View Full Version : pic: 4901 won't run out of air this season. That's for sure.
JohnFogarty
12-02-2015, 10:01
[cdm-description=photo]41311[/cdm-description]
The_ShamWOW88
12-02-2015, 10:03
What's the weight?
Daniel_LaFleur
12-02-2015, 10:06
[cdm-description=photo]41311[/cdm-description]
How long does it take to charge that thing?
... and for that matter, how long does it take to dump after the match?
nuclearnerd
12-02-2015, 10:08
Harbor Freight has the tank listed at 15 pounds. About the same weight and capacity of 30 clippard tanks.
I'm smiling looking at this photo. We had similar air use issues with our pneumatic elevator in Week 4 because of the way we (mis)read the compressor specs. Our choice was either mount 30 tanks, or retrofit a motorized winch. We went with the winch, but the switch ate up most of Week 5 (and a good chunk of our budget). I hope the "more tanks" choice works well for you!
MrForbes
12-02-2015, 10:33
it takes our little Viair compressor just over half a minute to fill our one long skinny (2012 KOP) metal storage tank. I'm guessing it will take that compressor at least 5 minutes to fill the big tank. Hopefully you can get it done before each match....
Richard Wallace
12-02-2015, 10:55
We are using that same compressor, and a metal Viair tank. However, we are thinking that half a gallon of air should be enough.
Five gallons is a lot of air. Based on measurements my team reported earlier (http://www.chiefdelphi.com/forums/showthread.php?p=1438207#post1438207), I would estimate this compressor would require about four minutes to recharge a five gallon tank from ~100 PSI back to ~120 PSI. So with a tank that large, it is unlikely you would see a benefit from have the compressor on board.
I'm guessing it will take that compressor at least 5 minutes to fill the big tank. Hopefully you can get it done before each match.......without burning up that compressor that I'm guessing wasn't designed for continuous duty.
rich2202
12-02-2015, 11:04
Last year, I saw a team from Mexico do something similar. It took them about 5 minutes to recharge. If they made it to the finals, I have no idea what they would do to reset for the back to back matches.
maths222
12-02-2015, 11:12
...without burning up that compressor that I'm guessing wasn't designed for continuous duty.
Actually, the VAIR 250c is rated for a 100% duty cycle.
tickspe15
12-02-2015, 11:14
...without burning up that compressor that I'm guessing wasn't designed for continuous duty.
The compressor they are using, the viair 250C, is rated for continuous duty.
... and for that matter, how long does it take to dump after the match?
Why would they dump their stored air after the match?
MrForbes
12-02-2015, 12:38
Why would they dump their stored air after the match?
Without seeing the rest of the robot design, we can only guess.
Why would they dump their stored air after the match?
I believe that this was explicitly required in previous years - that all stored air must be dumped at the end of the match. I couldn't find anything stating or implying so in the 2015 game manual.
If you find yourself close on weight, go for the 7gal aluminum one at HF. Saves a little bit and then you'll really have to try to run out of air.
JohnFogarty
12-02-2015, 17:36
We did a lot of math on the volume of air our Cylinders use per stroke and we found that an air tank with volume like this is almost a necessity.
The tank is 15 LBS. (I am aware of the light weight version at harbor freight and we'll keep that in mind if weight is problem, which at the moment our robot is about 30 pounds under weight without the tank on.
Our plan was to use the compressor off-board. If we needed extra weight...on it would go. The compressor is also roughly 15 pounds.
100% Duty cycle at 100 PSI. Charge time is 5 minutes from empty to full. We don't need to empty the system after every match. We would only do so in the times where we needed to. I also checked the rules for that.
Well I guess we aren't the only team going with a lot of air this year, although we do have you beat by one gallon :D
orangemoore
12-02-2015, 22:53
We did a lot of math on the volume of air our Cylinders use per stroke and we found that an air tank with volume like this is almost a necessity.
The tank is 15 LBS. (I am aware of the light weight version at harbor freight and we'll keep that in mind if weight is problem, which at the moment our robot is about 30 pounds under weight without the tank on.
Our plan was to use the compressor off-board. If we needed extra weight...on it would go. The compressor is also roughly 15 pounds.
100% Duty cycle at 100 PSI. Charge time is 5 minutes from empty to full. We don't need to empty the system after every match. We would only do so in the times where we needed to. I also checked the rules for that.
Finals Could Be a problem if you have to fix something during that time.
JohnFogarty
12-02-2015, 23:00
Finals Could Be a problem if you have to fix something during that time.
Having been through elims at orlando last year, I think we should be fine. We wouldn't need a full charge to be effective either. The number of actuations we get from a half charge is at the minimum of what we'd need to score around 100+ points by ourselves.
Our goal with this design was extreme simplicity and speed. Come reveal night you should see that we've achieved just that.
100% Duty cycle at 100 PSI. Charge time is 5 minutes from empty to full. We don't need to empty the system after every match. We would only do so in the times where we needed to. I also checked the rules for that.
Cool - when I looked for Ultimate Ascent (our primary climber actuators were pneumatic, as well as the "trigger" for the frisbee thrower), the only 100% duty cycle compressors I found were significantly larger.
JohnFogarty
13-02-2015, 00:04
Cool - when I looked for Ultimate Ascent (our primary climber actuators were pneumatic, as well as the "trigger" for the frisbee thrower), the only 100% duty cycle compressors I found were significantly larger.
I did a search on compressors on CD and found this thread http://www.chiefdelphi.com/forums/showthread.php?t=129321 easily which had a spreadsheet that gave a lot of useful info that helped us decide on the compressor.
MrForbes
13-02-2015, 00:08
Inspection will be fun, you get to wait around for the compressor to refill the tank.....
Sounds like a neat robot, hopefully we'll see some video soon!
chapman1
13-02-2015, 00:08
Well done! Tongue in cheek is sorely lacking not only in today's world, but also in FRC
Chinske4296
13-02-2015, 22:12
Our team went with an airless robot design. (No compressor or air tanks) early prototypes had pneumatics, but they were voted out.
Sperkowsky
25-02-2015, 22:31
we may use this as mass air storage for a t-shirt cannon. Could you explain how you set it up ;)
Thanks - Sam
JohnFogarty
25-02-2015, 23:21
we may use this as mass air storage for a t-shirt cannon. Could you explain how you set it up ;)
Thanks - Sam
The air tank comes with a bronze output fitting. That fitting has two outputs on it one 1/4 NPT port and one 1/8 NPT port where the gauge is normally. We simply plugged the 1/4 NPT output and then put a fitting into the 1/8 NPT output to allow for use with the pneumatic tubing allowed within the rules.
Funny enough. We now use a 7 Gallon Aluminum air tank on our bot.
Sperkowsky
26-02-2015, 10:52
The air tank comes with a bronze output fitting. That fitting has two outputs on it one 1/4 NPT port and one 1/8 NPT port where the gauge is normally. We simply plugged the 1/4 NPT output and then put a fitting into the 1/8 NPT output to allow for use with the pneumatic tubing allowed within the rules.
Funny enough. We now use a 7 Gallon Aluminum air tank on our bot.
Alright thanks
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