Solenoid LEDs not on / VEX Base Leak

popnbrown · February 14, 2015, 9:05pm

We’re having trouble getting the solenoids to work. The compressor works fine and is running, but the solenoids are not lighting up nor working.

I think the solenoids are wiring up fine, and we seem to have lost our multimeter…so I can’t tell if there’s any voltage going.

We’re using the VEX Solenoid Base Mount - http://www.vexrobotics.com/solenoids-and-manifolds.html, and this also seems to be leaking. I presume it’s because the solenoids are not getting power and are not blocking out the air.

I would love to show you wiring, but it’s incredibly messy that even I have trouble following it sometimes. The connections were initially not weak, the solenoid wires popped out at a slight tug but we re-secured them.

Firmware for the PCM is at 1.62, it’s reading no faults, and showing all the Solenoids as off.

I’m attaching our Begin.vi and our Teleop.vi.

Chris_Ely · February 14, 2015, 9:19pm

If your manifold is leaking, you have a plumbing problem. How do you have it plumbed? Pressure should go into the port labeled P, and your cylinders should be connected to ports A and B. EA and EB are the exhaust, so leave these open. Does every fitting have Teflon tape, and are they tight? Put soapy water on the fittings, and look for bubbles to find out where the leaks are.
Try to clean up your wiring; diagnosing spaghetti at a competition is not fun, trust me.
Are you using single or double solenoids?
Unfortunately, it is difficult to diagnose problems we can’t see. Can you post pictures, even if things are messy?

popnbrown · February 15, 2015, 12:06pm

Yeah, we got advice on this base from another thread. You can see the BaseTubing image, the first picture, attached below

All those that have threads have Teflon tape.

This is the current plan, I’ll also double check the Teflon.

Fortunately, this is just our test platform. Unfortunately, it’s not even fun diagnosing it right now. But the only way to learn is to do it wrong, and realize it’s wrong. I hope there’s at least one lesson learned about wiring here.

Single solenoids. SMC ones from VEX

I attached a close up of the PCM but it’s not really helpfu this is the second picturel. The BaseWiring (third picture) is the better picture. You can actually attempt to follow the wires.

orangemoore · February 15, 2015, 12:12pm

Is your PCM jumper set to 12V or 24V?

Chris_Ely · February 15, 2015, 12:14pm

It’s a little hard to tell, but it looks like the voltage selection jumper is set to 24V. The solenoids from VEX are all 12V. Switching the jumper should fix the problem.

popnbrown · February 15, 2015, 12:25pm

I swapped it to 24V after posting this. It was originally 12V.

It was still not working when 12V.

Mark_McLeod · February 15, 2015, 12:25pm

Concur on the PCM 24v jumper. Those are 12v solenoids.

Are the LEDs for the individual solenoid 0 output on the PCM lighting up when button 5 is pressed?

orangemoore · February 15, 2015, 1:39pm

What is the CAN ID of your PCM? Does it match the one referenced in the code? I think it should be 0.

popnbrown · February 15, 2015, 2:02pm

Well. that would be why. We were thinking they were supposed to light up indicating the Solenoid was being powered or it was initialized. I’ll test out the buttons and see if that works.

popnbrown · February 15, 2015, 2:03pm

It’s 0. We don’t reference it in code. Using LabVIEW and I didn’t think we had to reference it in code. Following the Solenoid example here - http://www.team358.org/files/programming/ControlSystem2015-2019/labview/index.php

I’m going to test pressing buttons and seeing it light up.

popnbrown · February 15, 2015, 2:05pm

General update, we’re finding the solenoid base mount to be leaking quite a bit, from where the ports of the mount We unplugged the regulator and solenoid and just capped the other end, and it was finally starting to build some pressure. There was still some leaks, and it’s because the Teflon on the threaded joints wasn’t looking great and we didn’t actually tighten them all the way.

popnbrown · February 15, 2015, 2:09pm

Solenoid lights are working when pressed. Thanks for the clarification Mark.

Now to fix the leak.

cglrcng · February 15, 2015, 2:22pm

Begin by removing all the black tubes 1-by-1 from the block and check for flush tube end cuts (square), tube ends, trim as necessary properly, and re-insert them, push all the way into the connector & pull or tug out to make sure they are fully seated properly…I can see the bottom second one in pic#3 is not all the way in, see how the connector is higher than all the rest nearby. *That should not stop the lights from working on the individual sol’s, but minimum air pressure is needed to actually make them fire. No doubt in my mind that port is leaking much air.

Will the system currently hold stored air for say 15 or 30 minutes or more if you pump it up to 60~100PSI without leaking down much? If not, get that right first. Start at the compressor and find the leaks first, 1 connection at a time. Once it does, try overnight. Pump it up, turn off robot power, watch gauges for pressure bleed down.

I’m sure you already found that speed controller in the pics w/ only the ground attached and the positive not attached any longer upper left in pic #1…Looks like it (the hot), is in your fingers. And need a bit more insulation tape on the PDB connectors main power connections (IMPORTANT not to see any of the silver connectors there). Also suggest blowing that bot out w/ some compressed air to clean out the debris a lil’.

Addition: I just looked at Pic#1 and the second black tube in the top row also isn’t seated all the way in either.

cglrcng · February 15, 2015, 2:42pm

Also, if you have more tubing avail., I would replace both the inlet and outflow tubing to/from the regulator (and maybe even the connectors to straights from 90’s maybe) w/ a little longer tubes as they are pulling the connectors off center which can also lead both (all 3~Reg. in/reg. out/ & block in connectors to leak.

That yellow locking collar on the regulator is half way up, half way down in the pic…Up to adjust regulator pressure, down to lock. Get it into 1 or the other positions also…right side is down/left up in the pic. When it is in the adjustment position it leaks very slightly on purpose to help you adjust the regulator pressure so after adjusting it, always lock it.

Can you attach a few more pictures?

Start at the compressor and work back to the block please. Getting the High Pressure side completed first and holding air (always insert a pressure relief valve in it), dividing the system into sections, and then working towards the low pressure section 2nd. seems to work best when making sure the system doesn’t leak.

popnbrown · February 15, 2015, 3:02pm

Some more pictures. Sorry some of them are crappy quality. Let me know if there are close-ups of anything specific you’d like.

We’ve been re-doing some of the tubing because it got frustrating trying to debug things would get pulled out.

So we had a leak right out from the compressor, and then a leak near the release valve and the high pressure gauge. The air tanks all seem to be good even though the one T joint seems a little iffy.

We were able to get both the High Pressure side working, although I’d like to run a test to see how the pressure may bleed, so we’ll do that.

We also just setup a low pressure side with the outlet of the regulator just sent to a release valve, and that also seemed to build pressure, although it was going to about 40 PSI, and would keep going while it was still at 40.

So with the solenoid base, the orange connectors on the base being close to each other means that it is fit better than when the orange connectors are farther apart?

cglrcng · February 15, 2015, 3:08pm

Also, if you have more tubing avail., I would replace both the inlet and outflow tubing to/from the regulator (and maybe even the connectors to straights from 90’s maybe) w/ a little longer tubes as they are pulling the connectors off center which can also lead both (all 3~Reg. in/reg. out/ & block in connectors to leak.

That yellow locking collar on the regulator is half way up, half way down in the pic…Up to adjust regulator pressure, down to lock. Get it into 1 or the other positions also…right side is down/left up in the pic. When it is in the adjustment position it leaks very slightly on purpose to help you adjust the regulator pressure so after adjusting it, always lock it.

Can you attach a few more pictures?

Start at the compressor and work back to the block please. Getting the High Pressure side completed first and holding air (always insert a pressure relief valve in it), dividing the system into sections, and then working towards the low pressure section 2nd. seems to work best when making sure the system doesn’t leak.

Please do not take anything as being critical…Just trying to help. Yes, if it hits 40 PSI and compressor is still running and does not stop running, but does not build pressure, the system is absolutely leaking.

Look very closely at pic #1 and pay strict attention to just the tubes and air connectors…If the tubes are perpendicular to the fittings, and the fitting collars are not highly tilted, their tubes are usually long enough. But, if the tubes are too short, and I see many there in the pic, where the fitting collars are really tilted…Then those particular tubes need to be a bit longer (and or 90’s used in place of straights possibly, or the opposite maybe), to alleviate and stop the chance of air leaks. All pneumatics need to be troubleshot after assembly usually…Once the team gets really expert at it, they can learn to assemble it properly from the very start.

Take the hr. or so now (grab all already cut pcs. of tubing you can find in the shop 1.5" or longer), check every fitting for tightness, flush cut tubing ends, and switch out (always start at the compressor)…The too short pcs. w/ a little longer ones (or change fittings where necessary), and get that system holding pressure firstly (high side/ then low side/ then actuation side). Divide the system into parts (using plugs or tubing loops, and conquer it! If ours has zero to very minimal leakdown when left pressured overnight. Then it is ready to practice or compete with).

I’ll look at the new pics now. TY for providing them.

cglrcng · February 15, 2015, 3:20pm

Sravan…(I know you are a mentor and not a student…I would never ask to skype w/ a student directly)…Do you have skype? (Please answer only in a PM).

There are problems, and I’d like to help you get them sorted out quickly in real time (as I know your time is very short w/ Tuesday night coming very fast)…They did not teflon tape a number of threaded fittings at the compressor and the pressure relief valve Pic #4 (Fix those firstly, and always back that check valve at the compressor w/ a wrench not allowing it to turn).

That “T” at Tank #2 (right hand tank in the pic), in Pic #1 needs at least a 1" longer pc. of tubing (The tubing between the “T” and tank you cannot even see). Harder to remove from those fittings too! That will leak always!

The 3 potential leaks or more at the compressor (it appears they left out the teflon tape at the following threads…Compressor Check Valve to “T”…“T” to bell (though I cannot see that too well in pic #4), Bell to Brass Pressure Relief Valve…NOTE: Make sure that no teflon tape gets on the end with the hole or beyond the end of the threads or in the actual bell reducer…That could plug up the hole in the pressure relief valve!

OK, then follow the hose to the first “T” and 1st (left Clippard tank)…Remove and replace that tube w at least / 1" longer tube between tank/T.

cglrcng · February 15, 2015, 4:27pm

For reference (after the original skype call)…Here is the test manifold I asked you to build up using a “T”, 1 straight tube fitting, 1 pressure gauge 0~130 PSI or higher, and 1 pressure dump valve…a ball type valve)…Assemble using teflon tape on all threaded fittings.

This is how to assemble our test fitting!

(We will relieve pressure here)Pressure Dump Valve---------“T”----------Straight or 90 degree Hose Fitting (We will connect to the system many times here).
I
I
0~130 PSI Pressure Gauge (We will watch pressure and bleed down or look for leakage here).

Note: It does not matter which ends of the “T” each item is on.

Next: Make sure you can control the compressor on/off via the PDP & robot controls properly. Then we make sure that the compressor threaded fittings are all taped properly, and then we will disconnect from the tanks and install our new test manifold on that first tube.

Turn on and run the compressor up to 120~125 PSI and test the pressure relief valve. Turn off the compressor if it goes beyond 125 PSI before the pressure relief valve starts leaking at the hole in the end (DO NOT ALLOW IT TO EXCEED 130 PSI!)…You can feel leaking by putting a finger over the end where the hole is of the Brass Pressure Relief valve. It should start leaking somewhere between 115 PSI and 125 PSI (Do we need to adjust it?) We will do this action live on skype.

cglrcng · February 15, 2015, 8:09pm

Please refer to the PM’s received for the balance.

tStano · February 15, 2015, 8:36pm

My general philosophy on teflon is you can’t have too much on a fitting. I can’t see it poking out of any of your connections which would make me say you don’t have enough. Wrap it around there 3 or 4 times. I have the same philosophy for tightening the fittings. Tighten em until you can’t tighten them anymore. I don’t know if this is a good philosophy, but its always worked very well for me. Leaks are very mimimal.