Monday, November 30, 2015

Dual Sensor Bracket Completed & F-00060 Panel Modified For Additional Switches

The dual sensor mounting bracket being fabricated to hold the oil pressure sending unit in addition to the fuel pressure sending unit was finally drilled to a final size of 1" using the larger step drill that was recently purchased. After the bracket was drilled, it was painted.
The fabricated dual sender bracket’s mounting holes for the two sending units were drilled to 1" and now ready for paint.

Awhile back, a preliminary test was made to determine if the two extra rocker switches for the fuel pump and left landing light could be installed in the area above the AV-50002 ignition start module … although not an abundance of room, it appeared as though they would fit.  Figured it was time to establish the final position and cut some holes for the switches. Played around with the positioning and decided upon centering the two switches directly above the left and right ignition switches. Measurements were made and lines drawn onto the F-00060 panel so a paper cutout could be placed onto the panel to verify the switches would indeed fit. For a cohesive look, the switch spacing was kept the same as the A & B ignition switches and positioned so there is enough room for labeling the switches.
Locations for the two additional Otto switches were marked onto the F-00060 instrument panel. If one zooms in closely, the markings for the spacing can be seen.

Two #30 holes were drilled in the area of each switch location and then enlarged with a step drill. The two holes were then joined by using a Dremel with a cutting wheel and a file to enlarge the opening enough to allow access for the nibbling tool.
Using a nibbling tool to trim the opening just shy of the markings so a hand file could finalize the opening.

After shaping the switch mounting holes with the nibbling tool, the openings were brought to final size by hand filing and the switches were test fitted.
Completed openings with both Otto switches in position but not fully seated.
Did not fully install the switches at this time because the panel pieces will be sent out for powder coating soon.

Tuesday, November 24, 2015

Fabricating Mods - Throttle Quadrant and Dual Sender Brackets

Yesterday, Mike and I went over to Steffon’s fabrication shop and used the metal brake to bend the dual mounting bracket being created for the oil and fuel pressure sending units. Also bent the new mounting bracket being made for mounting the throttle, choke and cabin heat cables so the center section of the instrument panel can be removed in the future without the need to remove all the cables from the engine compartment … gee, may as well add the parking brake cable as well. A special thanks to Steffon for allowing me to utilize the equipment at his shop to bend the metal.
The new throttle mounting bracket and the dual sending unit mounting bracket after bending the pieces using Steffon’s metal brake. Both brackets still need shaping and holes drilled.
The throttle mounting bracket (which still needs shaping and holes drilled) will mount onto the underside of the instrument panel base. Still undecided about the mounting method, riveting it in place or using screws so it can be removed if desired ... leaning towards screws at the moment.

Upon returning from Steffon’s shop with the newly bent parts, decided to begin trimming and shaping the new dual bracket for the oil and fuel pressure sending units. One issue that needed to be overcome was the extra width of the new dual mounting bracket … it interfered with some rivets on the firewall. Instead of drilling relief holes in the bracket as one builder did, decided to just shape the bracket so it barely clears the rivets.
Partially completed bracket now clears the rivets on the firewall. Still needs more shaping on the edges and the two holes for the rubber mounting grommets drilled out to size.

After getting the bracket’s mounting flange to clear the rivets on the firewall, the holes for the rubber mounting grommets were drilled out using three step drill bits. The final size for both holes needs to be 1" to accommodate the rubber grommets both sensors will be mounted onto.
Using a step drill to enlarge the mounting holes for the rubber grommet the two sending units will mount onto.

My largest step drill only goes to 3/4", so on the way home this evening will pick up a larger step drill and bring the hole diameters up to the final size of 1" first thing during the next work session.

Sunday, November 22, 2015

Work Begins On Firewall Forward Electrical

Not being able to get to the metal shop to bend the parts being fabricated until Monday, decided to try to make some forward progress and begin working on the firewall forward electrical.

Yesterday, after taking some measurements and playing around with some thoughts for future modifications, thought it would be a good idea to make a little forward progress on the RV-12 assembly and begin attaching some of the electrical components onto the firewall. The ES24115 master relay was mounted along with the 992 819 starter relay and manifold pressure sensor.
Mounting the ES24115 master relay onto the firewall.
From top to bottom … the Dynon 100434-000 manifold pressure sensor, ES24115 master relay and Rotax 992-819 starter relay.

The firewall forward wiring harness (WH-00063) needed to be fished forward from the instrument panel area through the rubber grommet in the firewall. Some wires on the firewall forward wiring harness are already terminated and others will need to be stripped and have the appropriate terminations added.
Fishing the WH-00063 firewall forward wiring harness through the grommet in the firewall.

The wires going to the ES24115 master relay utilize a rubber boot on each of the three terminals which led to an interesting complication when installing the protection diode onto the master relay.
The WH-P150 positive lead from the battery and the protection diode (hidden by the boot) yellow lead with the red stripe go onto the BAT terminal of the master relay. One can see there is virtually not much room left and the small ring terminal from the diode needs to go through yet another smaller rubber boot then attach onto the center post of the master relay along with another wire.

The leads on the protection diode are rather short and the rubber boots are rather long so it was somewhat of a fight to get the diode attached onto the small center post of the relay along with the WH-P759 white/orange wire that goes forward to the instrument panel. This task would not be fun if the engine were installed.
Wiring on the ES24115 master relay completed. One can see the larger rubber boot is being stretched by the diode’s lead. May just put a small slice in the boot to give the diode lead some relief.

By this time it was raining and the forecast was for freezing rains, so decided to pack it in for the evening before the roads became a skating rink.

Monday, November 16, 2015

More Modifications

In addition to adding switches for the fuel pump and left landing light into the left instrument panel, and installing the airspeed indicator into the center panel …. a few more modifications are planned for the DOG Aviation RV-12.

Van’s designs a great airplane to be sure, but there are areas for improvement and the throttle quadrant is one of those areas. One of my dislikes in this area is the fact that all of the cables for the throttle, choke and cabin heat need to be completely removed from the engine compartment in order to remove the center section of the instrument panel. In my opinion, that is just totally daft. Sorry… just had to say it because it is true. Therefore the center panel is receiving some more attention and a plan is being devised that will separate the throttle quadrant from the center panel.
Proof of concept … creating a separate throttle quadrant piece that will mount under the instrument panel base.

While playing with my original idea of slicing the bottom off the center panel, I realized that Van’s had changed the hole diameter and position of the throttle cable hole when they recently began offering the upgraded McFarlane vernier throttle cable. It requires a much larger hole which is positioned lower to accommodate the larger body of the throttle cable and 1 1/4" lock washer … this I discovered while enlarging the hole in the old style center panel I was using as a proof of concept piece.
The new center panel is in the foreground. The old panel’s throttle hole is being drilled larger to 3/4" … it is hard to see, but the position of the throttle cable on the new panel in the foreground is lower.

My original thought was to slice off the lower portion of the panel and bend it to 90 degrees on a brake and use some of the existing holes to mount in onto the bottom of the instrument panel base. However, because of the clearance required for the new throttle hardware, I fear the bend would need to start around the first row of holes putting them too close to the edge of the panel to be useful as attachment points, this would only leave the rear row of holes to attach onto the bottom of the instrument panel base. I feel that the weight of an arm on the throttle and the constant pulling and pushing will require more stability, so will be building a replacement piece from scratch with a larger footprint.
Measurements made and lines drawn on .063 aluminum to make a separate throttle quadrant piece with a larger footprint to be mounted onto the bottom of the instrument panel. If this piece ends up being a little flexi (which I doubt) a gusset can easily be added between the throttle and choke cable holes.

With the new throttle quadrant drawn up and ready to bend, moved onto another modification that will be made.  There have been issues in the past with the oil pressure sending units going bad with low hours of usage. One school of thought is that because they are mounted directly to the engine, they are receiving too much vibration and breaking down prematurely. Some builders have moved them to the firewall and mounted them using Adel clamps with good success. So the decision has been made to make a bracket for the firewall mounted fuel pressure sending unit that is double wide so the oil pressure sending unit can be mounted at the same location. Both sending units will be mounted in rubber washers on a single bracket mounted to the firewall with two holes in it.
Original white bracket in the background and the markings for the new two hole bracket in the foreground. After the bracket is bent on a brake, it will be cut to the proper height, shaped and the mounting holes drilled.

Will be away from the project for a few days but hope to get the pieces bent shaped and drilled by the end of the week.

Saturday, November 14, 2015

Work On F-00060 Left Instrument Panel Section Begins

Yesterday, Bernie swung by the hangar to lend a hand with the final fitting of the canopy. We needed to remove and replace the canopy a hand full of times before the canopy could be opened fully without contacting any metal it was not supposed to touch. Most of the problem was interference from the bottom edge of the canopy lay-up  touching the longeron/ fuselage side skin as the canopy approached fully open. Not wanting to get too aggressive, the lay-up on the lower forward portion of the canopy arm was sanded a little, test fit and sanded some more until the fit was acceptable. Basically a curve was sanded into the lay-up.
Bernie holding the canopy assembly open while I marked the area of interference with a Sharpie pen.

Unfortunately, I forgot to take a photo of the finished shape of the canopy arms so will need to edit this post later and post a photo of the final shape.

Now that the canopy is fitted, it will be set aside so there will be easier access for installing the instruments and wiring along with modifying each of the three panel sections. Not having the canopy fairing totally fitted has been holding me up some because all three of the panel sections will require some cutting … however, it has been necessary to keep the instrument panel sections screwed in place to hold the shape of the upper forward fuselage skin.

The plan is to add two rocker switches to the DOG Aviation RV-12 … one to control the electric fuel pump and the other to control the additional left landing light. I have opted to keep the left landing light switched so as to not overtax the electrical system. The wig- wag function will be controlled by the pulse switch already a part of the RV-12’s electrical wiring and this requires no additional power to operate the left light because only one landing light is illuminated at a time during wig-wag operation. However, do not want the left landing light to go steady on along with the right landing light, so it is being wired to a separate switch … should I need the landing light for a night landing, it can be turned on during short final, then off again when back on terra firma.

My original thought was to place the fuel switch above the AV-50002 ignition & start module and the left landing light switch in the glove box panel to the right of the existing switches in the center panel. However, upon review of “the look” … the left landing light switch would be an orphaned switch because of the spacing necessary to clear the mounting bracket for the panels. So have decided to install it above the ignition module adjacent to the fuel pump switch. A paper cutout was made utilizing the same switch spacing as the ignition A&B switches and there is just enough room for the two additional switches to be placed directly above the ignition switches. This should give the instillation a cohesive look and also provide sufficient room for switch labeling.
Planned mounting area for the two additional switches spaced the same and directly above the two ignition switches.
The paper cutout my finger is pointing towards represents the total space taken up by the existing two ignition switches including separation and bezels. As can be seen in the photo, there is enough room to place the two additional switches inline and directly above the ignition switches … this mounting location should create a cohesive look.

While having the F-00060 left instrument panel in hand decided to go ahead and countersink the #40 rivet holes for the nutplates and the F-00061 stiffener. Van’s calls for countersinking ALL of the panel’s mounting holes for flush #6 screws … however, I’m opting to change the look a bit and will either go with stainless Allen cap head screws or Torx pan head screws.
Machine countersinking rivet holes in the F-00060 left instrument panel using the countersink cage outfitted with a #40 100 degree countersink bit.

The plan is to get the instrument panel pieces powder coated so decided to have all the rivets in place prior to powder coating. The six nutplates and F-00061 stiffener were riveted onto the F-00060 left panel.
Riveting one of the six nutplates onto the F-00060 left instrument panel section.
Completed riveting of the nutplates and F-00061 stiffener onto the F-00060 left instrument panel section.

All that is left to do to the F-00060 panel is finalize the position of the additional switches and cut the two holes for the additional switches and it will be ready for powder coating.