[Date Prev][Date Next][Thread Prev][Thread Next][Date Index][Thread Index]
RE: (ET) linear actuator power steering?
Actually, one can (and I have seen it done) mount a two direction
momentary toggle on the shaft requiring
turning, and affixing the toggle portion to the steering wheel. IF there
is just a tiny bit of play in
the system, when you turn the wheel to the left for example, the toggle
and the actuator turns left until
the wheel and shaft positions agree, at which time the actuator stops. It
works well. It has no real tactile
feedback. The important part is the mechanical reference is the SHAFT
REQUIRING TURNING and NOT ground. A
friend of mine did this for a very early electric power steering in 1969.
Larry Elie
Ford Research and Advanced Engineering
-----Original Message-----
From: elec-trak-bounces cosmos phy tufts edu
[mailto:elec-trak-bounces cosmos phy tufts edu]On Behalf Of pieter
Sent: Wednesday, June 30, 2004 7:22 PM
To: jim leuba; Elec-Trak Tractor
Subject: Re: (ET) linear actuator power steering?
Good thought. The converted Yanmar compact tractor I referenced
apparently
uses an on-off-on momentary switch to do the steering. This is simple, it
works, no problem. But I am so based by my thousands of miles behind a
steering wheel that I would prefer a simulated "normal" steering
system. Yes - the idea of using an encoder on the steering shaft to
"tell"
an actuator controller how far to step the screw is far harder to
implement
than a switch and a screw. But how cool would it be to have a
"fly-by-wire" ET?
I understand what you are envisioning when you describe a zero turn radius
ET. This seems to be a major engineering challenge - way beyond what I
will undertake!
By the way, my steering gear is worn too. I have been told that a large
punchout from a breaker box is almost a perfect fit as a spacer to take up
the slack in the steering shaft. I haven't tried it yet.
At 05:52 PM 6/30/2004, you wrote:
>Why not just a toggle switch to control the linear actuator right or
>left. If the switch was wired to brake the DC motor when off, the
>actuator positioning would be pretty crisp (no drift). Steering would be
>like on a Dozer.
>
>My E20 has worn steering gears, I have been looking for a linear actuator
>to replace the steering mechanism with.
>
>The other way to go would be to eliminate the entire drive train and
>replace the front wheels with 2 hub motors and 2 PWM motor controllers
>and replace the back wheels with 2 swivel wheels. Then the steering
>would
>controlled by varying the speed of the 2 hub motors using a
>joystick. Essentially "zero steer" control. No belts, no transmission,
>no relays, and better steering control.
>
>Jim Leuba
>
>
>Herb Crary wrote:
>
>>A good source for all manner of items, including linear actuators, is:
>>http://www.herbach.com/Merchant2/merchant.mv?
>>This link is to their search page. I have been buying from them since i
>>was
>>in college in the late 1940's. They had lots of WWII surplus then. They
>>have
>>both new and surplus now.
>>Herb Crary
>>Boulder CO
>>E10M
>>----- Original Message ----- From: "Pieter" <pvcl plitch com>
>>To: "Elec-Trak Tractor" <elec-trak cosmos phy tufts edu>
>>Sent: Monday, June 28, 2004 2:39 PM
>>Subject: (ET) power steering?
>>
>>
>>>All this discussion of using linear actuators as front or rear lifts got
>>me
>>
>>>thinking.
>>>
>>>My E-15 has a very heavy loader on it, and the steering is a real two
>>>handed job. I was looking around the 'net for info on linear actuators
>>>to
>>>use for a lift and came across an article on an old Yanmar diesel
>>>tractor
>>>converted to electric.
>>>
>>>http://www.angelfire.com/ca4/renewables/tracpage.html
>>>
>>>Well - why not do the same thing to an ET?? He used a linear actuator
>>>controlled by a joystick of sorts to steer. It would be a simple matter
>>to
>>
>>>place a linear actuator between the frame and a steering knuckle
>>>parallel
>>>to the tie rod. I don't think too much force would be required, which
>>>is
>>>good because you want fairly fast response (screw travel), so leverage
>>will
>>
>>>be reduced. There are a number of dish positioners that run on 36 volts
>>>and use a revolution counting circuit to stop at a predetermined
>>>position. If the steering wheel ran an encoder that "told" the actuator
>>>where you were pointing it, the actuator would then move to that
>>>position,
>>>steering the front wheels. A dish positioner would be very cheap to
>>>try. The hardest part for me to design is the steering wheel encoding
>>>mechanism. Any engineers out there?
>>>
>>>
>>>
>>>_______________________________________________
>>>Elec-trak mailing list
>>>Elec-trak cosmos phy tufts edu
>>>https://cosmos.phy.tufts.edu/mailman/listinfo/elec-trak
>>
>>
>>_______________________________________________
>>Elec-trak mailing list
>>Elec-trak cosmos phy tufts edu
>>https://cosmos.phy.tufts.edu/mailman/listinfo/elec-trak
>>
>
>--
>CNC Repair.com www.cncrepair.com toll free 1-877-cnc-repair. Rebuilders
>of servo & spindle drives, monitors and power supplies for most Japanese
>CNCs.
>
>_______________________________________________
>Elec-trak mailing list
>Elec-trak cosmos phy tufts edu
>https://cosmos.phy.tufts.edu/mailman/listinfo/elec-trak
_______________________________________________
Elec-trak mailing list
Elec-trak cosmos phy tufts edu
https://cosmos.phy.tufts.edu/mailman/listinfo/elec-trak