[TowerTalk] 80M 4 Square Array Material options

[Matt]

There are lots of ways to do it.   I happened to have a lot of 20' sticks of
.051" wall 3" dia irrigation pipe.   My solution for connecting the
irrigation tubing together was to use 2.5" SCH 40 aluminum pipe stubs welded
onto 1/8" thick 6061 plates.  The welds are made with a spool gun running
100% argon cover gas.   The combination produces a joint with about .010"
radial clearance when the tubing is slipped over the pipe.   The square
plates are drilled in the corners for guy rope attachments thereby avoiding
high bending stresses at the joint connections.   Joints are drilled &
bolted after slipping the irrigation tubing over the stubs.   Raising is
done ala N6RK style...

Matt
KM5VI





-----Original Message-----
From: TowerTalk [mailto:towertalk-bounces at contesting.com] On Behalf Of
Patrick Greenlee
Sent: Friday, January 29, 2016 2:49 PM
To: towertalk at contesting.com
Subject: Re: [TowerTalk] 80M 4 Square Array Material options

How about welding the lower non adjusting pieces?

Has anyone ever heard a credible story about a 4 square made of irrigation
pipe that failed?  You could always insert a structure inside the irrigation
pipe to stiffen it. A design in wood should be inexpensive.  Some of the
spray foams might be just the ticket.

Patrick        NJ5G

On 1/29/2016 9:22 AM, Stan Stockton wrote:
> I know aluminum irrigation tubing has been used by many with success.
> Personally, I don't like it beacuse the wall thickness is so thin.
>
> This is just my suggestion:
>
> Buy two 24 foot lengths of 3.5 inch schedule 40 6061-T6 from your 
> local metals supplier.  Also buy two 24 foot lengths of 3 inch x .125 
> wall.  Cut those 4 pieces into 12 foot lengths so you have four of 
> each size.  Use 3/8 inch stainless steel SOCKET HEAD CAP SCREWS and 
> the Optibeam style of element fastening (larger hole on one side to 
> allow head to clear one wall of larger OD tubing) to join those 
> together for each element with 3 bolts for each.  With a 12 inch 
> telescope you will have 23 feet ending with 3 inch x .125 wall.  Then 
> for each element buy 6 foot lengths of every size DXE has of .120 wall 
> tubing starting at 2.75 inch OD.  You will need four of each size 
> except the 1.5 inch OD where you would just have 3 feet of that size 
> for each vertical - so you need two six foot lengths of the 1.5 OD.  
> Use the same fastening method and telescope everything through the
> 1.50 inch OD by six inches with two bolts for each joint.  Then for 
> the rest, starting with 1.25 inch telescope them by four inches and 
> use bolt sizes shown below.  The 1.25 through 1 inch is just regular 
> .058 wall also available from DXE.  The total length of this vertical 
> will be about 70 feet.
>
> So the taper schedule for what I described is:
>
> OD      WALL     EXPOSED Length      Socket Head Cap Screw Size
>
> 3.5       .216        144
> 3.00     .125        132                           3/8 x 4 inch
> 2.75     .120          66                           3.8 x 3.5 inch
> 2.50     .120          66                           3/8 x 3.5 inch
> 2.25     .120          66                           3/8 x 3 inch
> 2.00     .120          66                           3/8 x 3 inch
> 1.75     .120          66                           3/8 x 2.5 inch
> 1.50     .120          32                           1/4 x 2.5 inch
> 1.25     .058          68                           #10 x 2 inch
> 1.125   .058          68                            #8  x 1.75 inch
> 1.00     .058          68                            #8 x 1.50 inch
>
> Although it would free stand with probably a 40 MPH wind, I would guy 
> it one time, maybe from the top of the 2 inch section.
>
> I am just guessing the total cost will be well less than $1,500 for 
> four verticals.  You will have to use a drill press and a V block to 
> drill a bunch of holes and engineer the method to walk it up and have 
> it insulated from ground.
>
> 73...Stan, K5GO
>
>
>
>
> On Wed, Jan 27, 2016 at 9:05 AM, Daniel Hileman <n9wx at hotmail.com> wrote:
>
>> Hi All,
>>
>> I am looking for advice on material to use for an 80m 4 square. 
>> Looking for the cheapest way to build an 80m vertical.  I have looked 
>> at towers,used utility poles etc. (Utility poles look like the best 
>> option so
>> far.) Curious what you guys use. I know that it may not be cheap, but 
>> I would like to do the verticals as cheaply as possible and looking 
>> for your input. I do not have 70' trees to hang a wire from (hihi) as 
>> I know this would be SUPER cheap. ;-) Like I said, I do not expect it 
>> to be free, but
>> $1,800 for an 80m vertical from "Zero-five" antennas is crazy, and 
>> really dont want to spend $3,000++ on a 4 square! Looking at options! 
>> lol. I know it's alot of aluminum,etc.
>>
>>
>> 73,
>> Dan N9WX
>>
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