What I have talk to you guys about today is nothing new in the auto industry. As most of you know a lot of the new vehicles are switching over to electric steering because of gas prices. I know your thinking why the hell do I care a about how much gas my jeep, or buggy consumes. Also why do I care about a 1-5 hp lose because of my power steering pump? (Except for those motor heads)
So why the hell, are you still reading this? Because as most of you are already running hydraulic assist steering or full hydraulic or plan on it some day. This is where I feel electric steering can play a big factor for most of you in the off-road industry. I am currently in the works of switching my hydraulic steering over to electric, using my same pump and for about $100 bucks. Why? Because when I do go hydraulic assist I will be able to adjust my steering as to what I am doing. I have seen over my time on here a lot of guys saying that they’re steering is awesome for rock crawling but anything over 35-45 mph gets hairy. The answer has always been put a bigger ram on.
Well, I was thinking about it and thought why not attach an electric motor to your existing pump and use a variable speed controller so you can adjust your pump for what your doing, not what the motor is doing. Slow crawling you can have your pump turned up as if you were red lining the motor, yet your just idling along. Or when your pre running threw the desert bouncing off the rev limiter your pump is running at idle.
I searched around a bit and found a couple of electric motors that I think would be fine for us that DD our rigs as the motors max rpm is 1500. I found a 12vdc variable speed controller off E-bay for $21 bucks. I am sure if you searched more you could find a higher rpm motor but for me I think that will about do it.
A good article to read and kind of school you on the history and “how it works” of electric steering is here:

http://www.automotivedesignline.com/howto/165600237

That is truly an article billavista could love and fully understand. Below are links to the motor and controller I found. The hot rod guys have been running water pumps off electricity for a long time and like I said this is nothing new just a new way to apply it to our industry. I hope to get this going soon because like they say everything looks good on paper till you actually do it. Hope you guys at least enjoy the tech.


12vdc pwm controller

http://cgi.ebay.com.sg/DC-Motor-Speed-Control-PWM-Controller-12-30V-30A_W0QQitemZ160309132752QQihZ006QQcategoryZ78190Q QcmdZViewItem

12vdc electric motor

http://cgi.ebay.com/ebaymotors/Mr.-Gasket-4396-12vDCElectricMotorJEGS_W0QQitemZ200305770945QQcmdZ ViewItem#ht_2096wt_1048

I like the idea. Very curious to see how the difference in RPM's will relate to real world driving.

What I have talk to you guys about today is nothing new in the auto industry. As most of you know a lot of the new vehicles are switching over to electric steering because of gas prices. I know your thinking why the hell do I care a about how much gas my jeep, or buggy consumes. Also why do I care about a 1-5 hp lose because of my power steering pump? (Except for those motor heads)
So why the hell, are you still reading this? Because as most of you are already running hydraulic assist steering or full hydraulic or plan on it some day. This is where I feel electric steering can play a big factor for most of you in the off-road industry. I am currently in the works of switching my hydraulic steering over to electric, using my same pump and for about $100 bucks. Why? Because when I do go hydraulic assist I will be able to adjust my steering as to what I am doing. I have seen over my time on here a lot of guys saying that they’re steering is awesome for rock crawling but anything over 35-45 mph gets hairy. The answer has always been put a bigger ram on.
Well, I was thinking about it and thought why not attach an electric motor to your existing pump and use a variable speed controller so you can adjust your pump for what your doing, not what the motor is doing. Slow crawling you can have your pump turned up as if you were red lining the motor, yet your just idling along. Or when your pre running threw the desert bouncing off the rev limiter your pump is running at idle.
I searched around a bit and found a couple of electric motors that I think would be fine for us that DD our rigs as the motors max rpm is 1500. I found a 12vdc variable speed controller off E-bay for $21 bucks. I am sure if you searched more you could find a higher rpm motor but for me I think that will about do it.
A good article to read and kind of school you on the history and “how it works” of electric steering is here:

http://www.automotivedesignline.com/howto/165600237

That is truly an article billavista could love and fully understand. Below are links to the motor and controller I found. The hot rod guys have been running water pumps off electricity for a long time and like I said this is nothing new just a new way to apply it to our industry. I hope to get this going soon because like they say everything looks good on paper till you actually do it. Hope you guys at least enjoy the tech.


12vdc pwm controller

http://cgi.ebay.com.sg/DC-Motor-Speed-Control-PWM-Controller-12-30V-30A_W0QQitemZ160309132752QQihZ006QQcategoryZ78190Q QcmdZViewItem

12vdc electric motor

http://cgi.ebay.com/ebaymotors/Mr.-Gasket-4396-12vDCElectricMotorJEGS_W0QQitemZ200305770945QQcmdZ ViewItem#ht_2096wt_1048

i'm not sure if that motor will have the umph to turn the steering pump for the pressures we require. seems if your PS pump pulls 1-5HP, you would need a 1-5HP motor to power that pump... give it a shot though, let us know how it works :)

when i say 1-5 i am saying varying the differnt types of motors that all of us are running i did just find a motor that is a 1/2 hp 2,500 rpm motor here's the link:

http://www.davis.com/catalog/product_view.asp?sku=7007110

also there are two differnt methods i was thinking of for setting up one would be to drill out the shaft on my ps pump and then use a small cross shaft to hold it in. second if need be i can get a high rpm small motor and use gear reduction to get more power out of it so really i would have to test to see what motor works. i am going to go for the cheap ne first because the motor above is very expensive but if it works so some and they don't want to mess with it its definatly doable. those KOH guys have all the money so they can buy that one:flipoff2:

also i found this website that you can build your own motor but you have to buy ten so if i do it and it works would anybody be interested in buying some motors to convert your steering to electric?

You've been looking at the RC Crawlers too much haven't you? :laughing:

I will be definitely keeping an eye on this...I too want the capability of Driving on the street/highway with safe steering that can handle offroading and crawling as well.

Electric Power Assisted Steering ("EPAS") is a great idea, but today's 12V systems limits its use to smaller vehicles.

When EPAS shows up in Class 3-4 trucks, there will be something that could be adapted for the torque requirements of off-road use. 'Til then, we're stuck with our hoses, reservoirs, pumps and fluids.

I think THachiya just answered this but you are not talking about a 100% electric steering system are you? I assume that would be just as illegal as full-hydro for on-road driving. You are talking about a traditional PS system with an electric "assist". Is that correct?

Subscribed.

If your looking at a typical Hiflow power steering pump, lets say they put out 4 gpm @1500 psi. That works out to 4 HP at max flow/pressure. So your looking at a 12volt motor similar to what is on a winch ( 4.6 hp on mine Warn) How long do you think your battery would last if you used your winch to move your vehicle down the trail, not very long and you would be using alot of amperage to power this motor in a full time situation, your going to need some big ass Alternators.

Reducing your pump flow by reducing your electric motor speed, sounds good, but the pump has nothing to do with the speed of your steering, your orbital valve determines how fast the steering reacts based on a fixed flow output per revolution of the steering wheel. By reducing the pump flow all you are going to do is starve the orbital of fluid which will take away its power advantage and your steering wheel will lock up waiting for more fluid to be delivered a very jerky experience.

If you set up your steering for between 2.5 and 3.5 turns lock to lock, you should have a system that is not overly responsive at high speed, yet still gives you reasonably fast control at low speed.

My rig is 2.62 turns lock to lock with full hydro and I have no problem running down the road at 60 mph with one finger on the wheel and it still turns fine in the rocks, with a 2.5" bore ram with a 1.5" rod that gives me 4710 lbs of force pushing in both directions from the ram @ 1500 psi.

If you cant drive over 35 mph without white knuckling the steering wheel, you have not set up your system properly, it' as simple as that.

I assume that would be just as illegal as full-hydro for on-road driving. You are talking about a traditional PS system with an electric "assist". Is that correct?

Subscribed.

There are both Elec/Hydro and full electric systems. Until you eliminate the hydraulics completely, I am having trouble seeing any real advantages of EPAS for our applications.

But, that's just my opinion, and I could be wrong.

No hi-jack intended

My rig is 2.62 turns lock to lock with full hydro and I have no problem running down the road at 60 mph with one finger on the wheel and it still turns fine in the rocks, with a 2.5" bore ram with a 1.5" rod that gives me 4710 lbs of force pushing in both directions from the ram @ 1500 psi..

I'm guessing your using a 7.5 c.l. (orbital) steering control valve.

Electric Power Assisted Steering ("EPAS") is a great idea, but today's 12V systems limits its use to smaller vehicles.


When EPAS shows up in Class 3-4 trucks, there will be something that could be adapted for the torque requirements of off-road use. 'Til then, we're stuck with our hoses, reservoirs, pumps and fluids.

true but if you've been reading your popular mechanics magizine:flipoff2: they have been talking about starting to introduce this into larger vehicles. i just got off the phone with a sales rep for an electric motor company and i am going to be talking with them in designing a motor per my specifications.


ok lets say you have an electric motor that puts out 750 oz-in you convert that to lb-ft and you would have a 3.9 lb-ft motor. times that by 2 (if you were to use gear reduction) and you get 7.812 lb-fts. you take that number and use the rpms of the motor lets say 2650 and you get .01984126984127 hp.i guess the issue here isn't some much the horse power anymore but the lb-fts and the rpm speed and how you can maintain the torque through out the rpm range. horsepower isn't really what makes the motor turn. it's the torque. as you know horsepower in lets say your muscle car doesn't really come into play until higher rpms. winch company's and such use a hp number for you to be like," wow a 5 hp winch motor damn thats big."

I think THachiya just answered this but you are not talking about a 100% electric steering system are you? I assume that would be just as illegal as full-hydro for on-road driving. You are talking about a traditional PS system with an electric "assist". Is that correct?


Subscribed.

yes correct i am talking about a "bolt on" variable steering controller.

If your looking at a typical Hiflow power steering pump, lets say they put out 4 gpm @1500 psi. That works out to 4 HP at max flow/pressure. So your looking at a 12volt motor similar to what is on a winch ( 4.6 hp on mine Warn) How long do you think your battery would last if you used your winch to move your vehicle down the trail, not very long and you would be using alot of amperage to power this motor in a full time situation, your going to need some big ass Alternators.

Reducing your pump flow by reducing your electric motor speed, sounds good, but the pump has nothing to do with the speed of your steering, your orbital valve determines how fast the steering reacts based on a fixed flow output per revolution of the steering wheel. By reducing the pump flow all you are going to do is starve the orbital of fluid which will take away its power advantage and your steering wheel will lock up waiting for more fluid to be delivered a very jerky experience.

If you set up your steering for between 2.5 and 3.5 turns lock to lock, you should have a system that is not overly responsive at high speed, yet still gives you reasonably fast control at low speed.

My rig is 2.62 turns lock to lock with full hydro and I have no problem running down the road at 60 mph with one finger on the wheel and it still turns fine in the rocks, with a 2.5" bore ram with a 1.5" rod that gives me 4710 lbs of force pushing in both directions from the ram @ 1500 psi.

If you cant drive over 35 mph without white knuckling the steering wheel, you have not set up your system properly, it' as simple as that.

ok, so i guess by what your saying this wouldn't work with full hydro steering. you would need some type of maunal steering still involved because as you said when you starve the orbital the manual steering can take over. i am assuming with full hydro that would mean your steering "jumps." but what i am trying to say is that you are never totally taking away that flow to the orbital. you are slowing it down to a point where its as if it was at idle. because as your rpms increase so does the flow, thus allow your steering to react quicker, correct? by reducing flow this doesn't allow your orbital react as fast thus slowing down steering speed. what i am talking about is playing in between the medium of your vehicles idle speed (750-1000 rpms) and lets say redline. (though we should all know that after a certain rpm your power steering pump isn't going to pump any faster.)

I've designed electric power steering motors before, we used *slightly* more powerful motors. (60-90 amps per phase, 3 phase DC brushless motors).

I don't see this going anywhere, really. Sounds like all you are doing is adding an electric powered pump instead of the pulley drive?

So, is this poor motor spinning all the time? How are you controlling the power you need? I have more things to do on the trail than constantly be dialing up and down the power on my hydraulic assist.

I don't see that controller being up to the task, nor that motor. There's no sensors/feedback to determine how much assist you need and dial up the motor on the fly to match need.

No hi-jack intended



I'm guessing your using a 7.5 c.l. (orbital) steering control valve.

No, 9.6 cuin/rev with an 8" stroke cylinder


ok, so i guess by what your saying this wouldn't work with full hydro steering. you would need some type of maunal steering still involved because as you said when you starve the orbital the manual steering can take over. i am assuming with full hydro that would mean your steering "jumps." but what i am trying to say is that you are never totally taking away that flow to the orbital. you are slowing it down to a point where its as if it was at idle. because as your rpms increase so does the flow, thus allow your steering to react quicker, correct? by reducing flow this doesn't allow your orbital react as fast thus slowing down steering speed. what i am talking about is playing in between the medium of your vehicles idle speed (750-1000 rpms) and lets say redline. (though we should all know that after a certain rpm your power steering pump isn't going to pump any faster.)

If you could find a way to give a constant RPM to the pump that would be ideal. I was thinking a long time ago of a snowmoblie drive, so at low engine RPM you have higher than idle RPM to the PS pump and as engine RPM increases the RPM's to the pump stay somewhat the same. Power Steering pumps are a Vane pump which for the most part needs 600 rpm to start working, above 4000 rpm, the vanes will start floating and your flow curve will flatten out.

If all you want to do is take the pulley drive power steering pump off the motors drive and run it off a 12VDC motor why not purchase a 12VDC pump itself which is already made to do what you want?

http://www.surpluscenter.com/item.asp?UID=2009020614320981&item=9-7313&catname=hydraulic

This is just an example and too small for a primary but it shows the idea.

I've seen them used as backups to pulley drive systems for safety and also as aux setups to run rearstear and other accessories.

I do not think there is much advantage since the current electrical will not be able to keep up with either setup with modifications.

I've designed electric power steering motors before, we used *slightly* more powerful motors. (60-90 amps per phase, 3 phase DC brushless motors).

I don't see this going anywhere, really. Sounds like all you are doing is adding an electric powered pump instead of the pulley drive?

So, is this poor motor spinning all the time? How are you controlling the power you need? I have more things to do on the trail than constantly be dialing up and down the power on my hydraulic assist.

I don't see that controller being up to the task, nor that motor. There's no sensors/feedback to determine how much assist you need and dial up the motor on the fly to match need.

the motor listed isn't going to be the one i am using. i just put it there to give u guys an idea after more research i do realize ill need more power. yea thats all i am doing an electric pump yea the motor is going to be running all the time. i am still trying to figure out if i want to use a variable controller like the one above or use a 3 way switch with low speed being idle (highway driving) and high speed being 3-4000 rpms (crawling). its not rocket science, its a knob you turn down alot when driving fast and turn way up when driving slow. can you turn the volume up on your radio?:flipoff2:

not sure if this is anywhere close to what you're thinking about, but my DD, a 08 saturn vue, has what I think they call "speed sensitive power steering".
when stopped, or moving slowly, there is more assistance from the power steering(really easy to turn the wheel). but at highway speeds, there is less assistance from the power steering, which requires more force to turn the steering wheel.
maybe something similar could be incorperated into a hydro assist(or maybe full hydro) system.

thats exactly what i am talking about but i am trying to do a cheap version of that. to buy a whole new steering setup for your vue would be $$$$. and i don't think it would have enough power. plus the system moniters itself which actually wouldn't be bad if i could figure that out. but like thats getting way too much $$$ and to fancy you'd have more whiling into your steering then your whole jeep combined:D

Keep in mind that 12V electrical systems are on the way out. 48 volts is talked about a lot, and 100 volts has been on Ford diesels for years (and maybe others). As system voltages go up, it's easier to get the power you need to run pumps an such.

not sure if this is anywhere close to what you're thinking about, but my DD, a 08 saturn vue, has what I think they call "speed sensitive power steering".
when stopped, or moving slowly, there is more assistance from the power steering(really easy to turn the wheel). but at highway speeds, there is less assistance from the power steering, which requires more force to turn the steering wheel.
maybe something similar could be incorperated into a hydro assist(or maybe full hydro) system.


I believe ford did this in the late 70's on the Mustang. (amazing, I remembered something from the 70's, I think:laughing:)

your right they are trying to push 48v in a lot of new cars. i could use a 12v to 24v converter module and be able to use a stronger motor. i am really not to worried about all of this because every problem you guys find there is a solution for something else that can be adapted. i mean come on guys all this is, is some wires and magnets:flipoff2:

I don't mean to piss in the punchbowl, but EPAS has been around for about 10 yrs. (Delphi & TRW) Beyond the torque density issue of electric vs. hydraulic, you also have to deal with the sensors, the control algorithms, and actuators needed to pull it off. Now if 21st Century steering means an electric motor driven pump, it's simpler, but what do you really gain?

The industry has been talking about a lot of stuff, (e.g. 42V) but the technology needs to be in volume production for awhile before it is affordable for the aftermarket. Consider digital fuel injection and you can get a sense of the lag between widespread adoption and aftermarket availability.

Hey, it's nice to dream, but I'm not holding my breath.

Keep in mind that 12V electrical systems are on the way out. 48 volts is talked about a lot, and 100 volts has been on Ford diesels for years (and maybe others). As system voltages go up, it's easier to get the power you need to run pumps an such.

your right they are trying to push 48v in a lot of new cars. i could use a 12v to 24v converter module and be able to use a stronger motor. i am really not to worried about all of this because every problem you guys find there is a solution for something else that can be adapted. i mean come on guys all this is, is some wires and magnets:flipoff2:

It was 42 volts, and has been on the back burner for 10 years, and isn't going anywhere. The Vue system isn't electro-hydraulic, its a servomotor on a rack and pinion I believe.

I'm not trying to be a jerk, I just find people tend to not understand how difficult DC motor control design is. Developing an automotive rated PWM controller for the 40-60-100+ amps you'll need isn't trivial.

Variable speed electric powersteering pumps already exists, why reinvent the wheel?
Subaru electric power steering pump is speed sensitive, I'd bet you could wire it up to manually control it.

Bunch o' info in this first thread:
http://www.pirate4x4.com/forum/showthread.php?t=493877&highlight=subaru+steering+pump


http://www.pirate4x4.com/forum/showthread.php?t=417746&highlight=subaru+steering+pump


i just got off the phone with a sales rep for an electric motor company and i am going to be talking with them in designing a motor per my specifications.


Custom built electric motors sound expensive. So, what happens when your custom built electric motor shits the bed? Oh yeah, you have 9 extra because you have to buy at least 10 and you are the only one using it.:rolleyes:

The Concept is already out there, on the new Hybrid SUVs from GM have full eletric steering system that run off 42 volts, its a eletric rack and pinion setup. My question is wouldnt the electric draw from the motor make the alt. work harder causing more power to be robbed from the engine. But i do under stand the idea and in concept it should work. So let the guy spend some money and try it. if it works then great and we all got some new stuff to try on our rigs.

Ok so now for a little help from someone that has also thought about this. THere are orbital valves that go in line with your steering shaft. they were used back in the 60s on larger cars to give them power steering. so why not run your stock power steering put one of these in line with your shaft and run the electric pump to this, so you would have two systems your stock pump for road use then turn on the electric pump for when you are in the rocks to run your hydro assist.

Variable speed electric powersteering pumps already exists, why reinvent the wheel?
Subaru electric power steering pump is speed sensitive, I'd bet you could wire it up to manually control it.

Bunch o' info in this first thread:
http://www.pirate4x4.com/forum/showthread.php?t=493877&highlight=subaru+steering+pump


http://www.pirate4x4.com/forum/showthread.php?t=417746&highlight=subaru+steering+pump



Custom built electric motors sound expensive. So, what happens when your custom built electric motor shits the bed? Oh yeah, you have 9 extra because you have to buy at least 10 and you are the only one using it.:rolleyes:


The weak point is almost always the controller.

As someone earlier, you have a high power requirement to keep up that kind of hydraulic power.

Say you have a basic pump putting out 2.5 gpm @ 1400 psi. Pretty typical stuff.

OK, so, mechanical requirements for powering that is (2.5)*(1400)/(1714)*pump efficiency. That is not all that great, in the 50% range I believe. Lets say its even 75% efficient, then you need 2.72 horspower to turn that pump. Now, you have a DC brushed motor, thats about 75-80% efficient, we'll say you got a good one and its 80%. You need about 3.40 'hp' of input power, which, as 746 watts/hp is about 2500 watts (2539).

OK, at normal battery of say 13.8 volts, then its drawing 184 amps. Actually more, because that PWM controler is taking more amps and converting them into heat. Enough to cook your breakfast on.


You need to have enough flow to power the hydraulic ram, so there just isn't much you can do.


Its an interesting idea, but its just not practical. Just get a variable ratio steering box if you are concerned with twitchiness. Changing the pressure won't change how much your wheels turn for each turn of the wheel.

What about the pump from a Subaru XT6 or Toyota MR2? Both 12v constant duty pumps.

What about the pump from a Subaru XT6 or Toyota MR2? Both 12v constant duty pumps.
I was wondering that too.
For those of you asking why re-invent the wheel? I'm personally interested in the space-saving potential. I can mount an electrically-driven p/s pump out of the way of a manifold/turbo/downpipe alot easier than a belt-driven one.
But it doesn't sound like any of these readily-available/affordable 12V motors would be up to running a full-hydro system...