Peoples Views On Pneumatic Lift

Hello, i am just a bit concerned that our lift is slow, we have the money, what are peoples general opinion of using a pneumatic lift … this set in particular

thanks in advance :smiley:

Pneumatic lifts take months to perfect and require a fair bit of investment into pnuematics. The kit that you linked to will provide you with one reservoir, but teams that I have seen use pneumatic lifts have packed 4-6 reservoirs or more into their robot. Even with this much air, I don’t think pneumatic lifts are the best. They are difficult to adjust to multiple heights (which may or may not be a problem in Sack Attack) and they get weaker as the match goes on. I also don’t think the desired capacity this year goes well with a fully pneumatic lift.

Alternatively, you can look to use pneumatics to add little capabilities to your robot that will increase its effectiveness more than a pneumatic lift. Many teams have opted to use pneumatics for:

-High goal scorer
-Bucket angle-changer (flat for intaking, angled for scoring)
-Intakes (pneumatic shovel flippers)
-Catapults integrated into buckets for better scoring
-Etc. etc.

thank you for your views, i will consider them :smiley:

I agree with all points by SweetMochi, but would like to add one more thing:

  • You are going to be adding a TON (not literally :D) of weight by adding 4-6 resevoirs and will significantly slow down your robot than if you didn’t.

Oh, and SweetMochi’s comment about pneumatics getting less and less effective, remember that as you add more weight, the actuators require more pressure in order to effectively push the lift up/down. So you will get an even lesser number of “actuations” per charge.

Another problem with a pneumatic lift is it generally is very weak. If you want to lift more than a couple sacks you will need a ton of pistons and reservoirs. Although it is possible, it is only an option if you are prepared to spend the time/money to get it perfected.

Agreed, we had trouble lifting 6 game objects last year in Gateway with a pneumatic lift.
The lift required lots of tweaking to keep the performance reliable. Here is a video if you are interested.

Hi

Depends what your goal from competing in VEX is. If your goal is purely performance, then it is probably unlikely that a pneumatic lift robot will out perform a motor powered lift robot. If your goal is to take on a difficult challenge, learn heaps in the process and hopefully design + build a unique robot then I say give it a crack. Just beware that the road may be rocky :slight_smile:

Have you thought to try and pneumatically assist say 2 motors on a lift to give more speed/capacity? We tried to prototype one but it proved to be very difficult.

Good luck, Paul

I’ve seen this idea here in Puerto Rico team #2320 or Softech Robotics as they are know have 6-bar power by 2 motors with a 1:7 ratio but have 4 pistons to aid them and it does work cause its a beast it lifts about 12-14 sacks no problem only thing is that it even with 6 resevoirs I’ve seen it run out of air mid-match but it isnt really a problem to them cause they can just keep going with the 2 motors only with a much less capacity and lower speed

Pneumatics are awesome simply because its unlimited free motion if you have the resources. I am using them on a lift this year and will be using somewhere about 6-10 pistons total on the robot. Multi stage lifts are a little more difficult than a one or two piston arm to a fixed position. But months of time really don’t go into them. I find that a little more exaggerated than what most people think. You just have to know what you are doing and be logical with how you do the air system.

Make sure you using Teflon tape on all the fittings so that there isn’t any leaks. Don’t kink your hoses. Make sure its a secure fit. Simply things like that.

  • Andrew

My robot (the two photos on the right) uses a pneumatic lift. I used 6 reservoirs and 4 double acting pneumatic pistons and lots of rubberbands. This gave me a capacity of 7 at the beginning of the match and 4 at the end of the match. The reason I am no longer using the pneumatic lift is I found the capacity too low for my liking. However the pneumatic lift went to trough height nearly instantaneously and also left motors for an 8 motor drive :D. Yes, that robot was heavy but it didn’t slow it down due to the powerful drive. If anything it gave more traction in pushing battles. It took a while to build to get it sturdy, lift to the right height and find a good balance of rubberbands but in saying that it isn’t much longer than it takes to perfect a motor lift. In the nz scrimmages i have quite often made it to semis so i disagree that a pneumatic lift can’t be competitive. My personal opinion is that a pneumatic lift is not better than a motor lift due to capacity however the extra motors do allow you to have a more powerful drive which can be a huge advantage in pushing matches or blocking.

If one is willing to trade off the ability to drive while raising/lowering the lift you could use a Power Take Off system which requires only one pneumatic piston. I’ve never seen one done in VEX before but it would be easier than making a mesh-shifting drivetrain transmission. An eight motor lift should be able to lift almost instantly which negates most of the negitives from not being able to drive while lifting.

If one’s looking at a completely pneumatic lift another thing to consider would be using your piston(s) to pivot an overcenter locking linkage lifting the arm rather then directly lifting the arm with the piston(s). With one of these the arm would be mechanically locked once raised so it wouldn’t be reliant on air pressure to hold it in position, just to lift it.)

Our robot had a pneumatic lift last year which had the capability to actively hit all the different heights (4 positions) with 3 pistons on each side of the lift. We were able to lift 6 pieces to the 30" goal (~ 3 pounds) with 6 tanks. This year, the maximum height is not 30" but 15" (assuming you aren’t bringing the lift to the high goal). That would mean you could design a lift to bring about 6 pounds of sacks to the trough reliably. (much simpler as well, because there are only 2 positions). However, as stated before, pneumatics take months to perfect, and will add a lot of weight to the robot. I don’t think that pneumatic lifts are the way to go this season.