/diy/ - Do It Yourself

A neat little project would be to launch a cheap little model rocket.

Instead of using a electronic ignitor, user a cannon fuse and work it out so that the engine will ignite after the coil gun has launched it.

You'd have two climb phases: The coil gun climb phase, and the solid-fuel rocket engine phase.

Work out the fuse length and firing timing so that the SRB ignites at the moment the rocket reaches the apex of coil-gun climb phase flight.

Then, you'll have a back-yard demonstrator of a real world peaceful(ish) application (i.e. space flight) for coil (or rail) accelerator.

This would be perfect. Maybe I'll try this.

https://www.youtube.com/watch?v=38xVBd60yas

Just so everyone is clear, high voltage/current, gamma ray radiation, free neutron radiation, and x-ray radiation will, of course, all be protected against.


>>561171
Neat

>>561178
>A fusor is not a damn lava lamp. We are talking high voltage and xray dangers even in the weakest of setups.
If I had the resources, and thought she might like one, I would create a damned black hole in our backyard. (Carefully, of course.)

>http://www.fusor.net/
I'll be proceeding soon enough.

So, /diy/kes, I want to build one of two things: Either a Farnsworth Fusor capable of entering "star mode", or some sort of Soniluminescence lamp capable of producing light visible to the naked eye.

See, when my wife and I were still a new couple, I used my super nerd powers (the Internet) to discover that a very bright Iridium flare was going to be visible from our apartment's parking lot about ten minute after she got home from work. So, I told her that I had stolen a star for her, and that after she had seen it, it would vanish because it was HER star, and no just anyone could see it. So, I took her outside, showed her where to look, and right on cue, there was the Iridium flare. Then, after a few moments, it vanished. She was pretty confused, but we had a lot of sex that night, so I think the romance worked.

So now, I'd like to give her a "star in a jar". There's no way I'd be able to finish it by Christmas, but I'd like to make her one, and then give it to her for some special occasion.

Does anyone have any experience making either one of these? I've very little machinist experience, and don't have access to my own workshop, BUT, I'm a very fast learner, and I'm pretty good with complex things, so I'll be able to pull at least one of these off without accidentally killing or harming anyone/anything.

So, any tips, /diy/?
>pic related

>>537568
It's all coming back to me now. I'm a fool.

To be honest, not that I have a chance to see it on a big screen, if that waterfall display in OP's pic is supposed to be the "signal", then yeah, I call B.S.

I'll be darned, I thought posting the word "/b/" was still prohibited on /diy/.

I've visited the threads, and if we go on the supposition that it's just a mystery that needs solving for the sake of solving (not aliens or conspiracies or anything like that) it might be fun.

I've been on my cellphone all day, so no real chance to look into this myself.

Hi /diy/kes,

I've posted here a few times recently about network host discovery, and rooting Android, and /diy/ has been a monumental help to me. I'm very grateful to /diy/ for this.

Now I'm coming back with a question about a hardware level "mod" or "hack" or whatever you would like to call it.

This is the Craig Netbook I've posted about before running 4.0 (It's a POS netbook, but it was $65, so whatever).

>WHY I WANT TO ROOT IT:
It's pretty awesome the way it is for network administration. It has an Ethernet port, and a physical keyboard, and supports USB stuff like HDD/SDD, mice, etc, but it's lacking ONE THING: root. It's great to be able to plug it into a switch, fire up terminal emulator or something, and config what I have to config with something that fits in my pocket. But, it has shortcomings that rooting will overcome:
*WiFi tethering: I can't tether to ad-hoc without running a root only app
*Loop Devices: This is a big one. It would allow me to install BackTrack5 for Android (not to be some l33t haxor, but so I can run nmap, wireshark, etc, for troubleshootnig)
*Google app store: Because side loading is a pain in the dick

Real quickly, let me break it down. The three USB ports are host mode only, so no ADB, etc. No option to put into USB debugging. The update-via-SD card does not work, even with the legit manufacturer firmware.

BUT if I open the little access port on the back, there are some solder points that look like a way into the good juicy bits of the device.

The red box (pic related) is what I suspect is a JTAG interface. I've messed with those before modding DishNetwork receivers about nine or ten years ago, but I'd rather not mess with that, because I'm afraid of frying the board. (There's also the possibility of a JTAG-to-USB adapter, like with SheevaPlug computers, where I could use the cu utility in Linux to interface with the device.)

The white box (pic related) is what I believe is an un-soldered USB interface, possibly NOT host mode USB, like all the visible ports on the device. A very helpful Anon told me in another /diy/ thread that most times those Rock chips have a USB interface like this that the factory uses to program the machine.

I asked a buddy of mine who used to work with electronics how to test this. I hooked the black probe of my multimeter to the AC-in plug, and probed the ports, and they matched the USB mappings (something like -4.9VDC; 0.8VDC; 0.8VDC; 0.0VDC), so it seems this is the place for me to start.

I'm hoping /diy/ can offer some advice or warnings on this, and what I should do after that.

Wish me luck!

Device:
>clp281a

>>517938
>>517942
I opened this little panel on the back (no time to really open the whole thing today) and right away I see what looks like some sort of interface, maybe for when the factory loaded their firmware and bloatware...

Does anything in there look useful? USB? JTAG? Anything like that?

>You know how to solder?
Yep, so that's a possible avenue of attack.

Still would have to know things like which binaries to replace, what partitions should be remounts as rw, etc.

>>517504
>Open it and find the processor and the chipset. Search for firmware for the specific CPU model(Probably an Allwinner).
Okay I'll try that.
>Rooting uses a bug in some software to raise the user from common user to root
That's what I gotta figure out a little better. My goal now isn't really to root any specific device, but to be able to write my own root exploits for any device.

>>517532
>>517678
Not exactly the same as what you're talking about, but I use the app Android on Linux to help with installing a Linux distro into a chroot jail. I usually have under-powered devices, and I've found that the ARM version of BackTrack 5 is the most stable for me, but there's also an LXDE Debian that worked really well.

>>517537
Pic related!!!
I've got all the info I need, and now I'm trying to work sorting it out around all the other stuff I'm doing. Tuesday I'm installing a new server rack, two new UPSes and extra batteries, and then sorting out our clients existing servers. In the meantime, my company will be building and configuring a new server farm for the client... plus we're understaffed, so I'm also working on things like users who lost their files, adding email boxes, fixing printers... the bitch work of IT. But, on the bright side, my college buddy is starting there next week, so I'll be able to get back to mapping the network, and then going to other clients to put out their fires.

Thanks /diy/!

I'm posting this here as a long shot.

I've got an Android powered device, and I want to root it. However, there are no "roots" or "root hacks" available for it. Sucks.

So this got me wondering what specific changes are being made to the OS in order to be able to "su" or "sudo"?

I've been all over xda-developers, and xda-university, trying to figure this out, to no avail. There are plenty of explanations to the benefits of rooting, what the effects of rooting are, and many many "roots" for specific devices, but very little explanation of where these actually come from and how they're made.

So I'm not asking for a workable exploit for a particular device, I'm trying to figure out how to get root on Android OS.

If any /diy/kes know the direction to point me in, please tell me. I'm getting more and more into Linux, so I feel like I'd be pretty familiar with Android's inner machinations. Whether there's a website or a bagillion dollar book with a gazzilion pages, I'm just pretty desperate to know how to root Android powered devices from scratch.

Oh my God you guys... it was a switch the machine was plugged into! It doesn't name-resolve either. Derp. I *did* pull it out of the broken pile, after all.

Anyway, just to follow up with you guys, every host has been identified now, and with /diy/'s encouragement, I'm on my way to create a master viseo network diagram for the client.

I use the -sn switch for most scans, but whenever there was blocking in place by another pesky cisco switch, i ran the scan without any switches. It took way longer (about 6 seconds per node) but it was only one 254 node segment at a time, and the extra details proved invaluable in identifying the nodes on those particular segments.

Thanks again, /diy/

(polite saged)

So ona whim, I tried running it on the crappy work laptop I was issued. It's low on RAM and CPU, so I booted BackTrack5 into CLI mode and what do ya know? It's working!

Whateves. Maybe even though my other laptop was running nmap as root, maybe the GUI loading up has something to do with it? Hell if I know.

Thanks /diy/

>>511275
>>511278

I'll look into these. I'm kinda booked up today, but I def want to let /diy/ know how/if it works out (and now the rest of IT wants it down too! lol)

>>511343
Nope, but you're close. I and the client are located in Ohio.

>>511292
I started messing with computers the first chance I got because no one in my family knew jack about them. I took a few computer classes in highschool, and then went to a vocational school that had computer classes, went to college at KSU and majored in aviation, got a divorce, lost all my money, and then got a computer science degree from ITT-Tech ( not the best school, but not the worst)

The best advice I can give is to just mess around with the stuff and practice as much as you can. Don't do anything that can get you arrested or sued, but DO NOT let that discourage you.

At a very early age, my dad told me not to click on things that I didn't know what they do. I ignored him immediately. Had I listened, I wouldn't know a fraction of what I do know about computers.

Thanks /diy/, I'll keep you posted.

>>511292
OH! I almost forgot. GOOGLE! Google as much as you can! :-)

>>510867
>shitty sounding network.

And that's exactly what it is!

First I did:

># nmap -sn 172.16.202.1-20

as a test, and that went well. It gave me the first 20 in that range, the IP, up or down, and the MAC/manufacturer. No hostname, but I can work around that.

Then I did one more test before splitting the task between two machines, and writing to a log.

>#nmap -sn 172.16.0-254.1-255

That gives me this error:

>Starting Nmap 6.00 ( http://nmap.org ) at 2013-08-19 15:33 EDT
>nexthost: failed to determine route to 172.16.3.255
>QUITTING!

So now I'm stumped. All the Googling I've done says that this error is caused by a WiFi adapter in monitor mode, but I'm using an Ethernet adapter in managed mode.

FML

Is there a way to tell nmap to ignore that catagory? If my machine can't route to it, I can come back to it later. We don't even use that ".3." range.

>>510865
Hey thanks Anon! I bet that will be helpful.

One of the workstations at that remote site is set to a specific IP so that her scanner can send images to it via FTP because - get this - some one told her FTP was secure and encrypted!

A few times, I couldn't get her NIC to ping 127.0.0.1, so I'm not really convinced that the IP conflict warnings were legit, and changing her IP to anything other than the original static one it was set to resulted in total lack of connectivity.

I asked the PC guy to replace her NIC, but it.'s kinda on the back burner, and I'm rambling.

Thanks again Anon and /diy/ in general.

>>510861
Thanks for the kind words and luck, Anon! I *am* gonna need it!

(I like xhamster and nnotherless)

>>510862
Yeah I noticed that too. I leave mine plugged in when I'm not using it, and take the battery out when I know it can't be plugged in for a while - but you're right, it's a pain!

Hi my fellow /diy/kes,

First off, I'd like to say that I haven't been on 4chan since probably March. My life was going down the toilet, and all my interests went by the wayside.

In the meantime, I went from being unemployed, to working for an IT consultancy where I was placed at a client site as the network administrator.

(/tech/ and /g/ are dead to me by the way)

The prior director of IT at this client got canned. There is NO documentation. It's fubar in there. We're doing an over-haul, and we don't even know what all the servers are, or what, if anything, they do. Plus, there's lots of static IPs set, and some conflicts from time to time.

My plan was to use nmap to list the IP of every host that's up, and just its hostname. I'll compare that to the DHCP scope to locate anything anomolous. I'll do port scans on anything really interesting.

(I'm pretty sure the previous director left backdoors when he got canned)

The down side is that the client employs a class b network, so there are over 65,000 possible hosts to be checked.

Plus, there are two ranges i'm going to skip because they're remote sites with crappy T1 connections.

I read that I should set the "chunk" to 256 hosts. I'm also thinking I can boot one of the crap workstations into linux and scan half from my personal laptop, and the other half from the crappy workstation.

What I want to avoid is having to leave my personal laptop there overnight. I have a motion activated camera in my office, but i don't trust the non-consultant IT staff - they're convinced we're going to take their jobs.

dey took err jerbs!

I still uses my modded PSP slim every day (and i'm almost 30). I seem to remember needing to perform the "Pandora" mod on the batterry in order to get it to accept custom firmware. You can undo that mod with a pencil. I think I use M33.

This was the only thing I wasn't sure about, but I think I'll give this a shot.

http://youtu.be/0_mze6kZb94
>Rocket Engine Nozzle

This was the only thing I hadn't decided on yet, but here's a tutorial that clears it up.

http://youtu.be/0_mze6kZb94

>>445685
>The thing with the pre-made engines is that the nozzle is rather difficult to make well.
I, uh... wut?
I don't really know what you're trying to say here. First you say "pre-made", and then you talk about "making".
So, incase you didn't read the OP, there will be no pre-made engines. If you're just trying to give me a heads up on making an appropriate combustion chamber and nozzle, thanks.

>>445847
/diy/ has NOT let me down today!

Thanks Anon.

Good heads up on the cp/cg issue (pic related)

>I would suggest testing them on some sort of static test stand first.
Oh yeah baby I've looking forward to this part almost as much as shooting the thing off.


Pretty nice website too.