Paul & Sabrina's cheap DIY 144v motor controller

[MazdaMatt]

There's nothing special about the soldering in this project. From the components that I have seen, it is actually extremely basic. Through-hole soldering takes about 2 seconds per pin once you're on a roll and those mosfets need to be redesigned to mount correctly (through-hole).

Paul... possible reason for exploded leads - maybe the leads were not touching the copper at all. I would REALLY think about going through-hole with those leads. Even if you feel you must solder on top. Plated vias in a professionally made board would make a LOT more sense than surface soldering high power components.

[MPaulHolmes]

Wherewolf is looking into all that stuff with the pcb and vias. I know the mosfets failed shorted when the controller was turned off, and the legs blew off because of excessive current once it was turned on again. I've taken care of the mosfets not sitting flat against the heat spreader and the pcb. I think it will be OK until vias become available. We are probably going to go with 6 ounce copper, so it wouldn't be bad to cut little isolated islands on the capacitor side for the mosfet/diode legs to poke through, and still allow the capacitor current not to be too high for the copper paths.

I talked to a couple experts, and I'm getting closer to the control section being done really well.

[MazdaMatt]

Ya know... the going rate for engineering time around here is 80/hr. You are getting a hell of a lot of free engineering hours on this project Paul. People really believe in what you're doing for that sort of donation of time and effort.

When beta testing is done, it is time to get a board house to make power and control boards for you. Everything will have plated vias and will be perfect. I'm looking forward to seeing that.

[Blue Bomber Man]

I think I am ready to help make a 3d design of this for you paul if you are interested. I would need sketches, names of components, and dimensions.

Solidworks is has a free 3d file viewer that others could use to examine the unit. It also has the ability to do a 3d html website, which I have not used yet. I'm sure if I got the html working we could find a host for it though.

Also I believe the 3d viewer (called Edrawings) allows non-solidworks users to make comments to collaborate design ideas in the 3d sketch.


Later on when I get better with Solidworks we could also do thermal analysis to improve cooling efficiencies. It also has some sort of circuit wizard which would probably be incredibly useful if I knew how to use it, lol.


Anyways, let me know if you want me to get started with this and I'll try to do my best.

[GrahamMc]

Hey I can help with the modeling, too. I am decent at Solid Works but I use Unigraphics at work. I actually started looking at some of the spec sheets on the websites and the dimensions are usually listed. Once the BOM is sufficiently frozen we could make models and send the part/assembly files around.

[MPaulHolmes]

That would be awesome if you guys could help with modeling. The experts are finished with the first revision. Just a few minor revisions to the control section. I now sent that back to them, and they are going to see if anything else needs to change, and then we should be relatively firm on all the components. Thank you for your help!

$80/hr? I could make that much money in 5 seconds! (Napoleon Dynamite)

I thought the controller had arrived, but it was my mother-in-laws stuff. I hope she doesn't get mad about me opening her package, rifling through it, and then throwing it out the window once I realized that it wasn't the motor controller. hahaha! (just kidding about throwing it out the window)

The copper bus bars came today from Wherewolf! They come that way standard in his telecommunications (or something) industry! I measured the holes that are already there, and they're 1.5" apart! They need to be... 1.5" apart! How in the HECK did that happen!?!? They are completely unnecessary to modify. I may enlarge the holes just a hair, but I don't think that's necessary! What the heck!?!


Hmm... The 4 ounce copper is here. I should go to the garage to start etching the power section.



I have the flu, so I don't know if I'll etch it right now, but soon!

[xtian999]

Wondering how much of this great hardware and software is applicable to brushless and a/c systems? if modular, then maybe some parts could be seeds for open source controllers for those systems too.

[bennelson]

Sweet Buss Bars!!!!!

Those things look SOLID! Kilo-Amps Solid!

PS - make sure to remove amp-limiting for my burn-out version controller!

[Wherewolf]

Once we are firm on the bulk of the components, I would like to price quantities to get us some pricing options. As I mentioned previously, I have the time and resources to hunt this stuff down...(I'm a frugal shopper by nature, but no cutting corners on quality!)

I suppose a poll of both stateside and intl interested parties would tell me the qty of each part for an initial order. The intl folks could price them locally and if the qty buy + shipping is cheaper, then they could join in on the party. Comments? Ideas?

Wherewolf

[esoneson]

Wherewolf,

Let me suggest that we PM you if we want to be included in a group buy. That way, we don't clog up the thread with "me too" stuff. Then you can periodically update the list of buyers to the thread, minimizing impact on the more important stuff like getting Paul well so that he can continue with the control portion.

If that's OK with you Ww?

Eric