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-   -   Total Pneeumatics Pneub (NEED HELP)!!!!!!!! (http://www.chiefdelphi.com/forums/showthread.php?t=63364)

nukelear1991 05-02-2008 21:48

Total Pneeumatics Pneub (NEED HELP)!!!!!!!!
 
So I dont understand the pneumatics at all. I dont get how to hool them up, program or anything. I am the new programmer,electronics, and recently elected the pneumatics guy (with no pneumatics knowledge at all). can someone post pictures of their pneumatics systems,coding examples and the like just so I can get somewhere. Dont bother posting links to the manual because I looked at that and didnt understand.

sorry for the trouble and thanks for the help,
Mike

Miner 05-02-2008 21:58

Re: Total Pneeumatics Pneub (NEED HELP)!!!!!!!!
 
Quote:

am the new programmer,electronics, and recently elected the pneumatics guy (with no pneumatics knowledge at all).
Wow! That is a real handfull that you've got there. How many people are on your team?, and can anyone help you at all?

I dont have any pics of our pnumatics board right now, but here are some suggestions. I am just the electronics guy, but I have worked on pnumatics too. If you know alot about electronics you should be fine. Just think of the compressor as your positive power supply.

There are tubing holders that you screw into the solenoids (which control the pistons), the pistons (which are the metal tubes that extend), and the accumulators. They look like bottle type things and store all of the compressed air. I really wish I had some pics to show you.

REMEMBER TO USE TEFLON TAPE WHEN SCREWING IN CONNECTIONS. If you dont, there wont be a tight seal and you will loose pressure.

Also remember to put on the automatic pressure release valve (look in the KOP check list to find what it is). This can be set from 0-60 psi and must be attatched before the solenoids.

Have a couple other people from your team help you. It is a really tedious job and is quite time consuming. Have them look at the pnumatics manual too.

Good luck,
Jacob

DonRotolo 05-02-2008 21:59

Re: Total Pneeumatics Pneub (NEED HELP)!!!!!!!!
 
The best place to start is to read the pneumatics manual.

Joe G. 05-02-2008 22:00

Re: Total Pneeumatics Pneub (NEED HELP)!!!!!!!!
 
Look in the FRC pneumatics manual

http://www.usfirst.org/uploadedFiles...ics_Manual.pdf

It contains diagrams of all the major parts, and how they fit together. We have our system set up as follows:

Compressor, wired to a spike relay. On one end, brass T-fittings are used to attatch the pressure switch, which is wired to a digital input. It should be set up in code so that the compressor is on when the switch is closed, and off when it is open. On the other end, we usually have more brass fittings, connecting it to a pressure gauge and a relief valve. This allows us to see our pressure, and easily release everything at once. From there, air flows to the air tanks, and then through the regulator. This limits the "working pressure," meaning that it only lets so much pressure through, no matter how much pressure is in the tanks. Depending on your needs, you may need multiple regulators for differant pneumatic circuits. The air then flows from the regulators to the solenoids, which are used to turn the flow on and off to differant cylinders. The solenoids must be wired to spikes, which power them. Air from the solenoids then goes to the piston, which uses flow control valves to limit its speed.

As said above, remember to teflon tape your fittings!

I think that sums up the system. Feel free to post if you have more specific questions.

kmcclary 05-02-2008 22:45

Re: Total Pneeumatics Pneub (NEED HELP)!!!!!!!!
 
Quote:

Originally Posted by nukelear1991 (Post 692934)
So I dont understand the pneumatics at all. I dont get how to hook them up, program or anything. I am the new programmer,electronics, and recently elected the pneumatics guy (with no pneumatics knowledge at all). [...]

The first thing you want to do is pull the 2008 Pneumatics Manual and The Robot PDF, from the DOCS area.

Docs & Updates area:
http://www.usfirst.org/community/frc...nt.aspx?id=452

Within that area, are the two manuals -

2008 Pneumatics Manual:
http://www.usfirst.org/uploadedFiles...ics_Manual.pdf

"The Robot" PDF (as of this writing, Rev E, page 26 - get the latest at "node 452", above)
http://www.usfirst.org/uploadedFiles...Robot-RevF.pdf

The Pneumatics Manual gives you the connections. There are nice pics of an entire system built up there, as well. "The Robot" PDF gives you the general robot build rules. That will specify things like how many storage tanks you're allowed to use (4), and the like.

In addition to the "sample" cylinder, you're also given a "coupon" for up to three free Bimba cylinders. Added to the basic air power plant provided in the Kit of Parts, this allows you to choose whatever cylinders you'd like for your application, by stroke and diameter. (In general, the diameter of the cylinder determines your overall maximum force available and air consumption per operation, whereas the stroke determines the distance you are acting over.)

Once you've determined your needs, go here to order the free cylinders:
http://www.bimba.com/FirstFree.aspx
Remember, you only get three free ones, so BE SURE before you order that you're asking for the right ones! They are NON-RETURNABLE.

NOTE - Bimba BUILDS TO ORDER, THEN ships. This means that their Just In Time system can take SEVERAL DAYS *just* to complete the manufacture of your cylinders. Therefore, even if you request "overnight shipping" and pay for it, it may still take several days before you see your cylinders, so be sure to allow for that!

Also, if you do NOT specify "overnight" and give an account to bill against, your cylinders will be shipped UPS GROUND. That can add up to another week to the delivery! Since we're already in Week 5 of the build, in a worst case scenario this may mean you won't see your cylinders until the build is almost over, so I highly recommend providing a billable shipping account to get them ASAP. (Someone over 18 on the team can easily open a FedEx account, so this isn't normally a problem...)

More "gotcha" notes, if you plan to use more than the three free cylinders:

1) The Coupon cylinders AUTOMATICALLY come with clevis, mounts, and (if you request magnetic cylinders) magnetic sensors If you order a fourth cylinder, you will also need to order those accessories separately, or you'll get ONLY a raw cylinder.

2) Use the Bimba price calculator to figure out the best use of your coupon:
http://12.48.113.100/mrcjava/servlet/BIMBANET.M00600s
(IOW, use the coupon for the most expensive cylinders, THEN buy more with real cash. Be sure to add in all accessory prices, too!)

In addition to the FIRST 2008 Pneumatics Manual, here's a link to the full Bimba catalogs for the Bimba Cylinder line, for more tech information:
http://bimba.com/Catalog/Download/
The "Original Line" catalog has the basic cylinder data.
The "Pneu-Turn Rotary Actuator" catalog has the rotary actuator data.

Here are a few other useful pneumatic links for you:
- Pneumatics FIRST.org (kit training)- http://www.pneumaticsfirst.org/
- Festo Valve Assembly - http://a1989.g.akamai.net/f/1989/710...TValveAssy.pdf
- SMC's FIRST component catalogs and assembly data - http://smcusa.com/sections/first/assembly.asp
- SMC's Training links, for FIRST teams: http://smcusa.com/sections/first/first.asp


Overall though, the Pneumatics Manual and The Robot PDF are the two big sources of data. They should answer most of your basic questions.

IMHO, the air system does have a lot of weight overhead to get started. So, if you're going to use SOME pneumatics, my best advise is to use a LOT of pneumatics.

The other gotcha is that you have limited total amount of pneumatic work available from the air system. (IOW, what air you have stored at the start of the round, plus whatever you can compress in a couple of minutes during the round, determines the ENTIRE amount of energy available.) That means although the pneumatics are nice, be careful to match the application to them. Small amounts of work in remote locations (like at a gripper at the end of an complex arm, gear switching, hitch latches, bin releases, etc.) make for great pneumatics applications.

OTOH, if the application requires a LOT of work, you might wish to consider using kit motors driving winches instead of pneumatics, since the battery can provide more total work energy in the allotted time.

Does this answer your questions? If not, and I can be of more assistance, feel free to ask. Good luck!

- Keith
Chief Engineer, FRC 1502 "Technical Difficulties"


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