On-board air in a bag

[jscherb]

A few years ago at the SEMA Show I talked with a compressor company about different ideas for mounting a compressor in a Jeep and they supplied me with a compressor and tank to prototype with.

Since I have 3 Jeeps and may want to use the compressor with any of them, I decided not to do a fixed on board air mount so for a first prototype I mounted the compressor on a base that fits inside a Fat50 ammo can. There's enough room in the can for the jumper cables to connect the compressor to the Jeep's battery and a 25' coiled air line.

I've used it a couple of times and it worked well.

I also tested the compressor with the 2-gallon tank the compressor company gave me. I configured the tank with a pressure regulator with output pressure gauge and the larger gauge shows the pressure in the tank.

It takes less than a minute for the compressor to get the tank up to full pressure (100 psi). Airing up a tire is a bit quicker with the tank, but since my 32" tires have a volume of about 12 gallons, the tank doesn't go too far before the compressor has to kick in. Based on my tests with the tank it may not be worth using the tank if the main use of the compressor is airing up tires, especially since storage space is at a premium in most Jeeps.

One thing I don't like about the ammo can solution is that the hard ammo can is a little more difficult to store in some places in the Jeep than a more flexible soft fabric bag might be, so I designed a bag. There are compressor bags on the market, but as far as I know, they're all just bags for storing/carrying the compressor - they're not designed so the compressor can stay in the bag when it's being used.

I did some research on compressor sizes (ViAir, etc.) and sized my bag design so it'll fit all of the portable/on board air compressors of this type that I found. I included two outside pockets and two inside pockets into the bag design to hold common acessories and supplies, like tire plugs and tools. I sewed a prototype bag from olive drab military canvas:

It has a plywood bottom for mounting the compressor and opens diagonally to provide full air flow for compressor cooling. There are outside zipper pockets on both sides of the bag, plus pockets on the inside for things like tire repair supplies (tire plug tools, etc.). There's plenty of room inside for a coiled air line and long power cords to connect it to the battery.

It's wired with a pressure shut off switch and the hoses are set up so it's plug and play to use it with an air tank.

There's wiring to support the pressure shut-off function; that's on the plywood base and is protected with a swing-up cover:

There are two pockets on the outside and two on the inside as well as elastic to hold a pressure gauge and inflator. In this photo the contents of one of the inside pockets are laid out and the elastic for the tools is also visible.

 

[CharlesHS]

Very nice idea.... lots of room for repair, air up and air down tools.

 

[CaliSteve]

That is a nice compact design, I have an ARB onboard setup in the jeep but carry the larger VAIr product in my truck, That came with a carry bag but my concerns is that after use the compressor gets pretty hot and I have been leery about putting it back in the bag with the hose due to the heat, any issues with that on your setup?

 

[AndyG]

I think you should charge people a lot... And when they ask why say... Well you know... Inflation.

Really really cool work.

 

[jgaz]

Lots of thought in this design........as usual

 

[JEEPCJTJ]

I think jscherb is like the Swiss Army Knife of Jeep related products, except unlike like the actual Swiss Army Knife, we never know what we'll see next.

 

[joe98tj]

That is a nice compact design, I have an ARB onboard setup in the jeep but carry the larger VAIr product in my truck, That came with a carry bag but my concerns is that after use the compressor gets pretty hot and I have been leery about putting it back in the bag with the hose due to the heat, any issues with that on your setup?

i have the same issue with my superflow compressor. I'm also tired of pulling it out and packing it up so I'm switching to a york compressor setup. One less thing to carry in the back.

 

[Modoc Guy]

Wow, you sure are a handy Andy! Pretty slick setup, and I haven’t seen anything else like it.

I like the canvas bag that opens up completely, and the QD connection.

What’s the pressure switch’s cutoff in pounds? Is that for a plug-it-in-and-forget-it scenario?

And for the compressor, have you timed inflating an off-road tire? How does it compare to other popular compressors? Does it heat up quickly or not?


As an end user, I wouldn’t be interested in dragging around an air tank though.

I’m not trying to criticize, I’m assessing it like a potential customer. Because I am looking for a compressor, and what you’ve put together is something I’d be interested in buying.

Have you considered what the price point might be?

And thanks for letting us check out what you’ve been working on, as always, very nice!

 

[freedom_in_4low]

Very nice. I did something similar this summer using an empty case for an Ingersoll Rand battery powered impact. It's very slim and convenient, but it's biggest drawback is that the inside of the case looks like I cut it out in 20 minutes with a dremel. Because that's exactly what I did.

I hope to one day get anywhere near your level of skill and/or patience.

 

[jscherb]

Wow, you sure are a handy Andy! Pretty slick setup, and I haven’t seen anything else like it.

I like the canvas bag that opens up completely, and the QD connection.

Thank you. I researched everything on the market and almost all of them seem to be simple bags that hold the compressor when it's not in use, but I couldn't find any which the compressor can mount in and be used while it's in the bag. The diagonal full opening design is what allows the compressor to be mounted in the bag and used without removing it because there's enough airflow when the bag is fully open for normal operation of the compressor.

What’s the pressure switch’s cutoff in pounds? Is that for a plug-it-in-and-forget-it scenario?

The switch is closed up to 115 psi, then it opens and shuts the compressor off. When the pressure drops below 90 psi, the switch closes and the compressor starts up again. With just the air hose, it'll run for a few seconds at startup and then shut off and once you're using the air it'll run as necessary. WIth the air tank attached it'll run until there's 115 psi in the tank and then it will shut off, starting up again when the tank pressure drops below 90 psi.

And for the compressor, have you timed inflating an off-road tire? How does it compare to other popular compressors? Does it heat up quickly or not?

This compressor is just the one I was given to work with, I didn't do any comparison of compressors on the market to pick the best one. I'd think it's in the upper third of the pack when it comes to CFM and pressure and there are probably better ones around but this does a reasonable job at filling tires (and the compressor company supplied it to me for this project so who am I to complain ). I haven't timed inflating from aired-down to road pressure, I'll have to do that. Heat doesn't seem to be too bad.

I did research compressors on the market to compare sizes and when I did the design of this bag I sized it based on my research - all of the compressors of this type that I found will fit in this bag. This compressor isn't the largest on the market, it is on the large end of the scale but there's room in the bag for one that's several inches larger than this one.

As an end user, I wouldn’t be interested in dragging around an air tank though.

Me either. As I said in my original post, adding the tank doesn't appreciably speed airing up because this size tank gets emptied before the first tire is filled.

I’m not trying to criticize, I’m assessing it like a potential customer. Because I am looking for a compressor, and what you’ve put together is something I’d be interested in buying.

Have you considered what the price point might be?

And thanks for letting us check out what you’ve been working on, as always, very nice!

At this point I don't have any plans to turn this into a commercial product, but if a company wanted to market it I'd be happy to make the design available.

Price would depend on the company and their manufacturing cost and profit margin but the basic bag could be sewn quite affordably - many companies, such as Rothco (one of the larger manufacturers of Molle and quasi-military soft goods) do their manufacturing in India where sewing labor is fairly inexpensive but highly skilled. They sell "Tanker Tool Bags" which are simpler than my design for less then $25 (https://www.rothco.com/product/rothco-tanker-tool-bag); I think adding the features of my bag to something like that wouldn't push the retail price up to more than $50 if a company like Rothco did it. That's not counting the stuff that goes in the bag of course, and perhaps not the piece of plywood that forms the bottom that the compressor mounts to, but that's a trivial DIY. BTW the military canvas fabric I used for this bag I got by unsewing a Rothco duffle bag made in India: https://www.rothco.com/product/rothco-heavyweight-top-load-canvas-duffle-bag .

A year or so ago I did some prototype work with one of the Indian contract manufacturers that Rothco uses so I've got some experience to base those comments on. The project I did with that manufacturer was a tool bag to carry in the Jeep but a very different design than the Rothco Tanker Tool bag linked above. The design turned out to be extremely functional and useful but it so far hasn't made it to market. I can post photos of it if people are interested.

That is a nice compact design, I have an ARB onboard setup in the jeep but carry the larger VAIr product in my truck, That came with a carry bag but my concerns is that after use the compressor gets pretty hot and I have been leery about putting it back in the bag with the hose due to the heat, any issues with that on your setup?

So far in my testing it hasn't gotten hot enough for that to be a concern but it is something I'll keep an eye on.

Lots of thought in this design........as usual

Like almost all of my projects, I spent more time in the design phase than I did in the construction/sewing phase..... as usual .

 

[Jerry Bransford]

That size of single-piston compressor makes me think it wouldn't put out enough air volume to satisfy me. As in enough CFM, as in at least 1.5 to 2 CFM or more. Less than that and you're going to be waiting a long time to get all four tires aired up.

Exactly what is that compressor's CFM rating when pumping into a known pressure like 20 or 30 PSI? No one cares what its max PSI pressure is, that's a useless rating for this job. What is its exact CFM rating when measured into a known pressure, like when refilling a tire? A CFM rating into the open air is useless, our lungs can probably put 20 CFM out into the open air but 0 CFM when trying to inflate a tire.

Also, what is its duty cycle when airing up a tire? Many I see of that size tend to get hot and shut themselves off while airing up more than one big Jeep-size tire.

If it's not readily apparent I really don't trust small compressors for big Jeep-size tire refilling duties lol.

 

[jscherb]

That size of single-piston compressor makes me think it wouldn't put out enough air volume to satisfy me. As in enough CFM, as in at least 1.5 to 2 CFM or more. Less than that and you're going to be waiting a long time to get all four tires aired up.

Exactly what is that compressor's CFM rating when pumping into a known pressure like 20 or 30 PSI? No one cares what its max PSI pressure is, that's a useless rating for this job. What is its exact CFM rating when measured into a known pressure, like when refilling a tire? A CFM rating into the open air is useless, our lungs can probably put 20 CFM out into the open air but 0 CFM when trying to inflate a tire.

Also, what is its duty cycle when airing up a tire? Many I see of that size tend to get hot and shut themselves off while airing up more than one big Jeep-size tire.

If it's not readily apparent I really don't trust small compressors for big Jeep-size tire refilling duties lol.

This compressor is rated at 1.8 cfm at 0 psi and 1.5 cfm at 30 psi and the duty cycle is 100% - continuous use. It has a maximum pressure capability of 200 psi.

The company that supplied the compressor to me has models that have higher cfm capability although those generally have lower duty cycles.

I believe that a 100% duty cycle is critical for a Jeep application - having a compressor that has a 50% or 30% duty cycle will require far too much time to cool down between airing up 4 tires to be useful (or if you skip the duty cycle and run it continuously it won't have a very long life). I asked the company for this compressor because of continuous duty cycle and it had the highest CFM of all of the 100% duty cycle compressors they had on display that year at SEMA. They were nice enough to let me have the compressor and air tank when they were packing up their booth at the end of the show and I'm grateful to them for their assistance with my project.

If I decide I need a higher capacity compressor at some point, I can remove this one from the bag and install a new one - the bag is sized to fit all of the compressors of this type that I found during my searching while doing the design of the bag.

 

[Jerry Bransford]

This compressor is rated at 1.8 cfm at 0 psi and 1.5 cfm at 30 psi and the duty cycle is 100% - continuous use.

That 1.5 CFM at 30 psi is a good useful rating and the 100% duty cycle is, as you say, what we need. Thanks for those specs!

 

[jgaz]

The design turned out to be extremely functional and useful but it so far hasn't made it to market. I can post photos of it if people are interested.

I’m always interested in the designs that come out of your shop(s)
There is something to learn from almost everyone.

 

[jscherb]

I’m always interested in the designs that come out of your shop(s)
There is something to learn from almost everyone.

That project was about designing a useful, compact tool bag to carry a common set of tools I use a lot. It wasn't intended to replace a full tool bag, it was just to be a bag to hold and organize the most common tools I use. It had to be compact, and have good organization inside to make selecting the right tool quick and easy instead of rooting around in a bag.

The shell of the bag was sewed by a contact sewing company in India that does a lot of work for companies like Rothco. I collaborated with them on the project when I was in India a year or so ago. After they sewed the shell to my design I took it and sewed the inside tool holders and I added the attachments on the rear. I've been using it in my Jeep ever since and it's extremely handy.

Here's how it works:

It's got Molle straps on the back as well as a belt clip/Grab & Go clip so you can hang it on your belt or you can hang it on a suitably strong Molle panel.

 

[jscherb]

You may have noticed the "Keep Calm and Air Down" patch in the first photo of the bag...

When I was doing the bag design I decided it would be fun to have something like that on the bag so I designed the patch and had a patch company make a prototype. I posted a photo of the preproduction sample in another thread and some people seemed interested in getting patches for themselves, so I ordered enough to make some available. I don't sell anything myself so I asked a company I've done some design work for if they'd be interested in selling them and they agreed.

When the patches arrived the other day I took a few out of the shipment for myself and turned the rest over to that company. They just got them up on their web site and you can order them now: https://www.overland-outfitters.com/store/p42/Keep_Calm_and_Air_Down_patch.html#/ I had only a small quantity made so if anyone wants a patch you might want to order quickly, I don't know if the company will make them a regular product or if selling this batch will be a one-time favor they're doing for me.

The patches are 2" wide and 3" high. They have a Velcro hook backing so they'll stick to any Velcro loop surface, and they come with a matching piece of Velcro hook in case you need to sew that onto something (the loop piece is offset on one patch in the photo).

For the record: I will receive none of the proceeds and no compensation from the sale of these patches. The company will reimburse me for the expense of having these patches made and they will keep all of the proceeds from any sales.

 

[Viking Jeeper]

That size of single-piston compressor makes me think it wouldn't put out enough air volume to satisfy me. As in enough CFM, as in at least 1.5 to 2 CFM or more. Less than that and you're going to be waiting a long time to get all four tires aired up.

Exactly what is that compressor's CFM rating when pumping into a known pressure like 20 or 30 PSI? No one cares what its max PSI pressure is, that's a useless rating for this job. What is its exact CFM rating when measured into a known pressure, like when refilling a tire? A CFM rating into the open air is useless, our lungs can probably put 20 CFM out into the open air but 0 CFM when trying to inflate a tire.

Also, what is its duty cycle when airing up a tire? Many I see of that size tend to get hot and shut themselves off while airing up more than one big Jeep-size tire.

If it's not readily apparent I really don't trust small compressors for big Jeep-size tire refilling duties lol.

Just curios, what do you feel is a reasonable time to air up 4 tires back to street pressure?

 

[AndyG]

Sir, I don't know what you do daily, or your background, but you have a talent for design and efficiency that I'm glad isn't going to waste.

 

[Jerry Bransford]

Just curios, what do you feel is a reasonable time to air up 4 tires back to street pressure?

I'd start getting cranky if it took me more than about ten minutes which is double what it takes me now. Before I knew anything about trail compressors, I bought my first compressor which was a Truck Air. I was in for a rude awakening when I discovered it took 45 minutes to reinflate four 32" tires from 12 to 30 psi after 3 days in Death Valley.

Hearing a Jeeper's tiny compressor drone on for 45 minutes on a Sunday morning in a campground when I'm trying to sleep in a little doesn't make me happy.

 

[Viking Jeeper]

I'd start getting cranky if it took me more than about ten minutes which is double what it takes me now. Before I knew anything about trail compressors, I bought my first compressor which was a TruckAir. I was in for a rude awakening when I discovered it took 45 minutes to reinflate four 32" tires from 12 to 30 psi after 3 days in Death Valley.

Hearing a Jeeper's tiny compressor drone on for 45 minutes on a Sunday morning in a campground when I'm trying to sleep in a little doesn't make me happy.

Holy cow 45 minutes! Thats not acceptable at all.

My two tires at once setup and Viair 88 will do 2 tires in 4-5 minutes.