SparkFun Forums 

Where electronics enthusiasts find answers.

Questions relating to designing PCBs
By Pedro147
#186133
I have a quadcopter flight control board that I am working on. It is from a board that has been in successful commercial production for eighteen months, and the circuit schematic, but no board file, was released under Creative Commons. I am developing a board file from this schematic I have done as much of this work as I can and then paid someone to tidy up the routing on it for me. To cut a long story short, whether it was through miscommunication or just a case of him not asking the right questions, even though all the pertinent information was provided. the job is unsatisfactory..

The basic problem is that he did not understand the potentially high current draw the four little brush less motors could draw and consequently he made the power traces for the motor to battery connections and the motor control mosfet drain connections far too small at 0.4064 mm The rating of the mosfets Q1, Q2, Q3 and Q4 is 6.3A continuous drain current, and even though this high current requirement is not always present, it is a possibility, albeit for short periods of time He endeavored to increase the trace size up to what I wanted but as far as I am concerned the VCC trace right at the bottom of the board from D5 to D9 was far too close to the edge of the board. I have not linked this file seing as it is virtually the same as AW_V6 aside from the offending 0.8128 mm VCC traces

I have access to another different set of both Eagle board and schematic files, that is pretty much the same as mine aside from an additional 5v regulated supply and reverse current protection circuitry. As far as I can see, this board Classic-Narrow-5V has been designed with both a power and ground plane and this is how I would like mine to be done too, but as I say my electronics and Eagle skill set is not high. These files are hosted on my https://www.mediafire.com/folder/2ew8ee ... ii%20Eagle at as Classic-Narrow-5V.brd and .sch The board that I wish to finish / modify are also there at Mediafire as AW_V6.brd and .sch

Currently the board AW_V6.brd has an ground plane on both top and bottom of the two layer board. What I would like is for there to be one VCC plane and one ground plane to get rid of the VCC line that runs between all the motor sockets. All the components need to remain in exactly the same place seeing as I have already purchased a SMD solder template for the existing layout and because of cost constraints the board needs to remain only a two layer board.

Any help would be appreciated, I have tried to delete one ground plane and make a VCC plane then re-route but got polygon has fallen apart error and I really cannot see how to move forward with this project, thanks Pedro.
User avatar
By Ross Robotics
#186141
There is a few concerns besides the trace width. Shoot me a PM with your addy. Is there a reason why you want/need to use a VCC plane? Far as I can see, you have plenty of room.
By Pedro147
#186148
Hi Ross
thanks for replying. I just felt that the VCC plane was a good solution. The guy who tidied up the routing for me did increase the trace width to an appropriate width but I thought that the VCC trace between D5 and D9 to 0.8128 mm was too close to the edge of the board. What are the other concerns you feel there are with the board.
Here is the last board file he modified for me http://www.mediafire.com/view/jndxdj3rl ... AW_V6d.brd

I tried to pm you but it says "The requested users to be added do not exist." Can you pm me maybe and I will reply to you