Elevators revisited

Well, turns out we weren't quite done with the elevators.  After we thought everything was fine, we took a closer look and noticed something wasn't quite right.  We had clamped the front of the elevators to the horizontal stabilizer and drilled the holes in the elevators as recommended.  But after doing so and installing the bolt, it turns out that something moved on us and the two elevators were no longer lined up with the horizontal stabilizers.  Ughh.  Very frustrating.  

So then we investigated some more to see how this could have happened.  What we found is that one of the holes in the elevator horn was slightly too large (slightly over 3/16 inch).  Because of this, there is enough slop that allows for relative movement of the two elevators when the bolt is installed.  So if the two elevators were (ever so slightly) misaligned when the hole for the push-pull tube was drilled, then this leads to a misalignment that is not easy to recover from.

Elevator horn holes repaired via TIG welder

So we decided that a "do-over" is the best way to recover from this.  We used TIG welder to fill in the previously drilled holes on the elevators.  Then applied primer to protect the metal.  These are now ready for re-drilling.  Since we are creating new holes, we can properly size and align them carefully before drilling.   Hours: 2.0

Elevators primed and ready to go

Elevator Trouble Resolved

After a lot of consternation the last few days, we finally got the elevator figured out.  A posting to the WingsForum Just Aircraft Support Group( http://www.wingsforum.com/viewforum.php?f=218 ) brought the answer from multiple builders who've experienced the problem.  Actually it was no problem after all. The guys at Just Aircraft have imbedded a slight warpage into the elevator to stop flutter in flight.  The only problem is the builder's manual makes no reference to this fact and doesn't give any details on how to install the elevator for drilling of the elevator horn holes.  With the new details from the WingsForum support group we were able to quickly get the elevator installed.   The holes were drilled and reamed and the pushrod to the control sticks was connected.  The down elevator travel was 28.5 degrees and the up elevator travel was 28.9 degrees.  We are very happy to finally have some control surface movement from the cockpit area!  Hours: 1.5

Up Elevator @ 28.9 Degrees

Down Elevator @ 28.5 Degrees

More Elevator Troubles

After re-installing the elevators and clamping the elevators level with the horizontal stabilizers we measured the right side down by 1/8" at the tip of the counter-balance, but the left side (with trim tab) measures down by 1/4" to 3/8" which is very noticeable.  We're still trying to determine the best course of action.  Hours: 1.0

Left Elevator Counter-balance

Elevator issue

Elevators were installed, but there appears to be an issue as we were unable to line up the left and right elevators.  If both of them were lined up with the horizontal stabilizer in front, then they are not lined up across the back.  It is difficult to tell where the problem lies, but the left elevator appears to be a bit off, and may have a slight warp in the shape.  We removed the left elevator and will spend some time examining it closely to figure out what is wrong.  Hours: 2.0

Elevator Installation

Nylon tubing, P/N 450005-131280 was installed into all hinge points on horizontal stabilizer and elevator and cut flush. The left and right elevators were installed using a AN393-79 clevis pin in each hinge. The matching cotter pin will be added during final installation.  Hours: 1.0

Reaming Elevator and Horizontal Stabilizer

The holes for the Elevator and Rudder attach points needed to be reamed to remove the powder coat in the holes.  The matching holes on the horizontal and Vertical stabilizers also need reaming.  Most of the holes were easily done with a drill attached HSS reamer.  There were a few hard to reach holes that needed some ingenuity.  The reamer was attached to a drill bit extension which provided the leverage to spin the reamer without an attached drill. Hours: 1.0

Flap Handle Installed

The flap handle was installed.  The assembly was positioned such that there was 3/16" clearance from a fuselage cross-member when the handle is full forward.  Three washers were used as temporary spacers to get the spacing right. The elevator push-pull tube had to be temporarily removed in order to drill one of the 4 mounting holes due to interference.  Once the flap handle was installed, the push-pull tube was reinstalled.  Hours: 1.5

Flap handle (center of picture)

Lost pins; Flap Lever

Frustratingly, we spent (too much) time trying to track down a set of clevis pins that we needed for assembly of the elevators.  Our inventory says we have them, and they were even checked off when we validated the inventory, but they are nowhere to be found.  It's a mystery, and the only solution is to order new clevis pins.

So while we are waiting on parts, we shifted gears and are working on the flap lever.   We drilled and deburred a hole in a precise location of the inner tube for the flap lever button.  This gives the flap actuator button sufficient travel, and also pre-loads the spring in the flap lever slightly so that it functions correctly.   Hours: 1.5

Elevator Trim Tab

The elevator pitch trim tab was installed on the left elevator using a MS20257-1 piano hinge.  First the piano hinge was cut to the size indicated in the builder's manual.  We had to rely on the picture as the text did not have an actual hinge size.  The size ended up being 12 inches in length.  The piano hinge halves were pre-drilled with a #40 bit.  All the parts were then put in place and the final holes were drilled with a #30 bit, which is the final size for CCP-42 rivets.  The parts will not be riveted until after the elevator is covered and painted, so in the meantime, it is held in place with clecos.  Hours: 2.0

Ed Drilling Trim Tab Hinge Half

Trim Tab Installation Complete

Rudder Pedals

The painted rudder pedals were re-installed with their fresh coat of paint.  Like the first time we installed the rudder pedals, we had to experiment with each attach point to get bind-free rotation.  The Elevator pushrod was also re-installed.  Hours: 2

Nose gear

The front nose gear was assembled.  The spacers on each side of the axle bolt that came with our kit were too short (possibly sized for the Escapade, and not the Highlander wheel).  New spacers were fabricated to fit our nose wheel, and the lengths were 2 1/4" on one side, and 2 7/16" on the other side.  With these new spacers, the fork legs were held tightly against the spacers, which were in turn held tight against the wheel bearing as required.

Nose wheel with new spacers

The nose wheel fork assembly was then fitted onto the shaft of the nose gear leg.  The friction bushing (part F-3590.3) that was supplied with the kit was previously found to have an opening that was too small, but a new part was quickly obtained (thanks Amazon), and fit perfectly.  The nut had to be tightened to the point where it took at least 20 lbs of force to move the fork assembly.  This was measured (as recommended per the manual) with a scale attached to the fork near the axle.   Once 20lbs was achieved, the nut was rotated just far enough to get the hole in the nut to line up for a cotter pin.  We remeasured the force again to see exactly how many lbs of force were then required to move the wheel, and it came out a bit over 23 lbs.

Point where fork just begins to rotate (20 lbs, 2 oz)

Point where fork rotates after nut aligned and cotter pin attached (23 lbs, 13 oz)

Once the nose gear was attached, the back of the plane was raised slightly with the rear rotisserie point so that the airplane was sitting on all 3 wheels  (A rear attach point is still currently needed because the plane is tail-heavy without an engine).  Hours: 2

Image of Fuselage sitting for 1st time on 3 wheels

Additional Nose Gear Work

The fitting of the pin on the Nose Gear was finally completed.  A couple of the oil sintered brass bushings had to be reamed to allow the pin to fit correctly.  The nose gear firewall attachment segment in the builder's manual is a little out dated.  Looks like the factory has changed the design without updating the builders manual.  With the parts provided, we were able to figure out the new design.  Here's a picture of the finished installation.

Nose Gear Firewall Attach Block and Pin

The suspension pin F-3450 was attached to the top of the gear leg using an AN4-14 bolt and associated hardware.  We had added the rubber shock absorbers and washers to the suspension pin earlier and attached it to the nose wheel mounting frame, F-3400.

We started to attach the nose gear fork assembly (F-3570.4).  Again the two oil sintered brass bushings had to be reamed to allow the fork assembly to be installed.  We ran into a part issue. The F-3590.3 friction bushing supplied has a much smaller hole than required for installation. To make the part work, we would need to make the inner hole 1-1/4".  We decided to order a Thrust Bearing Washer from Amazon with the same thickness and inner diameter, but a slightly larger outer diameter.  Should be here in a few days.  Hours: 3.0

Nose wheel mounting frame

We received the right size bolts for attaching the Grove gear to the aluminum attach brackets (AN5-21A bolts), so we replaced our temporary bolts with the correct ones.

The firewall brackets for the nose gear were attached to the fuselage, and the nose wheel mounting frame was also attached.  A 1/8 inch hole (for a cotter pin) was drilled through both the short tube pieces that act as stops, and the steel tube that serves as the pin for attaching the gear leg to the firewall brackets (at the lower mounting point).  Some time was spent time fitting the gear leg (part F-3490), but it has not yet been attached permanently.  Hours:2.5

Michael is bolting on the firewall brackets for the nose gear

Rudder Pedal Paint

Painted Rudder Pedals

A few coats of the final paint color was added to the rudder pedals. Paint used was Rustoleum Gloss Enamel 7786 Smoke Gray to match the Fuselage Powder Coat.  Hours: 0.5

2nd Axle and Wheel Installation

As we indicated in our previous blog posting, we fixed the brake shoe rubbing the tire.  Originally, we had removed three spacers behind the brake disc.  This gave us the space we needed so that the brake disc didn't rub the Grove landing gear.  But this had the negative result of causing the tire to rub on the brake shoe.  After consulting the factory, and a little experimentation, we added two washers in the original spacer location.  This gave us sufficient space on the brake shoe and brake disc.

Hours: 1.5

Original Spacers vs Two 1/4" washers

Washer/Spacer location

Brake Shoe to Tire Spacing

Brake Disc to Grove Gear Spacing