Anyone tried to make a 3D Printer controller?

~Straw

Ray

Perhaps we should start a KiCad and PCB thread?

Ive finally finished producing my first board using KiCad, and its been relatively painless

Well, there have been problems, but when I first started to use Eagle, I think I had the same, steep, learning curve.

I sent the files to DirtyPCBs yesterday, and they accepted them after I manually fixed a problem with the edge-cuts file extension ( they want .GML not .GM1)

It was going to be a STM32 board, but I bottled out in the end, and I will use a Maple Mini attached to the board via a 5 wire ribbon cable.

The board has both high voltage, high current, 240V 20A, and low voltage devices on it, (optocouples and a Hall effect current sensor; so has been a bit of a challenging design, trying to keep the HT and LT sections apart but not make the board to big.

I’ve used air gap slots in several places, so it will be interesting to see how they are handled by DirtyPCBs. ( Note, I used DirtyPCBs old system, as the new one has only just come back online following bug fixes)

I will let you all know how the boards look when they come back, and if they are OK, I will move to version 2 which will have the STM32 on the board.

Would you share some pictures of the gerbers ?

Ciao !

Would you share some pictures of the gerbers ?

Ciao !

As its my first, rather simple board, done with KiCad, I don’t think its that good. But its OK as a prototype board.

Its not a commercial board, its ultimately for my sister.

I initially wanted it to be all surface mount, but it was impractical to use high voltage SMD capacitors. Theoretically you can get them, even on AliExpress, but I didnt trust that the ones on AliExpress were really 400v working.

Also, I couldnt easily find specs on the 1W SMD resistors, so I ended up using through hole on those as well. So as I had to do all the HT side as through hole, I decided, at least to start with that the LT side may as well be through hole as well.

I had to make footprints for the connectors and the power triac, as I couldn’t find existing KiCad footprints for the BTA41, and not for the Dimple 40A screw terminal. (nor for the ACS712-20, or for a SMD bridge I was going to use, and for SMD versions of the optos (which again I didnt end up using)

I also initially routed all the tracks on the top of the board, which was a bit of a mistake for the power through hole stuff, so I had to reroute with most tracks on the bottom.

I then has issues with stitching the copper pour zones for the ACS712, as its SMD, but I wanted to use both sides of the board, as there is 20A going to those tiny SMD pads (yes, it really is rated at 20A though 2 SMD pads !!!)

Probably overkill

Anyway, I’m sure you’ll see problems with it, but I’ve uploaded a screengrab, and I guess its probably not to late to catch problems as its not gone to the board house yet

PS. I think I’ve already uploaded it at least 5 times, (the first 2 were because it didnt accept the edge cuts file), the next 3 or 4 where when I say errors e.g. annotation text on the wrong layer, and problems with the stitching vias etc etc

Note. There are air gap slots in the middle of the board and under the optos, (in case you wondered what those polygons where…)

Oh. And there is no ground plane, as it most of the board is high voltage and I have to maximize insulation distance, hence large areas of the board with no copper on at all.

Also note some of the HT tracks, are larger than they need to be, but as long as I preserve creepage distance (if possible 2.5mm or more), then I may as well go for large tracks even if its not carrying much steady current – only pulse / switch-on current of perhaps 1A to the BTA41-600 triac

Argghh, In hindsight I can swap pins 4 and 5 on the pin header, it doesnt make any different … and it would save a via….
But I’ll leave it for now.

Edit (again)

Any my other mistake.

The triac is not in the middle of the board. I should have probably made the board a bit wider, but I can’t be bothered now to change it.
Its really just a prototype.

So I see if they accept it, and whether they can cope with the air gap lots etc.

The other thing that will be interesting if how KiCad copes with the zones that don’t have thermal relief.

I had to use “Solid” instead of thermal relief around the high current pins on the mains connectors and also on the triac, as it needs to handle a relatively large amount of current (20A) sustained, as it will run a electrical water heater.

So it will be interesting to see how this comes back, as I have a concern that selected Solid for the zone’s thermal relief setting may mean that the pads for the triac and power connectors may not get created correctly, and I’m likely to have to scrape off the solder resist.

I really hope the through plating doesnt get screwed up on the connectors, as it will be a pain to solder them on, especially for the neutral connectors which go to the SMD current sensor (ACS712)

But I will know in a few weeks just how screwed up the boards are…

KiCad didnt seem to default to “plotting”the solder mask.

So I didn’t send solder mask files to DirtyPCB’s ;-(

I think the board will still be usable, as there is only 1 smd component, but I’ll see what i get back, or whether they even make the board with those files missing.

i was expecting pictures of the boards’ top & bottom layouts as well

srp

and i’m not a seller from Venice either

srp

~Straw

I see now the gerber view looks different, now I also have those layers, but I didnt know what it was supposed to look like.

Ideally DirtyPCB’s should give a warning if some common layers are missing.

The boards should be usable even with the solder resist missing, except one SMD part may be hard to solder, but it has large pads, so should be OK.