I would prefer to use compressed air but there was a space issue. You can store more C02 in a smaller space than you can with air. At least using commonly available tanks. A 20oz Co2 tank can be filled to 2000+ pounds while an air tank can only be filled to 150 ish max. And to find a compressor that is capable of compressing air to anything over 150 psi is tough. But Co2 can be refilled from a larger stationary tank.
I prefer compressed air anyday, but Co2 suited this application better.
ok, when I read 150 psi I thouht you said that they didn’t sell bottle with over 150 psi… they have like 4500 psi, of course it’s expensive… 
but to fill it up you would have to go to your local (it depends…) paintball place 
that youd be funny, you arrive with your 100 lbs robot, and ask to fill your tank. 
So, how is the robot doing? any avancements?
If this thing is to be used by law enforcement, then you could use the air tanks from the SCBAs used by firemen (they usually have their own compressor stations for refilling). The newest version air tanks are fiberglass or carbon fiber wrapped and have a service pressure of 4500 psi. and are very light (below link). If co2 is being used, the heat from the motors and batterys could be used for vaporization of the liquid co2 and help keep those components cool.
Air tanks, not Co2 tanks. Air tanks that can hold over 150 PSI are not common or small.
I’ve used scuba tanks for Paintball before. But the problem lies in the space I have.
See the Air Supply is mounted inside the ball Turret for one reason. The Turret has infinite rotation. I had to custom build a Contact Cam that would allow the signal and power lines on the turret to spin freely without twisting. This is basically multiple metal contacts that rotate around and stay in contact with metal tracks the send the signal into the chassis. This means no wires connecting the turret to the chassis, all the contacts run through this rotating cam. Now the contact rings have to be in the center of the turret. If they are on the outside edge, there is too much surface area of track to travel and it becomes difficult to eliminate broken contact and wear. Keeping it in the center of rotation means you reduce the distance traveled on the tracks to a minimum.
If I had a large tank mounted on the chassis, I would need a rotating fitting to supply the air to the Turret, since a hose or line would tangle and pull off if it rotated around in circles. If I use a sealed rotating air fitting, it has to be placed in the exact center of rotation as well, meaning that I would have to integrate my own rotating air fitting, into my electric cam assembly which was difficult enough to build.
So keeping the air supply on board the turret, eliminates these problems.
And small Co2 bottles will last longer than small small air bottles with 150 psi in them. And to fill a 2000psi air tank, you usually need to find a welding or Oxygen supply shop, and they won’t fill anything but approved bottles used as intended.
So Co2 simplifies things for both me and the end user of the product. If not because of the design of the turret but because anyone can get a 5 foot Co2 tank from a welding shop and use it to refill their smaller tanks.
Might i suggest an array of camera flashes and a air horn or load speaker too play Disco classics ,that would make me surrender 
“Freeze!!”
“Well you can tell by the way I use my walk, I’m a woman’s man, no time to talk…”
“Noooooo, I surrender!!”
Please tell me you looked up the lyrics! lol
LOLLOL. Well I knew it all but the woman’s man part. I thought it was wanted man. So I had to look it up. Where were you in the 70’s? Like you didn’t shake it on the catwalk while you were rollerskating up a sweat in bell bottoms. We all did…didn’t we?..anyone?
‘click’; inserts casette tape into stereo.
“Foot loose, foot loose, kick off your Sunday shoes!! …”
(cricket sounds) chirrrp chirrrp chirrrp…
[size=200]SAVE ME!!![/size]
A long long time ago… 
…??? oh yeah…
I can still remember
LOLOLOLOL
[size=150]LMAO[/size]
awesome!!!1 LOL LMAO !!! OMG
Looks like Fat Albert on a diet.
How is your project going?
Going good. The medium sized version ended up about 4 feet long. I have my local plastic guy CNC cutting the large templates for the track modules. The axles, bearing blocks, idlers and suspension are ready and I’m still building up the Chassis from the CAD plans. Once I can get the dxf files to my plastic guy for cutting, he can make a few chassis.
I’m also redesigning the turret rotation cam to make it thinner and integrate the large spur pulley into it.
I’m so backed up on bracket orders right now, I’m not getting much time for other projects or posting. Sorry about that. I’m having problems with the reliability of my bearing supplier and my resin supplier. I’m getting some help with the brackets so I’ll be caught up soon. Plus work is getting really busy so that is taking up alot of time as well. I’ve had to turn down some requests for other products.
I’ll get some pictures up as soon as I get the chassis finished and the track modules attached to it. I’m shooting for about 200 pounds finished weight with turret and a payload ability of 100 pounds continuous, and 600 pounds for short distances. And a top speed of 40 to 60 km/h depending on payload.
man that going to look nice … cant wait to see more.
Sorry guys. My previous post was referring to the new medium and small sized track platforms. I got the threads mixed up. I’m losing my mind. 
MARV is still under construction although almost mechanically complete, has alot of electrical work to go. He is currently limited by a shortage of funding and I’m having trouble putting any more money than I already have into it. We have done many test runs with her but there are alot details to fine tune. Once we find some funding, she will be back on track.
