DIY / Open Source EV technology  - Page 1
Forum section: electronics / general

author: BMK
author_rank: Regular Contributor
timestamp: August 02, 2019, 10:37:34 am
content: Slight ramble here.. and likely there were several meetings I missed..Are there any DIY / Open Source projects aiming at a complete, sensible sized EV that is road legal and competitive with commercial offerings eg Model 3?It seems to me that we are dealing here with mostly mature motor / inverter tech, with very little left to differentiate auto makers in performance. They will differentiate themselves by the amount of spangly nonsense attached in the form of infotainment, cloud and driver assistance. To secure revenue, auto makers will not be able to resist the temptation to 'DRM' things like inverters or make them inextricably linked to the other junk to lock in customers for repair etc. You can bet that regulations worldwide will be moved to assist in securing this business model.So if there was a open source project aimed at 'minimum viable' road legal EV could it succeed and where would we start.

author: f4eru
author_rank: Super Contributor
timestamp: August 02, 2019, 11:45:02 am
content: QuoteYou cannot have all this.There will be compromises on some of that.But it's feasible.

author: Brutte
author_rank: Frequent Contributor
timestamp: August 02, 2019, 02:05:51 pm
content: Quote from: BMK on August 02, 2019, 10:37:34 amSo you download the open documentation/firmware/cad files, you send: step files to machine shop, bom to Digikey etc, they ship you pressed metal/components/PCBs and from there you want to assemble that and get a driveable "open" EV?Ambitious. Any references?Can this work in such scale?Maybe if you want to start, start small.Start from open design of some hardware mass product item that people need in their IC cars in millions. Like for example an open design of an oil filter, silencer, wiper blade, light bulb etc.If that is possible in small scale then maybe at some point could be scaled up to an electric motor, battery pack, ABS module etc.

author: BMK
author_rank: Regular Contributor
timestamp: August 02, 2019, 02:50:40 pm
content: Obviously a huge task and I am being deliberately over the top ambitious for the sake of discussion.The main focus would be the 'EV' components.No OEM designs an ABS/ESC module or a wiper blade. They choose an off the peg part/system which are tweaked for them usually only with the goal of making parts incompatible between car brands.If we begn with for example the Hyundai Kona. A vehicle that is an impressive EV, yet a directly derived from IC vehicle. How feasible is it that suitably motivated amateurs could come up with equivalent battery/motor/inverter for retrofit in a donor vehicle of their choice?

author: ogden
author_rank: Super Contributor
timestamp: August 02, 2019, 03:10:10 pm
content: Quote from: BMK on August 02, 2019, 02:50:40 pmThis guy EV-converted VW bus:https://www.youtube.com/user/jehugarcia. Disclaimer: I do not agree to some of his claims or technical solutions. What's important - he did it. BTW youtube is full of DIY EV-conversionsBMW M3 for example

author: Brutte
author_rank: Frequent Contributor
timestamp: August 02, 2019, 08:03:17 pm
content: Quote from: BMK on August 02, 2019, 02:50:40 pmAh, ok, misunderstanding, you do not want "open" EV, you want "open" electric powertrain to retrofit powertrain of an existing mass-produced design. Good direction - start smallSo a potential user, instead of buying a closed EV design:1. buys a closed design vehicle,2. guts it,3. retrofits powertrain with an open design4. participates in an open design by improving it a bit.I doubt retrofitting closed EV powertrain with open EV makes as much sense as retrofitting closed IC powertrain with open EV. I can imagine the advantages of having an open design. It is ok with software and maybe PCB / ECU but as for the motor, battery and inverter, I can see some obstacles on the way.Interesting concept but how to make the mechanical design open and evolve from generation to generation, iteratively improving that by a community? Can you give ANY reference to any small scale open designin mechanics?I think out of all the components of powertrain a differential is an essential part of any car and is the least safety-related, the least complicated, w.r.t design (I'd say much easier than motor, inverter or battery management). If a differential cannot be made open - forget about serious open EV powertrain. IMHO.

author: ogden
author_rank: Super Contributor
timestamp: August 02, 2019, 08:35:06 pm
content: Quote from: Brutte on August 02, 2019, 08:03:17 pmYes. Mechanics of many open source 3D printers. Kinda offtopic, *very* small scale, but still qualify as an example.

author: BMK
author_rank: Regular Contributor
timestamp: August 02, 2019, 09:41:40 pm
content: Quote from: Brutte on August 02, 2019, 08:03:17 pmThis is what I mean.Main focus on the 'EV' parts. Not things that are decades solved already and where free market conditions have long since found the optimal price/perfomance of. In the specific case of differential, it may or may not require something new to be invented -remains to be seen.Lithium cells are also arguably commodities already. I cannot see much hope that this could be furthered much by amateur effort. Pretty sure that the aftermarket sector will provide fair pricing for batteries and /or cells.The Motor / Inverter tech I think has potential for open development and in my mind, the most interesting part.

author: ogden
author_rank: Super Contributor
timestamp: August 02, 2019, 10:07:10 pm
content: Quote from: BMK on August 02, 2019, 09:41:40 pmImagine you got all the design & manufacturing documentation of Nissan Leaf motor. Then what? You will manufacture it in your garage?Developing and testing >=100kW motor and inverter requires gigantic amount of money and resources not to mention manufacturing capabilities and capacities. Open source EV powertrain will remain just wishful dreaming - never happen unless some big company just release their intellectual property into public domain. Even then it will be not up-to DIY to manufacture inverter, not to mention motor. I mentioned Nissan Leaf motor for a reason - because it is integrated and it's "form factor" resemble common IC engine. This is what you are planning to develop and release as Open SOurce Project and DIY-manufacture? - Good luck with that.

author: BMK
author_rank: Regular Contributor
timestamp: August 03, 2019, 09:32:32 am
content: Quote from: ogden on August 02, 2019, 10:07:10 pm'I' am not planning on designing or manufacturing anything. I am asking if people think such a project is doable / could happen.I should have just googled first becasue I find that large parts of this are being tackled by people already.This project for example apparently can drive the power electronics of lobotomised inverters, taking the place of all the OEM electronics.http://openinverter.orghttps://github.com/jsphuebner

author: Brutte
author_rank: Frequent Contributor
timestamp: August 03, 2019, 09:35:33 am
content: Quote from: BMK on August 02, 2019, 09:41:40 pmAftermarket, OEM or amateur - that is another topic. It does not matter who manufactures it as long as it is an open design (w.r.t this discussion).QuoteInverter for fish tank pump - I agree, I see the potential.Inverter for powertrain of a vehicle - this is safety related. It might have potentialafteryou solve the issue how to manageASILin open design. That is the discussion for another topic.With differential (the reduction gear, crownwheel, oil, bearings, halfaxles etc) there is no ASIL involved. Unless you integrate that with something like a parking brake or ABS or stop light.No, I cannot see a potential of an open design development in safety-related automotive for now. If it could ever happen, it would start not from a complete open EV or even EV powertrain but from open designcomponent.Quote from: ogden on August 02, 2019, 08:35:06 pmIt is not only a "small" scale, it is not even close to the technology that is needed for automotive.Also, open design does not mean that you have to be able to manufacture it in your garage I think. It means that the design is open, with all the available BOM, shape, manufacturability and testing process documented and you are free to use all that design by for example buying it from a company that manufactures that item according to the open design. Just like PCB fab that can manufacture open-hardware for you.

author: ogden
author_rank: Super Contributor
timestamp: August 03, 2019, 09:57:36 am
content: Quote from: Brutte on August 03, 2019, 09:35:33 amYou did not say anything about "automotive". You asked "any small scale open design in mechanics". Pay close attention to wording:anysmall scale.QuoteI said it already. In myother post. Your idea of open source design then is - invest loads of work into design and then give it away for free to manufacturers in China to make profit out of it?

author: ogden
author_rank: Super Contributor
timestamp: August 03, 2019, 10:04:25 am
content: Quote from: BMK on August 03, 2019, 09:32:32 amRight. Not only that. You had to read replies as well. Before coming with idea "let's build intergalactic space ship", first thing you do - research what "intergalactic spaceship" actually is, what could be your chances to build something of such complexity.QuoteNo. Project of such scale is many orders of magnitude out of reach for individuals. It is doable only by big business.