Sunday, April 6, 2014

Fitting Elevators to Horizontal Stab

The right elevator was the first to be secured to the horizontal stab. I order some 3/16" temporary hinge pins to fasten the Rod End Bearings to the stabilizer. This will allow me to attach and detach the elevators very easy while fitting them to the stab.


Both the top and bottom stabilizer skin at the tips will need to be trim to allow the counterbalance arm to swing. I used a small Dremel tool with a cut-off wheel to make the cuts. Then finished them with a hand file and a Scotch-Brite pad.


The plans call to notch out the rear spare to allow movement for the Elevator Horn to move. Again cut with the Dremel tool and wheel. Note that the manual states not to get into the spar doubler.


Both Elevators are attached and the skin has been trimmed. The left elevator is a little light and the right one is a little heavy. At this time it is not important the they balance in the trailing position.


I believe the structure came out very nice and look forward to get started on the wings.


With the two Elevators clamped to the horizontal stab at the tips, the Control Horns align very well. The last step is to drill a pilot hole in the Control Horn using a 1/4" drilling bushing as a guide. Once both are drilled and the holes enlarged, the two gets bolted together. 


Total time this session, 4 hours.

Build Meter: 271 hours.
 


Saturday, April 5, 2014

Left Elevator Final Assembly 2

The gap between the trim tab and elevator needed a slight adjustment, so after little filing toward the trailing edge, the gap came out really nice.


The threaded stainless steel rod is still rubbing on the skin, will need to extend the slot aft some more. 


Rolling the leading edge is next, so I used the edge roller to taper the edge down so it will lay nice and flat when the two sections are
joined. As I found out, over working the edge is a bad thing, there is a fine line as to what is enough and what is too much.


As with the other structures, I used 3/4" steel conduit, Gorilla Tape, clamps and a monkey wrench to bend the two surfaces. Again I perferred to work on each small section at a time rather than trying to do the entire length all at once.


The outboard tip was the first to bend, this went uneventful and the two sections turned out really nice.



All but the middle section turned out really nice, and when Clecoed together the edges laid down flat against each other but one. That darn middle section. I had a bad feeling that would cause me some trouble after over working the edges with the edge roller.




A close up as to how nice the two sections turned out. Not bad, not bad at all if I say so myself.



Once all sections have been bent and Clecoed, each hole was increased to #30 so the blind rivets can be set.


Blind rivets along the leading edge are set and the elevator is almost complete.


A overall view of the elevator, the middle section gave me some trouble and turned out less than expected. The only good thing is that the leading edge is not seen as it is hidden by the trailing edge of the horizontal stabilizer. 



The last step is to install the control bearings. Make sure before screwing them in for the first time, you use some type of lubricant such as Boelub to help them go in smooth the first time.


Control bearings are complete and set to the proper length as per the plans using the special homemade tool.


Before fitting the elevators to the stabilizer, I wanted to temporary wire the Trim Tab servo motor, rocker switch and indicator light to see the trim tab move through the full range. Below the tab is moved to full nose down position.



And then to full nose up position, no binding or rubbing was noted. All is good.


Total time this session, 12 hours.

Build Meter: 267 hours.


Sunday, March 16, 2014

Left Elevator Final Assembly 1

The process is basically the same to assemble the skin to the skeleton as the right elevator. The two inboard rivets on the Counterbalance Skin E-713 are set first which allows 426AD3-3.5 rivets to be used rather then using to "blind" rivets if done at a later time.


The inside of the E-702-L Skin and how the E-712 fastens to it. After the skeleton is placed in the skin, the four rivets are not accessible.


The lead counterweight, E-714 gets installed and Clecos are added to the counterbalance skin. Unlike the right side this weight is not trimmed down due the extra weight of the trim tab and servo motor.


Rivets are set using the pneumatic squeezer. Make sure to check your rivet size as there are two places that a 3-4 rivet is used, all other are 3-3.5.


The End Rib rivets were the next to be set. Note the blue tape on the holes that do not get riveted at this time.


Only the rivets along the E-609PP bottom side are set at this time as the top side will have the hinge for the trim tab installed later. 


As stated in a earlier post, I elected to trim the tabs off of the elevator skin and make a "riblet" in its place. By doing this it will help with the clearance issue between the skin and the end of the trim tab. The holes were measured twice, marked once, and drilled once.  


The riblet is clamped in placed and the holes in the skin are matched drilled.


Perfect fit, Clecos are in and is ready to be rivet. The gap between the riblet and spar I will fill with some fiberglass to keep critters from climbing in and building a home.


The rivets are set on the bottom side of the Trim Tab. The top will not get riveted until the hinge is aligned and Clecoed in place.


All rivets are set on the bottom of the trim tab including the E-717 and E-718 control horn.


Using a straight edge the trim tab is test fitting and Clecoed in place. This task took a while until I was satisfied with the fit.


The view from the bottom, again checking to make sure the trailing edge is straight as possible.


The Trim Tab hinge is riveted in place once I was satisfied with the alignment and checked three or four times.


The hinge on the the elevator was then rived in place. Again take extra care not the bend the hinge while setting the rivets in this tight place.


The end of the Trim Tab is drilled to #30's and is ready for the blind rivets.


The inboard end of the Trim Tab is held together the three blind rivets. Note the oops rivet second from the end on the hinge. I had drilled that hole first when I was aligning the hing and ended up enlarging the hole after the final adjustment 


The outboard end of the Trim Tab gets two blind rivets to close up the end. Make sure the rivets clear the the riblet on the elevator. This is the main reason I choose to go that route rather then folding the tabs on the elevator.


The hinge is riveted to the rear top edge of the spar. Care is need here as to not bend the the hinge while setting the rivets, as it is a real tight space to get to with the squeezer.


All rivets are set and I am very pleased the way it came out. The gap between the tab and the elevator came out very nice.


The trailing edge appears to be very straight, I am pleased how it came out.


The Trim Tab is finally complete. That took a lot longer then it should have for such a small piece. 


 The servo trim tab motor is installed and the steel threaded rod is marked and cut the length. Clevis are fastened on both ends. Clearance between the rod and the skin is checked and some adjustment is required to the slot to allow clearance when the rod is in motion.


Total time this session, 15 hours.

Build Meter: 255 hours.

Saturday, March 1, 2014

Trim Tab 2

Well after thinking and fitting the trim tab to the elevator, I decided to order a new skin, spar and hinge assembly fro Vans. After several failed attempts to fabricate two riblets for the ends, I thought I would not cut the tabs off the second skin and bend them per the plans. The second skin arrived and I marked the bend lines on both ends of the tab.



Using some oak blocks cut at a 12 degree angle and some double sided carpet tape to hold the blocks from slipping, I clamped everything to the table to really tight. In reading other builder sites, many have the blocks slip during the process thus messing up the tabs.  



Using a nylon hammer and a oak block, the first tab was bend with no issues. The top tab was then bend to overlap the bottom, again with no issue.



The inboard tab looks fine and once a rivet is set the two piece's should lay flat and close end of the tab.



According to the plans, the hinge will extend past the last hole on the Trim Tab Spar 3/8". A mark is made at this point.



The outside tabs are the next to get bent. Again the oaks blocks and two sided carpet tape is used to keep the tabs from slipping during the bending process.


The blocks are clamped to the bench and is ready to start the bend.



Again, I am ok with how the tabs turned out.



Last step is the match drill the E-717 and E-718 Control Horn to the skin and spar.




The hinge alignment on the trim tab is another area were many have gone wrong, me included. This is my second attempt on this part. When I received the second tab, the hinge was stamped -2, (1-1/4") wide where as the hinge that was shipped as part of the kit was -3, (1") wide. After a email to Van's I was told that ether hinge would work.

I clamped the hinge to the spar aligned the edge per the dimension on the plans and drilled and Clecoed the hinge the the trim tab spar. All was good.



I continued drilling and Clecoing the hinge stopping to checked that the hinge was not binding in any spot. All is still good.



After I finished all the match drilling I took the hinge off to deburr the holes and then I noticed, the holes look very close to the edge. The measurement from the edge at the hinge pin on the plans shows 1/4", using this 




Total time this session, 4 hours.

Build Meter: 240 hours.