Paul & Sabrina's cheap DIY 144v motor controller

[adamj12b]

Jay, those are etched outlines. I'm attachine the code I created for the top of the board. This includes the holes.

-Adam

[MPaulHolmes]

Yes, etched outlines. Each island has a little hole in it. The islands are there to give the gate resistor a little isolated spot to sit on. One lead of the gate resistor goes through the hole in the island and gets soldered to the TOP side of the board.

I finished compiling and adding the PI loop and all that stuff for reorganizing the interrupts. Now I need to make sure everything is volatile that should be. Then I'll simulate it some, and then take a drive. I can't wait to see how long everything takes now. There isn't a single while loop that just waits anymore! ya!

[rsandberg]

Following this thread with great interest.

May I suggest a "photos" area in the ReVolt wiki?

I have a gutted and ready '94 SAAB 900 and an ADC9 inch motor (mated to the tranny). This project looks perfect for me but I am a little unsure of the layout.

I am interested in group buys and pcb buys. I can offer to host a group buy. My company buys through Newark mostly (not the lowest prices I know), but we get a discount and I can piggy back off another order for no shipping charges.

Thanks,
Rick

[MPaulHolmes]

Ya, we need to get more pictures. I think that's a great idea about adding pictures to the wiki. Also, my wife was going to add a bunch to our website. Lots of high resolution pics. Are you unsure of the power section layout (for the PCB)? I'd be happy to hear any concerns!

A group buy would be awesome! That would really drive down costs. We should run the numbers to see how much it would all be. I'm sure a few things will change after the 3 controller testing, though.

Man, I'm still simulating all that stuff. Several bugs and very subtle things have popped up that I'm fixing. Getting close to taking a drive. ya!

It's now 2:32, still simulating. Fixed a few more super sneaky bugs. Interrupt A, Interrupt B, cli, blah blah blah! Oh! % is super slow if it's not a nice number like powers of 2. Fixed that issue.

This program is running realllly clean and nasty now. ya! I think I can increase the A/D conversion time. Whoever rides with this software will be ridin' dirty.

http://www.youtube.com/watch?v=-xEzG...eature=related

Oops, I think that's the wrong song, but somehow more appropriate.
My son's sleeping, so I can't go try it in the car yet.

[JayC]

A preview of the job. I need to get the thickness of the 4oz board and know to what depth to etch to remove the copper but it's easy to change those and recalculate. And this is done using Vectric Cut2D

Jay

[MPaulHolmes]

Originally Posted by JayC

A preview of the job. I need to get the thickness of the 4oz board and know to what depth to etch to remove the copper but it's easy to change those and recalculate. And this is done using Vectric Cut2D

Jay

OK, now you're just showing off! That looks real! How in the heck did you DO that? Well, it's actually 3 ounce copper on each side. The total thickness of the pcb (including both copper layers) is 1.6mm. Each copper layer is 0.11 mm thick. So, the FR-4 fiberglass material is about 1.38 mm thick. The cutting depth needs to be such that the cut width is about 0.1". Somewhere in that ball park. I was never able to get a definitive cutting depth. Too much variation in my case. I would find the right depth by trial and error each time, looking at how wide the etched path was that I just cut. I would start sort of shallow, and increase until it seemed about right. Sorry about the unscientific approach. .

Here's the bit I was using:

It was 7/32" wide, but I didn't go all the way down.

[adamj12b]

hi jay,

Just wanted to tell you that the 14 large holes are to be milled with a 1/4" endmill.
-adAm

[JayC]

Ok, did some Google research and found this.

3oz = .0042" thick which agrees closely with you .11mm ... found a surplus house that has some bare PCB. Where did you get yours? I recall you posting a photo of the package .. guess I'll have to dig through and find that

Jay

Update: Found it

[JayC]

Originally Posted by adamj12b

hi jay,

Just wanted to tell you that the 14 large holes are to be milled with a 1/4" endmill.
-adAm

Shouldn't matter. If the hole is 5/16 or .3125 and I use a 1/6" endmill to cut out the insides, it's just as good. My Proxxon spindle only goes as high at 1/8" shank.

Jay

[JayC]

Paul you say it was 3oz, but the board you show says 4oz 2 sided 6x9 ... $16.98 at Digikey