[Date Prev][Date Next][Thread Prev][Thread Next][Date Index][Thread Index]

RE: (ET) Satellite Actuator Arm

When I said "cut off the peak" I was referring to exactly your point about mountain climbers.  However, the strap and winch mechanism must be capable of handling the force - a stretchy strap will still require the winch to support 300 pounds (for example) after it has reached the limit of its elasticity. When your mountain climber is stationary, a cable and a strap can both support him.  If he falls with a slack line for a while, the strap will be decidedly kinder.  But when the stretch is all gone the line anchor will be required to resist the same amount of force as would have been the case with a solid cable attached.  Since one of the issues here was the gear drive in the lift motor, I made the point that at some load level, a strap and cable will both stress out the lift gears equally.  I am guessing that lifting a heavy tiller will take 99% of the stretch out of the strap - it is close to becoming a cable at this point.


At 09:07 PM 11/29/2004, Rob Brockway wrote:
If you consider the bump as imparting a fixed quantity of energy, then the force is inversly proportional to the distance that the energy is absorbed.  So I think the softer strap would lower the forces.  A rock climber wants his safety rope made of strong stretchable rope - Low force over a long distance.  Not aircraft cable that would stop him in a short high force distance.
 
I find it hard to believe however, that the complience of the tires would not be a larger factor than the strap vs cable.

Pieter <pvcl plitch com> wrote:
At 03:56 PM 11/29/2004, Markus Lorch wrote:

It seems to me that the total force exerted by a lever on a cable is the same if that cable is stiff or "forgiving."  I'll grant you that the nylon strap may "cut the peak off" of some transient noise in the application of the load, but the force is the same no matter what you use as a cable.  That being said, I would suggest that you could always double the winch cable - anchor the hook end at the winch (but not on the winch) and use a snatch block at the load.  The would double the load the winch's internal gearing and the cable could handle.  Of course, your  raise/lower speed is cut in half too.  But safety first.  I use a snatch block with an ATV winch quite often - sometimes to pull in some other direction than straight ahead, more often to lessen the load on the winch.

I use electric actuators (12 volt) to raise and lower a dump box on an ATV trailer and the cutting edge on an X-C ski trail groomer pulled behind a snowmobile.  The dump trailer uses an electric trailer jack, and takes about a minute extending 24 inches.  The groomer actuator is one I picked up on e-bay.  It will extend 12 inches in about 15 seconds.  In both cases, the actuator does not carry a lot of load during normal operation.  For example, the dump cart is only transported in the fully down position with the load entirely resting on the trailer frame.  The force against the cutting edge of the ski trail groomer is mostly horizontal while the actuator is vertical, so virtually no shock impacts the actuator.  If you do a Google search on  +36VDC +"linear actuator"  you will find a lot of info. 

I have written here before about building a front bucket loader using 36 volt linear actuators rather than hydraulics.  While the electrics might be slower, I am guessing that they could be cheaper and less power hungry.  There are a few technical problems (like "synching" the actuators on both sides to each other), but it is an interesting concept.



Bob and others,
 
the new elec-trak.org forum has the capability to publish your posts incl. pictures. So you could
create a thread there on satelite actuators, copy your text that you send via emails
and add the pictures. Then sent a note to the list informing us about the location of the pictures.
 
If you don't want to go this route I'd be happy to put your pictures on my webserver and
make them available to everyone. I think thought he forum is the way to go.
 
One note about the actuators. I am not sure how well they handle the forces of implements
when driving over bumps with the implements lifted. I got a warning from Warn winches about
me using a 1700# winch to lift a bucket - they thought the lever distance and the high forces
envolved when absorbing a bump may be too much for my geartrain when driving with a full
bucket. The original elec-trak strap would absorb some of these forces as it is a little bit
elastic. I am considering putting a nylon strap on my winch instead of the steel cable
to get the same effect.
 
Markus
 
-----Original Message-----
From: elec-trak-bounces cosmos phy tufts edu [ mailto:elec-trak-bounces cosmos phy tufts edu] On Behalf Of Kleinbrahm, Bob 
Sent: Montag, 29. November 2004 15:46
To: Elie, Larry (L.D.); elec-trak cosmos phy tufts edu
Subject: RE: (ET) Satellite Actuator Arm
I am not at the location of my tractor during the week, so I won't be able to time it until the weekend.  It seemed to have adequate movement within 10 - 30 seconds, and doesn't stop me from using it.  I will take pictures next weekend, but do not have a place to post them on, so am not sure if I can share them or not.
 
Bob
-----Original Message-----
From: Elie, Larry (L.D.) [ mailto:lelie ford com ]
Sent: Monday, November 29, 2004 11:39 AM
To: Kleinbrahm, Bob; elec-trak cosmos phy tufts edu
Subject: RE: (ET) Satellite Actuator Arm
Great!  Pictures Please!
 
My actuator (Von Weiss) was too slow to implement, nearly a minute for 24"; how fast can you raise/lower your tiller?
 
Larry Elie
 
-----Original Message-----
From: elec-trak-bounces cosmos phy tufts edu [ mailto:elec-trak-bounces cosmos phy tufts edu]On Behalf Of Kleinbrahm, Bob
Sent: Monday, November 29, 2004 1:58 PM
To: elec-trak cosmos phy tufts edu
Subject: (ET) Satellite Actuator Arm
 
To the Group:
 
All the current talk about lift straps breaking prompted me to send this message.  I too was plaqued with those darn straps and the limited support that they provide.  A few weeks back I posted messages about using a Satellite Actuator arm to replace the front lift on my E-20 tractor.  I have since modified the rear lift to use an actuator in place of the strap, etc..  I used the actuator this weekend on my rear tiller and it works great!  Basically I removed all the et lift assembly stuff, i.e. motor and strap, down to the actual rear mounting bracket.  The actuator mounts directly to the upper pin assembly of the rear bracket, with the end mounted to the tiller pin bracket.  It does not require the chain to support the tiller, nor any straps that were crummy and under powered to say the least.  The actuator I use is a Jack Venture 18" unit, that is powered by 36 volt from the aux power plug, through a dpdt/switch on tractor firewall.  The actuator arm is rated for moving up to 800 lbs and easily lifts and lowers the heavy tiller on back of tractor.  I used this same unit on the front of tractor to lift my modified dozer blade with great success.  In fact I like these units so well, that I just ordered another one on ebay, so that I can leave both of them on the tractor, without having to move them from front to rear, etc..   I am going to wire two power receptacles, one in front and one in back, on tractor that I can plug unit(s) into as needed.  The only down side that I have found with these actuators is that they are slow in operation, but who cares.  "No more lift strap problems."  Do a search on ebay for satellite actuators to see what is available.  Got mine for $39.95 - sweet!
 
Bob
 
 
 
Bob Kleinbrahm
Senior Network Engineer
First Republic Bank
San Francisco, CA.
415-288-1478

 
-----------------------------------------------------------------------
The information transmitted is intended only for the person  or  entity
to which it is addressed and may contain confidential and/or privileged
material. Any review, retransmission, dissemination or other use of, or
taking of any action in reliance upon, this information  by persons  or
entities other than  the  intended  recipient  is  prohibited.  If  you
received this in error,  please  contact  the  sender  and  delete  the
material from any computer.



-----------------------------------------------------------------------
The information transmitted is intended only for the person  or  entity
to which it is addressed and may contain confidential and/or privileged
material. Any review, retransmission, dissemination or other use of, or
taking of any action in reliance upon, this information  by persons  or
entities other than  the  intended  recipient  is  prohibited.  If  you
received this in error,  please  contact  the  sender  and  delete  the
material from any computer.

_______________________________________________
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


Do you Yahoo!?
The all-new My Yahoo! ? What will yours do?