Pneumatic

Quote:Mario is going to make me a Cylinder that has a 70mm bore and 100mm stroke. I will also use AL paintball tanks it keep the weight down. I think that I should be able to keep the whole system at about 10 pounds. I hope to get another robot to fly about 10 in the air with this large cylinder



Marauder has a 70mm bore 50mm stroke Maddox ram in it and I can vouch for a fact that it can launch 30lb (13.6kg) robots 5-6ft into the air! I had my own robot launch into the polycarb at my own face height (Im 6ft tall) and this was not a pleasant thing to have happen. Watching Marauder selfright from one side of the 4m arena to the other side was pretty spectacular too :proud:

Mario builds some top quality pneumatics, so you wont be dissapointed!

Do I need to do any calculations for a high pressure system, or is it trial and error?

Depends Kevin. It all depends on what you want.

I dont bother about calculations. I let experience talk.

Kevin, you could tell Mario how high you want your bot to throw the opposition and ask him how much he would charge to build the pneumatic system.

Designing your robot around the weapon is a good idea.

I still think that a front hinged flipper would be effective on a featherweight. I think flipping a robot in the air plus OOTA is just showing off.

So am I to understand that alot of the big flippers in the UK have no actual hard connection between the arms and the cylinder? Makes sence I guess. It would keep the ram from bending and if the arm did get bent, it would still work.

I made a simple paintbrush picture of what my arm will look like (on profile now). I have the center of the ram 8 Away from the center of the pivot. From the tip of the arm to the middle of the pivot is 25. The ram is parallel to the arm.

Dose this sound like a good placement? Comments and advice are very welcome.

Also kinda for woody here. A firend of mine is thinking about making a clone of this at LP, I have sent him the e-mails that I saved.

With so much power to spare, id place the ram further back.

Woops, Mis Calc.. The tip to end legnth is 16 and I will place the ram 5 back.

That placement sound ok to yall? I will have a pic of my rough CAD later.

~Chad

Mario has started to make my cylinder, with some luck he will be able to ship it Friday. So then it will get to me in like a month! :-p We took the size down to 70x80.

In other news I have changed my mind on the type of system that I will use. I will go with something alot more simple for my first time. I am going to use a system just like Cutlet from the lambsey team. Something simple like that will make for an easy build. I think I should get a 10 flip with that. 16 arm, with the cylinder 3.5 back.

So a question. What tanks do you guys usually use? I would assume a paintball tank, but are some brands lighter than others?

~Chad

Small fire extinguishers or paintball bottles are favourite over here in the UK.

I dont think theres a favoured lighter weight bottle.

nearly everybody uses 600g bottles. weigh about a kilo empty.

I found this page.

http://www.whitewolfairsmithing.com/cci%20parts.htmhttp://www.whitewolfairsmithing.com/cci%20parts.htm

This looks to be just what I need! The 22oz tank is ALOT lighter than the 20oz regular paintball tank. I will just need to get an On/off Valve for it.

~Chad

Ummm ....... What 22 oz tank?
I can see a 22 cubic inch tank ....... I think thats about 9 oz of Co2.
A 600g or 20oz tank is 50 cubic inches.... so the tank youve found is approx 1/2 the volume and therefore 1/2 the weight.

Woody

Link for weights and specs on various sizes.......their 20 oz cylinder is 1.5 lbs

http://www.catalinacylinders.com/http://www.catalinacylinders.com/

http://www.all4paintball.com/detail.asp?pid=84019

(Message edited by woody on October 11, 2005)

Cylinder on its way. Tanks are here, Valve is here.. All I really need to do is order my fittings and hose. What do you all usually use? And what size is the top of a paintball tank? I need to get a T for it and I am not sure what size. I am going to use a mix between .5 hose and 1/4 hose.. Comments, tips, suggestions, links.. all would be good! Thanks!

5/8-18UNF-2B Is a tank top size... Nevermind :) But still cant find good hose that will take the 3000PSI of a FP system. Anybody have some extra that they would box up and send to the US? No, not for free!

~Chad

3000 p.s.i. !!!

750 psi is around the normal pressure for co2.

Heres a source for your 1/4 tube and fittings .

http://www.newageindustries.com/nylon12.asphttp://www.newageindustries.com/nylon12.asp

OR

http://www.airsoldier.com/fittings/index.shtmlhttp://www.airsoldier.com/fittings/index.shtml

Id suggest that you try and pipe up the cylinder valve and tank in solid.

Heres a link to Paul Coppers site.. ( Technobots ).

The pics should give the general idea.

http://www.technobots.co.uk/M2XT/M2XT-Home/M2XT_Build/Custom_Ram/custom_ram.htmlhttp://www.technobots.co.uk/M2XT/M2XT-

Home/M2XT_Build/Custom_Ram/custom_ram.html



(Message edited by woody on October 17, 2005)

Anybody know where I can find a 1/2BSP (or whatever your standard thing is) to a 1/2 NPT fitting? Marios cylinder has that, which I cant seem to find. . .

Tap the ram 1/2 NPT .........our 1/2 BSP .825 - 14 tpi and is close to your 1/2 NPT.. .838 - 14 tpi

Adaptors here....http://mdmetric.com/prod/R631/MetricConversion-steel-pg1.htmhttp://mdmetric.com/prod/R631/Metric...-steel-pg1.htm

Just going to run a 1/4 npt tap through it when it comes... From Belgum, um... should take like a month :-p

Run a 1/2 tap through it Chad, 1/4 if for the weak :proud: With a 1/2, you should theoretically get 4 x the flow rate over a 1/4. More Flo is good :proud:

Marauder has a 70mm bore ram with a 25mm Burket valve on it running with full pressure CO2 and it rockets bots around...
http://www.robowars.org/forum/album_pic.php?pic_id=478http://www.robowars.org/forum/album_pic.php?pic_id=478
http://www.robowars.org/forum/album_pic.php?pic_id=909http://www.robowars.org/forum/album_pic.php?pic_id=909
Marauders ram/valve

woops, that should have been 1/2.... I am actually thinking of making my bot look something like Marauder. I will have the 4 angled sides and then weld up some Ti tube into the fork assembly. Should look something like complete controls front end. I am thinking 6.5 Tall x 15 x 12 All ish. Armor is probably going to be a kevlar shell with some Ti attached to the bottom. As soon as I get the cylinder I will make the CAD. The gears are starting to turn. I need to have it done by Feb next year! :-p

~Chad

Been a while since I have made a post! But I got my Mario cylinder yesterday in the mail and it is now time to start building I guess. Their is a pic of the valve and cylinder on my profile. I need to order the fittings that I will need and another on/off valve to meet the RFL rules. Anybody know a good on/off that is rated for more than 600PSI? All the ones that I have found on McMaster are only good for 600. I orderd 2 of the new banebot gearmotors for the drive.. ( http://banebots.com/osc/product_info.php?cPath=36_63&products_id=224http://banebots.com/osc/product_info...roducts_id=224 ) I also have a 3 cell 11.1v 2600 Li-p batt that will make this beast move. The shape will be kinda like the auzi bot I think. I am also going to get a little RC gizmo made that will open the vlave for a set time, in order to save Co2. I will just hit the button on my radio and the valve will open for .5 Seconds (or whatever time I want) then close again. It will also boots the voltage to the vavle @ 30v. What do you all think is a good time for the valve to be open? .5 seconds, .3, 1.0, .43957693? With any luck I should be able to fire the cylinder in a week or so. Any tips or comments are welcome. Thanks!!!

You could try a paintball valve for an on/off valve (assuming you dont want high flow). There are ball valves available that are rated to 1000 psi. I have a 3/4 inch one that weighs about 300 g.

I replaced the 24 v coil for a 12 v coil on mine so that I could fire it from 18 v.

Well, I got all my brass fittings but the tanks will not screw into the 1/2 NPT fitting. I thought that the tanks were 1/2 NPT. Anyobdy know what the thread size is on the outter and innter of most paintball tanks?

CGA 320
Cylinder valve outlet thread: .825 - 14 TPI

1/2 NPT .840 - 14 TPI
1/2 BSP .825 - 14 TPI

Also known as an ASA Thread


(Message edited by woody on November 24, 2005)

5/8-18UNF-2B http://www.catalinacylinders.com/http://www.catalinacylinders.com/

Ok, Well I am ready to test everything... But I need some info on this burket. Is this a NO or NC valve? I hooked everything up and it seems to be a NO valve... I thought it was NC. Anybody care to tell me what it really is? Thanks!

---Ok, well I found a .PDF with all of the info on this valve. It is indeed a NC valve, But when I open my Co2 tank it passes right through it and right into the cylinder! From what I understand the valve is closed, them when you apply power to it, it will open and fire the ram. Why is the valve just letting all the air pass? Anybody have this problem? I have a switch made by a friend that sends 30v to the valve for .5 seconds when I flip a switch on my radio. Do I need to wire the valve differently? I am kind of lost here. Any help would be great. Here is a pic of the switch and valve.

Or do I have to wire it so that it has the power to it all the time then when I want the cylinder to fire I turn it off? . ? . ? And if I do that will the valve still be able to take the constant 30v? Ok, enough for now.

http://www.teamwazio.com/alive.jpgwww.teamwazio.com/alive.jpg

~Chad

(Message edited by wazio on January 12, 2006)

Well, I figured out what was the matter. The direction was wrong. I had the CO2 in the ram end and the ram in the CO2 end. So, I switched that and it worked like a champ! With all the pneu stuff, the batt for the robot and the drive motors the weight is about 11pounds. That will give me 19ish pounds for my frame and armor! Its lookin good! :)

The arrow on the side of the valve .......showing direction of flow ....is normally a dead give away :).

(Message edited by woody on January 13, 2006)

Do you have any progress pictures, Chad.

The new picture on my profile is what I have been testing with. As soon as I get another on/off valve I will hook up the buffer tank. How big is your bot Mr. Taylor?

Marauder is 560 mm * 480 mm and 140 mm tall. The four sides slope up at 45 degrees. I need to make my bot smaller. It is far too large. Marauder is also too big.

Have you drawn any possible layouts, Chad? Will you need to take any special precautions with your polyquest battery?

I would like to keep my bot no bigger 18x18. I think I should be able to keep it less than that actually, I hope. My bot is probably going to look alot like yours with the pyarmyd shape.

I think I will have a 1/4 base plate and have a shell of armor.. Some sort or titanium and UHMW mix I think. I should have about 10 pounds for armor.

The batt I am going to put into a box of foam. From testing here in the US, we have found out that they will break if they have alot of shock, so I will do all that I can to protect it...

I will start the CAD of the bot tonight now that I know that the system works.

I set a roll of duck tape on top of the ram and it went about 10 in the air. from what you all tell me this thing should send a 30lb bot about 6 in the air. So when I see a roll of duck tape only go 10 I wonder how high a 30lb bot will go. So went I add the arm will that change this? I am kinda worried about how well it will work now.. I am still going to put the ram 3 away from the pivot point.

But the last big thing that I am going to need help with is the arm shape... Anybody have some pictures of a good arm shape? Will it matter if I have a long wedge looking one, or will I need a short one that shoots straight up? Tips would be great!!! Thanks guys.

You suffer from a lack of flow.
The valve and ram entrance are big enough, but the let trough of a pinvalve is feeble compared to the valve.

For arm form, we found the Gravity style shallow wedge most satisfactionary

Well, then it sounds like a bigger valve, or at least one that has more flow. . . How can I improve my flow? And where can I find some up to date pics of Gravity?

ere ya go

http://www.bugs.nl/media/album/view.php?&path=L3J3L3J3Ny9ubC1tYXJpZW4vcGljMTAuanB nhttp://www.bugs.nl/media/album/view....ZW4vcGljMTAuan Bn

Theres been a few incarnations since then but they havent been half as good at launching bots. Remember that its a very long arm and the ram is placed very far back, giving lots of speed at the end of the arm. You need a BIG ram to do this with lots of flowrate, hopefully yours should scale down from a gravity design ok.