how the development team imagine the layers will be used. Many of us have developed our own practices for layer use. Inertia and old habits are difficult to overcome.
I put this kind of information on the “Dwgs.User” layer. This keeps all the details about the board in one place (the KiCAD file), for easy reference when you place the NEXT order, or revise the design documentation, etc. I also place selected dimensions on that layer. It reduces the time spent answering questions like “Was this board done in 1 oz copper or 2?”, “What plating material did we order last time?”, etc.
The key outline dimensions are also on this layer. That’s an old habit going back over 20 years, when board fabricators almost always asked for a dimensioned sketch, preferrably 1:1 scale, of the board. It’s also useful when working with the folks doing the packaging and mechanical design, where various forms of the question “How big is this thing?” arise repeatedly. (Cutting out the outline, after printing to a reasonably accurate 1:1, gives a paper-doll puppet that you can hold in your hand, push around inside a chassis, check for alignment with other features, etc.)
The “Notes” from this layer typically get duplicated in the README file I email to the board fabricator, inside the *.ZIP folder containing the Gerbers.
I use the “ECOx.User” layers for assembly information, including cartoon-like sketches of the components that help visualize the completed assembly. This GHOM hasn’t yet taken the leap into 3-D modeling. My “Margin” layer carries information about mechanical interfaces, such as outlines of the enclosure where the board will mount, locations of front-panel controls and connectors, projected outlines of places with height restrictions, etc.
Dale
That should be done in pure information form these days via a STEP 3D model that can be used in MCAD tools to test/design the mechanical side of things.
For real world size testing a rough 3D print from the same STEP data will also be the way to go.
Most often the outline of the pcb already originates in MCAD in those situations anyway.
And their tools for dimensional drawing documentation are lightyears ahead of what KiCAD can do (=takes them a 10-20th of the time to compared to KiCAD).
I just wanted to say your drawing looks great. Seeing things like this makes me truly believe KiCAD could one day soon be used in professional environments.
Thanks for the compliment. Back in 1970 I was in the technical graphics and communications course required of all engineering students. The instructor said that if we stayed in a technical field, we would be making drawings for the rest of our career. I didn’t believe him, since I was in electronics rather than, say, civil or mechanical engineering. I wish I had paid better attention in that class . . .
The basic tools and materials are there. Sometimes it takes a lot of searching, or experimentation, to get the results you want.
Dale
[quote=“Joan_Sparky, post:4, topic:6684”]
That should be done in pure information form these days via a STEP 3D model that can be used in MCAD tools to test/design the mechanical side of things.For real world size testing a rough 3D print from the same STEP data will also be the way to go. Most often the outline of the pcb already originates in MCAD in those situations anyway.[/quote]
I wish I was good enough to work in a shop that operated that way!
The place I’m working now does after-market adaptations and add-ons to other companies’ products. Usually we’re fortunate to have a 2D *.PDF outline drawing; I don’t know if there’s anybody in the company who can efficiently operate a 3D cad program, even if the company owned a copy. Last fall one of the senior managers chastised me for doing drawings and documentation, instead of doing engineering. (I’m employed as a manufacturing assembler and test technician, so any engineering they get is done for free.)
Yes, I’m aware of what is possible. I have been fumbling my way into LibreCAD for the last week and appreciate how much more efficient it is than KiCAD’s drafting tools.
Dale
Mr. Dale, if you could please elaborate more on this part, I would be grateful. Aren’t the drawings in the previous post made by KiCad itself (your two screenshots) ?
Yes, the two screenshots in Post #3 of this thread are directly from KiCAD.
My previous comment:
[quote=“dchisholm, post:6, topic:6684”]
Thanks for the compliment. Back in 1970 I was in the technical graphics and communications course required of all engineering students. The instructor said that if we stayed in a technical field, we would be making drawings for the rest of our career. I didn’t believe him, since I was in electronics rather than, say, civil or mechanical engineering. I wish I had paid better attention in that class . . . [/quote]
was an admission of my arrogance as a 19-year old college student. Older and wiser people had designed the course of study for degrees in engineering, and they had determined that engineers should be familiar with technical drawing. Not just the mechanics of how to manipulate tools like the compass, T-square, and divider; but also more conceptual ideas such as what information can be determined from drawings (and the situations where the determination is easy, or difficult), the roles of drawings in design and manufacturing, how to organize and present a drawing so that it communicates your intentions, etc.
I could see the value of such things if I was creating, say, bridges or automobiles, but in my naive mindset I failed to comprehend the crucial function of drawings in electronic engineering. I saw drawings as primarily an administrivial afterthought, mainly used to archive historical information. Surely (I thought), electronic designers would only be concerned with drawings when we handed sketches to the draftsman who created the formal paper documents. I decided that “Engineering Communication in Design” was an interesting class for showing how graphical techniques such as projections could save you from working out a lot of complicated trigonometry, but in the long run it didn’t apply to electronic engineering much more than “Introduction to Sociology” did.
Well, the draftsman has mostly gone the way of the departmental stenographer and the typing pool. Even when draftsmen were commonplace the individual engineer was responsible for producing more than crude sketches. And . . . I radically underestimated the roles of drawings as inputs, and as intermediate products, of the design process.
It was almost a decade after graduation that I realized my errors. (To be fair, for about 7-1/2 of those 10 years I was quite removed from design engineering.) Then I spent about a year fighting the system rather than learning from it. Eventually some of that early training returned to my mind, and what I didn’t remember from Michigan Tech, I had to re-learn in the School of Hard Knocks.
Dale
