Paul & Sabrina's cheap DIY 144v motor controller

[dcb]

Very nice, looks like a couple motion conservation optimizations are yet possible on the cuts (like around 3:40, cut a 33% square wave all the way across in one direction and fill in the remaining corner cuts on the reverse direction), but an inspirational bit of automation there certainly

[JayC]

Nice job. What weight of copper clad is that and where did you buy it?

[adamj12b]

Originally Posted by MazdaMatt

*sigh*... beautiful

Matt,

O it is, Isnt it. I love watching a project come to life right in front of you.

Originally Posted by dcb

Very nice, looks like a couple motion conservation optimizations are yet possible on the cuts (like around 3:40, cut a 33% square wave all the way across in one direction and fill in the remaining corner cuts on the reverse direction), but an inspirational bit of automation there certainly

DCB,

Yes, I wasnt happy about the amount of time wasted in the cuts there, but I wanted to get these back to Paul as quick as possible. I am working now on optimizing the code to run as efficient as possible.

As for the 33% square wave you talk about, I have no idea what you mean. LOL Could you explain some more?

Originally Posted by JayC

Nice job. What weight of copper clad is that and where did you buy it?

Jay,

This is the 3oz stuff Paul is using for the boards. I got it from him. Ive made 2 of these. They are going to be the other 2 Beta controllers. Im sending them back to him today. 2 day mail. They will be there Wednesday so he can get going on them.

-Adam

[dcb]

Originally Posted by adamj12b

As for the 33% square wave you talk about, I have no idea what you mean. LOL Could you explain some more?

No prob, here is a pic, choose which direction to start the red 33% square wave from based on where the bit is right before you start the cut. After cutting the red "square wave" in one direction, do the blue corners going in the opposite direction and you can shave off a couple overlapping cuts and a bit of repositioning time. You should never have to "back up" with this approach for this pattern.

[MPaulHolmes]

Originally Posted by adamj12b

Thats alot better then Pauls 2-3 Hours by hand.

Enjoy

-Adam

Actually, it's 2-3 days by hand including drilling holes. I need lots of breaks so I don't get sloppy.

DCB: The economy of motion issues come from the fact of making it easier to do it that way by hand. Also, the paths should be changed a bit. I chose them so that everything was a multiple of a half crank on the mill. That's not quite optimal.

Also, my mill has some slop, so I try to only go from up to down, and left to right to avoid any gear slop. (It's sort of hard to explain)

JayC: Ebay for 3 ounce copper.

[Royal]

Originally Posted by watt-a-mezz

Hi,Paul. Looks like you have been busy. Listened to the podcast, and took a look at all of the pictures. I can see why you would want a pre made power board, the control board I could assemble (with large amounts of concentration). I would like to participate in a group buy, whenever you decide to do one. Hope the B'day party went well, and to you, and all the dads out there, have an awesome Fathers Day. Take care, Watt

Hello Paul:

I listened to your podcast today. Count me in on your group parts order. Let me know when.
Thank you,

Royal

[watt-a-mezz]

adamj12b, hi. Enjoyed the video, have always liked watching cnc milling machines. Nice part is, the quality of the hand milled boards remain, but the machine can do it so much faster. Wonderful Good, as my old Dutch uncle would say, Keep us posted. Watt

[dcb]

Originally Posted by MPaulHolmes

DCB: The economy of motion issues come from the fact of making it easier to do it that way by hand.

Lol, I sorted it out and am embarrassed to say how little motion you would save with my proposal but its about 0.2 parts out of 13. You would have to make a lot of boards to make it worth the effort to change a working thing.

[MPaulHolmes]

I'm going to try to put the tin plating on the bus bars and pcbs when they arrive. I'm sorry, Adrian! I tried to mail some of the tin salts stuff that you dissolve in hot water that tins the metal, but the shipping people were really worried that it wouldn't make it through customs, since it was just in 2 separate plastic bags. Oh no! Crack Cocaine! haha!

It would be nice to figure out a good safe way to get the bus bars soldered to the PCB (but not too hot!) so the silver conductive epoxy wouldn't be necessary. That crap is expensive! Any cheap easy suggestions to not let it get too hot, but hot enough for solder? Once it's tinned, I think the solder will spread out nicely. Could there maybe be a hot thingy that you attach to one end that slowly heats the whole bar to solder temperature. I think it would be good if the bar was already bolted before soldering, to make sure it was nice and tight against the pcb. However, then the pcb would act as a heat sink. How tough is that glue that keeps the PCB together?

Today, I cut some of the other bus bars, and smoothed out the holes in everything so there would be good contact. Adrian will have to do that with his too (well, if he wants! hehe. He can do whatever the heck he wants!).

Here's some of the smoothing process.


ghetto superstar! That is what you are:


This is necessary, because copper gets sort of hot and stretchy sometimes:


My dog died with a sausage in her mouth from breakfast:
Note: She's not dead in this picture. That's how she used to sleep. Her name was doggie. I put her on here by accident, because she's the same color as a bus bar, so I got confused.

[blackpanther-st]

Originally Posted by wjdennis

Black Panther, this discussion has moved to another thread "Open ReVolt as Charger". But with the setup you mention, how would I control the amount of current that the lower C pack delivers? The purpose of the controller was to not let the lower C pack go above 70A. If the two packs were just connected through Mosfets, I wouldn't be limiting that. In that case, I might as well just do away with the Mosfets altogether and just connect the two packs directly to each other.

Bill

wjdennis

I couldn't find the new thread. anyway the idea is that the second pack would be smaller capacity, but newer tech with a high C rating and the same nominal voltage. if preserved as a fresh pack until that hill, when you paralleled them, the second pack should supply the majority of the current simply by the balance of each packs capability to deliver the current. your low C pack will tend to sag as it approaches its c rating and when paralleled to a high C pack which maintains the voltage, the low C pack will not be able to push as much current because the paralleled voltage is higher than what it can push that much current in to.

Without the second pack connected, the voltage would drop more under load and your low C pack delivers more current at the expense of battery stress.

With the high C pack connected, the high C pack will not stress until much higher current loads, so it can keep the paralleled voltage at a respectable level until you have nearly depleted them.

I hope this clarifies it somewhat.