SpudFiles

Estoy sin palabras.

jimmy101 wrote:

Fnord wrote:
One more issue. What happens when you put a pencil in a high vacuum? I'm not sure. I suspect that a hundred pencils probably do a hundred different things. Little bit of moisture in the pencil's wood? Perhaps a small void in the wood? Pencil explodes (probably with minimal force) under vacuum. Not only is the pencil destroyed but all those bits floating about in zero G is not a good thing.

In an extreme high vacuum, the internal pressure is no more than 1 ATM or about 15 PSI. Vegetables are flash frozen and placed in a vacuum to sublimate out the water without damaging the cell structure. This is called "Freeze Drying". If peas and carrots don't explode, I doubt wood would even bulge noticeably.

That was just wrong, funny, but wrong!!

Damn volcanoes eating our cars...

being 18 and i know ive made many mistakes and so does everybody else, but im proud that my lil man is healthy and growing strong, and cant believe he will be 2 this saturday, boy oh boy where did time go? aiden i love you buddy!

With a lot of concrete, that Caldera would make one hell of a high speed skateboard bowl!

velocity3x wrote:With a lot of concrete, that Caldera would make one hell of a high speed skateboard bowl!

Haha indeed it would!

By the way, I think this one is a crater. I did a few geology courses at uni but I still have trouble telling the difference from photographs alone so I might be wrong

http://hackaday.com/2012/07/02/hack-a-d ... more-78636

not very impressive but still I thought you might want to see it

Guess who fixed his f*cking chrony? Me! w00t

Replaced the LCD display ($11) and re-soldered the annoyingly short-length display connector and it seems to work fine. Re-soldering the connector really was a b|tch but if I had to do it again it wouldn't take as long.

now that you've mentioned chrony... why don't we design a simple arduino based chrony?

I guess it would require 2 IR diodes and IR phototransistor plus a few extra parts like an LCD display (probably parts wouldn't cost more than 15$)

I reckon you go with three or four PTs per 'sensor block' to allow for a wider range for the projectile to pass over. With arduino, I imagine it wouldn't be too difficult to add some nifty features (projectile weight input so as to calculate muzzle energy, shot memory, average velocity for several shots, fps or m/s capability etc.) if you can find./write the appropriate code.

edit: how many PTs can you realistically add anyway?

It would also be much easier to reinforce the chrony as you can make your own box unit for it too.

MrCrowley wrote:Guess who fixed his f*cking chrony? Me! w00t

Did you add an inch of polycarbonate in front of the screen to stop it happening again

how many PTs can you realistically add anyway?

The arduino UNO you has 14 digital IO pins
that's more than you need, but seriously there is no point in using one pin for each phototransistor - you can get an IC with triple OR gate (found it -> CMOS 4075)

Though I am not really sure if you really need to have more than two PT


As far as storing results is concerned you could either use arduino inbult eeprom memory, inbuilt flash memory or use a seperate eeprom chip

I imagine it wouldn't be too difficult to add some nifty features (projectile weight input so as to calculate muzzle energy, shot memory, average velocity for several shots, fps or m/s capability etc.) if you can find./write the appropriate code.

Personally I don't really think this is needed - I would much rather have something cheap and simple that can be set up, fire check last velocity measured and then plug it in to my computer, upload results and output them as a .csv file

jackssmirkingrevenge wrote:

MrCrowley wrote:Guess who fixed his f*cking chrony? Me! w00t

Did you add an inch of polycarbonate in front of the screen to stop it happening again

Got that 10mm thick Perspex I bought last month to use for camera protection

In a few years, I will probably sound like this guy

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