Pneumatics General Discussion

[MangaNOID]

I had this setup a little while ago to bleed pressure from multiple pumps.

 

 

 

[mocbuild101]

1 hour ago, aminnich said:

Probably a terrible idea, but has anyone ever ran water through their pneumatics? I would think water does my compress as easily as air, so the cylinders could withstand more pressure. 

I don't know, what do you think? 

Once again..

1 hour ago, Leonardo da Bricki said:

Sariel's handy-dandy Unofficial Lego Technic Builder's Guide 2nd Edition will give you all you need to know.

Not that I'd ever try it...

Edit: It's on page 129, and I only know that because I had it open right in front of me... ON THAT PAGE!!!

Edited September 26, 2017 by mocbuild101

[degenerate]

Thanks for the advice guys, I will try and build some sort of pressure relief system then, just adds to the fun of building

[aminnich]

So I have some pneumatic cylinders now and I have never really messed around with them, so I decided to see what I could do with them today.  

I thought about using them to extend the gear ack outrigger parts, but it is 2 studs shy of full extension, I wonder why they did not make the cylinder 13L instead of 11L

 

[Saberwing40k]

I have just what you need.

42043 Crane MOD by Barman76, on Flickr

 

Barman came up with this linkage idea, so all credit goes to him.

[aminnich]

Now there is an idea!  Thanks, I'll try that out 

[Aris]

On 7/10/2015 at 11:05 AM, Nazgarot said:

You can spring load the cylinder to make it more in balance with the weight. This way, if done correctly, the cylinder needs to apply a small force to move the arm either way. You can use the standard lego shock absorber springs of different hardness, and test with the whole shock absorber assembly to find the right spring strength.

I did this to make a pressure switch a few day ago: Link.

-ED-

Totally agree with that.

On 7/10/2015 at 11:08 AM, allanp said:

letting the air out slowly via the valve is the best way. You can do that by hand or by making an adjustable limit stop which mechanically limits how far the valves lever can move in the down direction.

You can control the valves using servo motors and have a compressor that turns on whenever the pressure drops below a certain threshold.

Great idea. But what if you want to return fast to the up direction, by using a slow air switch-actuator limit mechanism. I guess that this one works for the down direction like you correctly said. Expect for using mindstorm servo motors with suitable gearing, you may control up direction too.

Edited May 10, 2020 by Aris

[Aris]

On 7/11/2015 at 11:39 AM, skaah said:

The 8851 used some rubber bands to make lowering the digging arm more, euhm, say graceful.

Great idea. What about raising the arm with the rubbers? Was the movement smooth?

On 8/11/2015 at 10:16 AM, gmshades said:

Anyone else confused on calling the new pneumatics "v2"? Should be "v4" in my opinion. First we had the square bottom 1 port cylinders. Then the square bottom 2 port. Then the 2 stud wide round bottom 2 port. Now we have 1 stud wide round bottom 2 port.

Indeed. I guess that V2 refers to the their almost double length mostly, rathen than cylinder's bottom.

[Maaboo the Witch]

Wonder if we'll ever see motorized pneumatics again with CONTROL+ taking over from PF?

[Aris]

On 7/31/2015 at 5:06 PM, slopemodified said:

I'm having trouble with some of my pneumatic parts. I got them from an old set, 8862 Backhoe, and I'm trying to use them in a garage MOC as a car lift, and I've positioned the cylinders upright. Pumping down works just fine, but going up doesn't always work - sometimes it works, sometimes it doesn't. I have to pull them up and push them down by hand, and then it will work for a while.

Some backstory: When I first brought out the set after many years in storage, I found it was hard to disconnect the rubber tubes from some of the nozzles as they had somehow become stuck. I thought the plastic had degraded from being wrapped in a rubber tube for so long. When I was using them yesterday, I cleaned out some plastic stuck inside the tube, and I thought I had removed a blockage.

I will be trying to see if one of the tubes has a leak or change out the switch to test. Can anyone advise me on how to troubleshoot this issue?

Has the same problem with 4-5 large cylinders with square bottom. I guess that it's due to the face that they have been used quite a lot in the past.

[allanp]

Just now, Maaboo35 said:

Wonder if we'll ever see motorized pneumatics again with CONTROL+ taking over from PF?

Man I hope so!!!

[Maaboo the Witch]

8 minutes ago, allanp said:

Man I hope so!!!

I'm not so sure we will. All of the C+ motors run off the app, so that means switchable battery boxes are out.

[allanp]

Just now, Maaboo35 said:

I'm not so sure we will. All of the C+ motors run off the app, so that means switchable battery boxes are out.

But there is a "dumb" hub coming ain't there? 

[Maaboo the Witch]

16 minutes ago, allanp said:

But there is a "dumb" hub coming ain't there? 

We don't know for sure.

[Aris]

On 12/1/2015 at 1:43 AM, Saberwing40k said:

I do, as a matter of fact.

Pneumatic cylinder bracket by Saberwing007, on Flickr

step2 by Saberwing007, on Flickr

the track link can be replaced with a 3L thin liftarm if so desired, but I prefer the track link as it is thinner than a liftarm, so allowing a better connection. However, there is a caveat. when incorporating this assembly into a structure, one should orient the two cylinder so that the force applied is more likely to push the cylinders into the bracket, as the inlets could snap if enough pressure were applied to them.

Great extension! Seems stable enough, didn't try it yet.

On 9/26/2017 at 1:14 AM, degenerate said:

Hey,

Last time I played with pneumatics was some 18 years ago with the 8462 tow truck, don't have any experience with the V2 parts. 
I remember hoses flying off their connections due to high pressure, is this fixed with the V2 ones?
I plan on building an excavator where I'll have 3 small pumps run by a PF motor, is there some part that dumps air when the pressure reaches a certain level or does the pumps have a similar feature built in nowadays?

Cheers

I am sure that is not the problem of the cylinder . As far as I remember, in 90's, the pneumatic hoses where much soft and thin than e.g. in 2015 and couldn't withstand the high pressure of more than 2-3 bars. Could be easily mounted to the cylinders contrary to the new hoses which demand more power to be fully mounted so as not to pop out.

[Aris]

1 hour ago, Maaboo35 said:

Wonder if we'll ever see motorized pneumatics again with CONTROL+ taking over from PF?

Yes of course. I am sure that huge lego technic sets will be motorized, so definitely should be more complicated sometimes and have pneumatics.

At least there should be an electric compressor in some sets. I suppose that we may see a set with motorized valve in the future, if I compare current set prices with old ones. 

PF unfortunately belong to the past now.

[Aris]

On 7/10/2015 at 9:29 AM, sm1995 said:

I'll start off, is there anyway to make the retraction of a pneumatically actuated arm/ crane more controllable? In my experience, the weight of the crane arm( or whatever) always makes it drop down too fast when the valve is opened. You could make it controllable by adding another cylinder on the opposite side of the hinge, but is there any other way to overcome this problem?

Yep there is one. Add counterweight! 

[9v system]

good to see this thread is still alive, i havent visited this for years and i should really update the main post,

on a side note i brought a V2 6L pneumatic pump and noticed that they can be prone to cracking, mine has not done this yet, but if it does can i still get a replacement? or is pneumatics discontinued now?

[Maaboo the Witch]

31 minutes ago, 9v system said:

or is pneumatics discontinued now?

Thanks for that little bit of nightmare fuel. 

[CrankyCraig]

12 hours ago, 9v system said:

good to see this thread is still alive, i havent visited this for years and i should really update the main post,

on a side note i brought a V2 6L pneumatic pump and noticed that they can be prone to cracking, mine has not done this yet, but if it does can i still get a replacement? or is pneumatics discontinued now?

I had half a dozen or so replaced by Lego less than 6 months ago, almost all of which had cracked and been super-glued over the years. The sets were bought several years ago, so I wouldn't have thought it entirely unreasonable on their part if they'd refused to replace them, but their customer service was impeccable. I'm betting you should still be able to get a replacement.

I'd have a hard time believing this to be the last we see of powered pneumatics. That would be a sad day.

Was the Arocs the success (sales-wise) that it deserved to be? The brilliance of that set still astounds me.

[Mestari]

I hope it was, we need more of that kind.

I am also waiting for another source of manual pump, we only got one so far.

[allanp]

I'd be very surprised (and disappointed obviously) if there were no more pneumatic sets, even as soon as next year. They are clearly well liked by fans and they have invested quite a lot in new cylinders, valves and so on. And with all the pneumatic tubing in 42100, I was surprised by there being no pneumatic sets this year.

[CrankyCraig]

6 hours ago, allanp said:

I'd be very surprised (and disappointed obviously) if there were no more pneumatic sets, even as soon as next year. They are clearly well liked by fans and they have invested quite a lot in new cylinders, valves and so on. And with all the pneumatic tubing in 42100, I was surprised by there being no pneumatic sets this year.

Oh man, when I saw the first pictures of 42100 

...then when I realised the tubing was just for show 

Pneumatics are by far my favourite, but most other Technic fans seem to favour RC. I'm not a hugely into control plus, but if it continues to sell Lego I'm all for it - there'll always be something of interest amongst it.

It's a little surprising we aren't getting a pneumatic flagship this year, but no pneumatic sets whatsoever?! C'mon! Still, it's an opportunity to save until they release another - I bought 3 Arocs last time around.

[howitzer]

People have been fearing that pneumatics might become discontinued for at least 30 years, as there has always been gaps of few years in pneumatics releases but every time the fears have been unfounded. It's only two years since the last new pneumatics parts were released and those were made for a set which isn't very complex or interesting in it's pneumatics functions. I'd be really surprised if TLG just abandoned those moulds and decided that there's no more profit in pneumatics. I'm guessing that in a year or two we'll be seeing a flagship set which combines pneumatics and Control+ into a model with many RC functions, considering especially the new valve, which seems to be designed for motorized operation.

BTW, I wonder if anyone has remodeled 42100 to work with pneumatics in place of linear actuators?

[pleegwat]

8868B is possibly my favourite of the sets I own.