How the fuck do you guys just slap drones together just like that without any calculations and still get it to work? I am building my first drone, an octocopter (I need it for work) and seeing as these things are expensive to put together, instead of trial and error I'm taking a mathematical approach and it's pretty deep stuff for something usually done as a hobby. You have to match the electronics with the physics like if the physics say you have to spin the prop at a certain RPM in order to get a certain thrust you need to supply a certain voltage for that. Any more... Comment too long. Click here to view the full text.
The voltage thing is really mystifying me. For a 45 minute discharge each motor gets 13.3 A and it needs 375 W to fly. Therefore to provide that with 13.3 A I need 375/13.3 = 28.2 V. But the battery is 22.2 V? How does this work? The only way to reduce the voltage requirement is to reduce the power requirement and the only way to do that is make the props bigger. So is this calculation straight up saying that my drone can't fly with the propeller size I chose?
And the propeller RPM that is even more of a mystery, Thrust depends on RPM right? And RPM only depends on voltage right? I assume this because of the kv rating thing. If you want to increase thrust you have to spin the props faster and more thrust equals faster discharge. BUT increasing discharge rate only increases the amperage? Therefore for thrust to increase amps must be being converted to volts in the electronics?
Bought a house in a suburban neighborhood. Has a shed in the back corner of the property. Behind the shed there is a 55 gallon drum of mineral spirits slightly hidden. Wtf!? Why did somebody have this and what can I do with it now? Dispose it? EPA concern?
have you ever encountered a business that won't give a quote?
some places won't give a binding one, or a quote for free because so many people waste their time, I get that
but this laser cutting place won't even give me a non-binding price range, or examples of what they have charged in the past they got mad when I asked for a quote on a 20cm circle, knowing that I was trying to establish a baseline cost
it would take days to get my work in their vector format, and I need to know that when I do it they arnt going to give me some ridiculous... Comment too long. Click here to view the full text.
>>965662 I've had this problem before trying to find some cheap metal gears. called all places, and it was either "well it will cost you $3,000" or. "sorry you have to order 30 units or more" and that always pisses me off. especially the "minimum" orders. even worse when its local and they aren't even mailing it. a lot of steel yards pull that shit around here so they don't have to sell to non-business related people. they don't want billy joe coming in, buying one piece and never... Comment too long. Click here to view the full text.
i don't want to offend anyone and i ask this out of pure curiosity: does matthias wandel have some kind of issues? i always wonderend, for the goofy manners and the rage he shows in replies to criticisms on his youtube channel
beside that he is pretty fucking good in what he does, just wondering
>>965208 >and the rage he shows in replies to criticisms on his youtube channel
I was taken back by this when I first saw some of the stuff he was posting. He is very short with all people, even if they arent criticizing him. Its like he doesnt understand social cues or subtleties of conversation.
I bet you could put him on the autism spectrum somewhere., Seems to have a high intelligence and an inability to filter himself or understand social situations. He is pretty eccentric.
>>964812 >brand or model not important as long as it fits (and certified)
>filters an analogy here would be like shoes. You can ask, the selection of shoes seems really complicated, are there any shoes that are good for all purposes? the answer is, it depends on what shit are you walking on, or if you are walking at all, etc. But if you are at home, just slippers will be enough.
harbor freight has a $17 respirator that's rated P95 (95% of air particulates filtered). if you need biohazard shit it won't work, but anything /diy/ should be fine. it's cheep and meant to be disposable, so after you use it up you throw it away and get annudder. if you do a heavy or particularly messy painting job or a demo/cleanout you might have to buy one every day or two of work. but, it's so cheep who cares? i do light wheeling, polishing, and buffing, as well as some spray adhesive and spraypaint work and one of these would last me like a year.
>cops knock on your door >"Sir we have reports that you might be blah blah blah can we see your garden?"
You can either make the mad, be a dick and say no come back with the legal prerequisites to search your home, in which case they will make your life worse because you were being difficult or
>Sure officer >show them to your backyard >show them your vegetables >"Sorry to have bothered you sir, have a nice day"
And then never have to deal with it again.
Again, this is the worst that could happen, it is much more likely that nothing will happen because people have greenhouses in their backyard all the damn time and cops don't have the time to check every single one. Unless you are filling your backyard with hundreds of these, I doubt they would bother.
>>963796 dont buy pic related they are shit. also if the cops bust down your door and find so much as ayylmao in your saliva, their ayyyy will be justified and they wont cover the cost of having a new door installed.
>>961059 I understand simple circuits but when they split like that on the left between the capacitor and the transistor then I have no clue what the person is trying to accomplish. In this case my best guess would be a pull down bot the others I have no clue.
what cool stuff have you done working in plastics guys? what are some things that someone working with various plastics need to worry about? how would you rate the stuff you've worked with in terms of workability?
what's what in Flexibility, impact resistance, overall strength, or other details?
anyone with experience laser-cutting any of these?
ITT: People who find unwanted electronics, working or not, rebuild them or harvest their organs.
What I'd like to see: Stories (I found a $10,000 X that just needed a new power cord.), and tips (Junk microwaves can be disassembled for a free HV transformer.) (You can find Y for free, but it just isn't worth it for Z reason.)
Bonus level: State what you do with the parts.
I'll start. I like to desolder PCB's. It's a decent source for common and sometimes not so common components.
>>956961 >i collect loads of stuff and don't do anything with it this will be the same as every other 'recycling' i.e it will become hoarding: the thread then someone will post rps this thread is bad op and you should feel bad
Hello, im a cunt, from QLD ausfailia, and im trying to make a big fucking trailer so i can have a moterhome and fuck off to the middle of nowhere, because im also part gypsy and being stuck in one spot is killing my soul
so, freinds, cunts, people doing the right thing and fucking off because we are full, tell me, how do i make a box shaped trailer here, that is 4 meters high, 8 meters long, and 3 meters wide, without breaking laws in a way that will be road legal, if that cant be done, whats the closest i can do, and how do i do that?
>Lol... Comment too long. Click here to view the full text.
>>967954 tripfags not welcome. also, a trailer that size will need an engineering certificate anyway. you're better off buying a trailer and just attaching something to live in as cargo. or just buy a LWB van or shortbus. they can be comfy. you can't DIY something this large. australian auto engineering firms are cunts and a major way to launder money is through custom vehicles. hence why buying a 10k$ used bus is a better buy than spending a few million on a custom vehicle.
Hi guys, I'd like to make my own frameless laser harp, but I'm kinda stuck on some technical aspects.
Here's how it works: A laser is sent over a mirror, creating a "string", then it is turned off, the mirror turns a little bit (thanks to a motor), and turned on again, to make the second string, and so on... Not gonna explain the reception part here, because it's not related to my problem.
After some researches on internet, I found that I could use a <100mW green laser pointer to get a cool effect, but I really don't... Comment too long. Click here to view the full text.
>>965417 >Servomotor ? Galvanometer ? consider a multifaced mirror that continuously rotates. this is how scale barcode scanners operate. a brushless motor will be practically silent if that is important
out of your two suggestions a galvanometer would probably be better because less mass, friction and momentum than a servo.
If it continuously rotate, getting the feels that the string is there (and not blinking to much), and beeing able to know what string is beeing "displayed" at any time (Mandatory in order to know what note is beeing played) seems pretty hard, no ?
The galvanometer is also more expensive, isn't it ?
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