This post contains a summary of information related to the manufacturing and assembly of the wing jury strut sub-assemblies. The – 45 jury struts are the streamlined strut version. A standard round 6061 T6 aluminum tube version is also an option.
Drawing number 57-45-00 jury strut assembly is an overview dimensions for the jury strut on the left side of the aircraft. All of the drawings in the database are for the left side of the aircraft. Extrapolation will be necessary when manufacturing the forward and aft jury struts as the cuts on the lower end of each of those struts is required to be reversed for the right wing.
Overview of the jury strut subassembly
There are currently 2 options available for the jury strut sub-assembly. This post is dedicated to the streamlined strut version. The jury strut subassembly is manufactured from 6061 T6 aluminum extrusions. The attachment to the wing is through a 3/16 inch diameter eyebolt. And the attachment to the streamlined wing struts is through a 1/4 inch diameter eyebolt with a 3/16 inch hole. The eyebolt attachment at the wing strut is a modified eyebolt, That is bent to match the profile of the jury strut plane. The forward and aft jury struts have a 3/16 inch hole drilled at both ends for the attachment. Have a total of 6 different jury strut connectors are used in the attachment of the diagonal and lower 3 strut segments. Each of the attachment locations require 2 different jury strut connectors because of the profile of the streamlined strut material which is not possess enough clearance inside of the extrusion profile to accommodate to pop rivets adjacent to each other. The jury strut connectors are similar but the opposite side connector has the holes located one quarter of an inch further outboard to avoid this interference. In addition the jury strut connectors are attached to the struts with CCP-4-3 stainless steel pop rivets. These pop rivets just barely have enough room inside of the strut to properly engage during the installation process, as a result it is necessary to apply pressure against the head of the stainless steel pop rivet during installation.
Aft jury strut
To begin the project you will need to go to the builders database for the jury strut sub-assembly and download the necessary PDF files. Remember all of the files that you may find in the blog may not be up-to-date. You always want to download be latest version from the builders database.
Jury strut connectors.
There are also a total of 9 drawings showing the jury strut connectors that are used in the subassembly. If you wish to manufacture these yourself can utilize these files to do that for you can just buy the CNC machine connectors ready to be bolted onto the aircraft. The easiest way to manufacture these components yourself is simply to print out the drawing, spray the backside with contact cement, pasted onto the piece of aluminum, center punch the hole locations, and then using a bandsaw we cut out profile, you can use a sander and I file to finish the part. If your patient and you enjoy doing this kind of work you can make these parts as accurately as the CNC machine parts.
Jury strut stock material
We will start of process by cutting each 1 of the jury strut segments from stock material. It will take a total of 3 lengths of the stock streamlined extrusion to manufacture both right and left jury strut sub-assemblies. Remember that we want to start with manufacturing the largest segments 1st. If you make a mistake and cut off too much material you can simply convert that into the next shortest of the 4 segments.
Marking and cutting the tubing
We recommend that you use a tape measure with increments in decimal format which will make it easier to transfer the numbers from the drawings which are all in decimal format of course. You'll notice the drawing dimensions are typically to .001". Most of the time these dimensions are way more accurate than you would ever possibly need however some people like to have the exact dimensions to a closer tolerance.
Angle measuring device.
You may find a typical angle measuring device to be very helpful in marking the tubing for the proper angles. It's also helpful to lay the stock material on top of the drawing after you have market in order to get a fairly close verification you've market properly.
Wood miter saw.
We have a miter saw that we use in the shop for cutting wood primarily, that also works very well for cutting stock aluminum such as the streamlined strut segments. The saw used for wood spins faster than we would typically like to see for an aluminum cutoff saw, in fact almost twice as fast. However if you have a carbide tooth find cut blade installed you will find that it works very well for cutting these aluminum extrusions.
Cutting with the miter saw
When cutting with the miter saw remember to wear eye protection, and you probably will like to have a face shield as well. The flying chunks of aluminum are typically hot and will embed into your skin during the cutting process.
Tilting the miter saw
There is one cut on the lower forward jury strut and one cut on the lower aft jury strut that are a mitered cut where the saw has to be tilted and adjusted to the angle to accommodate the angle of the wing lift strut. In this picture here you can see the adjusted to 23°.
Right and left strut assemblies
They drawings that are in the builders database are for the left side jury strut subassembly. The right side is nearly identical however you have to remember that it is simply a mirror of the left side. This means that the 2 lower cuts that interface with the wing struts will need to be cut exactly the opposite of the left side.
Miter cuts on all other struts
Both the diagonal and the bottom jury struts segments are simple angle cuts with no tilt in the saw. This means that these parts can be made identical and use on either the left or right side of the aircraft.
Acute angle cuts
Several of the cuts are more acute than the adjustment of the miter saw will allow. This means that you'll have to clamp or hold tightly the jury strut material while cutting.
Forward and aft jury struts
The forward and aft jury struts attached the wing strut to the spar. This means that each of these struts have 3/16 holes drilled through the top and bottom locations for attachment. Temporarily attach the jury struts to the spar and lift strut using an AN 3 bolt.
Attachment of the jury strut connectors
There is a total of 6 different jury strut connectors that are required for the installation of the diagonal and lower jury strut segments. The inboard jury strut connectors should have the 1/8 inch rivet holes located closer to the attachment for them the outboard rib for locations. Once again this is so that the rivets do not interfere with each other during the installation process. Attach and tighten the jury strut connectors at the forward top, forward bottom, and the aft bottom locations. Tightening these jury strut connectors will squeeze the jury strut enough that it will hold the diagonal and lower strut segments in place while you are preparing to drill.
Alignment of the jury strut connectors
The lower end diagonal jury strut segments should have the centerline mark placed on each side and each end of each strut segment. Align the rib falls in the jury strut connector so that they are in alignment with the rivet holes and the centerline of the strut.
Fit all jury strut segments
Before beginning any drilling install each of the jury struts segments and position in place properly with the jury strut connectors.
Positioning jury strut connectors
Each of the 3 connection locations should be taped place to hold alignment during the initial assembly and before beginning to drill.
Drilling the jury struts
Using the jury strut connector rivet holes as a guide drill through the backside of the jury strut extrusion. After each hole is drilled place a Cleco to hold the position of the jury strut.
Drilling the jury strut connectors
The very first hole in each one of the three strut connectors should be drilled and clecoed in place to ensure proper alignment before beginning the rest of the drilling.
Drill and cleco
After each goal install the Cleco and then proceed to the next hole.
Ensure alignment during the drilling process
Keep checking to ensure that the jury strut connectors are properly align as you proceed.
There are a couple of rivets that are fairly close to the lift strut may require an angle drill. If you do not have an angle drill, no problem, you will simply have to remove the jury strut subassembly as a whole to get the last 2 rivet holes drilled.
Ensure that you hold the angle drill perpendicular to the face of the jury strut connector during the drilling process.
Once the holes of been drilled and all of the holes filled with clecos, you will be riveting the jury strut connectors to the diagonal and lower jury struts using CCP-4-3 stainless steel pop rivets. Remove one Cleco at a time and replace it with a rivet. Because of the close tolerance between the 2 sides of the jury strut extrusion you will need to ensure that you are holding pressure against the rivet gun to properly seek the rivet during the polling process.
It's acceptable to have a small gap between the jury struts. Just ensure that you have at least 5/16 edge distance between the rivet centerline and the edge of the jury strut. (Edge distance)
Upper jury strut installation
This picture shows the upper jury strut installed. You may notice that the tip of the diagonal jury strut has been trimmed. This is a very pointed sharp are and trimming is not only acceptable but recommended.
Duplicating the process for the opposite wing
The jury strut assembly for the opposite wing is identical other than the cutting angles at the lift struts which have to be mirrored to the opposite side.
The completed jury strut assembly
Completed jury strut subassembly should look something like this.