Posts by mlg@mastodon.sdf.org
(DIR) Post #AFFckCtz7lnUd6RZz6 by mlg@mastodon.sdf.org
2022-01-09T01:47:37Z
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@cjd http://wiki.gekgasifier.com/w/page/30448258/Spark%20conversion%20for%20Lister%20slow%20speed%20diesel%20engines
(DIR) Post #AFFckDlrtQtnKDebyK by mlg@mastodon.sdf.org
2022-01-09T02:02:20Z
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@cjd i've strated drinking the booze to cope with the cold and lack of electricity. but I'm pretty sure woodgas and ethanol (another interesting alternative fuel to me) idealy operate at higher compression ratios and different air fuel and compression ratios than gasoline engines but can also be made to run on stock engines
(DIR) Post #AFFckEfWYVQ06ph3iq by mlg@mastodon.sdf.org
2022-01-09T02:14:40Z
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@cjd careful i used to have a life a few years ago then i discovered driveonwood
(DIR) Post #AFFckFzlcjCmDuAjui by mlg@mastodon.sdf.org
2022-01-09T02:33:33Z
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@cjd I warned you its a huge rabbit hole. theres people injecting water into their wood gasifier to increase the H2 %. and even crazier people trying to enrichen their gas with CH4 methane via catalysts. buts its a big equation. do you want to chase higher ultimate efficiency, or follow the efficiency of using off the shelf mass produce gasoline engines designed for 14.7 air to fuel ratio and whatever comperssion ratio
(DIR) Post #AFFckGQi0YkvZSmFuK by mlg@mastodon.sdf.org
2022-01-09T02:36:50Z
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@cjd https://en.wikipedia.org/wiki/Water%E2%80%93gas_shift_reaction
(DIR) Post #AFFckHGSu89k9yzaa0 by mlg@mastodon.sdf.org
2022-01-09T02:50:49Z
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@cjd ok yeah, but can they use less dense fuel? because wood is less dense. there is an alternative path trying to convert woody biomass into densified fuel. and then provide THAT to trucking or agriculture. its an open question as far as i can tell
(DIR) Post #AFFckHhPHxhtVXb6Zd by mlg@mastodon.sdf.org
2022-01-09T02:51:44Z
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@cjd methanol, dimethyl ether, etc. its a specialists concern which is thne best densified fuel to create from woody biomass
(DIR) Post #AFFckKKpUMQhgO3cIa by mlg@mastodon.sdf.org
2022-01-09T03:02:27Z
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@cjd thats the question. what does it look like for ag equipment? if you go to to driveonwood yuo see some teenager drove coast to coast back and forth across the USA on wood. on a stock pickup with the gasificaton equipment in the bed.but thats a pickup truck. not a combine
(DIR) Post #AJcmzYOK4E1YqLPHNY by mlg@mastodon.sdf.org
2022-05-17T04:07:00Z
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@klardotsh from what i've seen with ebikes & onewheels, the BMS is the point of failure. seen batteries heavily used sans bms, no problems. this type of BMS is not necessary, it is a collection of functions (eg over|undercharge protection, short circuit protection, cell balancing?) that can be addressed by other components or system design. cool project idea there is a lot to think about.
(DIR) Post #AJcmzZ4VXNlgxB8y8G by mlg@mastodon.sdf.org
2022-05-17T15:09:43Z
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@klardotsh especially if you're not super weight/space constrained, imo theres a better/safer/robuster design for all the other features this BMS brings.it sketchy you mention need to heatsink these. fuses and contactors dont overheat :)
(DIR) Post #AJcmzZOMLZeDwkQp4i by mlg@mastodon.sdf.org
2022-05-17T15:13:43Z
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@klardotsh also consider the inverters you are installing between the batery and the motor has a lot of intelligence (microcontroller) and basically the same solid state switches that are designed to withstand the full current and voltage of the motor/battery. That can save your batteries just as much as the BMS if its programmed right, unless you're also running hardwired 48VDC dumb loads in parallel.whats your biggest house load while also motoring?
(DIR) Post #AJcmzZg5HfpGpiiyhc by mlg@mastodon.sdf.org
2022-05-17T15:18:14Z
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@klardotsh i'll leave you alone now sorry for the spam, again cool project best of luck.i recently converted a 2 wheel tractor gas to electric, slightly different concerns but also used a ~48V battery and 10kw motor. & ~10yrs ago worked at shipyard so have some idea of boat electrical systems
(DIR) Post #AJcmzacDnWKXk1vPJw by mlg@mastodon.sdf.org
2022-05-19T02:24:56Z
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@klardotsh this varies who you talk to, ie different industry, academia, manufacturers, hobbyists, but basically of these things can be synonyms:(brushless)(motor) controller(variable frequency) drive(motor drive) inverter(electronic) speed control and many variations,its all basically the same thing. for this kit, its Sevcon Gen4 G4855. That can be programmed to only operate in a voltage range, to prevent depleting battery
(DIR) Post #AJcmzbErTrErfs0GY4 by mlg@mastodon.sdf.org
2022-05-19T21:52:53Z
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@klardotsh re:thermal1) enough parallel capacity to lower temp rise at max load2) battery protected by fuse, breaker and contactor2a) contactor energized only by completed "safety circuit" ie series connected wiring of "normally closed" devices that will open up the circuit in a fault, INCLUDING the fault output built into your motor drive, thermal limit switch built into your motor winding (hopefully), PLUS extra safety devices added by you, E-stop button, battery temp sensors
(DIR) Post #AJcmzbXeM0Gec8nGpk by mlg@mastodon.sdf.org
2022-05-19T22:02:01Z
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@klardotsh 3) (less good, but fallback) program accurate thermal model into motor controller. this is a simple math model of temperature based on how much power is flowing between motor and battery. its as good or bad as the configuration data you provide it. 4) thoroughly and regularly test whatever design and equipment you go with, use redundancy on measuring temperatures, and be conservative with setpoints relative to absolute limits :)
(DIR) Post #ANZcTJgUFr93sWjt8S by mlg@mastodon.sdf.org
2022-09-14T22:21:05Z
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(DIR) Post #ANarScnBQ2qFK0xXXM by mlg@mastodon.sdf.org
2022-09-15T16:09:43Z
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@publius Understandably people are always going to look for a nice soundbite, but "does less harm" seems un-nuanced to me.I see a distinction into at least two categories, soemthing like "Safety Record" and "Risk". Safety record being a statistical measure of historical operational data, and risk being an analytical assessment of failure modes and their severity.
(DIR) Post #ANax5JxHt7YVxqxNFw by mlg@mastodon.sdf.org
2022-09-15T16:15:50Z
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@publius a performer juggles machetes on a unicycle no problem, and I tripped and rolled my ankle while going for a moderate walk in a park. lets imagine a survey:have you ever injured yourself 1) while juggling machetes on a unicycle? 2)while going for a walk or jog?would any results on this survey convince you juggling machetes on a unicycle is safer than walking or jogging?
(DIR) Post #ANcxEyvB8X1fMtG5Oi by mlg@mastodon.sdf.org
2022-09-16T16:23:54Z
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@publius it sounds like you respect the regulations. i read many opinions that blame regulations for high cost and/or lack of increased performance.
(DIR) Post #AspfNHbJkCU1baEKDQ by mlg@mastodon.sdf.org
2025-04-07T01:28:57Z
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https://www.experimentalfarmnetwork.org/project/35