'72 K5 - Greg's @MightAsWellK5 Build

[Greg72]

interesting, been following you on Drivetribe - nice to see the rest of the story.

Thanks!

Yeah, I try to keep it pretty high-level on DT..... but for the in-depth struggles and technical discussion, this is definitely the place to be.


BTW -> Turns out my last order of square nuts were "non-graded" versions... which is to say Gr-2 (or less!) for strength. Unfortunately, the cost to ship them back for a refund probably exceeds their original cost, so I'll just throw them away. I found a source for "real" GR-8 Square Nuts today and now have some good quality stuff en-route.


-G

 

[Greg72]

RESEARCH REQUEST:

I've been in contact with RideTech (formerly Air Ride Technologies) about using their airbag suspension controller as the basis for my CTIS air-management system.

It seemed like a total slam-dunk to me, but they gave me the bad news that their system calibration has a lot of other "logic" that will not allow it to simply "add air" to 4 tires until they reach a preset value. Apparently, there are a whole host of other algorithms that are suspension-specific to prevent things like cross-loading the suspension... so there is quite a bit more to the system than just adding air until each corner hits the preset values on the controller. There was also some concern about the accuracy of the sensors at low pressures (like 5 - 10 psi) which are not appropriate for airbag suspension application. So even if there was a way to make the controller work, the air pressure could be off by several PSI in the tire vs. the indicated pressure on the controller.

So that leaves me to figure out a more "analog" solution... which isn't necessarily a bad thing. I figure the criteria would be something like:

• 3 galllon (minimum air tank)
• 100% duty cycle 12V compressor (Viair, or other quality brand)... with high SCFM rating
• Two "zones" controlled by solenoids (one for the two front tires, one for the two rear tires)
• Pushbutton controls to either call for 36PSI (Inflate to street pressure) or 10PSI (Trail Pressure)
• Ideally, I don't want to have to hold the button the entire time it's airing UP or DOWN. Some kind of sensor could determine when the target pressure is achieved and close the fill / dump solenoids.
• It would also be nice to tweak the "preset" values if desired.... without a lot of extra effort (regulator type setup?)

Anyway... I am just starting to look into all of this based on the disappointing news I received. I guess the simplest thing is to first look at the Hummer H1 solution for ideas, but I'm sure it's super-expensive and may be a lot more complex (and costly) than I really want.

If anyone has ideas, or knows of some other application that might use a setup like this... let me know. I need to start brainstorming, and understand what sort of air-handling stuff is already out there.


-G

 

[blazinzuk]

I'd just do a button. Why? Because the cool thing about ctis is the fact you can change pressure to the terrain.

Or a switch. I also think you should do 3 gallon tanks front and rear. For quicker reactions.

Also I think 36 psi is way too much for what you have. Your rig will be heavy but I think I run like 28 psi in my front 37s and 24 ish in the rear.

 

[Greg72]

I opened up the valvestem cores to allow more airflow... but I think they are going to be the limiting factor in how fast I can air up / down.

Tankwise, I don't know if I can find enough available space for 6 gallons. I know it's a balancing act between compressor run-time vs tank size but hopefully with a high SCFM the system can get the tires to target pressure quickly!

No idea on actual tire pressure but I just threw 36psi out there as a ballpark target for max pressure

-G

 

[blazinzuk]

I just think a manually operated system would be much more useful.

How are you gonna monitor pressure in the tires?

 

[Greg72]

I just think a manually operated system would be much more useful.

How are you gonna monitor pressure in the tires?

That's where I'm kind of stuck. I just don't understand the plumbing of air systems very well.

I know that I can use RideTech-type solenoids to control inbound (air up) and outbound (air down). The RideTech system uses a total of 8 solenoids IIRC... a pair for each corner. I could use maybe 4 solenoids total if I just did a "front axle" and "rear axle" system. I could foresee needing to air-down just the front axle to get more traction, but I don't know if having individual control for each tire would actually prove valuable in real life situations. One problem with only using 4 solenoids though is that if one tire pops.... both tires on that axle will go flat since they are "sharing" the airline. Might be safer to use 8 solenoids after all and just control them in pairs??

I think it's important to have at least one pressure sensing switch designed in... looks like there are lots of choices out there, so I could put a "failsafe" cutoff switch at say 40psi to make sure that the system didn't ever try to inflate my tires to 130-150psi!!! This would be critical if I built a system that was "unattended" and I just wanted it to hit a PSI value and stop automatically. I suppose a low-pressure sensor would be nice too... without beadlocks, I don't want to accidentally dump air below maybe 10PSI... and blow 4 beads at the same time. No Bueno.

So the question really becomes: Can I design a system that is fast enough that I'd be willing to hold the button the whole time the adjustment was happening, or do I design something that just starts with a momentary push-button and then runs until hit hits a pressure sensing switch and shuts itself off?

(this is starting to feel like another case of those "unknown unknowns" we were discussing a few days ago...)



-G

 

[blazinzuk]

Find a lowrider shop go talk to em

In all seriousness it might help. I would think you would need a valve on all the tires that would prevent any loss of pressure. Gonna need to talk to someone way more knowledgeable than me on pneumatic systems.

 

[dremu]

This is screaming, begging, for an Arduino. I'm just saying.

You still need the compressor and sensors and solenoids and whatnot. But the button(s), even an LCD or LED display, that would be trivial for a 'Dweeno. And tremendous fun.

-- A

 

[Greg72]

This is screaming, begging, for an Arduino. I'm just saying.

You still need the compressor and sensors and solenoids and whatnot. But the button(s), even an LCD or LED display, that would be trivial for a 'Dweeno. And tremendous fun.

-- A

If you are willing to endure countless questions and help me come up to speed with something like that I'd be game to check it out!!!

I'd be starting a learning curve from zero... so whatever gets me up to speed quickly would be appreciated.


Did find this already: (Fast forward to around 4:55)

The system DOES have some intelligence for things like stopping the fill process intermittently to confirm individual tire pressures, then turns system back on to continue filling.... This one is also speed-sensitive and will change "modes" based on road speed to prevent being underinflated for conditions, etc. Certainly overkill for what I want, but like you say... once you commit to throwing a small computer into the mix, adding features like that is as simple as adding new code modules.


-G

 

[superbuickguy]

I've always thought a blue-tooth deflation system would be the cats pj's - filling up at the end of the trail is a safety check time as well for me, so CTIS just doesn't have the same attraction. Even more reasons why not, the H1s had run-flats so should the system fail, you're not stuck beside the road with a tire you can't take off and an O-ring you can't easily replace. Filling up is really quick since I have a York a/c based on-board air compressor (12 cfm).

(btw, I'm Aaron on drivetribe)

 

[Greg72]

I've always thought a blue-tooth deflation system would be the cats pj's - filling up at the end of the trail is a safety check time as well for me, so CTIS just doesn't have the same attraction. Even more reasons why not, the H1s had run-flats so should the system fail, you're not stuck beside the road with a tire you can't take off and an O-ring you can't easily replace. Filling up is really quick since I have a York a/c based on-board air compressor (12 cfm).

(btw, I'm Aaron on drivetribe)

Bluetooth? I don't want the CIA hacking my air pressure!!!!

BTW ->I figured out who you were a little while ago. Matched up photos from both sites and cracked the mystery.


-G

 

[superbuickguy]

but they do need oxygen - I hear they're still hyperventilating over the whole wikileaks thing. good investigative skillz - hoping you're not CIA

seriously though, there's this think called a valve-stem-cap.... if you put the controller inside the wheel like TPS, it would simply operate a valve that opens to reduce the pressure and look just like a regular schrader valve. As you see, I've given some thought to this - problem is it'd cost $40-$60k to develop it and I don't think the market is there as it'd be off-highway only.

 

[ashman]

This is screaming, begging, for an Arduino. I'm just saying.

You still need the compressor and sensors and solenoids and whatnot. But the button(s), even an LCD or LED display, that would be trivial for a 'Dweeno. And tremendous fun.

-- A

lol, I was thinking the same thing, only Raspberry Pi. It would be a fairly simple program to monitor a few sensors and run a few solenoids for sure.

 

[superbuickguy]

about providing air. You'll never go back to a Viair or similar (I have two on my H3 hummer for inflation purposes) once you convert a york compressor to air compressor duties. Best of all, you can turn on and off with a switch...
here's mine
york compressor in front and then air driers are on the firewall to the right


the tank is to the left of the transfer case

 

[bp71k5]

Greg,

Might be missing something but I'm not sure you need all the electronics. Many air compressors have a pressure valve with a dial on it to adjust the pressure. I can just turn the knob to the setting I want and the compressor turns on to increase the pressure and stops when reached. If I turn the knob down, it bleeds air out until the lower pressure is reached.

Seems like you can plumb air lines right up to the dash to do something close to that or run electronic solenoids ala ARB?

 

[Greg72]

Greg,

Might be missing something but I'm not sure you need all the electronics. Many air compressors have a pressure valve with a dial on it to adjust the pressure. I can just turn the knob to the setting I want and the compressor turns on to increase the pressure and stops when reached. If I turn the knob down, it bleeds air out until the lower pressure is reached.

Seems like you can plumb air lines right up to the dash to do something close to that or run electronic solenoids ala ARB?

Brian,

Probably true. I suspect that the only downside is that all tires are tied-together with a single regulator system....and I'm guessing that "airing down" is going to be a lot slower than dumping pressure via solenoids??

Anyway... @dremu is a bad influence and AmazonPrime is the debil.





-G

 

[dremu]

I hear you about Prime. A surprising amount of my bulldozer came from the Amazon reindeer.

Happy to help with the Arduino, you know how to find me. Hell, I can code that, easy enough.

With the possible exception of a fancy screen display, the Raspberrys are total overkill for stuff like this, IMO. You really just want a microcontroller, not a full-on computer. Regardless, sounds like you can find multiple resources here.

-- A

 

[bp71k5]

Brian,

Probably true. I suspect that the only downside is that all tires are tied-together with a single regulator system....and I'm guessing that "airing down" is going to be a lot slower than dumping pressure via solenoids??

Anyway... @dremu is a bad influence and AmazonPrime is the debil.





-G

I see. The snowball is already rolling...

 

[Greg72]

I hear you about Prime. A surprising amount of my bulldozer came from the Amazon reindeer.

Happy to help with the Arduino, you know how to find me. Hell, I can code that, easy enough.

With the possible exception of a fancy screen display, the Raspberrys are total overkill for stuff like this, IMO. You really just want a microcontroller, not a full-on computer. Regardless, sounds like you can find multiple resources here.

-- A

I see. The snowball is already rolling...

Yeah well..... This one transcends my typical "Might As Well" logic.

First of all, I can design a pretty simple analog CTIS system regardless separate from the Arduino componentry (compressor, tank, fittings, solenoids and pushbutton switches).
Adding the Arduino sounds like I just clip the wires from the pushbutton switches and connect them as digital inputs, then wire in an analog pressure sensor (or two) and write some code. It becomes an electronic "finger holding the fill button" for me.

Second: I can already think of a few "other" projects that Arduino could be really cool to implement. Nothing that is critical for getting this truck finished for Moab2018 but stuff that would be easy to do in a weekend a couple of years from now. LED brakelights that actually have the old-school "decay" of an incandescent bulb when turning off is one that I've wanted to do for a while... and it sounds like there are PWM outputs that I could program with decay curves to create all sorts of different "dimming effects" with LEDs. Sounds like it's easy to control servo motors as well.... so for things like motorized lifting of hidden displays it's possible to contol how quickly they open or close and even put in some safety logic that would detect if the mechanism was closing on someone's finger, etc. and reverse direction.

Most Importantly: Charlie is probably going to go to his first "computer camp" this summer to learn basic programming concepts (He's 6 now).. I can really appreciate how well one of these little Arduino Starter Kits could evolve into father-and-son experimental projects at the kitchen table a few years from now. Being able to introduce this type of electronics / hardware / programming in a fun, simple way would be incredibly rewarding for him (and if I'm being 100% honest, it would be a lot of fun for me too).... being able to think of an idea, and then develop the logic for how it would work... then creating it quickly and observing results is the kind of creativity that I'd love to nurture with him.


So there you go. Hopefully not a huge rat-hole, time sink sub-project in the short term... but more of a placeholder for bite-sized, Charlie-and-Dad creations in the future.


-G

 

[JoshHefnerX]

You're going to need one for each wheel, if you get into an off camber situation and both tires on an axle are tied together you could squeeze the lower tire down.