Recent content by streety

I don't think there is anything unique about this combination of gases. While not all combinations are going to work, there is more than just one. What you're aiming for at each stage is a phase change between the high pressure warm side and the low pressure cold side. As the pressure drops...

I'm no expert, but by my rough calculation I would say yes, this should work. You would need a compressor on the oxygen stage capable of drawing a vacuum of 0.05 atm/5 kPa/50 mbar. That should give you a lower limit of 68.8 K. However, if building such a system myself this gas mix would not be...

There is a lot of practical advice at http://www.xtremesystems.org/forums/forumdisplay.php?80-Vapor-Phase-Change-Cooling&s=8f2366fc1e1b11bf60ad81cff4364507 One thing to consider is that each stage not only cools the gas of the next stage, but also the heat produced by the compressor of that...

Sounds like a decent approach. Not sure what to suggest for further modifications. Perhaps video the device in operation and track the ball to see where the inaccuracies start appearing?

Having separate launchers definitely simplifies the aiming. Is there not a risk that the ping pong ball would bounce against the rails as well? If anything it may be a bigger issue as the ball can travel further from the two rails. The barrel doesn't need to be anything special - a rolled up...

Are you aiming to hit multiple targets as shown in the video (the xylophone bars) or your simpler written description of launching a ping pong ball from a fixed launcher to a fixed target every time? If you have a photo or a diagram of what you currently have that would be also be useful. If...

What aspect of your current design is insufficiently accurate? Is it the loading? Power? Direction?

It may be useful searching for information on quadcopter camera stabilisation. The concept is similar and with the recent surge in popularity it may be easier finding information.

I've finally remembered to revisit this thread with my copy of Make magazine in hand. The Printrbot Simple Metal is listed as one of the standout units, described as the "thin wallet win". It also scores well for print quality. Out of ~23 printers it is tied for second place. The top scoring...

https://www.physicsforums.com/threads/liquid-nitrogen-generator-n2-gas-generator.756538/ Have you seen this?

The latest issue of Make magazine is dedicated to 3D printing. They review quite a few different models on a variety of different metrics. I don't have my copy with me at the moment but will try to revisit this thread later. I don't have any personal experience with 3D printers but my guess...

This is a really interesting project. Congratulations on your success. It would be impractical for me to attempt this at the moment but it is definitely going on my list of projects to attempt in the future. For now I will limit myself to the theory. That compressor is a beast. The temperature...

Hi I'm a biologist / biochemist. I've signed after reading a post on liquid nitrogen generation. I've only briefly browsed through some other threads but there seems to be lots of interesting discussions going on so I may well branch out at some point.