Quote:
Originally Posted by nukelear1991
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). [...]
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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"