I use a 120 vac winch to raise lower a crank-up. It is Harbor Freight
120vac winch with a max pull of 1500 lbs. It is the smallest ac winch they
had. I think you would be disappointed with a "jump pak". I have two of
them and think there is just not enough amp hours in one to do the job. A HD
diesel truck starting battery (my Dodge has two each 100 AH+ batts in
parallel) will give you a hundred amp hours or more at the 20 hour rate,
i.e. 5 amps but you want maybe 30-40 amps or more and you won't get it for
long with a 100 AH battery before you cause damage to the expensive battery.
The more amps you take out of a battery the less AH you get. It is
non-linear, you pay an accelerated premium for taking heavy current.
A small 120vac winch or a good hand winch are workable alternatives if the
HD battery charger with the starting position (50 amps or better) doesn't
appeal.
Patrick NJ5G
-----Original Message-----
From: Mike Reublin NF4L
Sent: Monday, February 03, 2014 8:45 AM
To: towertalk reflector
Subject: Re: [TowerTalk] HF winch
Thanks Patrick,
Even considering the load halving of the pulleys, it seems like at best it
would be on the or above sane operating parms. BTW I had a hard root beer
the other day. Pretty tasty!
The tower isn't up yet, so the first trial would be raising it. The battery
charger is a good idea, and I thought of one of those starter packs, but
haven't looked at specs yet.
A better idea may be an AC powered winch.
Mike NF4L
On Feb 3, 2014, at 9:08 AM, Patrick Greenlee <patrick_g@windstream.net>
wrote:
I think you will be greatly disappointed trying to run that winch with a
20 amp supply. If you insist on trying, consider that it is better to
experiment by trying to lift the tower than to lower it. If the winch
were used to lower the load via its "power out" capability you might get
the tower down and then find you can't raise it back up. Those winches
are notorious current hogs and as you may have noted by the duty cycle
specs, are rated at the edge of or past the envelope. I hope you are
successful and safe in your efforts. If it works just fine lifting the
tower on a 20 amp supply with no other assistance then I owe you a Root
Beer float the next time we are together.
The brush type DC motor in that puppy doesn't care about good filtering or
precise voltage control. If you can come by a good used xformer that will
put out 12 to 18 volts at 50 amps then slap on a full wave diode bridge
rated for maybe e about 100 amps (put it on a heat sink) and you are ready
to go. Alternatively find a 24 to 30 volt xformer with a center tap and
put on a two diode bridge with cooling for the bridge and go for it. A
slow blow fuse or thermal breaker rated at or above the max current in
normal use would be a good idea too. Another possibility is a heavy duty
battery charger, typically on wheels and will have a start position that
sources serious amps, well above the normal charge rates. These are duty
cycle limited so choose wisely "grasshopper" and consider adding a fan to
lengthen the duty cycle. I have seen working used units go for under $50.
Check the specs on the Harbor Freight u nit. It might just make the cut.
Consider you will have a terrif
ic battery charger/jump starter as well as a winch power supply.
73 and best of luck,
Patrick NJ5G
-----Original Message----- From: Mike Reublin NF4L
Sent: Monday, February 03, 2014 6:46 AM
To: towertalk reflector
Subject: [TowerTalk] HF winch
I picked up a 2500 lb. rated 12V. winch from Harbor Freight intending to
use it for tilting my HG-70HD tower. Weight with antennae and rotor etc.
is between 1200 and 1300 lbs. I was hoping to run it from a 20A power
supply.
I plan on a pulley arrangement that will give me a 2:1 advantage. I could
go to 3:1.
If I read the specs right, the winch draws 55 amps when the load is 1000
lbs. The duty cycle is 45 seconds on, 14 MINUTES off. Mounting is 2 bolts,
M8-1.25x35 mm.
Seems a tad sketchy. Your opinion?
73, Mike NF4L
_______________________________________________
_______________________________________________
TowerTalk mailing list
TowerTalk@contesting.com
http://lists.contesting.com/mailman/listinfo/towertalk
_______________________________________________
_______________________________________________
TowerTalk mailing list
TowerTalk@contesting.com
http://lists.contesting.com/mailman/listinfo/towertalk
_______________________________________________
_______________________________________________
TowerTalk mailing list
TowerTalk@contesting.com
http://lists.contesting.com/mailman/listinfo/towertalk
|