Power Steering (Electric)

[Guest Lenny]

Currently have the front framework of my Trooper torn up. Installing a new steering rack with an electric assist. I was so impressed with how well Kinarfi's worked I decided to go electric. He is right about it staying stable when rough stuff. I drove his across a rocky stretch and took my hands off the steering wheel and it stayed straight without kicking the steering wheel back and forth. I went with an electric power steering rack that is out of a Smart car that I found on Ebay. It takes about a third more turns of the wheel to go from side to side and has a motor which is somewhat larger then what Kinarfi is using. It's also a very well built unit with alloy and hardened steel gears and ball and roller bearings. It turns silky smooth without any play and is a closed sealed and lubercated assembly. With my big tires (31 x 10.5 x 15), it was real hard to steer when going slow and nearly impossible to steer when stopped and the front locked out. As a result, I felt I needed a heavier unit then Kinarfi's. I also ordered the Bi-directional motor controller that Gumball dug up. http://www.electronickits.com/kit/complete/motor/k166.htm

Still working on the interface between the controller and the steering coulmn but will somewhat follow Kinarfi. He uses the slop between the upper and lower steering shafts. I'll also short the motor leads when it is not active like Kinarfi did to hold the steering steady. Won't have the electrics hooked up by the Jamboree but should have the rack mounted and useable. Thanks to KIinarfis help and cleaver consepting of the electric steering approach, I think I have a viable concept that will work for the big tires.

Lenny

[Gumball]

I was surfing looking at electric power steering and I ran across this very interesting piece. Apparently the Honda NSX and E2000 have a very sophisticated electric power steering unit. I saw a complete unit on eBay at a really great price. From the looks of it it's to wide for our use but then again ???

Thought you power steering Guru's would like to see how it works.

Check it out at http://www.nsxprime.com/FAQ/Technical/eps.htm.

Gumball

[Detbohica]

you guys kill me with the things that you have done.

[Kinarfi]

Did some more playing with my Power steering, I put a .1 ohm resistor in line with the motor and measured the voltage across it. It indicated about 17 amp draw when turning, 1.7 volts, standing still in the garage and 2.3 volt stalled, end of travel. I then wired a 3 volt flash light bulb in parallel with the resistor and mounted it where I could see it easily as an indicator of how much power the motor was pulling. The interesting and unexpected thing I saw was that if I turn the steering will hard, there is no light or very little light, indicating the power is coming from me and not the battery. It seems like that if I had geared it down a lot more to where I turned the wheel faster than the motor, the motor would actually resist me. Another thing I'm wanting to see is if the light bulb lights when I'm not giving the wheel any input and the motor is stabilizing the steering, that is acting as a shorted generator.

Another thing I did was put two switches in the system to activate the steering with out using the wheel, haven't tried it yet but looking forward to it as soon as I get my rear axle replaced, tomorrow, imagine driving without using the steering wheel , If it works, I'll replace the switches with a joy stick, Pictures when I get around to it.

I'm also looking at that circuit Gumball suggested and Lenny bought. It's looks like a good circuit similar to some I've used in the past and working out how to use it with a relay so I can keep the motor shorting feature which is what makes it stable. But be careful Lenny, the specs say it's only good for 10 amps, as built. Lenny, if you have measured any of the outputs from your steering units in ohms, let me know what they are, and this circuit can easily be adapted to what I have.

Kinarfi

[Guest Lenny]

Good job Kinarfi. Wish I had your knowledge of electronics. I know just about enough to get me in trouble. I'll be interested to see how you intergrate the shorting feature into the Bi-direction controller circuit. I havn't played with the circuit yet so don't know if or how big the neutral center position is. Hopefully there is a little room to work with. If not we can design a primary rotating devise that rotates the dial on the circuit but includes a small space between the directions. Possibly a betterr way would be to insert a circuit into the bi-directional circuit that triggers a relay when the circuit is providing current to the motor. When no current is folwing, the relay could be shorting the motor. The bi-directional circuit info indicates that the board will take somewhat more amps if heavier wires are run to the connection pins. Bring your test equipment to Logandale and we can do some draw testing on my steering. If you would like me to send the bi-directional circuit to you for your analysis and testing, let me know and I'll get it right off to you. Message me your address, I probably have it but will have to search to fnd it.

Lenny

[Kinarfi]

a simple explanation of that circuit is: split your 12 vdc into 3 parts, 4 4 and 4 stacked on top each other, the middle 4 has a wiper centered a 2 which makes 6 to the bottom and the wiper can be adjusted up or down from 4 to 8. that's your input. It moves a stable ramp that goes from 3 to 6 and as you move the wiper, the ramp moves down to 1 to 4 or up to 6 to 9 depending on which way you move the wiper. Notice the 4 - 6 dead zone. If the motor starts left at 2, as you bring the ramp down to 1.9 - 4.9 it only goes under 2 for a moment or as you bring the ramp down to 1 - 4 it goes under 2 for a longer period, driving left harder. Turning the other way does the same going right.

Now stack your 12 volt 3 1 and 8, it can be made to work with almost any amount of resistance, so if you have a meter, measure the resistance as you turn your wheel back and forth if you can.

kinarfi

Minor re write for clarification, maybe.

[Guest Lenny]

a simple explanation of that circuit is: split you 12 vdc into 3 parts, 4 4 and 4 stacked on top each other, the middle 4 has a wiper centered a 2 which makes 6 to the bottom and it can be adjusted up or down from 4 to 8. that's your input. It move a stable ramp that goes from 3 to 6 and as you move the wiper, it moves to 1 to 4 or 6 to 9 depending on which way you move the wiper. Notice the 4 - 6 dead zone. If the motor starts left at 2, as you bring the ramp down to 1.9 - 4.9 it only goes under 2 for a moment or as you bring the ramp down to 1 - 4 it goes under 2 for a longer period, driving left harder. Turning the other way does the same going right.

Now stack your 12 volt 3 1 8, it can be made to work with almost any amount of resistance, so if you have a meter, measure the resistance as you turn your wheel back and forth if you can.

kinarfi

Thanks Kinarfi,

Wow, thats good. Let me refrase it with what I understood. @%*^(+@$%##^*&%$#!@!)*^+_+(*%^@_*%. Yha, thats it. We'll have to talk about it at Logandale with pencil and paper in hand. When you say to take resistance readings, do you want me to hook the VOM directly across the motor leads with nothing else (no current) hooked to the leads and turn the steering wheel back and forth. Should have the mechanical part done today so I can drive it. Why is it that everytime I comunicate with you on an electrical issue, I keep feeling more and more electrically illiterate?

Lenny

[Kinarfi]

you guys kill me with the things that you have done.

Come up to the Jamboree and check them out for your self.

Love to meet you in person.

Kinarfi

[showa]

Did this ever come up ???

http://www.streetperformance.com/part-show...r-steering.html

[Guest Lenny]

Did this ever come up ???

http://www.streetperformance.com/part-show...r-steering.html

Looks pretty neat. I'll bet it works great to but at $3500.00 it's over my budjet.

see http://www.autoblog.com/2006/11/03/sema-fl...power-steering/

Thats the problem with off the shelf solutions, they are too expensive for most of us, probaby all of us. Good research work though. Havn't seen this one yet. Thanks for the input.

Lenny

[showa]

Thanks...I didn't check the price tho............WOW........

[Guest Lenny]

Some guys can just do anything. Don't tell Kinarfi that though, you know, don't need him to get a big head and stuff. Now I feel like I have the pressure on to do the mechanical interface to his controller. Don't know if I can get it done or not but I'll try. Still working on how I want to make it then have to actually make it.

Lenny

[rocmoc]

Kinarfi,

GREAT! Can't wait to see it in person.

rocmoc n AZ/Mexico

[Guest Lenny]

Looks like I'm going to get the mechanical part of the interface done. Have about 1-1/2 hours left. Should still have plenty of time to pack up, load and get to Logandale Thursday.

Lenny

[Kinarfi]

I better do some CYA here. I got the design working, but waiting a few parts, like 12 vdc dpdt relays and IRF4905

FETs. If they get here early Fri, I'm, good If not, who knows,

Kinarfi

[Kinarfi]

My Power steering did excellent at Logandale, but started giving me a few problems when I got to the the dunes, turned out to be a bad solder joint. so now I have to get to work on the electronic some more.

[Guest Lenny]

Lets see Kinarfi, in the last week, Rocmoc has a trans shaft to fix, Showa has a drive shaft to fix, I have rear suspension componets to redo and you had to solder a joint for your power steering or did you say that after doing a joint that your power steering seemed fine. That puts us all in the same boat but somehow it seems you got the easier part of the weeks repairs.

Lenny

[showa]

Lenny,

Paiute3 has the drive shaft to fix....Please don't jinx me !!!! lol..............I just noticed a lap belt hook spring has gone awol..........Good exscuse to get new belts....

Shocks...

Tires...

???

I gotta say that this trip was the best for me and my wife.......She started telling me we need tires, shocks, etc after seeing your guys stuff.....Thanks to you all......

Kurt

[Kinarfi]

I didn't think Showa had any problems and mine were self induced, need to fix the gas line and plug the hole I drilled in the tank a bit better, my gas line developed a small leak at the dunes. The solder joint started failing while on the Paiute Trail area, so I turned it off and found that the additional resistance of the gear train and motor (not shorted) act like a steering stabilizer similar to a shock absorber on the tie rod, so it's a good thing even when not powered up. . Got some new ideas for the circuit and for the use of micro switches for a less bulky set up.

[Guest Lenny]

Lenny,

Paiute3 has the drive shaft to fix....Please don't jinx me !!!! lol..............I just noticed a lap belt hook spring has gone awol..........Good exscuse to get new belts....

Shocks...

Tires...

???

I gotta say that this trip was the best for me and my wife.......She started telling me we need tires, shocks, etc after seeing your guys stuff.....Thanks to you all......

Kurt

Sorry Showa, I take it back so any jinx is gone. I knew it was Paiute3, I just didn't stop to think. I have a tendency to have my thinking always be about 10 feet ahead of my body. Sort of like trying to take that first step on the comming stairway but your not there yet.

Lenny

[showa]

"Sort of like trying to take that first step on the comming stairway but your not there yet."

lol....I used to do that...Then I quit drinking......

Kurt

[Kinarfi]

I've been running around with my electric steering assist, when I wasn't broke down, and have been quite pleased with it. Lenny changed his steering over to an electric steering set up out of a Smart Car but didn't have a sensor system, so I've been working on one and I have decided to use a strain gauge on the steering shaft as the sensor to tell the motor which way to turn, how much power to use and added an inline resistor to sense end of travel or overload condition. I've got most the parts in and I have built the first prototype controller for Lenny's Trooper and thought maybe you'd like to see what it looks like so far. I'm hopeful to have it on Lenny's Trooper in July and we can get some reports from him as to if and how well it works. What you see in the pictures probably took about 15 hours over 3 day of actually putting it together and an awful lot more time designing and redesigning and drawing and testing. I sure hope this thing works good, I will be building one for my Trooper shortly.

This is what a Strain Gauge looks like and is super glued to the bare metal in the steering linkage and senses how much torque is being applied to the steering wheel. Pretty wild stuff, but interesting, notice the dimensions.

Kinarfi

[Kinarfi]

Got a strain gauge attached to my steering shaft and did some testing, it actually works, it can sense the torque on the steering wheel needed just to take up play in the linkage turning side to side standing still with only one tire on the ground. I must say that I am impressed with these little devices, it's the first hands on for me.

Still having a few problems with the electronics end though, If you know any really smart people that might want to help me, have them give me a PM or something.

Thanks

Kinarfi

When you look at this thing, click on the full size tab and then the + , it's pretty impressive.

[Kinarfi]

Had to delete photo to free up room, I'm sure no one will care -------- Can anyone guess what this is? It's (more or less) the final finished circuit design for Lenny's and My Electrical power steering assist. On mine, it works so smoothly that it just feels like my rig has very light resistance to steering. Haven't done a lot of 4X4 with Lock Outs yet, got to get rid of this cast in a couple 3 weeks, then I can go give it some real testing. Actually, this one is for Lenny and mine is in service in my Trooper.

Kinarfi

[Hammerdn]

I think Joyner should hire you and Lenny for their R & D

[Kinarfi]

I think Joyner should hire you and Lenny for their R & D

ME TOO!!!!

Kinarfi

[Guest Lenny]

Can anyone guess what this is? It's (more or less) the final finished circuit design for Lenny's and My Electrical power steering assist. On mine, it works so smoothly that it just feels like my rig has very light resistance to steering. Haven't done a lot of 4X4 with Lock Outs yet, got to get rid of this cast in a couple 3 weeks, then I can go give it some real testing. Actually, this one is for Lenny and mine is in service in my Trooper.

Kinarfi

Got through bugs and my electric power steering works really nice. It's smooth and not much different then my Dodge truck.

In testing, I found that steering with my one palm on the rim of the steering wheel would easily turn me through any and all type of terrain and tight stuff. Then I put it in 4x4 full lockout. This would be the real test. Same thing, steered with the palm of my hand even standing still on the dirt. I probably would feel a little more pull on pavement but then I can adjust for more gain if I choose. It's fully adjustable. Ran over a 6" dia. rock with one front wheel and didn't feel it at all thanks to the stabilizer circuit Kinarfi put in it. Thanks Kinarft for your knowledge, determination and the time you put into this complex design. I am certainly impressed. I'll do pics of my power steering installation after this weekend. Right now I'm going riding.

Lenny

[rocmoc]

And how much are these systems installed? Or the kit?

rocmoc n AZ/Mexico

[Kinarfi]

And how much are these systems installed? Or the kit?

rocmoc n AZ/Mexico

don't have any Idea yet. I assume you want one like mine, that is stock steering rack and pinion. Want to trade for installed shocks?

Kinarfi

OH yea FYI, My set up died due to stripped gears, so I have to change the gear and I'll report on that when I get it done, pretty soon, but for a long time, it did not have an end of travel current limit set up. I'm sure that contributed to the stripped gear, I going to look for some metal gears, but haven't seen any yet. If you have a power wheels ride on toy for your kids, steal the motor and gear box off it.

[4x4x454]

don't have any Idea yet. I assume you want one like mine, that is stock steering rack and pinion. Want to trade for installed shocks?

Kinarfi

OH yea FYI, My set up died due to stripped gears, so I have to change the gear and I'll report on that when I get it done, pretty soon, but for a long time, it did not have an end of travel current limit set up. I'm sure that contributed to the stripped gear, I going to look for some metal gears, but haven't seen any yet. If you have a power wheels ride on toy for your kids, steal the motor and gear box off it.

If you can get another set of plastic gears you could have them cast in metal. I used to work in a dental lab and cast lots of stuff. Check with one in your area and I bet they would do it for you.