Questions throughout 28Pins Course

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Hello,

I completed the 28Pins project, after a long three months. I learned so much to do with Altium and I am very thankful. I noted down some questions I had along the way, with the lesson and timestamp. If you get the time could you answer these for me:

---This project was done with Altium 18/19---
1) Lesson 1: 49:20 => What is the formula to work this out? I was struggling to figure this out for another chip (PIC16F877A TQFP).
2) Lesson 5: 04:39 => How do you change the grid size to something smaller than 10 Mils, couldn't find this option?
3) Lesson 6: 24:50 => Where is the undo/redo option in Altium 18 version?
4) Lesson 7: 3:50 => Where is the option "Only show enabled Mechanical Layer"
5) Lesson 7: 25:07 => Where is this option? Is it the checkboxes?
6) Lesson 9: 15:00 => Has this changed significantly for Altium 18/19? When I make mechanical layer 30, then do the pairs it seems like the original layers are replaced?
7) Lesson 9: 46:33 => Why do you change the track widths to 0.2mm, as opposed to leaving them thicker? Is this recommended for PCBs in general, or should tracks be dependent on size and space? You did mention the cross talk, but for simple PCBs is it necessary?

Addition Questions:
8) Why was three out of the four mounting holes grounded and fourth one not?
9) Should you ground mounting holes in PCBs, which will be mounted with metal screws?
10) For through hole components, what is recommend dimensions to use when designing components in the footprint wizard. I noticed you changed values slightly depending on the component.

[robertferanec]

I do not have access to altium and the videos right now, but I will try to answer what I can:
2) in system preferences you can add another grid. Then press G you will cycle between them. (System preferences are accessible through the wheel / gear in top right corner)
3) I think I saw something in the Advanced settings. If I remember right it could be located in System preferences -> General -> bottom right corner, there should be a button
4) I am not sure if this exists in AD18 / AD19. I think you just see all the layers which are added to the project or are not empty
6) Not big change - still similar - you only can par one existing with one empty layer. You can have a look at my youtube video https://www.youtube.com/watch?v=KpgT...puSXz6sROQmO6R
7) it will increase space between them and they will be nicely routed. If I route the with 0,2 from beginning, I would have to use a big gap rule which is sometimes not very practical. There are also there reasons e.g. impedane matching and adjustments, but this is for more complex designs
8) I believe, in original Arduino use of the forth hole is limited because the connector was extended - and unplated hole had to be used (plated would just not fit correctly?)
9) I ground them and if you find out it is causing problems you always can use plastic spacers or isolation
10) simply to say - to be able to route at least 1 track between the holes (sometimes two tracks) and still be able to solder the pins properly .. that is what I use

[robertferanec]

1) no special formula. you just calculate the space without pins and divide it by two (the space is on both sides)
5) Do you mean tenting VIAs in AD18? It is in the settings (be sure you use latest Altium, I think in some versions it was not available - I guess a bug)