Bot Bench I'd Rather Be Building Robots
The Pneuma-Snatcher is a very ugly robot based on the very nice looking Snatcher, designed by Laurens Valk.
I used the two valve kits that Mindsensors sent to me a week or so ago. They work very well for controlling the pneumatic valves. If you hook them up to the NXTServo controller, you end up with a very nice way to pneumaticify (yes, that’s a real word) your creations. The only problem I had with this robot was the really, really, really slow compressor. It takes ages to fill and the pressure drops very quickly once it is used by one of the cylinders. More air tanks and a better compressor design would probably solve this issue. I used the Dexter Industries dPressure sensor to constantly monitor the pressure in the air tank and top it up when necessary.
I shot a quick video of the Pneuma-Snatcher in action. I cut out a lot of the waiting for the tank to refill so you won’t be bored to death watching it.
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| NXTServo controller hidden under the compressor | Air tank plus small mini pumps. The black thing is a battery pack for the servo controller. It also acts as a counter-weight. |
Very cool! Any idea how much it’ll lift?
No idea 🙂 I have not tested that.
A simplified version of the pressure control: Have a pneumatic cylinder control an electric switch, witch controls the pump. This may require adapters now, but was relatively easy in the days of the RCX.
I also recommend the smaller pumps w/out springs for the pump assembly. Place two of them 180 degrees apart, connected to a motor with relatively good speed for the torque required, Philo’s site may be of use: http://www.philohome.com/
I have used the buggy motors for compressors. They are really fast. If you are only using one or two pumps, the RCX motors seem pretty good. The NXT motors are really REALLY slow (like 170 RPM max I think). For faster pumping, you should either gear up the NXT motor, or use the large pumps with it.
Snatcher, designed by Laurens Valk: The simplest & most reliable Bot of it’s type. It should be in the NXT Hall-of-Fame!
Great mods Xander!
If only we could track down a 7-9v, 20+ PSI hih-volume compressor that was to Lego Technics scale.
[…] The PneumaSnatcher […]
welk programma gebruik jij om je filmpjes te monteeren?
Please ask your questions in English so that others can read it, too.
As for the program I use to create my movies, it’s Windows Live Movie Maker.
oke i wil ask my quiestions in english
Sikko, if you’re not sure how to ask a question in English, you can always use Google Translate. I’ve used it many times in the past when talking to people from places like the Ukraine. It’s very handy! Anyway, it’s great practice for you to write in English 🙂
[…] had an awesome time showing everyone what the robots did. The pneumasnatcher and HTWay with Rotacaster wheels are super popular. Tammy took a lot of pictures of Monster Chess, […]
[…] been playing with this little beauty and I modified the Pneuma-Snatcher to make use of it. I added a Magic Wand as a pressure indicator, I think it looks pretty cool. […]