Paul & Sabrina's cheap DIY 144v motor controller

[MPaulHolmes]

I'm making another controller so that I can take video and pictures of some of the process that I missed last time due to dead camera batteries and because my process last time was sort of not that good sometimes, now that I'm not just making it up (as much) as I go along. I'm using the wiki for ordering parts to give me a chance to see if there are any bugs. I've fixed a few. There ain't nothing like actually doing something to see if it works!

One thing I noticed that would streamline the parts ordering process is having an Excel file on the wiki so that people can just cut from it, and paste it into the FAST BOM LOADER on Mouser. There's not that much from Digikey, so it's not as much of a problem.

Also, there are some components like bus bars and whatever that we don't have sources for listed yet.

[wjdennis]

Paul, what was the coding change you made to fix the 80A jump problem? Also, are versions still being saved? How do I compare code in different versions?

Thanks.

Bill

[goge]

Hello-
Been lurking this thread for a while... I'm very interested in the DIY controller!

I converted an old BMW 2002 (that's the model #, not the year!) to electric over the past couple of months. I've done it on the cheap, and I bought an older Kelly controller. I'm a little leery of this controller- though it does seem to work so far. But- there are all sorts of rumors about them not being able to handle their stated amperage among other things. Thus the interest in Paul's controller. Plus it sounds like fun to make your own!

Anyway, a possible source for buss bars might be McMaster-Carr

They have alot of hardware there, and for the most part prices seem reasonable. I'm not sure what dimensions are needed for the buss bars, but i'm sure they have some bar-stock that would work. We use them for buying alot of odds and ends at work (we're a small injection molding/tooling shop)

-Todd
evalbum #2411 (not recently updated, my bad)

[fritzgutten]

hey guys, what size are we looking at for the copper? did a search, couldnt find much, 'cept paul saying he just used the bars wherewolf gave him.
just doing some price searching.
Fred

[MPaulHolmes]

heat spreader size:

0.75"x1.5"x8"

bus bar sizes: 3/16"x3/4"xlength (I forgot the length. hehe). Length is around 11 inches or something like that, but they are not all the same length.

1/4"x3/4"xlength works well too.

[fritzgutten]

ok, looking at the "ampacity" chart on storm copper, Ampacity Chart for Copper Bus Bar, do we want to stick with the 1/4x3/4 or go with a larger bar size? 30C rise at 500A for a 3/8x1"

[MPaulHolmes]

How the heck does curtis get away with their puny bus bars with the 144v 500 amp controller? Maybe because the 500amp is only for short periods of time. It would wreck lead acid if you did it a lot.

[fritzgutten]

probably true,
anyhow, for what i can find with Google, McMaster-Carr is the best deal for both sizes coming in at
$5.91/ft on 6ft lengths of 1/4x3/4
$29.68/ft of 6ft lengths of 3/4x1 1/2
next lowest was onlinemetals.com out of 4 direct sellers i was able to find prices on.
so we have 1pc of 3/4x1 1/2 x8" and 3pcs of 1/4x3/4x~11" per controller?
fred

[MPaulHolmes]

Check these out:

1/4" x 3/4" 110 Copper Flat 45-1/2" Long!(Bob) - eBay (item 390035402543 end time Aug-02-09 13:17:35 PDT)

They seem to have a never-ending supply of them.

[fritzgutten]

well that gets us down to about 2 bucks a foot, assuming they still have them. thats why i didnt hit ebay to look, but we can do that at the time of purchase to get best price. thats a whole lit cheaper that their site price of $8.54/ft at 6ft length