Hi everyone!
It's been a long time since I last posted here on AAC. Previously I was looking into thermisters for my brushed DC race bike, but that bike has long since gone. I later built Voltron Evo, and had it on track in 2014. Danny Pottage rode it to victory that year, and did it again in 2015. The bike is awesome; 172 kW at the rear wheel and 0-100 km/h in about 2.9 seconds. It steers pretty sharply around a circuit, but the weight is still an issue. At 212 kg its heavy for a race bike, but not bad for a road bike. We're racing it again this year in the eFXC series, and now we have a sick swingarm on the back for a bigger tyre.



The battery is made up of 336 individual lithium cobalt cells, aka LiPo, in a 2-parallel, 168 series arrangement. Yes, that's 700 V fully charged. I measure the voltage at the dash via a large voltage divider inside the battery pack which sends 7.00 V to the digital panel meter (where I remove the decimal place). Likewise with amps from the shunt.

Anyway, the battery is quite a detailed bit of kit, and it constructed through these PCBs where the tabs fit through the slots in the board and are folded over and soldered underneath a piece of 2 mm copper busbar. There's a whole thread on Endless-Sphere dedicated to how I put these together, but this leads to my query on AAC.

I've started designing my own PCBs using geda PCB. It's not a bad program, and I think I'm getting the hang of it. I designed all of the PCBs for the battery packs and had them fabricated by a firm in China who have usually done a good job. Except this time. The boards arrived with a few problems - namely, they didn't have any slots!


Making them kinda useless. The board to the right is what they are supposed to look like, except this time I'm trying to incorporate some 3.1 mm holes for soldering brass nuts to the underside and enabling a screw-terminal system. More on that another time...

But it appears that the drill layer wasn't included. I exported the files as gerbers and sent the lot to OurPCB who then make them up and mail them out. So can someone who is well versed with geda PCB help here? Are my layer settings right?

Thanks in advance,
Chris

 

That is a neat project. Congratulations on the wins.

I believe the drill file that is needed is a separate file from the Gerbers and is called Excellon (.xln extension). At least, last time I submitted a project to Oshpark, I included that file and had no problems.

Fixing your boards on even a manual mill with DRO should not be that difficult.

John

 

Yeah, I figure I could do that, but I want to know for sure if the mistake was theirs or mine. If it's the fabricators mistake I'd be happy for a new lot. If it was my mistake, I'll cop it sweet and get out with a router...

I do have a drill file called ...plated.drill.cnc however it's only a 2 kb file. Should it be bigger?

 

If you did not include the Excellon file, I suspect the error was yours. Some of the houses with which I have dealt will accept the Eagle file itself; however, when I have sent Gerbers, creating the Excellon file was a separate step, and that file needs to be added. Do you have a Gerber viewer?

Gerbv is popular and is what I have used. It also allows viewing the Excellon file. If that was not in your order... Here is where I downloaded from:
http://gerbv.geda-project.org/

John

 

Hi all,
Turns out we were both at fault. I had provided the drill layer, however it was labelled as "Group2". Because I explained that there were only the top component layer, the bottom solder layer and the drill layer, they ignored any other layers not labelled as such. So they are happy to repeat the production run, and I will be clearer in future!
Chris

 

I have found that simple holes are easy to convey, but slots and non rectangular outlines can be a killer.

Make sure they understand your slots. Send them other drawings to check against before you get another batch of slotless boards.

 

Slots are like traces - they have a start and an end and are output as Gerbers. You have to be clear with your vendor that they are routs and not regular traces. You also have to specify whether or not you need your slots plated (determines where the slots are done in the board production cycle).

Some cheap vendors will not do slots.

 

Cheers guys,
I draw the slots as traces (lines and arcs) on the drill layer.
They do get them plated through, as I've typically soldered the cell tabs in the past.