Chuck and Ryan's Build Tips

[ceslaw]

Lasers and Levels. The adjustment of the wings is described in the manual using a bubble level. How primitive. Time to move on to digital levels and lasers.

Once the wings were set in place with the temporary ‘bullets’ exactly per the manual, measurements of the wing angles (using the wooden stick tool), washout, and dihedral are obtained.

Wing angle. We checked it exactly per the manual using the wooden stick. But then we did it again simply using a digital level, facing forward on one side and aft on the other to assure the measurements were for the same relative angle, left to right. (This technique avoids any error in properly zeroing the digital level). This revealed measurements within less than .2 degrees, left to right.

Dihedral. Per the manual a string is run from left to right and the height measured at the inboard spars. String sags. Laser beams don’t. A laser placed at the end of the right wing was aimed at the end of the left wing. The beam was interrupted with a ruler over the inboard spar to take the measurement. Note that one must compensate for the laser beam originating some distance above the wing tip, depending upon the design of the laser being used.

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Final check. Here is the fun one. The laser level was placed between ribs adjacent to the landing light on the bottom of the right wing, as if measuring the wing angle, and aimed at the strut on the opposite side, a distance of about 18 feet. The point where the laser landed on the strut was marked with a piece of tape. This was repeated on the opposite wing. The point where the laser landed was within a fraction of an inch of 13” to the top of the strut on both sides. This confirmed that the wing angles were accurately adjusted and was more reassuring than a measurement with a two-foot bubble level.

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No adjustments were needed. The reflects well on the precision with which Cub Crafters manufacturers the parts that go into the kit. Of course the real test will come when this Cub flies.

[ceslaw]

Glare shield fans. A method for directing warm air to the inside of the wind screen and drawing away heat generated by the electronics was the goal.

A pair of 1.5” computer fans was used. Even though these are ‘higher end’ Noctua brand they are quite inexpensive by Carbon Cub standards; less than $30 for the pair. Most of these little fans are black, but the ones selected are beige / brown color. The beige / brown color scheme did not cause any issue with glare. Black colored fan guards were purchased separately.

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A pattern was prepared to assure they were located properly. Anything on the glare shield needs to be symmetrically aligned.


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A 1 ½” hole punch was used to make a precisely sized and smooth opening. Four small holes were drilled to attach the fans and guards again emphasizing precise alignment to preserve the symmetry from the pilot’s seat view.A wiring harness was made to connect the two fans into a single wire using the same style micro computer plugs that come with the fans. This will make detaching the fans easy, should the need arise.


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The fans were wired through an in line 2-amp fuse to the GEA fuse terminal. The fans will operate when the master is switched on. The MTBF is something like 10,000 hours, so they will certainly outlast me, let alone the plane.

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I have not yet had a chance to see if they will aid in keeping the wind screen clear in cold conditions but the movement of warmer air can only help when the need arises.

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[ceslaw]

Spring Connections. Univair provides the springs used on the tailwheel. The instructions recommend “that AN42-7 eye bolts be installed on each leg of the steering arm . . . .”. So we did.

It looks cleaner and makes placement and removal of the spring much easier but otherwise does not seem to have any functional difference.

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[Neale]

Thx for your prompt reply, I will be proceeding today with a lot more enthusiasm than would otherwise have been the case. I will respond later once I have fitted the seat.
Cheers Neale J, Australia

[Pete D]

[QUOTE=ceslaw;29180]The instructions recommend “that AN42-7 eye bolts be installed on each leg of the steering arm . . . .”.





Univar recommends that in the context of using those springs on a PA18 or Piper rudder that has a cast aluminum rudder horn. The replacement ones have a thin steel bushing in the hole for the spring, original ones did not. The steering springs would wear out the hole on the rudder horn.

All of the CubCrafters products have a steel tube welded to the bottom of the rudder in place of the bolted in aluminum horn on the Piper airplanes. The steel tube on a CubCrafters holds up much better and the eye bolts are not technically necessary.

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[ceslaw]

Thanks Pete. Excellent information explaining the "why" which was not in the Univair instructions. In other words, this little modification was completely unnecessary. But I'll leave it in place for now. I like the way it looks.

[Dan L]

I like the eyebolts for another reason also, it improves the steering geometry on the tail wheel. The same is true of the optional up-bent steering arms on the ABW tail wheels.

[ceslaw]

Good point. I'll leave them in place.

[ceslaw]

Video Camera. The G3X has an input jack for a video camera. Being able to see the gopher holes before landing seemed like a nice option.

The first challenge was finding an appropriate camera. Cameras referenced on other blogs are typically 170 degree wide angle with accompanying distortion. A search led to a NATIKA camera with a 135 degree angle of view which has minimal wide angle distortion. It also has the advantage of adjustability once installed because of the way it is mounted. NATIKA 960H CVBS/720P, available from Amazon and other sources for around $40.

Since the G3X has a BNC female connector and the camera comes with an RCA male plug a simple connector is needed to bring the two together.

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Locating the camera was the second challenge. By experimenting with different locations an image that captured the tires in the lower corners was found. The goal was to provide some visual perspective by including the landing gear in the corners of the image and also provide an idea of how much the suspension deflected. Once the best position was found, installation began.

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An opening was cut on the belly pan per the dimensions noted.

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The camera was mounted on a section of aluminum with nutplates in each corner so that it could be easily removed from the belly pan when accessing the area below the seat. Note the cord opening which passes through a small grommet is off center.

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The camera comes with a very long connecting wire. It was shortened and spliced. There is a connecting plug in the line which was located behind the right kick panel near the cup holder. This will enable disconnecting the camera and replacing it should the need arise.

Since we did not want the camera powered at all times, it was wired to the switch for the landing lights (terminal #6) through an in line 2-amp fuse. By using the landing light as the connection point, it will be on only when the landing lights are operating. Note that the camera does not activate when the wig wag lights are activated; only with the landing lights.

Because of the way this camera is mounted, it can be adjusted both left / right and up / down. Once adjusted the camera captured the image we were seeking nicely.

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The final installation is inconspicuous and out of the way. If damaged, it can be easily replaced.

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[Ak Paul]

Thanks for the details, we’ll look into doing the same.