On 11/8/2011 1:23 AM, Dick Dievendorff wrote:
> I'm going to try the shim idea first before drilling the clamp.
>
> I've ordered a 5" length of 3" OD 0.0625" wall stainless steel tubing. I can
> slit it with a hand grinder if I can't get it over the existing mast.
Some stainless alloys can be a real bear to slit using a grinder.
Depending on the alloy some will plug up the grinding wheel much like
Aluminum.
They do make "slitting or cutting" disks for most of these. SS is
usually tough rather than hard.
> I
> have to figure out how to secure the mast in position and then remove the
> rotator, shim the mast, and reinstall the rotator. It's going to be a
> two-man job.
I use a home made mast clamp and come along to raise the mast the 6 or 8
inches and then clamp it in place.
The come along will support it but I don't like the idea of working
under a mast with 300 to 500# only supported
by a come along.
>
> I had Custom Metalworks make up a rotator plate with just a 3" + hole in it
> that was mounted above the rotator.
What material is the rotator plate? The hole should be relatively easy
to open up depending on location and material. A high speed grinder
with a metal bit should be able open up the hole and even move the
center a bit although they take some learning to hold onto.
> It had a U-bolt saddle welded in so that
> we could have clamped the mast in place. Unfortunately the hole wasn't big
> enough and it didn't line up so we pulled it out to get the mast in. Now
> I'll be securing the mast with angle iron and U-bolts or something along
> those lines.
You can just use a plate with a hole for the mast and instead of welding
a clamp in place, mount a piece of angle on it with a couple of bolts
and then
put a U-bolt or saddle clamp through the angle.
The Angle iron should work, but you heed to anchor it in all 3 axises.
It not only needs to support the load, but hold it some where near the
center of the tower nd prevent any rotation should the wind come up
while working.
The last time I used angle iron I used saddle clamps and two pieces of
angle. One across one face of the tower and the other at close to right
angles to it and anchored to the third leg of the tower and bolted to
the angle across the face of the tower. It won't be at right angles
because of the size of the mast and it might be a good idea to 'fit' it
in place and use a bolt hold a bit over size so it can be adjusted
properly to keep the mast centered.
I've also used 2X4's and 4X4's with large U-bolts
73
Roger (K8RI)
_______________________________________________
_______________________________________________
TowerTalk mailing list
TowerTalk@contesting.com
http://lists.contesting.com/mailman/listinfo/towertalk
|