www.robowars.org

RoboWars Australia Forum Index -> Technical Chat

Pneumatic / CO2 megathread
Goto page Previous  1, 2, 3, 4, 5

Post new topic   Reply to topic
  Author    Thread
Valen
Experienced Roboteer


Joined: 07 Jul 2004
Posts: 4436
Location: Sydney


 Reply with quote  

hmm, if you had a modest buffer it could help you by allowing the compressor to run and store up some air so it'll pop that first 3 inches. I'm not awake enough to work out if there is some magic combination of check valves or something you could use to bypass the buffer when that side of the system is at the same pressure as the lifter side.
_________________
Mechanical engineers build weapons, civil engineers build targets

Post Thu Jul 09, 2015 7:14 am 
 View user's profile Send private message Visit poster's website AIM Address Yahoo Messenger MSN Messenger ICQ Number
Knightrous
Site Admin


Joined: 15 Jun 2004
Posts: 8511
Location: NSW


 Reply with quote  

quote:
Originally posted by Glen:
Maybe Aaron can dig up vids of mite or mite-e-er but from hazy memory it did work, the lift started off about the same as a linear actuated lifter then had quite a pop to it.


I'm struggling to find anything, best I can find is an old photo of the robot, which funnily comes from an old photobucket account of yours Razz



All the previous videos and images were on the ABBL.org server when it when down.
_________________
https://www.halfdonethings.com/

Post Thu Jul 09, 2015 9:50 am 
 View user's profile Send private message
marto
Experienced Roboteer


Joined: 08 Jul 2004
Posts: 5459
Location: Brisbane, QLD


 Reply with quote  

Dig out the Metal Mayhem DVDs
_________________
Steven Martin
Twisted Constructions
http://www.botbitz.com

Post Thu Jul 09, 2015 10:15 am 
 View user's profile Send private message Send e-mail MSN Messenger
Knightrous
Site Admin


Joined: 15 Jun 2004
Posts: 8511
Location: NSW


 Reply with quote  

quote:
Originally posted by marto:
Dig out the Metal Mayhem DVDs


Just tracked Marshall down on Facebook, will see if he still has the robot around Smile
_________________
https://www.halfdonethings.com/

Post Thu Jul 09, 2015 11:10 am 
 View user's profile Send private message
marto
Experienced Roboteer


Joined: 08 Jul 2004
Posts: 5459
Location: Brisbane, QLD


 Reply with quote  

Sportsman at Ipswich? Would probably qualify.
_________________
Steven Martin
Twisted Constructions
http://www.botbitz.com

Post Thu Jul 09, 2015 11:18 am 
 View user's profile Send private message Send e-mail MSN Messenger
maddox



Joined: 21 Dec 2006
Posts: 786
Location: Belgium


 Reply with quote  

How to regulate CO2 without liquid issues?

It's a serious question, especialy for heavies.
In Project One it was bottle orientation that avoided the regulator swallowing liquid CO2.
Luckely for us, it was Dutch series one, what is comparable with the UK series 3. So we didn't get flipped.

After that, under guidance of the masters Mike Lambert, Alan Wood and Ian Watts I learned about FP, and made that technology my own.

But now I have a rebuild of a heavy that uses normal pneumatic pressures.
The thing to be avoided is a regulator that cannot take liquid CO2. Not even the Victor can do that.
With the headscratching problem, the main bottle is mounted horizontaly.

We can add an Up-tube in the bottle, but that means it will draw liquid whenever it's been flipped.

Lowering flow rate is a potential solution, but not ideal, not for an axe wielding machine.

Anybody bleeding edge idea's?

Post Mon Aug 10, 2015 1:27 pm 
 View user's profile Send private message Send e-mail Visit poster's website MSN Messenger
Nick
Experienced Roboteer


Joined: 16 Jun 2004
Posts: 11802
Location: Sydney, NSW


 Reply with quote  

vertical spinner! Razz
_________________
Australian 2015 Featherweight champion
UK 2016 Gladiator champion

Post Mon Aug 10, 2015 2:46 pm 
 View user's profile Send private message
maddox



Joined: 21 Dec 2006
Posts: 786
Location: Belgium


 Reply with quote  

Not a lot of work for a heavy spinner over here.

Also, it ain't my machine. I would have rebuild it as FP.
With the availablity/affordability of the Chinese Burkerts, using 4 of those as a replacement for a 5/3 valve it's not even that expensive anymore.

Post Mon Aug 10, 2015 3:03 pm 
 View user's profile Send private message Send e-mail Visit poster's website MSN Messenger
Glen
Experienced Roboteer


Joined: 16 Jun 2004
Posts: 9481
Location: Where you least expect


 Reply with quote  

If you didn't have the VAT / customs charges they'd be even cheaper, i got a few for $34 posted Very Happy

Not sure if it would be permissible under the rules, but what about a 3mm orifice nitrous valve connected to the main tank, and use that with a pressure transducer to pulse gas into the buffer at the correct pressure. The fill rate would be slow enough i think that'd be perfectly achievable.

With the low pressure pop off valve down stream it might pass safety?

The nos valves handle liquid and expanding it out into the buffer tank at a lower pressure should alleviate liquid problems. No expensive regulator needed then Smile
_________________
www.demon50s.com - Minimoto parts
http://www.youtube.com/user/HyzerGlen - Videoooozzz

Post Mon Aug 10, 2015 3:19 pm 
 View user's profile Send private message Send e-mail Visit poster's website MSN Messenger
maddox



Joined: 21 Dec 2006
Posts: 786
Location: Belgium


 Reply with quote  

I did hear a few roboteers in the past tought about that , but never seen a working example.

Will trow something together.

Post Mon Aug 10, 2015 3:37 pm 
 View user's profile Send private message Send e-mail Visit poster's website MSN Messenger
Glen
Experienced Roboteer


Joined: 16 Jun 2004
Posts: 9481
Location: Where you least expect


 Reply with quote  

Maybe they're using too big of a valve or too small of a buffer, in a heavyweight surely it would be fine, specially with a small valve Smile
_________________
www.demon50s.com - Minimoto parts
http://www.youtube.com/user/HyzerGlen - Videoooozzz

Post Mon Aug 10, 2015 4:33 pm 
 View user's profile Send private message Send e-mail Visit poster's website MSN Messenger
Valen
Experienced Roboteer


Joined: 07 Jul 2004
Posts: 4436
Location: Sydney


 Reply with quote  

If you want permanent gas pickup from the tank I think just put a mechanism in the tank. Like the opposite of a floppy hose with a weight on the end for a liquid pickup.
_________________
Mechanical engineers build weapons, civil engineers build targets

Post Tue Aug 11, 2015 8:07 am 
 View user's profile Send private message Visit poster's website AIM Address Yahoo Messenger MSN Messenger ICQ Number
maddox



Joined: 21 Dec 2006
Posts: 786
Location: Belgium


 Reply with quote  

I did think about such setups for years.
Problem is the 20mm hole useable in the neck of the main bottle.

I even tried to find a way to make a float that stays whole in the different pressures and temperatures.
Anything foamy will desintegrate very fast in liquid CO2. Light, small hollow floaters will crush in the pressure differences.

Solid HDPE sounded possible, but the difference in mass between that and liquid CO2 isn't what is needed.

Post Tue Aug 11, 2015 3:00 pm 
 View user's profile Send private message Send e-mail Visit poster's website MSN Messenger
Valen
Experienced Roboteer


Joined: 07 Jul 2004
Posts: 4436
Location: Sydney


 Reply with quote  

perhaps make something like a ball bearing check valve, but instead of a spring to reseat the ball, use gravity.

It's not ideal to be sure. but its simple at least.

Perhaps something along these lines would work better
[img]http://imgur.com/Fu2OSzW[/img]
put a pair of bearings in a "cork" (green) in the neck of the bottle, and run a dip tube with a counterweight (red and blue) in there.
(obviously you set the bend in your tube/counterweight system such that it will actually fit into the bottle ;->)
Use hollow pipe for the tube, glue the cork into the neck and call it done.

It won't work in all orientations, but it should work so long as the bottle is laying down.

Dunno if its "robot combat tough" though.
_________________
Mechanical engineers build weapons, civil engineers build targets

Post Tue Aug 11, 2015 3:27 pm 
 View user's profile Send private message Visit poster's website AIM Address Yahoo Messenger MSN Messenger ICQ Number
  Display posts from previous:      

Forum Jump:
Jump to:  

Post new topic   Reply to topic
Page 5 of 5

Goto page Previous  1, 2, 3, 4, 5

Forum Rules:
You cannot post new topics in this forum
You cannot reply to topics in this forum
You cannot edit your posts in this forum
You cannot delete your posts in this forum
You cannot vote in polls in this forum

 

Last Thread | Next Thread  >
Powered by phpBB: © 2001 phpBB Group
millenniumFalcon Template By Vereor.