SirNadroj Posted February 5, 2009 Posted February 5, 2009 I'm looking for a set of pneumatic parts; most specifically, an airtank. The other parts are a little cheaper on bricklink. However, a full set of whatever I need would be nice. Willing to buy or trade. (I plan on using them with this: http://flickr.com/photos/sirnadroj/3254219740/ ) Thanks!
Siegfried Posted February 5, 2009 Posted February 5, 2009 You can't have any of mine as I want more too, but as a tip, don't buy one of these; Only the old one-way-cylinder system used those. If you have any questions feel free to bother me!
CP5670 Posted February 5, 2009 Posted February 5, 2009 You can't have any of mine as I want more too Same situation here. The airtanks are super expensive on Bricklink these days. If you need an entire set of pneumatic parts including the tank, the Lego Education pneumatics set at $55 is probably your best bet. As Sinner said, the distribution block and the one sided pistons are part of the old pre-1989 system, which is generally inferior to the new one.
SirNadroj Posted February 5, 2009 Author Posted February 5, 2009 Thanks, Sinner. Now, what's the bear minimum I need. I assume: Air Tank Piston T-pins/Tubing Switch The type of part you pictured (or is that an early switch?) Pump Is that correct?
CP5670 Posted February 5, 2009 Posted February 5, 2009 All you really need is a pump, switch, piston and some tubing. The T joints are needed to link up multiple pistons or switches, but they're common in non-Technic themes these days and are easy to come by. The airtank can make movements smoother but is optional, and the thing Sinner posted is something you don't want. The only reason to use the old pneumatic system is its suction ability. If this is for your big humanoid robot though, you are probably better off avoiding pneumatics altogether and instead using LAs with normal motors. Integrating pneumatics into the NXT system is complicated and hard to get precise movements with, although it's possible.
SirNadroj Posted February 5, 2009 Author Posted February 5, 2009 All you really need is a pump, switch, piston and some tubing. The T joints are needed to link up multiple pistons or switches, but they're common in non-Technic themes these days and are easy to come by. The airtank can make movements smoother but is optional, and the thing Sinner posted is something you don't want. The only reason to use the old pneumatic system is its suction ability.If this is for your big humanoid robot though, you are probably better off avoiding pneumatics altogether and instead using LAs with normal motors. Integrating pneumatics into the NXT system is complicated and hard to get precise movements with, although it's possible. Well, the movement created with pneumatics will not be hooked up to the NXT brick; it'll be completely seperate, and manually operated. Unless hook the switch to a motor, but even that motor will be seperate (not the NXT servo motor.... or maybe it could be.... hm....)
Siegfried Posted February 5, 2009 Posted February 5, 2009 Minimum parts you need (They are all links); (Enough length to go from the pump to the switch, and for two lines from the switch to the piston.)
SirNadroj Posted February 5, 2009 Author Posted February 5, 2009 Many thanks! Now, what's the signifigance of the air tank?
Siegfried Posted February 5, 2009 Posted February 5, 2009 Now, what's the signifigance of the air tank? It serves as an air reserve. You put it in series with the pump and air is stored in it. It stores around 15 pumps. The you can move the piston without pumping for a while. (Disclaimer: I haven't got one; it was cheaper for me to make a compressor! )
SirNadroj Posted February 5, 2009 Author Posted February 5, 2009 Ah, so a compressor can take the place of an air tank? That sounds like a plan...
Siegfried Posted February 5, 2009 Posted February 5, 2009 Ah, so a compressor can take the place of an air tank? That sounds like a plan... My word it can! Have you seen this?
CP5670 Posted February 5, 2009 Posted February 5, 2009 (edited) Well, the movement created with pneumatics will not be hooked up to the NXT brick; it'll be completely seperate, and manually operated. Unless hook the switch to a motor, but even that motor will be seperate (not the NXT servo motor.... or maybe it could be.... hm....) In that case it may in fact work nicely. The pneumatic pistons give you powerful and reasonably fast motion, although they can be slightly jerky and are not that precise. My word it can! Have you seen this? That is a great setup, and it actually uses that obscure Control Lab interface to run the whole thing. I'm tempted to get one myself now, even though I know of its limitations. The airtank and a compressor are separate things though. With the airtank in place, you first build up air pressure in the tank (either by hand-pumping or running a compressor) and then set a switch to release air into a piston. You can continue flipping the switches several times before the tank's pressure runs low. Without an airtank, you do it the other way around instead, first setting the switch to your desired position and then pumping to create the pressure. This is the best way to do it regardless of whether you're using a hand pump or a compressor. To be honest, I'm not convinced that the airtank is actually a good thing, at least not in every situation. There are both pros and cons to having it in a pneumatic setup. Edited February 5, 2009 by CP5670
Legoman Posted February 5, 2009 Posted February 5, 2009 My word it can! Have you seen this? Woah that's insane! Shesh.... thats beastly I managed to pick up the pneumatic technic Submarine for $15 NZD at a garage sale - but it aint going nowhere
SirNadroj Posted February 5, 2009 Author Posted February 5, 2009 Pnow, if I need two cylinders (one per arm), I should buy two cylinders, tubing and T-sections, switch and two pumps? Is that correct? (I'm so chock full of questions because this won't be dirt cheap). Or this is a great buy for me? http://www.legoeducation.com/store/detail....amp;t=0&l=0 That's what I'm leaning toward at this point...
Captain Green Hair Posted February 5, 2009 Posted February 5, 2009 Pnow, if I need two cylinders (one per arm), I should buy two cylinders, tubing and T-sections, switch and two pumps? Is that correct? (I'm so chock full of questions because this won't be dirt cheap). Or this is a great buy for me? http://www.legoeducation.com/store/detail....amp;t=0&l=0 That's what I'm leaning toward at this point... Seeing the size of your robot, the arms are going to be quite heavy. 2 large cilinders might do the trick better, this set only contains 2 if i'm correct. An airtank can also easily be made out of a water bottle or something like that. I'd say buy a bunch of cilinders, a pump, hose and T parts from BL, it'll be cheaper i think.
CP5670 Posted February 5, 2009 Posted February 5, 2009 (edited) Well, the pneumatic parts are individually quite expensive on BL, especially the small pump and piston. As you said though, the airtank isn't really necessary and it's possible to make a homemade version of it. You only need one pump for the whole system. Multiple pumps will speed up the pumping rate (especially if they're part of a double-acting compressor), but don't add any functionality beyond that. I was thinking of getting that Lego Education set myself since I really want the manometer, but I have plenty of the other parts and don't want to buy the whole thing just for that. The BL prices for it are too high though. If you end up buying the set and find that you don't need the manometer, I could buy that piece from you and help defray the cost of the set, if you're interested in selling it. And I like your P's everywhere. Edited February 5, 2009 by CP5670
SirNadroj Posted February 5, 2009 Author Posted February 5, 2009 Well, the pneumatic parts are individually quite expensive on BL, especially the small pump and piston. As you said though, the airtank isn't really necessary and it's possible to make a homemade version of it.You only need one pump for the whole system. Multiple pumps will speed up the pumping rate (especially if they're part of a double-acting compressor), but don't add any functionality beyond that. I was thinking of getting that Lego Education set myself since I really want the manometer, but I have plenty of the other parts and don't want to buy the whole thing just for that. The BL prices for it are too high though. If you end up buying the set and find that you don't need the manometer, I could buy that piece from you and help defray the cost of the set, if you're interested in selling it. And I like your P's everywhere. I probably wouldn't pneed the manometer, so if I do end up buying the set, I'll let you know. Maybe we can work something out.
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