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how you do attach PC to the chamber?

Posted: Fri Mar 19, 2010 12:44 am
by bighead33
how do you attach PC to the chamber?

SP: i all ready read burntlatke and the spud files wiki but i want to know how you do it.

Posted: Fri Mar 19, 2010 12:51 am
by MrCrowley
I'm sorry but what does PC mean? Perhaps I've forgotten but it isn't ringing any bells at the moment.

Posted: Fri Mar 19, 2010 1:08 am
by Lentamentalisk
I am suspecting that he is talking about the computer, with which they recorded pressure, or speed, or something like that.

It requires special sensors, and data acquisition software. Both are very expensive to buy, but if you don't care too much about quality, you can make them yourself for pretty cheap.
Granted, if you don't know how to do it just by looking at the photos, it is WAY beyond your league at the moment.

Posted: Fri Mar 19, 2010 3:38 am
by chinnerz
im with SirCrowley, some more explanation is required

Posted: Fri Mar 19, 2010 3:49 am
by MrCrowley
I'm struggling to find examples of using a computer on a spudgun except for the homemade chrony's, digital gauges etc...
I'm curious as to what he means.

Posted: Fri Mar 19, 2010 4:02 am
by Crna Legija
You will need some polyepoxide

Posted: Fri Mar 19, 2010 5:04 am
by POLAND_SPUD
uhmm maybe he meant 'propane cylinder'

Posted: Fri Mar 19, 2010 5:36 am
by MrCrowley
Well you can't honestly blame us for that one :P

Hose clamps, most people use.

Posted: Fri Mar 19, 2010 7:37 am
by Hubb
He may be referring to the PC fan. If that's the case, you need to read just a little bit longer.

Posted: Fri Mar 19, 2010 11:30 am
by D_Hall
Lentamentalisk wrote:It requires special sensors, and data acquisition software. Both are very expensive to buy, but if you don't care too much about quality, you can make them yourself for pretty cheap.
To be fair, there's nothing particularly special about the sensors but you're quite right that it can be very expensive or pretty cheap.

On the expensive side, Vera has 3 GP50 pressure gages ($1k-$2k ea.). The data is recorded by a Genesis (no idea how $$, but very). And of course, between those two points are various signal conditioning amplifiers and such. Note that this is professional level stuff. The data will be as good as anything available anywhere...but it ought to be given what it costs!

On the cheap side. Jimmy has done some pretty impressive stuff using nothing more than piezo capacitive sensors (a couple bucks?) and a sound card (already in your computer). The upside of piezo capacitive sensors? They're CHEAP. They have very fast response times. The downsides of them? They tend to be very innacurrate and they drift badly with temperature fluctuations (which WILL happen in a combustion).

As with so many things... You need to decide what you're REALLY trying to accomplish and what you can afford before you decide what instrumentation is "right" for you.

Posted: Fri Mar 19, 2010 12:22 pm
by bighead33
i am so sory for the mix up but hubb is right i do mean pc fan. must have left out fan part :oops:

Posted: Fri Mar 19, 2010 12:57 pm
by Hubb
On my last combustion launcher, I mounted my fan like this.

Posted: Fri Mar 19, 2010 4:45 pm
by mark.f
What size is your fan (commonly, they come in 120, 80, 60mm sizes), and what size is your chamber?

If they are relatively close, I usually just wrap mine in tape until they fit snugly into the back of the chamber.

You can also use fans other than computer fans. I like cheapo fans from walmart...

Image

Older version... haven't seen these fans in a while

I usually connect them with threaded rod or machine screws. Also note that the blue fan needs to be un-bolted from the chamber to change the batteries. :oops: