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Cheap/free Mechanical Engineering 101 resources? by Cedric Passlefoot - Sat, 24 Oct 2015 21:36:21 EST ID:gQzPZ5om No.6824 Ignore Report Reply Quick Reply
File: 1445736981096.jpg -(298079B / 291.09KB, 600x350) Thumbnail displayed, click image for full size. 298079
Basically what the title says. I have an intense interest in Mechanical Engineering. I want to pursue a career as an Auto Mechanic and will be attempting to get into a decent college that has both automotive and mechanical engineering programs. But while I'm waiting on that I figured it best to educate myself outside of school I suppose. So I'm looking for a place to get really cheap introductory textbooks on the matter, maybe free or cheap online PDF's as well. Does anybody have any suggestions?

I know that taking courses in Mechanical Engineering isn't exactly a requirement to be an automotive mechanic but I want to create, design, and fabricate as well as do repairs. I seem to have at least a little bit of a latent talent when it comes to machines as I managed to partially disassemble an old motorcycle engine to replace a bad valve and gasket as well as adjust the timing chain after only watching a short instructional video. Sure I had to take apart and put the engine back together a few more times before it fired up but, hey, I got it. And this was with no prior experience with that sort of thing.

I also seem to really enjoy the work, I found it intensely fun. Anyway, I digressed quite a bit there. I was looking for books/resources on things like learning how to do C.A.D. and/or how to draw up design plans on a drafting table (do people still do that?). The math needed behind the subject (math comes naturally to me, especially things like geometry and calculating ratios which I think has at least a little to do with all of this?) As well as general education on the matter. I can't really give any specific examples but, I figured I'd start broad and work my way into more of a specialized area. I want to design everything from internal combustion engines (new and exciting configurations!) to glider planes. In essence I suppose I want to focus on vehicles and transport in general.

Anyway TL;DR - Cheap and/or free mechanical engineering resources, anyone? please?
2 posts and 1 images omitted. Click Reply to view.
>>
M - Fri, 30 Oct 2015 04:53:18 EST ID:orqtNuyi No.6829 Ignore Report Quick Reply
>>6826
I of course don`t know your financial situation, but I honestly think those books are way to expensive for just interest. I`d suggest only buying them if you are entirely sure what you want to do this.
Also; I`m in my uni library right now and found a book on CAD and heat engines, although I have absolutely no clue wether these exist online or not, here are the titles:
Engineering drawing & design, C Jensen J Helsel D Short
Heat engines A Walshaw.

I think both books are of interest to you.
Good luck.
>>
Isabella Shittingford - Fri, 22 Apr 2016 01:10:31 EST ID:7b780Sco No.6951 Ignore Report Quick Reply
>>6824
Nobody drafts on paper anymore...just kiddies in high school in an introduction to drafting class. I learned everything I needed to know about CAD (Pro-Engineer/Solidworks) via the internet and torrent sites. You can easily torrent a bootleg copy of either solidworks or Pro-E. I would say that solidworks is the more intuitive of the two and you can probably find some accompanying pdf text that will teach you the basics. Otherwise, Youtube is a treasure trove of tutorials for that. Good luck and have fun!
>>
Graham Bliddlestadge - Sat, 28 May 2016 23:45:03 EST ID:Zl+5ngCO No.6964 Ignore Report Quick Reply
>>6824
>implying mechanics in America are highly trained and qualified
Most of them are white trash. Go be a helper at a shop and they'll teach you what you need to know. Most places care about experience unless it's in the plants or government work.
>>
Sophie Clayspear - Sun, 21 Aug 2016 04:46:03 EST ID:7YnJeYuF No.6988 Ignore Report Quick Reply
Machinist's Handbook. Anything you could ever need will be in there. Mechanical Engineers are all pencil pushing know-it-alls cunts. I hate Mechanical Engineers. I left the field behind because of those shallow pedantic fucks. Engineer school teaches you a bunch of shit when a Machinist's Handbook would cover everything you'd use in the real world.

Pirate some ansys software, solidworks, Mastercam and blender. Learn them in that order, backwards. Ansys will be great, way way way down the road for you. Blender is good right now and it has input values so you can test designs to make sure you won't run into costly errors. It is going to take a ton of dedication but you can do it if you want it enough of course.

Machinist's math textbooks are aight. The rest are a waste of time or far too overly complicated to make engineer school more of a pain.

>Seriously though, Machinist's Handbook. Outside of design and that sort of shit, anything you need fabwise will be in there. And millions more.
>>
Hugh Dronningman - Mon, 28 Nov 2016 07:38:48 EST ID:IjPN+/1M No.7019 Ignore Report Quick Reply
>>6824
MIT has literally all the resources(lecture recordings, textbooks, software ect) necessary to get a complete undergraduate education in mechanical engineering available to download for free

https://ocw.mit.edu/courses/mechanical-engineering/


tool by Betsy Tootlock - Fri, 25 Nov 2016 07:29:05 EST ID:LcB05FSQ No.7018 Ignore Report Reply Quick Reply
File: 1480076945447.jpg -(79737B / 77.87KB, 1280x800) Thumbnail displayed, click image for full size. 79737
What's the tool called he uses to remove the bolts at 1:10?

https://youtu.be/rJEq9f5OTwQ?t=62
>>
Rebecca Ginnerstare - Wed, 07 Dec 2016 22:01:19 EST ID:dLNwpFpO No.7030 Ignore Report Quick Reply
>>7018
I would call that a ratchet driver.


Tesla Stuffs by Reuben Bubberbotch - Thu, 14 Feb 2013 21:10:41 EST ID:7rz8obbR No.5412 Ignore Report Reply Quick Reply
File: 1360894241017.jpg -(10341B / 10.10KB, 220x295) Thumbnail displayed, click image for full size. 10341
First year computer engineering student here, with failed subjects.

Well, what drag me into the waters of engineering is all about Tesla and his stuffs. Skeptical, as always, why his stuffs and other stuffs of aspiring people when it comes to Free Energy isn't wholly, or eventually, seriously taken by people.

It's quite mind-boggling for me, I don't even get how much 'value' it is for one to pursue this stuff. I mean, other people already did, no one gave a fuck and here am I just sitting here trying to conclude on a pessimistic matter on what could fucking happen on the next fucking years, or even decades.

I was literally keeping a library of all of stuffs related to free energy, like almost 40gb of it stored on my HDD. Just.. just irritating on why am I thinking this way.
9 posts and 2 images omitted. Click Reply to view.
>>
Fuck Worthingway - Fri, 23 Oct 2015 13:53:21 EST ID:7JSxEYqU No.6822 Ignore Report Quick Reply
I always wondered about the tesla turbine and it's efficacy. Tesla claimed it could reach 95% of it's carnot efficacy while contemporary ones top out at 90%.
The best small scale implementations are about at about 40-50% which is miserable. But I haven't seen anyone really try.
The geometry of the holes inside the disks for instance could be optimized with FEM and fluid simulation.
And in principle a tesla turbine could be made out of other more temperature resistant but more difficult to machine materials enabling it it operate at higher carnot efficiency.
At last it's very easy to machine the parts with just a regular three axis router and a lathe.
>>
Henry Bammledure - Sat, 24 Oct 2015 04:27:06 EST ID:l8g6dMpE No.6823 Ignore Report Quick Reply
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>>6822
The university of applied sciences where I study actually has a yearly challenge where anyone can show up and test their turbine.
http://zefirosteslaturbine.blogspot.nl/
The university is currently doing more theoretical research to improve efficiency.

The actual main advantage over classical turbines is that you can use wet steam, the small droplets in wet steam can destroy normal turbine blades (pic related, although I literaly took the first google hit).
And although I`m not sure who did, but Tesla didn`t claim the 95% stuff, someone else did, a lot later.
>>
Oh Niner - Thu, 15 Sep 2016 07:42:54 EST ID:m4ZDEG1O No.6989 Ignore Report Quick Reply
Tesla makes nice EV cars. Wait.. it's Elon Musk?
>>
Eugene Sondlefoot - Fri, 11 Nov 2016 07:12:16 EST ID:v644jtd6 No.7014 Ignore Report Quick Reply
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DICKS EVERYWHERE
>>
Lydia Curringnatch - Sun, 13 Nov 2016 09:00:06 EST ID:4M/IZJux No.7015 Ignore Report Quick Reply
1479045606267.png -(580244B / 566.64KB, 800x598) Thumbnail displayed, click image for full size.
DICKS EVERYWHERE


FFFF by Emma Daffingdock - Sun, 06 Nov 2016 00:32:25 EST ID:PXawepa+ No.7013 Ignore Report Reply Quick Reply
File: 1478406745093.png -(97144B / 94.87KB, 290x333) Thumbnail displayed, click image for full size. 97144
https://au.finance.yahoo.com/news/man-built-cutting-edge-stealth-020000859.html

Damn, no wonder military technology is still in the 70's.


Offshore expansion by Nathaniel Drapperhall - Sun, 14 Dec 2014 18:42:04 EST ID:y/HQD3oY No.6594 Ignore Report Reply Quick Reply
File: 1418600524061.jpg -(147984B / 144.52KB, 1614x935) Thumbnail displayed, click image for full size. 147984
Let's talk Sealand and other offshore constructions.

I'm no engineering expert, which is why I'm asking you guys this. If someone were to somehow acquire an offshore structure such as an oil rig, would it be possible to expand off of it? How would this be done? At what point would support struts be needed to hold up any extra land?

Yes, I was thinking about Outer Heaven.
7 posts and 1 images omitted. Click Reply to view.
>>
Hamilton Senderhall - Sun, 03 Apr 2016 09:20:26 EST ID:w9V7HL/2 No.6941 Ignore Report Quick Reply
>>6938
lel
>>
Shitting Gottingstodge - Thu, 21 Apr 2016 19:14:39 EST ID:uywTW9Q3 No.6950 Ignore Report Quick Reply
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>>6932
It depends on what shape the platform is in, and where it is. A software salesman bought this 85-foot high platform in the Atlantic Ocean in 2010 for $85,000 (then he paid $100,000 to repair it and refurnish it) and now it's a small hotel.
>>
Basil Suddlewell - Thu, 22 Sep 2016 04:16:06 EST ID:+tz+iBph No.6990 Ignore Report Quick Reply
Just don't try it near Italy or Haiti.
https://en.wikipedia.org/wiki/Republic_of_Rose_Island
https://en.wikipedia.org/wiki/Operation_Atlantis
>>
Eliza Pittville - Fri, 23 Sep 2016 09:09:13 EST ID:BKy0pcqN No.6995 Ignore Report Quick Reply
>>6950
Well, Sealand is a WW2 fort, Frying Pan is a lighthouse designed after oil rigs, and Rose Island was a purpose-built structure, presumably again patterned after oil rigs.

Any micronation better be prepared to defend itself, established nations HATE micronations, and other people with the micronation bug have been known to take over established ones by force.
>>
Basil Pedgelock - Mon, 31 Oct 2016 10:21:50 EST ID:mCRRFwWn No.7012 Ignore Report Quick Reply
https://www.behance.net/gallery/richard-buckminster-fullers-triton-city-project/2971307


Electrical engineering by Nell Hecklebury - Mon, 17 Oct 2016 08:20:05 EST ID:JoiHGtE7 No.7008 Ignore Report Reply Quick Reply
File: 1476706805377.jpg -(9203B / 8.99KB, 259x194) Thumbnail displayed, click image for full size. 9203
Hi i am at the 2nd year of computer engineering however i must study a bit of electrical engineering but from my book i don't understand a single word
anyone can suggest me a book or a site where everything is explained well?
>>
Alice Duckstone - Tue, 18 Oct 2016 13:03:13 EST ID:LMSWX1C6 No.7009 Ignore Report Quick Reply
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Like what sort of stuff don't you understand, what book do you have, and what's the outline of the course?
I'm guessing you're also ESL, which is going to be detrimental if you lack communication skills.


Chinesium by Basil Suddlewell - Thu, 22 Sep 2016 04:22:38 EST ID:+tz+iBph No.6991 Ignore Report Reply Quick Reply
File: 1474532558416.jpg -(85221B / 83.22KB, 720x960) Thumbnail displayed, click image for full size. 85221
So, what is this magical, and presumably very cheap substance that Chinese $2 shop crap is made out of? Is it metal or plastic, or some combination of the two?
Has anyone tried analysing this crud, or how they make things out of it? It seems too brittle to be machined, maybe it's moulded and sets like that play-dough stuff you bake in an oven. But put it under mechanical stress and it deforms, tears and crumbles like cake. Sometimes it has sparkles!
1 posts omitted. Click Reply to view.
>>
Cyril Dimmleford - Sat, 24 Sep 2016 00:25:46 EST ID:F9kDEmRB No.6996 Ignore Report Quick Reply
>>6991
Be careful with the sparkles, they're toxic.
>>
Eliza Driffingfield - Sat, 24 Sep 2016 03:27:18 EST ID:F2XRo4mh No.6997 Ignore Report Quick Reply
https://www.youtube.com/watch?v=1jJP0CcuJyE
https://www.youtube.com/watch?v=p-ID-wUYoHY

These locks are amazing. Are they made of candy?
>>
Samuel Bubbertadge - Tue, 27 Sep 2016 22:50:53 EST ID:LMSWX1C6 No.7002 Ignore Report Quick Reply
They're just made from pop steel you'd use for bottom barrel part fabrication. They're not even case hardened for the full length, as far as I'm aware.

Yeah, don't fuck around with garbage cutting tools. They'll bite you more than the material. If the manufacture isn't willing to provide you a name of the material it's tool is made from, I'd be hesitant. You know something telling you it's a M42, M2, C2, C12, etc.
>>
Isabella Dregglestone - Wed, 28 Sep 2016 05:55:39 EST ID:2R1lBWwz No.7003 Ignore Report Quick Reply
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I love the drill-bit where the threads have straightened out like spaghetti.
You Google image search for Chinesium and it's like a mechanical hall of shame.
>>
George Nuckleworth - Wed, 05 Oct 2016 23:23:52 EST ID:ZMpXliD1 No.7007 Ignore Report Quick Reply
>>7002
industrial supply places are the best for stuff like this. The bits I get at my shop are pretty solid.


WHAT HAS SCIENCE DONE by Basil Suddlewell - Thu, 22 Sep 2016 05:02:20 EST ID:+tz+iBph No.6992 Ignore Report Reply Quick Reply
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https://www.youtube.com/watch?v=CS71uIBvank
>>
Edward Brobblewill - Fri, 23 Sep 2016 02:05:48 EST ID:gO+6q97s No.6994 Ignore Report Quick Reply
test post please ignore


Pulley ratio calculation by Cornelius Blackcocke - Thu, 04 Aug 2016 13:53:21 EST ID:0ltnlAdQ No.6978 Ignore Report Reply Quick Reply
File: 1470333201242.jpg -(895764B / 874.77KB, 1520x2688) Thumbnail displayed, click image for full size. 895764
Hi, I hope this is the right board for this. After a few hours of looking online..I just don't have the math skills to sort this out.

I have this electric motor that spins at 1725 rpm. I need to reduce that to 25-30 rpm. I have an old 74 1/4" bicycle wheel that I hope to be able to use but need to know the size of pulley to attach to the motor, or even if it is possible with what I have. I want to use this motor because it is designed for extended use and has a sufficient amount of torque for my project.
3 posts omitted. Click Reply to view.
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John Blovingcocke - Fri, 12 Aug 2016 11:17:04 EST ID:0ltnlAdQ No.6983 Ignore Report Quick Reply
>>6982

I am trying to build a rock tumbler that uses a couple of 6 foot rods in order to accommodate a series of small drums. I want to experiment with a few methods I have devised without committing my big tumbler to the task.

I was going to trim a belt myself.

The drill idea is a very good one. I am pretty sure I can find one for much less than that at garage sales or pawn shops. I am trying to keep this build user $100...mainly because I like to brag about my resourcefulness.

I do have an old 10 speed kicking around .....but yeah. I really don't have the math for that.
>>
Jack Baffingshit - Fri, 12 Aug 2016 23:22:49 EST ID:LMSWX1C6 No.6984 Ignore Report Quick Reply
>>6983

No guarantee that you'll find one with that level of reduction. You're looking for a ~70:1 to ~57:1 reduction at 100% load. And I know the old Makita I picked up for a couple bucks recently is only something like 11:1. It's a really nice solid helical gear with decent bearing. Though if you wind up with an 11:1 then you would only need to reduce it about 5:1 more to get about ~31RPM, either with another gear box, or just a small cast aluminum pulley straight to the drive shaft. Plus you only need a small cheap belt from a regional industrial supplier(best if you can pickup to avoid the freight cost).
And btw, casting aluminum is pretty damn, easy. Obviously it's not certified free machining 7075 or anything. But this guy made some real nice large rounds.
https://www.youtube.com/watch?v=kNAfMtsAVd0
After you drill the center of your puck out and chamfer it, you can pop it on a mandrel and place it in a drill chuck and spin it(slap that drill into a vise if you got to), then clean it up with a rasp file, and then spin a flat groove into it for the belt to sit in. All the angles don't got to be perfect, just make sure you keep a even flat surface for the belt to sit on, any steps in it will wear the belt unevenly.
If you locktighted your mandrel on, just melt it out with a small torch.

If you need to trim a belt to width, don't just eye ball it with a razor and free hand it. Put a rod in a vise(or press fit into a block, and clamp it to a bench), and attach a blade to the end(braze, weld, bolt). Then the end of the vise will act as a depth stop so you have a constant width as you pull it through the blade.
>>
Jack Baffingshit - Fri, 12 Aug 2016 23:36:36 EST ID:LMSWX1C6 No.6985 Ignore Report Quick Reply
>>6984

Oh yeah, you really don't have to clean up the faces of the pulley either, an uneven cast surface is fine. As long as the surface the belt sits on isn't severely out of round(not enough even, constant pressure on the cut, or not not cutting far enough past the rough cast surface).
If you decide to clean the faces up, and want to do it with some speed. I know a lot of people often have something like an angle grinder laying around, so if you put the drill with the pulley to a low RPM, you can hit it with light passes of the angle grinder to speed up cleaning the faces up. If it's glued in, don't go to hard, or you could heat it up and melt it out.

Alternatively to a glue on mandrel is to take a rod, drill and tap the face. This goes in the chuck and the part is bolted to it, with a little touch of locktight. Just make sure the part spins in a direction that pushes the bolt tighter, rather than looser as you put pressure on it.
>>
Sophie Clayspear - Sun, 21 Aug 2016 03:51:28 EST ID:7YnJeYuF No.6986 Ignore Report Quick Reply
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Not sure why you are building a directly driven rock tumbler. Most are a 1:1 drive to one support rod that the drum rotates on. Usually with something rubber to prevent slippage. Pic related.

By Direct Drive I assume your design is a gang of linked 5 gallon buckets with one attached to a bicycle wheel as a driven gear?

This may be necessary given you are talking 6 feet long and 5 gallon buckets. Not sure what loads you will have. If you are turning 5-6 5 Gallon buckets with rocks, internal blades/mixer shelves and water, you could be moving a good bit of weight.

This is what I would do if you are attaching the wheel to one of the drums with all the other drums connected to the driven one. I assume by 74.25 you are talking about the circumference. So the diameter is 23.5 inches? This is going to make the design pretty... shitty. To gear it right. You'd need a .5" pulley. You'd also be going through belts fast with such a sharp angle unless you put the motor very close to make the belt's tangency less sharp. If you want to use the wheel and the motor you'd do best with a VFD device but those are about 110 dollars for a tiny one.

The math behind this is:

>5/8" Drive
>23.5" Driven
>1725 input.
>15" between centers and a ~3" gap between pulleys. A little over 3"
>Belt length should be roughly 75.5 inches. Of course you should be able to tension it by moving the motor. Or an idle I guess.
>55 RPMs at the driven. Still kinda fast. .5 inch would be optimal.
>>
Sophie Clayspear - Sun, 21 Aug 2016 04:38:59 EST ID:7YnJeYuF No.6987 Ignore Report Quick Reply
1471768739822.png -(19879B / 19.41KB, 1024x768) Thumbnail displayed, click image for full size.
>>6986
This is the optimal way of doing it unless you expect to be turning 60-100 lbs or more.

>Green is Drum. It rides on the two 6 foot bars. Wrap these in electrical Tape or something rubber. This won't work if these are tiny as shit. If they are over .5" in diameter, it should work.
>Black rectangle is the mounting for the bearings and shit.
>Red crossed circles are your pulleys.
>Yellow Cross circle is your motor pulley.
>Light blue around the circles is the belt.
>The blue lines in the black long rectangles is your 6ft pipe.
>Motor is self explanatory. Mount it in a way you can tension the belt. Threaded rod could work. You could put nuts on the threaded rod and tighten the nuts til the belt is tight. Then run a second nut under it and tighten them against each other so it doesn't vibrate down.

This is where things get complicated. This design is far superior, cheaper, durable and easier. But the math is more involved.

Firstly, I need to know the diameter or the circumference of the outside diameter of the pipe the drum will rest on. Then I will need to know the diameter or the circumference of the drums. Nothing too precise but I'll show you so you can work it yourself.
Comment too long. Click here to view the full text.


Ground Needed\Stray Voltage? by James Pillyhood - Wed, 13 Jul 2016 23:38:51 EST ID:LMSWX1C6 No.6975 Ignore Report Reply Quick Reply
File: 1468467531486.png -(73990B / 72.26KB, 300x180) Thumbnail displayed, click image for full size. 73990
So I got a new attic fan and lighting wired up and there is no ground available on the circuit coming from the breaker. Option one I'm seeing is to run a wire out the wall, tucked under the siding all the way to the ground rod, bloating this "simple" project even more; or just say fuck it and not run a true ground to it, even though I spent the time tying all the ground wires together; third option bite the bullet and buy a GFCI breaker.

Problem 2, when I put the voltmeter to the case of the fan, after flipping the breaker on, I get 1 volt on the case. Should I be concerned with this, is this excessive stray current?
>>
Cedric Cunkinferk - Thu, 14 Jul 2016 21:15:26 EST ID:3ODb0gls No.6976 Ignore Report Quick Reply
I would probably just install a fuse on the power wire to the fan.
>>
Lillian Brookbanks - Thu, 14 Jul 2016 23:37:17 EST ID:LMSWX1C6 No.6977 Ignore Report Quick Reply
Suppose that could work. Haven't seen a fuse outside of a car circuit in a long time. Don't think any stores even carry holders around here. Have to order one.


Instrument cable instead of speaker cable? by Alice Clayridge - Wed, 29 Jun 2016 19:07:44 EST ID:wpTfjl5n No.6972 Ignore Report Reply Quick Reply
File: 1467241664728.jpg -(626424B / 611.74KB, 1025x659) Thumbnail displayed, click image for full size. 626424
I let friends use my fucking sound system and I found out they ran instrument cable instead of speaker cable from the powered mixer to the speakers for their dance music show and now a.) there was popping for like 3 seconds mid sound-check the next day but hasn't happened since and b.) the power amp limiter LEDs come on for two seconds right when you start it up but has yet to come on any time after that. Should I be worried? This system is brand new and I'm really upset about this.

Pictured is the power amp used. The manual doesn't say anything about what the limiter lights are supposed to do at startup so I don't know if that's normal.
>>
Simon Hummlenot - Wed, 29 Jun 2016 23:44:42 EST ID:LMSWX1C6 No.6973 Ignore Report Quick Reply
/m/ Might be the proper board.

How many amps does it dump out the powered end, and how long was the line? If itt was a small 18ga instrument patch, under several amps, and wasn't remotely pushed to peak, it was probably not an issue.
Was the pop like when you plug in a line? That might be a loose jack issue.

Thing two. Don't lend gear unless it's a beater, or you know the individual will buy you a new one it they damage it(this works with coworkers, because you know they have actual income).


Electrical Sharegineering by Polly Dartville - Sat, 27 Feb 2016 03:24:15 EST ID:EGgJzstS No.6919 Ignore Report Reply Quick Reply
File: 1456561455718.gif -(1149890B / 1.10MB, 500x500) Thumbnail displayed, click image for full size. 1149890
Hi,

I'm a millionaire drunk stoner with a pretty complete knowledge of everything concerning electrical engineering. Ask me anything!
17 posts and 6 images omitted. Click Reply to view.
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Charles Chorringkag - Mon, 23 May 2016 13:06:20 EST ID:Mammg+Yw No.6960 Ignore Report Quick Reply
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>>6959
If I used a simple filter it would only work for the note that the filter removes. I would have to make the filter frequency controllable by the input frequency, so it would be just as complicated as what I'm trying to do now.

The circuit I have so far actually simulates rather well. With input signals above 1kHz, I can get the oscillator level to match the input rather well from 10mV to 1V, with a response time around 1ms. The problem is that lower frequency signals cause the control voltage to oscillate, which really garbles the PLL signal and thus the output. The filter following the recitifers is well overdamped, so I'm thinking the problem has something to do with the non-linear response of the JFET VCA. I wanted to keep using JFETs for cost reasons, but I may switch to something optoelectronic, since the response is typically much smoother/slower.
>>
Ian Sublingshit - Wed, 25 May 2016 02:50:49 EST ID:T91euWtk No.6961 Ignore Report Quick Reply
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>>6960
Ugh, dude. Here's a protip for this kind of thing; nobody wants to see your specific implementation unless they getting paid. Again I'll try to keep it simple.

So your high band frequencies work well with your shit. Great. USE FILTERS LIKE I SAID! Split your input signal into two, with one going through a lowpass filter to remove those sub kilohertz signals. Feed that signal into your existing setup and you're golden for that part of the frequency spectrum.

Take your other output and filter the high band with a highpass filter, then use a bandpass filter to eliminate whatever frequency range between 0-1kHz you desire. Tie those outputs together and wow you have the whole spectrum without having to deal with your nonlinearity.

Now this might sound confusing if you don't understand that filters can suppress a range of frequencies, not just a specific one. Go read up on how passive and active filters are constructed.
>>
Ebenezer Pummletork - Wed, 25 May 2016 13:04:02 EST ID:Mammg+Yw No.6962 Ignore Report Quick Reply
>>6961
I don't think you understand what I'm trying to do. I want to remove only the fundamental frequency of a note from a guitar or other instrument and leave the harmonics untouched. It should be able to do this over the entire range of the instrument. If I use any fixed-frequency filters in the signal path, it will only work correctly for a certain range. For example, if I eliminate 500-1000 Hz with a filter, the effect will work for this range of input frequencies; but if I play a note at 250 Hz, it will filter out the first and second harmonic (500 and 1k Hz) and leave the fundamental untouched; if I feed in a note at 2000Hz it won't do fucking anything. If I make the bandwidth any larger than an octave, it won't work for ANY input frequency because the for it will start filtering out the harmonics of any note within the filter range. There is no way to get more than one octave of useful range with static filters because I specifically want to remove "one" frequency which can vary over several octaves. Something MUST track the input frequency; it cannot be done with fixed-frequency filters.

Don't be so condescending. I understand how filters work. You mixed up highpass / lowpass as well as bandpass / bandstop.
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Emma Hommlefield - Fri, 03 Jun 2016 03:32:25 EST ID:T91euWtk No.6969 Ignore Report Quick Reply
>>6962

Yeah well fuck you. I can't see any way of doing this easily with analog components, because you CAN isolate a fundamental signal via analog methods but it becomes impractical with a large number of frequencies. Just use a cheap microcontroller to examine the current fundamental and apply the correct filtering. It's not expensive, like 10bux for a top of the line processor.
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Shit Bizzleforth - Tue, 07 Jun 2016 21:48:46 EST ID:7ztzoB70 No.6970 Ignore Report Quick Reply
Calculus, asides from obvious shit like wolfram alpha and its rubbishy pay to get step by step shit can you recommend any good resources or books to learn from?


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