[TowerTalk] TOWER ROTOR

[Tower (K8RI)]

Hi Hector,

First, a suggestion,  Turn off the caps lock as all capitol letters make it
difficult to read.

As to the rotor transmission, or gear box  it depends somewhat on your
antenna or antenna system.  If the antennas are relatively small you might
be able to go as high as 2 RPM on the antenna mast, but one RPM is usually
considered plenty fast for most antennas and a bit too fast for large
antennas and arrays.  So, I'd figure the antenna mast should turn at one
half to one full revolution per minute.

Now if you know the approximate RPM of the electric motor you can figure the
approximate ratio needed for the gear box, or transmission.

With a 1,750 RPM electric motor which is a common speed  you need somewhere
between a 1750:1 which would give one RPM output to a 2500:1 ratio which
would give a half RPM output.  You don't have to get all that in the gear
box, but a double worm gear drive can do it, or a single worm gear with a
reduction between the output shaft and the antenna mast. You can also use a
chain drive, or spur gear drive for a reduction on either the input, output,
or both.

However if the antenna is relatively small you might find a DC motor with a
single, or dual worm gear reduction and be able to vary the speed to suit.

Let your imagination be your guide and good luck,

Roger Halstead (K8RI, EN73 & ARRL Life Member)
N833R, World's Oldest Debonair (S# CD-2)
www.rogerhalstead.com




GUYS:

I WILL LIKE TO KNOW WHAT TYPE OF TRANSMITION AND MOTOR ARE THE BEST TO USE
TO ROTATE A TOWER, I HAVE A  FEW PHOTOS OF HOMEBREW ROTORS AND OTHER
COMMERCIAL OUT OF MY BUDGET.  I WILL LIKE TO BUILD THIS  AT LOW COST BUT
HIGH QUALITY , FOR THAT REASON I WILL TAKE MY TIME AND LOOK FOR THE RIGHT
PARTS.
I FOUND HERE IN A LOCAL JUNK YARD  SEVERAL TRANSMITIONS WITH MOTOR IN VERY
GOOD CONDITIONS AND GOOD PRICE 100-150 DLLS COMPLETE , THIS ONES COMES IN A
MACHINE  THAT WAS USED IN  SOME AGRICULTURAL PROCESS.  VERY STRONG AND  THE
SHAFT IS AROUND 1 1/8 INCH  , THE ONLY PROBLEM IS  THIS IS MOUNTED
HORIZONTAL.  IN THE LEFT THE MOTOR AND THE RIGHT THE LOW SPEED SHAFT , NOT
ABOVE LIKE THE ONE THAT APPEARS IN THE NCJ  THAT HAVE IN USE  A CONTEST
STATION IN OH0 LAND.

I WILL APRECIATE  IDEAS AND  YOUR OPPINIONS.

TNX IN ADVANCE
HECTOR XE2K
_______________________________________________

See: http://www.mscomputer.com  for "Self Supporting Towers", "Wireless
Weather Stations", and lot's more.  Call Toll Free, 1-800-333-9041 with any
questions and ask for Sherman, W2FLA.

_______________________________________________
TowerTalk mailing list
TowerTalk at contesting.com
http://lists.contesting.com/mailman/listinfo/towertalk