build your very own Lebowski controller !

Electric Motors and Controllers
Pinski1
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Re: build your very own Lebowski controller !

Post by Pinski1 » Oct 23, 2017 5:57 pm

Hi,

I've been using VESCs to control 6kW BLDC motors but have had to current limit the motors quite severely to avoid damaging the VESCs. I've been planning to make my own and was wondering if a Lebowski MCU would work?

I'd want:
bidirectional control
control via PPM, also known as servo signals.
high startup torque.

My motors do have hall sensors built in.

Which chip would suit me best and how much would it be to the UK?

Thanks!

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Lebowski
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Re: build your very own Lebowski controller !

Post by Lebowski » Oct 24, 2017 10:40 am

My chip does not take PPM, you would need to translate this somehow to an analog throttle signal and a forward/reverse signal.

Pinski1
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Re: build your very own Lebowski controller !

Post by Pinski1 » Oct 24, 2017 12:56 pm

Lebowski wrote:My chip does not take PPM, you would need to translate this somehow to an analog throttle signal and a forward/reverse signal.
That wouldn't be the hardest thing to do, nothing like driving the motors really.

progrock
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Re: build your very own Lebowski controller !

Post by progrock » Nov 26, 2017 1:59 am

Just got one of these boards, and waiting on the brain from Lebowski. Should be ordering parts in the next day or two, tho I have a few other projects that need a good amount of parts... so gonna take a while to build up my cart. I also usually prefer to order from Arrow... though they seem to have a slightly more limited selection than mouser/digikey, some times a bit tricky finding equivalent products, but I've had really good experience always with Arrow, and free overnight shipping is awesome (and 0% off the whole site right now... hopefully I get this order in before that's gone).

Do you guys think I'll be able to run a 3000w Cyclone mid drive with this? (Currently running a 20S pack, though was considering possibly trying a 24S, tho not definite)... also debating on how many fets to go with, and what kind... got a bunch of IRFB4110's laying around... but was also considering using something a bit better. I also have 20 x CSD19536KCS's that should be arriving any day now. While 20s is my current setup, it would be nice to at least support 24s, and I suppose both FETs do support 100V... and a 24s shouldn't really be charged past 100.8 (usually I prob will only charge to 80-90%... but my BMS' balance V is at 4.2V +/ .025V a cell, and is not adjustable). Seems like it may not be a bad idea to have FETs that support a little bit more than 100V... but not sure of many specific ones that are recommended... other than the IRFB4115... but I'm pretty sure the CSD19536KCS's are better FETs overall. As for how many, I kinda want to run the max, 24... though I'm guessing 18 would likely be more than enough. Is there any harm in having "too many?. I'd like the controlelr to be able to handle a pretty high amperage... nothing totally insane, but would be nice if it could at least handle 100A, even if I'm most likely gonna be running something close to 60A max.

I'm also planning on building some SMD Lebowski controllers, though need to do some more research, as well as figure out a good project for them. While I currently have a 3000W Cyclone, I've been admiring those pretty serious RC builds. I'm thinking maybe even trying an Astro 3220, but need to figure the mount and the reduction (likely 2 stage) designs. Would a Lebowski controller be a good fit for one of those?.. any recommendations what variation to go with... was planning to try bobc's SMD variation... but not sure what to mate that with to handle the power.

And lastly, on a slightly different topic... Are there any good DIY BMS designs around?... Seems like they should be drastically easier to design (compared to a controller like this), plus I've been wanting to get a good BMS that I could adjust some of the settings. Just ordered a few 24S HCX-D131's from bestechpower... but they are not adjustable (no 'smart' features at all). They did not have any smart controller's available a month or so ago when I ordered... and I was told that a comparable controller to what I ordered, but with smart features (and prob a bit better than I ordered), would cost something like $175 each. And for those familiar with bestechpower, I don't know of any good resellers, and ordering directly from them requires a min of 2 of each item, and when you add shipping and other fees, it ends up being A LOT more than the original cost. Just to get my hands on 1 smart controller, I'd need to order 2, and it would come to over $400... at the minimum, if the piece I was quoted was accurate. I figure a BMS is relatively straight forward... and was hoping there was a good design that is Open Source/Open Hardware. I don't know of any... but if I could find one, and it didn't already have smart functionality... I would love to redesign it to include an ESP32... and designing the interface for the smart features is something I can do very easily (and a hell of a lot cleaner than all the Chinese apps I've seen), I just don't want to have to design the electronics myself... that I am not as good at. Anyone aware of any?... and/or... anyone interested in teaming up on hopefully improving one... if not, designing a complete one to release OS/OH.

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Re: build your very own Lebowski controller !

Post by progrock » Nov 26, 2017 4:19 am

I'm having trouble creating the BOM. I opened the project in kicad, opening the schematic... got a few errors, file being out of date with a few references that needed updating.... seems like clicking OK fixed the out of date references... but also got errors when trying to create the BOM, more errors about libraries being missing, I believe it said something about the "special" library that was not found. I running ubuntu, relatively fresh install on a chromebook. Anyone else run into these kind of errors with this project?... know how to fix it?

Otherwise, can anyone post (or link) me to an accurate BOM?

whereswally606
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Re: build your very own Lebowski controller !

Post by whereswally606 » Nov 27, 2017 7:00 am

https://drive.google.com/open?id=1CwphQ ... 9nI8LoCpit

not all my work, this is emgees bulk buy spread sheet but i found it very useful + handy pics to place the components on the boards right.
Distributing "Lebowski" FOC Controller PCB (Through hole) since 2016
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progrock
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Re: build your very own Lebowski controller !

Post by progrock » Nov 27, 2017 10:27 am

Thank you... I def do need to figure out this kicad stuff as well... I would like to actually use it to make something in the near future... but this will help for now.

I must say, the way the positive/negative batery connections are done, with 2 sheets of copper literally sandwiched together with an insulator seems really strange... tho apparently it's for a very good reason... it's pretty funny that I don't remember anything like that being taught when I got my engineering degree... really wasn't taught much at all when it came to the real world... I think a large amount of undergrads get am EE degree without even knowing how to do basic soldering at this point. But this kind of design really interests me... I might be able to build a logic circuit with equations based on an ideal world... but this kind of stuff is way beyond me. Probably completely due to the fact that I never actually worked as an Electrical engineer... and the amount you can learn of practical knowledge in a few weeks, let alone months/years at a job is incredible. Lebowski, I can only assume you have a number of years under your belt of actually designing/building useful electronics (whether solely as a hobby, or as a profession)... I'd be very confused if you didn't.

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Lebowski
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Re: build your very own Lebowski controller !

Post by Lebowski » Nov 27, 2017 12:42 pm

I'm an analog mixed signal IC design engineer (22 years now). To give some examples, for work once I designed the receive ADC in a mobile phone. Also once build a complete audio path, digital 16bit in headphone out, over 103dB dynamic range, also for mobile phone.
Since it is IC design, this means everything is done using individual (on chip) transistors. So at a certain point you're looking at a 3000 transistor schematic, which then also needs to be converted to layout. Making a layout is like doing a 12 metal layer PCB connecting those 3000 transistors, all done by hand. When i started the transistors were 0.5 micro meter in size, now I am doing 15 nano meter transistors...
A large part of the work is knowing about signal processing and control loops, which came in handy building the controller IC program.
Hobby w8se, I used to build 500W tube transmitters for my Ham radio hobby, but stopped that a long time ago. Ive always liked assembly programming, wanted something complex to program, so got involved with motor controllers.

progrock
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Re: build your very own Lebowski controller !

Post by progrock » Nov 27, 2017 2:07 pm

Well... that is pretty close to where I had you pegged at. I somehow managed to get a CoE undergrad degree a few years back (at my school, CoE is literally 2-4 classes different than EE over the 4 years). I had done work on websites for a few years before school, and got somewhat bored and had taken some time off, including the whole time at school. Sadly, I am a truly horrific student (very few people are as bad of a student as I am and still get a degree, not sure how I did, nor did I really deserve it). I pretty much hated the work at school... even the enjoyable/interesting stuff just got destroyed by many different factors, and never really enjoyed all the calculus (much more of a discrete math kind of mind)... got out of school... after a few months of enjoying doing nothing, and a month of a few interviews where I barely knew shit... brushed back up on website work... a month later, had a good job. Luckily, every since then the technology has grown rapidly with what you can do on the web, and has surprisingly kept my interest, I now specialize in web based data visualization... and def not half bad at my work ;)

But... about a year ago, bought a 3D printer kit... built it... upgraded it many a time... then designed and built a couple of my own out of much heavier duty parts. Moved on to an ebike project, among other small things. What I realized was, when it's not school/work... I do enjoy electronics. On top of that... when it's projects of my own choosing, and there's a reward at the end... much more fun. So, slowly getting my feet wetter and wetter... and some of the limited amount I learned at school is coming back to me a bit... technically wasn't half bad at digital system design... and at least at a beginner level, was capable with VHDL and Verilog (though, if my work doesn't make it obvious, usually enjoy much more abstracted from the hardware languages... but it can be fun at times to go down to that level of coding). Hopefully I'll keep things going and just progress with whatever project I'm interested in next... tho I couldn't imagine it ever being more than a hobby... but so far it's a fun one. Building a couple of your controllers should be an interesting next step... def got a but to learn about all the functionality, and what not... but def seems like a logical progression with what I have been working on.

whereswally606
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Re: build your very own Lebowski controller !

Post by whereswally606 » Nov 30, 2017 5:57 am

Ive been having talks with Bas via private messaging about the possibility of him designing a powerboard to interface with bobc brain board. the initial design Bas sent as a quick sketch on a piece of paper (pic of). So using work id done in sketchup8 already on the original Lebowski board and other power stack projects that id envisaged to work with bobc before he'd passed on, I have produced a 3d mockup of what a Lebowski through hole power stack board might look like. He said post something in his thread a few days ago but ive been pretty ill with cold. Not sure whether he even meant this thread but he can always cross link it to where he wants with a quote.
3d mockup of lebowski proposed board2.png
3d mockup of lebowski proposed board2.png (81.41 KiB) Viewed 84 times
I think we could get it smaller with smd parts but then it loses the home gamer/diy with modest tools approach.
I also think this may not be the final iteration of design for placement of parts but its Bas' first draft, fairly closely followed.
Distributing "Lebowski" FOC Controller PCB (Through hole) since 2016
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