Fabricating Block to drill Elevator Horns - Suggestions?

[jimzap]

I'm at the point I need to drill the elevator horns together and trying to figure out what I can use as a block between them. I do not have access to a machine shop.
I've considered using a hardwood block but not sure what a "hardwood" is. What are some options for blocks?

Thanks in advance

 

[blaplante]

"hardwoods" ... typically not Pine and Cedar.
Common hardwoods in the lumber aisle - oak, walnut.

Having just gone through this, the most critical part is drilling perpendicular to the airframe. NOT perpendicular to the fuselage skin.
But the hardwood block gives me an idea...
Drill one horn. insert hardwood block *with a predrilled hole* (make on a drill press so it is perfectly perpendicular).
Clamp elevators to equal angle on HSTAB
Drill through to the second horn.

 

[Reflex]

"hardwoods" ... typically not Pine and Cedar.
Common hardwoods in the lumber aisle - oak, walnut.

Having just gone through this, the most critical part is drilling perpendicular to the airframe. NOT perpendicular to the fuselage skin.
But the hardwood block gives me an idea...
Drill one horn. insert hardwood block *with a predrilled hole* (make on a drill press so it is perfectly perpendicular).
Clamp elevators to equal angle on HSTAB
Drill through to the second horn.

This (above).

How I did it:

• I took a small piece of maple (roughly 18" long - available at Menard's, Home Depot, etc.)
• Ran it though a planer until it just "fit" between the horns
• Cut the block to size
• Drilled the hole with a drill press
• Clamped the elevator ends to the stab
  • Note: This is where you find out if you have any twist - not by looking at the horns, they won't align. You look at the trailing edges of the elevator.
• Placed the block between the horns and clamped
• Drilled slowly

Makes one of the more particular points of the build a no brainer.

Fred

 

[Larry DeCamp]

This (above).

How I did it:

• I took a small piece of maple (roughly 18" long - available at Menard's, Home Depot, etc.)
• Ran it though a planer until it just "fit" between the horns
• Cut the block to size
• Drilled the hole with a drill press
• Clamped the elevator ends to the stab
  • Note: This is where you find out if you have any twist - not by looking at the horns, they won't align. You look at the trailing edges of the elevator.
• Placed the block between the horns and clamped
• Drilled slowly

Makes one of the more particular points of the build a no brainer.

Another option is lay the elevators on a FLAT surface with the control horns up. put a bolt in the hole where the horns will have a bearing between them when assembled on the plane.

Drill a small pilot hole for the pushrod heim joint center location before bolting and clamping the two control horns together. Then drill both progressively larger to 3/16. Drlling square is still important but not as challenging as separated By a heim spacer substitute.

 

[Intruder]

I got lucky when looking around the garage for some hardwood that I must have thrown out. I found a steel bushing that was perfect ID to match the drill bit, and almost as long as length between the horns. Drilled a pine block squared on drill press to OD size of the bushing. Pressed the bushing into block. Worked perfectly.

 

[Mark Curley]

You probably already know, but here I go anyway. The point I would like to make is that you will want to allign the elevators in trail with the horizontal stab before drilling. Use a straight edge, top and bottom. The horns will not necessarily be matched evenly (mine were not). It's important to get the flying surfaces matched, the horns not so important. Mine were off enough that the second hole was off enough to be a little close for bolt clearance. I would recomend to check this before drilling the first hole.