PDA

View Full Version : Urgent need for Nason pressure switch!! PLEASE HELP!


haverfordfords
02-15-2005, 07:28 PM
DEFECTIVE NASON PRESSURE SWITCH... NEED REPLACEMENT ASAP!!!


Hi,

After several days of trying to figure out why our pnuematics does not work (the compressor will not shut off) - rewring, programming, ect. we have determined that our Nason pressure switch was defective.

We called Nason, and they have a 4-6 week lead time, because apparently, these things are custom made.

We have less than a week to complete our robot, and we can't even see our hard work in action.

We are a rookie team, and we are in dire need of assitance.

PLEASE PLEASE PLEASE PLEASE if anyone ANYONE has a pressure switch they could spare (we can even return it once we get our replacement) you don't know how much we would APPRECIATE this guesture. We'll glady pay for whatever it costs to ship it overnight express, we just need it ASAP!!!!! PLEASE!!!!!!

If you have one or know someone who does, please contact us immediatly.

Thank you in advance,
Jason, Team Leader 1656

Conor Ryan
02-15-2005, 08:53 PM
make sure everything is in the right direction (see the arrows on all the regulators)

also make sure that your system matches that in the pneumatics manual, keep in mind that the compressor usual cuts out around 120 psi

Steve W
02-15-2005, 09:34 PM
Have you checked that all of your pressure gauges are in the right place and that you have no leaks. There should be approx 120 in Clippards and 60 down line of the regulator. I would check all of these out first. The rest is wiring and programming. Check were you made your inputs and that your wires are good then check with the programming.

haverfordfords
02-15-2005, 09:49 PM
Have you checked that all of your pressure gauges are in the right place and that you have no leaks. There should be approx 120 in Clippards and 60 down line of the regulator. I would check all of these out first. The rest is wiring and programming. Check were you made your inputs and that your wires are good then check with the programming.

Thanks for all of your helpful suggestions. However, we tried everything. Upon taking apart the pressure switch (and drilling it apart) it is clear that the switch is stuck in the open position. It will not go to the "closed" position.

Nitroxextreme
02-15-2005, 10:09 PM
Have you gotten it to work off of the robot

we have had all of our pneumatics working fine off the robot, but as soon as everything is on the robot almost all pneumatics are not working

our pressure switch also seems to be not working but we are not going to drill it apart

worst comes to worst u can just run the compressor on a timer or something cause it will always vent at about 125

IF anyone can help with problems with the pressure sensor please pm me

haverfordfords
02-15-2005, 10:17 PM
Have you gotten it to work off of the robot

we have had all of our pneumatics working fine off the robot, but as soon as everything is on the robot almost all pneumatics are not working

our pressure switch also seems to be not working but we are not going to drill it apart

worst comes to worst u can just run the compressor on a timer or something cause it will always vent at about 125

IF anyone can help with problems with the pressure sensor please pm me

No, it doesn't work off the robot either, it has never worked, ever - even when directly connected to the battery without going through the system.

We are really looking for someone who can send us a pressure switch, even if its from prior years or anything... If we have to, for the time being we can hard code it like you said, but it would be nice to have the autoshutoff feature =)

Thanks!

BoyWithCape195
02-15-2005, 10:23 PM
It is illegal to not use the Nason Pressure Switch. You must have this wired correctly, if it wasn’t there, your compressor would probably burn out.

Steve W
02-15-2005, 10:35 PM
No, it doesn't work off the robot either, it has never worked, ever - even when directly connected to the battery without going through the system.

We are really looking for someone who can send us a pressure switch, even if its from prior years or anything... If we have to, for the time being we can hard code it like you said, but it would be nice to have the autoshutoff feature =)

Thanks!

Did you wire the battery across the terminals? The terminals are suppose to have a wire that goes to you contoller board that gives an open or closed message to the controller. AT NO TIME should you wire any current across this sensor. The compressor is turned on and off by a spike that is controlled by the main contoller after reading the pressure sensor. I hope that this is of value.

haverfordfords
02-15-2005, 11:06 PM
Did you wire the battery across the terminals? The terminals are suppose to have a wire that goes to you contoller board that gives an open or closed message to the controller. AT NO TIME should you wire any current across this sensor. The compressor is turned on and off by a spike that is controlled by the main contoller after reading the pressure sensor. I hope that this is of value.

Oh no, I meant during testing. We have it all hooked up into the main controller and through spikes, the whole deal, we check it a thousand times, we ruled out all the possiblities. It's definetly the pressure switch.

Thanks for your help though!

dan_h
02-17-2005, 12:08 PM
No, it doesn't work off the robot either, it has never worked, ever - even when directly connected to the battery without going through the system.

We are really looking for someone who can send us a pressure switch, even if its from prior years or anything... If we have to, for the time being we can hard code it like you said, but it would be nice to have the autoshutoff feature =)

Thanks!

Directly connecting the pressure switch to the battery could very probably cause the switch to weld itself shut, causing the exact symptoms that you are describing. The way that FIRST specs the pneumatic system, the switch would be handling milliamps. The way you had it hooked up, the switch would be handling amps, causing damage. If you do get a new switch, be sure that you don't ever connect the switch to anything other than a digital input on the RC, or you more than likely will end up with another dead switch.

EDIT:
From your latest post, it sounds like you 'tested' it with something other than the RC. Even if you only connect the switch that way during testing, it would be permanently destroyed. NEVER connect it to anything besides a digital input. If you _really_ want to test it, you can use an ohmmeter across the terminals without worrying about damaging it. It should go to 'zero' when the switch is closed.

dlavery
02-17-2005, 11:31 PM
If you still need one, we have a spare. Send me a PM with contact info and address, and we can send it to you tomorrow (but ya gotta promise not to connect it to the battery! :) )

-dave

Wayne C.
02-18-2005, 12:15 AM
If you want to send a driver out to NJ we have the whole pneumatics set not in use and you can pick what you want. We will be at the school all day for the next 4 days. We are in central NJ about 90 mins from you.

WC :cool:

Leav
02-18-2005, 02:04 AM
If you still need one, we have a spare. Send me a PM with contact info and address, and we can send it to you tomorrow (but ya gotta promise not to connect it to the battery! )

-dave

If you want to send a driver out to NJ we have the whole pneumatics set not in use and you can pick what you want. We will be at the school all day for the next 4 days. We are in central NJ about 90 mins from you.

WC

you, sirs, are most definately gracious proffesionals. http://www.chiefdelphi.com/forums/images/icons/icon14.gif