On 2/3/2014 2:43 PM, Mike Reublin NF4L wrote:
Boy was I off on this one!
Mike NF4L
On Feb 3, 2014, at 9:19 AM, Mike Reublin NF4L <nf4l@comcast.net> wrote:
"I think" it's Sin( angle from winch to anchor point on tower(Weight of
the tower X (ratio of length above the pivot to length below the
pivot)Normally is greater than 1 X (weight above pivot/weight below
pivot)) Assuming the cable fastens to the base of the tower rather than
part way up to the hinge. Then you'd have to take into account the arm
(length above the pivot/length to cable attach point below the pivot. )
That raises the load on the cable very fast.
The last time I did these was in 87 so I may be off a bit. No guarantees.
IE Assuming the tower is pivoted at 12 feet rather than tilted over on a
hinged base when the tower is vertical angle = 0, Max load in this
configuration is with the tower top is just above the ground..
73
Roger (K8RI)
Hi John,
I'm not an engineer, nor have I stayed at a Holiday Inn Express lately... ;-o}
but I have seen one on TV.
The pull will at worst be at about a 45 degree angle, and using double pulleys
effectively halves the load to about 600 lbs. I don't think the pull could be
more than the weight, unless it were horizontal, then you'd have to account for
friction or the fact that the load is pinned in place by the base bolts.
I don't know if that would actually cut the draw to something the PS could
handle, but the 55 amps is for a 1000 lb. pull. The power leads are 10 ga.
stranded.
Maybe we can get an engineer to chime in.
Mike NF4L
On Feb 3, 2014, at 8:53 AM, john@kk9a.com wrote:
I am not a mechanical engineer, wouldn't the pull on the cable be
significantly more than the weight of the tower when tilting it? Then you
plan on running a 55 amp motor with a 20 amp power supply?
John KK9A
_______________________________________________
_______________________________________________
TowerTalk mailing list
TowerTalk@contesting.com
http://lists.contesting.com/mailman/listinfo/towertalk
---
This email is free from viruses and malware because avast! Antivirus protection
is active.
http://www.avast.com
_______________________________________________
_______________________________________________
TowerTalk mailing list
TowerTalk@contesting.com
http://lists.contesting.com/mailman/listinfo/towertalk
|