[TowerTalk] Adjustments to Tower Base Pier J-Bolts
Steve Maki
lists at oakcom.org
Sat Jul 22 20:50:59 EDT 2017
One other thing:
I'm sure some folks worry that they might find, after plopping a self
support tower down on *level* bottom nuts, that their pride and joy is
not plumb. Not to worry, if the tower is a Pirod, or Nello, or Valmont,
or Rohn, or whatever well know tower - that does not happen.
-Steve
On 7/22/2017 20:36 PM, Steve Maki wrote:
> OK, but since Pirod's design spec, or instructions as it were, (and I
> love Pirod, believe me) is already faulty as you know, we are seeking
> after-the-fact solutions.
>
> First, there is no need for the bottom nut to be 1.5" above the concrete
> for leveling purposes. Unless your concrete is slanted severely for some
> reason. Put all your nuts down to the concrete. Find the highest one.
> Bring the others up to that level. You know where I'm going, right?
> That's going to save you at least an inch or more.
>
> Next, get rid of the lock washers. They are useless.
>
> Next, disabuse yourself of the need for the 3" of threads showing on top
> of everything for *leveling*. Not needed. If your bottom nuts are level,
> you can get by with a 1/2" on top.
>
> The critical task is to get the bottom nuts level. A laser level, or
> just a long straight edge and bubble level is all you need.
>
> -Steve K8LX
>
>
>
> On 7/22/2017 20:06 PM, Paul Christensen wrote:
>
>> Several folks want to know why there's 12" of exposed bolt above the
>> surface. That's Pirod's design spec., but also keep in mind that a
>> self-supporting tower base foot does not rest on concrete. It actually
>> rests on a nut as a leveling device. The nut under the foot is
>> adjusted to
>> level a self-supporting tower. So, here's the actual length needed:
>>
>> First, the nuts are all 2" in height and the bottom nut is spun to 1.5"
>> above the concrete surface -- again to allow for leveling. Next, add a
>> high
>> strength flat washer, lock washer, followed by the height of the tower
>> foot
>> which is 3.0". We then add more hardware and another nut to the top.
>> All
>> the washers together are 0.5" in height. So we end up with:
>> 1.5+0.25+2.0+0.25+3.0+0.25+2.0 = 9.0 inches, leaving 3 inches at the top.
>> Probably the most I'd ever cut is maybe 1 inch off the top and that means
>> cutting 1 inch off of four extra-high-strength steel bolts is almost
>> certainly not worth the effort.
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