High output OBA like Oasis (1 Viewer)

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PIP

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I'm disappointed by 12V air compressor shaped objects. I'd like something with a better air : noise ratio. Engine driven works well enough, but it's a complicated install in many situations. I've never needed OBA enough to make the commitment to mount up an engine driven York. Oasis looks like the perfect answer, but $1800 is a bit too steep for me.

My background in winch testing and manufacturing and selling winch parts like Albrights got me thinking about using a 12V winch motor to run a larger pump. My first thought was make an old school Warn Powerplant- Mount a compressor pump onto a Warn 8274 in a way that the sliding motor pinion would disengage from the winch gears to engage the pump crankshaft. However, mocking it up it didn't look right. Any pump that's small enough to put out much air is way too big to mount onto an 8274.

Even though a York isn't a real air compressor many people use them as such. Seems well proven enough to try it, but with a common 20 spline 12V winch motor driving it instead of a belt. Winch motors rev under low load to about 5000 RPM. Supposedly York compressors can handle that. The bigger Yorks are 9-10 cubic inches/rev

I don't know how a York compressor would load a series wound winch motor, but I'd expect lower pressure to be 4000 RPM+ with RPM dropping as the pressure increases. At low pressure with a 10 cubic inch York spinning 4000 RPM that would be 40,000 cubic inches per minute or 23.1 uncorrected CFM. Pumping isn't 100% efficient. Compressor's usually fall in the 65% to 75% efficiency range. If we call it 65% efficiency that would be 15 CFM at low pressure, like the first 20 PSI of filling a tire.

The max CFM would come down to the HP of the motor used. Most winch motors are advertised as having 4 to 6HP, but these are momentary meltdown ratings and winch real world HP is more like 2 to 2.5 HP for anything more than a few dozen seconds. In testing I've observed winches run continuously under load on dyno stands for hours at loads around 2 HP.

Searching around online I found it stated several times that one real motor HP equates to about 4 CFM airflow @ 100 PSI. That sounds believable to me. So in that case my goal for a motor driven York compressor would be 8 CFM @ 100 PSI.

I didn't find any rating for ARB compressors at 100 PSI. I found one specification sheet listing 4.68 CFM @ 29 PSI for their "big" maximum performance model.

I'm building this for myself and two friends, but if it works well I'd like to sell the winch motor mount and coupling as a DIY kit. Last week I sent out a winch motor and a new 8274 Warn coupling gear to a broach manufacturer for reverse engineering. I'm supposed to have a broach in 2-3 weeks.

I don't have anything to show until the broach shows up, but any build ideas or suggestions? Stuff that could be incorporated into the motor mount design?

york motor.jpg
 
interesting...im curious to see how this pans out!
 
I could see a 90° drive option being useful for space or possible gearing change.

That could be something to look into. Direct coupled, the overall size will be 15" long, 5-3/4" wide, 9" tall. I believe it's fine to lay the York on it's side as it's often used that way in AC systems. The size seems like it wouldn't be hard to mount it in/under a vehicle.
 
I can't imagine needing that much air on my vehicle, but I'm also curious to see how it turns out. Does the York compressor have any internal gearing or is it direct drive? I'm just wondering if a winch motor has enough torque to drive the compressor at higher pressures without gear reduction
 
I can't imagine needing that much air on my vehicle, but I'm also curious to see how it turns out. Does the York compressor have any internal gearing or is it direct drive? I'm just wondering if a winch motor has enough torque to drive the compressor at higher pressures without gear reduction

York is direct drive. A series wound winch motor has more torque than the York could ever use, but the motor does not have an infinite duty cycle. The motor will use energy from the battery(s) faster than the alternator can charge. The motor will heat up as load and time increases. I expect the York will pump a volume of air that justifies the power consumption.

My hope is that with a appropriately sized air tank a winch motor driven York can air up four 35" tires from 5 to 40 PSI within it's duty cycle.

Say it takes 40 minutes to air up your tires with a 1CFM ARB or similar compressor wouldn't it be nice to do it 8 times faster?

Also, moreso than just more air output there's the idea that you'd use the same winch motor and contactor as your winch uses so you have a spare for either if ever needed. A York pump is a higher quality pump to any of the arb/viar/pot metal junk compressors out there. Take one apart, they are a real joke inside for what they charge for them. Like the rod and piston are one piece with the intake reed in the piston and dirt/air intake goes through the "crankcase" on many. They are engineered to be built as cheap as possible and last through the warranty period most of the time.

If I build a winch motor powered York compressor the pump is rebuildable or replaceable for very low cost. If the motor fails the motor is replaceable for low cost.

Once the motor driven York is assembled I will be testing it. I have a power supply that was custom built for dyno testing 12 volt DC winches. I can power it to melt down while measuring current and pressure. I am considering picking up a flow rate sensor to measure CFM, but want to get past the proof of concept part first.

The broach design is finalized and currently being machined. It should be finished next week, but must be sent out for a high temp coating so it can survive running in tougher steel.
 
I like this idea! I had an Oasis OBA setup in my G-Wagen and absolutely loved it, coupled with a small tank it made airing up 37's a piece of cake, and I could run a 1/2" air impact gun with it no problem. Having similar performance without the eyewatering price would be really nice!
 
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Additional thoughts about the project-

My friend Matt will be using one of these on his rock crawler. He is building a low cost controller for the compressor using a $5 microcontroller. Screen would display pressure, temp and run time (for oil change interval). Programmable cut in/cut out pressures, possibly different modes, like low PSI locker mode vs high PSI air tool mode. It will have high temp shutdown for the motor or pump or both.

Other features that might be useful?

Which compressor temperature would be more relevant- The cylinder head temp or the sump oil temp?

Would a calculated flowrate display be of actual use to anyone? We could install a sensor to pick up crank revolutions. Combine that with pressure data and we could display theoretical compressor CFM.
 
Would it be possible to program in pressure set points that correspond to the user's desired tire pressure? I.e. have the compressor cut off so as not to overfill tires.

Another thought: given that you are looking at using a winch motor, would the unit be relatively watertight/sealed from the elements? I've been contemplating mounting a compressor and air tank up between my frame rails behind a skid plate. Obviously the air intake would have to be plumbed up into the engine bay or somewhere similarly high to avoid water, mud and dust ingress.
 
Would it be possible to program in pressure set points that correspond to the user's desired tire pressure? I.e. have the compressor cut off so as not to overfill tires.

Another thought: given that you are looking at using a winch motor, would the unit be relatively watertight/sealed from the elements? I've been contemplating mounting a compressor and air tank up between my frame rails behind a skid plate. Obviously the air intake would have to be plumbed up into the engine bay or somewhere similarly high to avoid water, mud and dust ingress.

Yes, it could have a mode for tire PSI.

I'm only planning on making the parts to connect the most common style of winch motor, ones with a 20 spline shaft, to any York AC compressor. Many winch motors are sealed up pretty good. Some have gaskets where they seal up to the winch. I don't think the York would care if it got dirty and wet. So if this thing ends up working well enough to turn into a product and you bought it, you get to decide what quality of winch motor to use on your build.
 
Very cool! I didn't realize you were just working on the parts to connect the motor and compressor. Sounds like it will be an awesome DIY kit.
 
Controller proof of concept. It's just displaying text currently. We're planning to use a small 120V portable compressor to test the functionality later this week.

prototype (2).jpeg
 
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The broach shipped Friday. When it arrives the coupling will be machined from 8620 followed by a trip to the heat treaters.

The controller project has morphed into a full custom board build utilizing the new RP2040 microcontroller chip from Raspberry PI. Additionally, all worthwhile projects need a catchy name- This pressure controller will be the Pipsi
 
Any updates on this project? Very curious to see what you've come up with.
 
Any updates on this project? Very curious to see what you've come up with.

The broach wasn't made right. never got that resolved with the manufacturer. We got slammed with work during the pandemic. Things have leveled out now and we're working on products again. I have a significant list of products to get to market in the next few years and this OBA setup is way down on the list.
 
Always frustrating to have a custom made item made that isn't made right.
 
I believe older oasis compressors were just yorks with winch motors. New ones seem to use a motor with a fan on the end plate.
 
I believe older oasis compressors were just yorks with winch motors. New ones seem to use a motor with a fan on the end plate.

Yeah, winch motors are series wound so they make lots of power for a short time. They aren't ideal for an air compressor application, but I thought it wouldn't be a bad deal for a DIY OBA since a lot of folks have winch motors and Yorks laying around.

I thought it would be cool to have the same motor and Albright on your OBA as your winch uses that way you got spare parts onboard if you ever needed them.

Back to this project, I'm considering picking up a minty Fellows 7A gear shaper loaded with tooling that would cut the involute internal splines perfectly instead of broaching them. I have a couple gear hobbers for external spur and helicals, but hobbers cannot do anything internal. The fellows would be great for this project, but it's another machine to house and maintain. It has to earn it's keep.
 
I believe older oasis compressors were just yorks with winch motors. New ones seem to use a motor with a fan on the end plate.
The motors they use appear to be an industrial, continuous duty DC motor, which is probably a large part of the hefty price tag.

That coupler looks interesting, I wish they provided some specifications for it; I am very curious to know the shaft and key size it is made for, and if it has the York taper on the other end. Looking at specifications for Oasis compressors on Grainger it appears they have a working speed of around 1500rpm, which is quite a bit slower than I would have expected. If that is the case, a winch motor from a Ramsey type winch with a keyed shaft and a 2100rpm free running speed might work just fine, and may even fit that coupler.
 

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