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| Cutout for trim tab |
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| Trim motor mount Note #3 rib from LHS rotated 180 degrees from plans |
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| Rear spar |
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| Rear spar fitted |
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| Drilling skins |
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| Trial Assembly |
Flying Legend Tucano-R at Rylstone Tucano build now MeWe - Gary Spencer Salt
Thursday, 30 April 2015
Trim - Factory
After completing my installation the factory forwarded the following images of the current method of mounting. The details will be covered in additional drawings to be added to the upgraded assembly package.
Tuesday, 28 April 2015
Trim Tab - Part 3
Cover
A cover was manufactured from 2024-T3 0.020'' aluminium to fit the available area on the underside of the elevator and mounting holes marked then drilled 3/32".
A duplicate panel was manufactured from the same material with additional width to provide 15 mm flanges on both sides and matched drilled from the front cover.
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| Match drilling |
Using the cover as a drilling template, it's positioned on the skin and holes transferred then drilled 3/32''. Once the holes are drilled a center-line's was marked through the hole's centers and a offset marked in 10 mm to become the opening.
At each corner of the opening a 3/32'' hole was drilled and the edges cut with the Ofla knife, a hole was drilled at the center then aviation snips used to cut from the center to the corner holes.
Once complete the 4 [four] waste pieces are removed and the edges dressed.
The holes were enlarged to suit the selected riv-nuts.
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| Elevator opening |
The reinforcing panel had it edges folded at 90 degrees and the hole's were enlarged to suit the riv-nuts. These were used to locate the panel over the opening which was transferred to the reinforcing panel with a felt tip pen and removed.
A 3/4'' diameter hole was drilled on the center-line of the opening then 3/32'' holes drilled at each corner. The Ofla knife was use to mark the perimeter and the aviation snips used to cut to the corners and the 4 [four] waste pieces removed and the opening was dressed smooth.
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Once the the component are finished and primed the reinforcing panel was re-installed and M3 riv-nuts used to fix the two components. The front cover had all the holes enlarged to 3.5 mm and panel fixed with dome head screws supplied with the kit.
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| Finished doubler |
To be covered in the next blog
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| Trial lower faring - Cover installed ready to be modified to take drive Note the pop rivet shown fouled on cover |
Monday, 27 April 2015
Trim Tab - Part 2
Trim Tab Drive Overview
The first decision is what kind of opening do I install for the trim tab. Reviewing the work of the RV clan shown opposite requires a lot of flush riveting and rivet nuts and I did not wish to invest the time required.
The decision was to manufacture externally mounted plate secured by M3 pan head screws fitted to rivnuts similar to the inspection hatch at the rear of the aircraft.
Trim Tab
A reinforcing plate was fabricated from 2024-T3 aluminium to mount under the clevis attachment supplied by the factory. The flanges were folded 15 mm and trimmed to fit inside the tab.
The shaft center was marked and the plate was attached using 0.005" double sided film adhesive to the inside face of the trim tab. The plate is located on its own center and about the shaft center line
The tape will hold the plate in position for riveting. OK - I was out of rivets and wanted to close the tab to allow the installation of the drive.
The location of the plate was marked onto the lower skin and 3 [three] 3/32'' pop rivets installed at each pitched 5 mm from the edge and at 30 mm centers. The clevis attachment will be fitted once the MAC trim drive is installed in the elevator.
The drive installation will be covered in the next blog post.
The first decision is what kind of opening do I install for the trim tab. Reviewing the work of the RV clan shown opposite requires a lot of flush riveting and rivet nuts and I did not wish to invest the time required.The decision was to manufacture externally mounted plate secured by M3 pan head screws fitted to rivnuts similar to the inspection hatch at the rear of the aircraft.
Trim Tab
A reinforcing plate was fabricated from 2024-T3 aluminium to mount under the clevis attachment supplied by the factory. The flanges were folded 15 mm and trimmed to fit inside the tab.
The shaft center was marked and the plate was attached using 0.005" double sided film adhesive to the inside face of the trim tab. The plate is located on its own center and about the shaft center line
The tape will hold the plate in position for riveting. OK - I was out of rivets and wanted to close the tab to allow the installation of the drive.
The location of the plate was marked onto the lower skin and 3 [three] 3/32'' pop rivets installed at each pitched 5 mm from the edge and at 30 mm centers. The clevis attachment will be fitted once the MAC trim drive is installed in the elevator.
The drive installation will be covered in the next blog post.
Trim Tab - Part 1
Trim Tab
The off cut was already modified when the decision to look at an alternative layout however the factory supplied blank skin was now employed.
The lower skin was folded to create a included angle off 80 degrees to create the lower flange.
A matching end cap was folded from 2024-T3 over size to be trimmed later.
The trim tab skin upper edge was marked with mounting hole center line using the mid point of the hinge width as a starting point.
Next the hinge and upper skin were match drilled at both ends and cleoced. The edge of the tab was positioned by aligning with the point of contact on the loops on the hinge.
The hinge was reassembled onto the elevator using the hinge wire.
The front cap was positioned on the rear of the hinge after removing the skin and 2 [two] mounting holes duplicated.
Rotated the assembly to check for correct operation and once satisfied marked holes onto the top side of the skin with a factory jig and felt tip pen - drilled 3/32''.
Reassembled the skin, hinge and front cap - checked operation and then match drilled all holes 3/32''.
Checked operation.
To assist in locating the lower flange of the trim tab a scrap angle was clecoed across the top of the elevator. These were cut and clamped to hold the trim edge in its correct location.
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| Modification - refer disclaimer |
The lower skin was folded to create a included angle off 80 degrees to create the lower flange.
A matching end cap was folded from 2024-T3 over size to be trimmed later.
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| First fitting Tab |
Next the hinge and upper skin were match drilled at both ends and cleoced. The edge of the tab was positioned by aligning with the point of contact on the loops on the hinge.
The hinge was reassembled onto the elevator using the hinge wire.
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| Match drill front cap |
The front cap was positioned on the rear of the hinge after removing the skin and 2 [two] mounting holes duplicated.
Rotated the assembly to check for correct operation and once satisfied marked holes onto the top side of the skin with a factory jig and felt tip pen - drilled 3/32''.
Reassembled the skin, hinge and front cap - checked operation and then match drilled all holes 3/32''.
Checked operation.
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| Alignment Jig |
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| Marking front cap |
To assist in locating the lower flange of the trim tab a scrap angle was clecoed across the top of the elevator. These were cut and clamped to hold the trim edge in its correct location.
With the upper skin aligned against that angle and the lower skin positioned by hand a point was marked onto the face of the front cap.
This was repeated at the opposite end and the assembly removed, line drawn and once satisfied the cap was cut to its correct depth and profile.
This was repeated at the opposite end and the assembly removed, line drawn and once satisfied the cap was cut to its correct depth and profile.
Trim was reassembled with the base two holes match drilled from the front cap into the folded flange of the skin and pop riveted.
The tab was remounted onto the elevator and the overall visual alignment checked, at this point all holes were matched drilled
Removed and reassembled - again.....!
The tab was remounted onto the elevator and the overall visual alignment checked, at this point all holes were matched drilled
Removed and reassembled - again.....!
Ribs
The outer rib was fabricated from one of the ribs supplied by the factory.
The next rib to be fabricated is the inner rib as the factory one did not fit correctly on this project - I suspect a error with the angle folded into the tab. This style of rib was taken from the RV series of aircraft. Both were cut from two of the factory supplied ribs. Note the inner rib is recessed to match the depth of the outer rib. The lower rib is pop riveted first then the outer.
All temporary pop rivets were removed in preparation for priming and final assembly
The trim tab components were primed for assembly ready to allow installation of the trim drive clevis reinforcement.
The outer rib was fabricated from one of the ribs supplied by the factory.
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| Outer Rib |
All temporary pop rivets were removed in preparation for priming and final assembly
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| Inner Rib |
The trim tab components were primed for assembly ready to allow installation of the trim drive clevis reinforcement.
This is to be covered in the next blog post.
Monday, 20 April 2015
Elevators - Part 2
Before commencing assembly the captive nuts needed to be fixed onto the main spar. The operation began by enlarging the factory 5/32'' rivet holes either side of the 3/16'' hole to 1/8'' to allow rivet insertion. After drilling these are counter sunk to suit 1/8'' countersunk rivets with the captive nuts were modified as per the previous blog - 12 per side required.
When complete all captive nuts were fixed using the supplied 1/8'' countersunk pop rivets.
Note: One set of the holes are close to the flange to allow the use of even a small micro-stop if one was available. Trying to use only the cutter resulted in a nick into the metal which had to be polished out.
This set of holes were counter-sunk using a 7 mm drill. This was done with the battery drill running at the minimum possible speed with extreme, extreme care. The clutch was set to just drive the drill.
Port Frame
Assembled the frame and fixed with the supplied dome head rivets.
Port side skin refitted and fully clecoed except to the attachment to the main spar to allow fitment of the D nose.
Starboard Frame.
Assembled the frame and fixed with the supplied dome head rivets.
The skin was refitted and clecoed to the frame.
The factory supplied with this kit, two [2] folded 90 degree angles to fabricate the end caps that form the mounting for the hinge of the trim tab. Also supplied was 4 [four] plain ribs for the tab and a full elevator skin.
The folded 90 degree angles for the frame were prepared and mounted. The top angle needed more that 90 degrees and after correcting the angle it was was curved by the process used - time to stop and think about it.
The conclusion was to begin again with new folded angles that were manufactured at the correct angle and had larger flanges making assembly less critical.
Schematic's of the assembly scheme is shown below and is unapproved - refer disclaimer above.
Elevator Trim Modifications
Two [2] angles were folded from 2024-T3 aluminum to match the opening profile at the rear of the frame. One was folded wider than the opening to be trimmed later. Both have a 20 mm flange to match the original.
The flanges of the two ribs were modified as shown opposite with the final profile shown on the right hand side.
The lower angle was fitted first with its overall depth reduced by 3 mm from the measured dimensions of the openings. Fitted the angle's 20 mm flange into the rib and match drill two mounting holes at adjacent ends using the skin and checked the alignment.
Once satisfied all the remaining holes were drilled and the angle secured with clecos.
Two aluminium angle tabs were fabricated to suit their location and attached at each rib with 2 [two] pop rivets, The lower angle was secured to each tab [rib] with a single 1/8'' counter sunk rivet after dimpling. This allows the top angle to be fitted on top.
The upper angle was positioned above the lower flange and drilled using the same method outlined above.
Using a straight edge the bottom was alignment was checked, then using clamps, fingers and eye the lower angle [rib skin location] was adjusted into its final location. Particular attention was taken to ensure the line of the skin follows the correct line of the rib profile. It was a balance between a straight line and the rib profile visuals.
Starting at the outer rib, drilled the first hole at the base and fix with a 5/32'' cleco, repeated the process at the opposite end then the center. This process created a single element that locks the top and bottom skins into their final location.
With a final check using a straight edge and eye, checked the overall appearance and when satisfied the last task was to drill the balance of the holes in the lower row then fix with 3/32'' rivets.
Note: The location of all mounting holes were marked using the drilling jig supplied by the factory using a felt tip pen.
The 3/4" wide piano hinge supplied with the kit was separated into its two components then one was drilled to match the rivets on the elevator at a 30 mm pitch to accept 3/32'' rivets.
Positioned the hinge and match drill the skin and spar - fixed hinge with 3/32'' pop rivets.
This blog must be read in conjunction with this later blog - Hitting a Wall
When complete all captive nuts were fixed using the supplied 1/8'' countersunk pop rivets.
Note: One set of the holes are close to the flange to allow the use of even a small micro-stop if one was available. Trying to use only the cutter resulted in a nick into the metal which had to be polished out. This set of holes were counter-sunk using a 7 mm drill. This was done with the battery drill running at the minimum possible speed with extreme, extreme care. The clutch was set to just drive the drill.
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| Frame ready for skinning |
Port Frame
Assembled the frame and fixed with the supplied dome head rivets.
Port side skin refitted and fully clecoed except to the attachment to the main spar to allow fitment of the D nose.
Starboard Frame.
Assembled the frame and fixed with the supplied dome head rivets.
The skin was refitted and clecoed to the frame.
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| Elevator Trim |
The unused portions of the ribs projecting from the skin were marked and the clecos from the first two ribs were removed once side at a time, the rib's are cut with aviation snips. The skin re-clecoed and the operation repeated on the other side.
Modification: Refer disclaimer
Trim Tab Mounting
The folded 90 degree angles for the frame were prepared and mounted. The top angle needed more that 90 degrees and after correcting the angle it was was curved by the process used - time to stop and think about it.
The conclusion was to begin again with new folded angles that were manufactured at the correct angle and had larger flanges making assembly less critical.
Schematic's of the assembly scheme is shown below and is unapproved - refer disclaimer above.
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| Elevator Schematic |
Elevator Trim Modifications
Two [2] angles were folded from 2024-T3 aluminum to match the opening profile at the rear of the frame. One was folded wider than the opening to be trimmed later. Both have a 20 mm flange to match the original.
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| Rib preparation |
The lower angle was fitted first with its overall depth reduced by 3 mm from the measured dimensions of the openings. Fitted the angle's 20 mm flange into the rib and match drill two mounting holes at adjacent ends using the skin and checked the alignment.
Once satisfied all the remaining holes were drilled and the angle secured with clecos.Two aluminium angle tabs were fabricated to suit their location and attached at each rib with 2 [two] pop rivets, The lower angle was secured to each tab [rib] with a single 1/8'' counter sunk rivet after dimpling. This allows the top angle to be fitted on top.
The upper angle was positioned above the lower flange and drilled using the same method outlined above.
Using a straight edge the bottom was alignment was checked, then using clamps, fingers and eye the lower angle [rib skin location] was adjusted into its final location. Particular attention was taken to ensure the line of the skin follows the correct line of the rib profile. It was a balance between a straight line and the rib profile visuals.
Starting at the outer rib, drilled the first hole at the base and fix with a 5/32'' cleco, repeated the process at the opposite end then the center. This process created a single element that locks the top and bottom skins into their final location.
With a final check using a straight edge and eye, checked the overall appearance and when satisfied the last task was to drill the balance of the holes in the lower row then fix with 3/32'' rivets.
Note: The location of all mounting holes were marked using the drilling jig supplied by the factory using a felt tip pen.
The 3/4" wide piano hinge supplied with the kit was separated into its two components then one was drilled to match the rivets on the elevator at a 30 mm pitch to accept 3/32'' rivets.
Positioned the hinge and match drill the skin and spar - fixed hinge with 3/32'' pop rivets.
This blog must be read in conjunction with this later blog - Hitting a Wall
Tuesday, 14 April 2015
Elevators - Part 1
Assembled both frame's as shown in the factory drawing's using clecos. The factory has identified each rib with letters making the task easier. The extra rib for the mass balance cover has yet to be installed on the assembly's shown below.
Trail fitted the skins to confirm that they were correct for both frames. Either skin will fit but as clecos are added and if the incorrect skin is fitted the elevator will begin to distort depending on where the start point was. If correct all the holes will line up easily and the trailing edge will remain straight.
Errors can happen, so check!
Why fabricate the trim tab?
In Australia to meet the 51% rule some fabrication is required by the builder when the kit was analysed under CASA regulation AC21.29. This rule allow a builder to gain full points for fabrication and assembly of an elevator trim tab. The points gained are then applied to the factory assembled wing as both carry equal weighting in the chart.
When you examine the chart it's a way for the regulators to force some fabrication skills to be developed while still allowing other major tasks to be done at the factory i.e. an quick build wing kit.
Trim Tab Skin
The starboard [left] elevator has the trim tap installed and this requires fabrication by the builder. The factory supplied all the necessary folding's but in raw form only.
Marked out the trim tab on the skin surface to the factory supplied dimensions - Check - THINK - RECHECKED and only then cut.
All cuts were undertaken using the methods outlined in the blog metal cutting. A piece of 6 mm plywood was inserted between both sides for this task.
Once the cuts are made begin at the separation at external edge, it was found if the cut's are deep enough start at the outside edge and separate using a tearing motion and where thicker area's are encountered a set of snips will cut that area of the skin easily.
Dress all edges smooth and nick free.
Note: Drill a 5/32'' [4 m] hole at each corner and cut to this - important!
The resulting scrap will become the skin for the tab when it is trimmed later in a following blog.
Placed to one side for reuse.
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| Elevator frame trial assembly |
Trail fitted the skins to confirm that they were correct for both frames. Either skin will fit but as clecos are added and if the incorrect skin is fitted the elevator will begin to distort depending on where the start point was. If correct all the holes will line up easily and the trailing edge will remain straight.
Errors can happen, so check!
Why fabricate the trim tab?
In Australia to meet the 51% rule some fabrication is required by the builder when the kit was analysed under CASA regulation AC21.29. This rule allow a builder to gain full points for fabrication and assembly of an elevator trim tab. The points gained are then applied to the factory assembled wing as both carry equal weighting in the chart.
When you examine the chart it's a way for the regulators to force some fabrication skills to be developed while still allowing other major tasks to be done at the factory i.e. an quick build wing kit.
Trim Tab Skin
The starboard [left] elevator has the trim tap installed and this requires fabrication by the builder. The factory supplied all the necessary folding's but in raw form only.
Marked out the trim tab on the skin surface to the factory supplied dimensions - Check - THINK - RECHECKED and only then cut.
All cuts were undertaken using the methods outlined in the blog metal cutting. A piece of 6 mm plywood was inserted between both sides for this task.
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| Trimming edge of skin |
Dress all edges smooth and nick free.
Note: Drill a 5/32'' [4 m] hole at each corner and cut to this - important!
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| Tearing cut line |
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| Cutting skins |
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| Off-cut becomes the tab skin |
Placed to one side for reuse.
Elevator Stab - Part 2
Riveting
The clecos were remove in alternative pairs then rivets inserted after chasing with #30 drill as required, no issues were encountered. Riveting began at the center of the front spar moving towards one end and down each rib to the rear spar as each rib was passed. The first rib was riveted about 50% then to the next rib. The next rib was riveted 50% the the first completed. Finally the lower spar was riveted with the counter sunk rivets at the nose last. These were done from the front spar up to the nose using a similar pattern.
The whole purpose of the procedure was to assist the skin to finding its original home, necessary - who knows but it made me feel better.
Fiberglass Fairings
The aluminium strip for mounting are now inserted under the dimpled holes in the skin and match drilled with the #30 drill. They were removed, primed and reinserted after the primer was dry.
These should have been dimpled and inserted with the skins so there was concern if there would be a good fit but the soft aluminium provided with the kit, combined with the raw power of the battery pop riveter ensured a tight fit.
The fairings were refitted, aligned and taped into position and using the same techniques to mark and install that were outlined in the top faring blog for the rudder.
No sanding was required fitted as supplied from the factory.
Cover Plate
The factory supplied cover plate was refitted to the factory mounting holes and the others matched drilled with a #30 drill using the cover as a template. The cover was removed and all holes enlarged to 4.8 mm to accept the M4 short rivet nuts. The hand riveter was a struggle at this size but all were inserted with no drama's. The holes in the cover were enlarged to 4.5 mm for ease assembly.
Note: The cover plate provides access to the AN3 nuts and washers used to secure the mounting straps and for major inspections.
Footnote
The whole assembly went together as per the drawings and no issues were encountered.
The elevator mounting frame shown in Part 1 worked well during for the riveting, placing the this builder at a good height either standing or seated as required. The electric pop riveter proved to be the ideal tool - lots of power and only noisy when required.
The dimples formed using the basic dimpling tool gave good result at assembly for my purposes - only wish they would provide more nails as they are hard to match in Au.
The clecos were remove in alternative pairs then rivets inserted after chasing with #30 drill as required, no issues were encountered. Riveting began at the center of the front spar moving towards one end and down each rib to the rear spar as each rib was passed. The first rib was riveted about 50% then to the next rib. The next rib was riveted 50% the the first completed. Finally the lower spar was riveted with the counter sunk rivets at the nose last. These were done from the front spar up to the nose using a similar pattern.
The whole purpose of the procedure was to assist the skin to finding its original home, necessary - who knows but it made me feel better.
Fiberglass Fairings
The aluminium strip for mounting are now inserted under the dimpled holes in the skin and match drilled with the #30 drill. They were removed, primed and reinserted after the primer was dry.
These should have been dimpled and inserted with the skins so there was concern if there would be a good fit but the soft aluminium provided with the kit, combined with the raw power of the battery pop riveter ensured a tight fit.
The fairings were refitted, aligned and taped into position and using the same techniques to mark and install that were outlined in the top faring blog for the rudder.
No sanding was required fitted as supplied from the factory.
Cover Plate
The factory supplied cover plate was refitted to the factory mounting holes and the others matched drilled with a #30 drill using the cover as a template. The cover was removed and all holes enlarged to 4.8 mm to accept the M4 short rivet nuts. The hand riveter was a struggle at this size but all were inserted with no drama's. The holes in the cover were enlarged to 4.5 mm for ease assembly.
Note: The cover plate provides access to the AN3 nuts and washers used to secure the mounting straps and for major inspections.
Footnote
The whole assembly went together as per the drawings and no issues were encountered.
The dimples formed using the basic dimpling tool gave good result at assembly for my purposes - only wish they would provide more nails as they are hard to match in Au.
Friday, 10 April 2015
Throttle Quadrant - Part 1
Something different was required to the standard offerings and a pistol grip design used by the Beech Mentor T34 looked to fill the bill but the problem was that none are available in that style. Using that inspiration and a few hours of solid modeling produced the pistol grip below.
A 3D-STP file was emailed to Wanfon Rapid Prototyping in China and in 5 days the grip arrived - total cost $US135 including freight. The attachment insert was machined from 2024-T3 aluminium bar and drilled 7mm through to allow the wiring of the switch's.
The next question was what control's to incorporate and throttle / rpm were the logical combination as propeller rpm can be linked into a FlyBox PC-1 controller using the two push buttons.
Originally I was looking at a different controller so why the change - simple the desire to use a 4 blade propeller to help capture that Shorts Tucano look. The supplier uses the Flybox as dose the factory aircraft and both give it a thumbs up for its operation.
The next item on the list was a suitable throttle quadrant and the Model CT-82F for a RV was selected. The mixture control knob will be painted yellow and will be used for choke on the Rotax engine. At 40 mm wide fits well within the available envelope and is a well made unit with friction brake - quite smooth.
Cables
The choke is simple and a standard wire Bowen cable was selected.
The throttle is complicated by the need to operate the two carburetors of a Rotax 912. A dual cable throttle cable was sourced with a knob, this will be removed and a suitable connection fabricated to suit.
Assembly will be covered in Part 2
Note:
The step file for the handle is available to other builders - contact through the Australian Dealer Web Site - http://www.flyinglegend.com.au
A 3D-STP file was emailed to Wanfon Rapid Prototyping in China and in 5 days the grip arrived - total cost $US135 including freight. The attachment insert was machined from 2024-T3 aluminium bar and drilled 7mm through to allow the wiring of the switch's.
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| Pistol Grip 3D Render |
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| The final product in ABS plastic |
The next question was what control's to incorporate and throttle / rpm were the logical combination as propeller rpm can be linked into a FlyBox PC-1 controller using the two push buttons.
Originally I was looking at a different controller so why the change - simple the desire to use a 4 blade propeller to help capture that Shorts Tucano look. The supplier uses the Flybox as dose the factory aircraft and both give it a thumbs up for its operation.
The next item on the list was a suitable throttle quadrant and the Model CT-82F for a RV was selected. The mixture control knob will be painted yellow and will be used for choke on the Rotax engine. At 40 mm wide fits well within the available envelope and is a well made unit with friction brake - quite smooth.
A four [4] core cable will connect the BC Specialty Products push buttons which are a press fit into their respective hole's with a washer preventing them being driven while in use.
Cables
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| Very smooth operation. |
The throttle is complicated by the need to operate the two carburetors of a Rotax 912. A dual cable throttle cable was sourced with a knob, this will be removed and a suitable connection fabricated to suit.
Assembly will be covered in Part 2
Note:
The step file for the handle is available to other builders - contact through the Australian Dealer Web Site - http://www.flyinglegend.com.au
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