[TowerTalk] Mast slipping

[Jim Thomson]

Grant sez...

There is no benefit to having the saddle extend further than the DXE 
single saddle clamps as there is no force from the U-bolt to provide 
clamping force. If more clamp is needed, there are the DXE "super-duty" 
saddle clamps with two saddles and through straight bolts.

##  The correct component for the job is the DXE  “super duty” 
saddle clamps.   I use 2-3 of these  to clamp the chromolly mast to the
8”  tall x 18”  wide x .375”  thick  6061 T6 plate.     I use  TWO  identical
plates, with one horizontal and one vertical.  ( same idea as the F-12 double
plate scheme, except done right).   The  super duty clamps are used on the vert plate
and the regular DXE  saddle clamps   are used to clamp the boom to the horizontal
plate.   This is for a 2”  OD  x .375”  thick chromolly mast.   (107 ksi). 

##  I also use those DXE .....”super duty”  mast clamps for my HB mast steps.  One
super duty clamp is used with a 2. x 2”  x 14”   long  x  .25” thick  6061-T6  angle AL.
2”  wide non skid stuff is applied to both  vert + horz portions of each mast step. 

##  The K7NV  small prop pitch + his superb mast clamp is used for the rotor. 

##  Since both plates are  identical, and are  8”  x 18”  wide,  with one vert and one horz,
where they overlap forms an 8 “ x 8”  square.  ( = .75” thick) .   The horizontal plate is shifted 
down slightly, so that ONE DXE  “super duty” mast clamp is at the bottom  of the vert plate,
.... and TWO  of em are mounted at the top  of the vert plate. 

##  The DXE  “super duty” mast clamps  use a pair of  G-8  armour plated  bolts. 


http://www.dxengineering.com/search/department/clamps-and-fasteners/product-line/dx-engineering-super-duty-saddle-clamps?autoview=SKU

http://www.dxengineering.com/parts/dxe-sdsbolt-5    bolts come in various lengths, and don’t rust. 

You can also use the “super duty “   mast clamps to  mount a boom to the H plate if you want. 

Do it this  way, and the clamp  cant  slip on the mast..even in 120 mph winds.   use thread locker..after using the TQ wrench  to dial in correct TQ. 

Where each boom is, I use em as climbing steps..since there are 3 of the dxe super clamps. 

If you folks torque balanced your ants  correctly, you would eliminate 90% of your TQ problems.  

As a  side note,  ALL my F-12 u clamps have rusted out  (used to  hold the  eles  to the  F-12 boom bracket).  
I replaced dozens of em with SS  DXE  saddle clamps...end of problems. 

Later... Jim  VE7RF