Pneumatic tubing management suggestions for an elevator


#1

Building team’s first elevator and working on pneumatic tubing management. Any suggestions or experience appreciated. Considering pre-coiled tubing, igus chain, lots of zip ties.
Only have one pneumatic on the actuator and wondering if it would be better to redesign and use motors instead and not have to worry about breaking the pneumatic tubing.
If you have suggestions on wire management for elevators, we would also appreciate that.
Thanks


#2

We used something similar to this in 2015 for our elevator. As long as it is properly restrained and routed to avoid any mechanisms from pinching it, it works like a charm.
Automation Direct Bonded Double Tube


#3

Last year mt team used a generic cable track to route pneumatics and wires, as long as you don’t pinch it even snakeskin should do the job. I can put pictures on later.


#4

If you replaced the cylinder with a motor, you’d have to route wires; same problem. I have used several solutions to this. The simplest one worked pretty well for a one-stage slide: attach a length of bungee cord from the base of the fixed part of the lift and the far end of the moving part of the lift, so it is straight but not stretched when the lift is down, and is away from pinch points. Raise the lift to the top of the stroke. Route the tubing along the bungee, securing with zip ties every foot or so. I suspect it would work better and look even cooler if you wrap the tubing around the stretched bungee, about 1 wrap every foot, and secure at each wrap.


#5

Amazon has very inexpensive energy change/wire carrier that is perfect for routing things to work on a hi-lo. Any non-rigid structure (like the coiled tube) will end up catching on something - either a mechanism on your robot or a mechanism on another robot. It’s a recipe for trouble.

Cheap energy chain:

We found out the hard way that it’s very worth the money to purchase the wire carrier that has split flaps or hinged flaps for putting wires in and out. Trying to snake them through can be tough.

Take a close look at 254’s robot for a good idea on how to run the chain:


#6

My suggestion would be to use Igus track, it often comes in the KoP. I don’t remember if it came this year, but chances are you have a bunch of it unused laying around.
It’s black track that bends in one direction.
Look at the picture of the Poofs above to see how to route it.


#7

So bend radius and other mounting issues would be the same for the wire and the pneumatic tubing? Basically we only have 2 pneumatic cylinders on the whole robot and the thought of replacing them and getting rid of the other pneumatic stuff is enticing. Looking for a nudge since we’re on the fence.
Thank you


#8

They’re not identical, of course. Most stranded wire can take a somewhat tighter bend radius than tubing without pinching off the flow of electrons. If those are your only pneumatic cylinders and they’re rather small and you don’t need to hold a significant force on them at either end, you may want to consider using linear servos instead. Do not expect a servo to be able to sustain that peak force for more than a couple of seconds; they smell terrible when they go. Remember the $75 limit for servos per R34, next to last row of table.


#9

I have ever seen a linear servo before. THose look intriguing but I get nervous using anything that says light duty. Do you have any experience with them? We can’t afford to replace them more than once probably.
Thank you for helping.


#10

I haven’t used linears, but I have used a variety of rotary servos. Servos are good for moving things from one place to another within their specs, but aren’t so good for things which have to be held in place with significant force. Good uses: setting/releasing a latch, inserting/removing a plug, sliding a lock bolt into/out of position, positioning an item left-to-right to align with a goal or to extend a manipulator from the frame perimeter to the bumper perimeter. Bad use: gripping game pieces.

As with pneumatics, do not make these provide a lot of lateral force; support that load with some sort of bearing.


#11

We used a coiled double pneumatic hose (from McMaster, 5612K43) with wires zip tied inside the coil. Because it was a three stage elevator, cable chain wouldn’t work because it would extend farther than the track could reach. It worked quite well.


#12

For mobile robots, I’d recommend snakeskin braided sleeve material, similar to this:

This will enable you to run your pneumatic lines and electrical wiring through the same abrasion-resistant sleeve. It’s lighter than plastic cable carrier chain, and available in several different diameters, so you can choose the size that best suits your needs.

For a mechanism such as an elevator, keeping it out of the way of the mechanism usually isn’t too difficult. You can also use surgical tubing to pretension excess slack away from the moving components.

For non weight-restricted applications, or if you do not have the real estate to keep the braided sleeve material out of your elevator, then I’d recommend the iGUS cable chain as the next best all-in-one solution.