[TC10] Box Factory

[lcvisser]

When TC10 was announced, I just had to come up with something. I didn't collect all those pneumatics for nothing...! 

However, due to work, I had very little time until now, but that gave me plenty of time to think about what to build when I would have time. I already saw a lot of great entries, and it was hard to come up with something original. It should have a sequencer, because I never built one before, except for the B-model of 8868 Air Tech Claw Rig. After much contemplation, I came up with the following (apologies for the crappy photo: it's late and the light is far from optimal):

This is not a dinosaur. It is my prototype box factory. It will move boxes as shown in the front-right (2x2x2 studs) in a GBC-like perpetual motion. Or, that is the idea at least.

In the back is a 4-step sequencer. Each cylinder toggles two switches, so that I can separate "logic air" from "work air". The contraption on the right is my "robot". The arm moves up and down, the whole thing can slide forward and backwards on the stands, and the "head", which contains the box, can rotate 90 degrees. The long 1x11 cylinder hanging from the back of the sequencer is going to push a box in the "head", and the small one is going to push it out again.

So far, everything sort of works. The big challenge is to make sure that the robot completes his motions within one step of the sequencer. I plan to do this by putting a multi-pump compressor with one or two air tanks on the "work air" channel and a "weak", single pump compressor on the "logic air" channel. I hope that the beefy compressor will make the motions of the robot quick enough. The prototyping with two hand pumps seems to indicate it's feasible.

So, I need to build two compressors, a guiding channel for the boxes to bring them from the dumping point back to the beginning, and prettify the whole thing. Four weeks to go, right?

What do you think? Can it work? Any advice?

Edited October 2, 2016 by Ludo Visser

[GroundskeeperWillie]

Looks like a great idea. It's related to my Useless Box, except it has slightly more purpose ;-) It sure looks like it could work.

While pneumatically very similar to my model, yours has significantly more complexity (four state cylinders vs my two) so you might run into some of the issues I've struggled with. For example, seemingly out of the blue, it stopped working properly - like the timing was suddenly off on some of the transitions. Since you completely separate work/logic pressure your model may be less prone to these issues but still, it only takes a little more friction or air loss somewhere and suddenly your loosing your hair over what broke.

One question - when you separate the logic/work pressure, do you intend to have separate pressure controllers and/or air tanks for both? That's what put me off because I have very limited space.

[grum64]

2 hours ago, Ludo Visser said:

...This is not a dinosaur...

  

[lcvisser]

7 hours ago, GroundskeeperWillie said:

One question - when you separate the logic/work pressure, do you intend to have separate pressure controllers and/or air tanks for both? That's what put me off because I have very limited space.

Yes, I intend to have two completely separate circuits. Especially moving the arm up takes more pressure than the sequencer needs, so I'm anticipating that if I don't separate the two circuits the sequencer will toggle before the arm moves.

 

[lcvisser]

Ok, this turns out to be tricker than I anticipated.

I built a compressor with three of these 5.5L pumps. When I use two of them to run the machine and one to run the sequencer, the machine moves pretty quick, but the sequencer won't move unless I help it. The other way around though, using two pumps to run the sequencer and one to move the machine turns the table around: the machine hardly moves, and the sequencer goes through its stages really quickly.

I have two of these 6L pumps, so I could build another compressor, but in any case my problem remains: the sequencer goes to its next step way too fast.

Any ideas how to approach this? Am I aiming too high? 

(I'm trying to figure out how 8868 B-model solved this; it only had one compressor so obviously was mixing work and logic air. It also had only two steps, but using three cylinders. I need to study this more...)

[GroundskeeperWillie]

I have run into the same issues. The higher pressure on the sequencer, the faster it runs. So you'll just have to have enough work air to get the job done in time. If there are regulators in play, this complicates matters, because this will cause pressure to vary over time.

Eventually I settled on using 2x11 cylinders for the sequencer because I found that runs most consistently and also not too fast. Another option is to use multiple cylinders, maybe only for the steps that need most time. An example of this from Mark Bellis who seems to be the go-to-guy for sequencers:

[Brickthus]

On 09/10/2016 at 7:10 PM, GroundskeeperWillie said:

I have run into the same issues. The higher pressure on the sequencer, the faster it runs. So you'll just have to have enough work air to get the job done in time. If there are regulators in play, this complicates matters, because this will cause pressure to vary over time.

Eventually I settled on using 2x11 cylinders for the sequencer because I found that runs most consistently and also not too fast. Another option is to use multiple cylinders, maybe only for the steps that need most time. An example of this from Mark Bellis who seems to be the go-to-guy for sequencers:

Happy to help 

I would usually use 25psi for pneumatic models.  I had a car tyre air compressor that would produce a continuous 25psi, till I broke it .  The practical limit for LEGO pneumatic air supply by hand is 6 hand pumps at 1 pump per second, which I used in my Pick and Place robot.  2 pumps per second can be done for a short time!

The experiment above was to show a) the power of the 1/11 cylinder and b) the amount of air needed by the 2/11 cylinders with the consequent pressure built up in the system.  Things were easier when we had just 2/6 cylinders and switch valves were not quite so stiff.  Practical models would make use of the twin 2/11 cylinders to move a heavy function and the 1/11 (or 1/5) cylinder for logic only, to move a switch but nothing else.

Mark

[lcvisser]

There's the expert! 

I'm actually using the old switches, because they are indeed easier to move. Also using the old cylinders. Maybe I should check all for leaks, as some of them are quite old (my first pneumatic was from http://brickset.com/sets/8042-1/Multi-Model-Pneumatic-Set).

What's your opinion on mixing "logic air" and "work air"?

By the way, I was first considering to include one of your AND or OR gates, but figured that would be a bit too much for me at this moment... 

[lcvisser]

Holy smokes it actually works:

Obviously, I have some hoses to clean up and general improvement of some parts of the structure, but heck, it actually works.

As you can see, I changed a lot with respect to the initial "dinosaur" prototype: it turned out that it was way too complicated to move 2 cylinders in one step, in time. So I came up with this "trebuchet"-like contraption, which works quite reliable. Like any other good contraption, the boxes occasionally get stuck, but it's quite reliable in general.

One cylinder of the sequencer is really slow (I guess it's one of the oldest in my collection). I might change it, but since it is the one after the raising of the arm, it is a bit convenient as it give the arm time to come up to the top. My little old compressor pumps struggle to make it all go, so hence the delay in pushing the box out.

What do you guys think?

Edited October 28, 2016 by Ludo Visser

[wissamms]

Very nice!

[Appie]

Very cool that you got it working!

[GroundskeeperWillie]

It looks cool Can't wait to see the final video.

[Didumos69]

Very nice! You made yourrself a factory that makes boxes out of boxes, haha. A so-called identity-factory .

[lcvisser]

Damnit.

I spent some time tidying up the hoses, reinforcing the structure, etc., and guess what: nothing works anymore. Not even the sequencer, which I didn't touch. Part of the problem seems to be the compressor, which is too weak, despite using three pumps. I guess that they're either too old and/or they have too much air to pump around, but I'm puzzled why the compressor worked fine yesterday and won't move anything today. With two hand-pumps it sometimes works, so maybe that can be my backup plan. But with just one day left to get everything else to work again, I doubt I can manage.

[MajklSpajkl]

Congratulations, you made a first in the wolrd LEGO GCC - great cube contraption :-) Who knows, maybe it will be a new hype ;-)

[lcvisser]

I managed... In the end I used the hand pump, since I couldn't get the compressor to work anymore. Hence the somewhat short video, since it's really exhausting to pump fast enough to keep the pressure high enough. But it works, and I'm happy with it  What do you guys think?

There's some photo's in my Bricksafe folder: http://bricksafe.com/pages/ludo/eurobricks-tc10-box-factory Apologies for the somewhat low quality, but it was already getting dark...

Did the video upload ok? Can someone confirm? I got a glitch twice when replaying it, but then it went well...

Edited October 30, 2016 by Ludo Visser

[mahjqa]

New video works like a charm. I really like the build. Shame to hear about the compressor, pneumatics can be finicky like that. 

[GroundskeeperWillie]

It looks really good. Good thing you had time to fix the rainbow colors. I with you about the hand pump - it gets tiresome real fast. Good luck - you have my vote.

[BusterHaus]

Glad you managed to get it working.  I noticed that the batteries in my build get worn down very quickly, maybe you were having the same issue with your MOC? Or maybe the compressor gave out...

[lcvisser]

I used the old 9v motors with the Technic Control Center for this very reason ; I'm not fond of batteries (maybe I need to buy the rechargeable battery box, so I can use the new PF). But I'm afraid the stress wore out one or more of the compressors 

[GroundskeeperWillie]

I like the BuWizz because it fixes these things. More power than the regular boxes and rechargeable. But sadly it is not available just yet.