13 February 2017

Fuselage Stand

With the fuselage safe and sound in the shop, next up was a jig to support the fuselage so I could begin work on it. Unlike the wing stands, everyone seems to have their own design for the fuselage stand. Not to be outdone, and wanting to get rid of a bunch of scrap aluminum that has been sitting in the shop I decided to make a metal jig leveraging some wheels from a previous project.



I made the uprights that connect to the center section out of 2x2 1/8 6160 24 inches long. The center section had some nice wood blocks already bolted into them, so I used that for my interface.



With a way to connect the center section to my jig, I started welding up a T structure that would support the wheels. The main structure of the jig was a 64" long  2x2 1/8" square tube that falls directly under the center section and connects to the main wheels and the 24" center section up-rights. The structure heading aft is 1x1 1/8" 6 feet long.



After I had the main T structure built up I ended up going back and re-inforcing all of the 1x1 connections with 1x2 angle. The jig was going to have two front wheels directly under the center section and one rear wheel under the tail, so there shouldn't be that many torquing forces on these joints, but with that said, I had this bad vision in my head of this connection failing sending 1x1 up through my fuselage.



The main structure complete:


This was really an after-thought, but I ended up really liking it. I was not exactly sure where I was going to need support under the belly of the fuselage. I was going to start putting cross braces in the main section heading aft, but I had some 5/4"x10" boards around and it just so happened that I built my structure ~9" wide. So I lag bolted the 10" board to the aluminum structure and everything stiffened up really nicely.



From there, I slide the jig under the fuselage and lifted everything into place. After that I added a couple more bolts to secure the uprights to the jig.



Done! I used a lot of material that was just around the shop and I when with a lot of the lengths that I already had sitting around. The height ended up being perfect and if I were to do it again from drawings, I would dimension everything the same way.

11 February 2017

Fuselage Arrives!

I ordered a quick build Fuselage in August of 2016 and Vans at the time had estimated that it would arrive in February or March of 2017. Around the first of the year I had contacted Vans to see if there was any update, and they gave me the great news that my fuselage was in transit to Vans and would be arriving in Oregon at the end of January 2017.

Late January, Tony Partain and Vans both called me saying that the fuselage was ready to ship. When all was said and done it was about 2K to freight the fuselage from Oregon to Virginia via Tony.



Tony started using a new shipper apparently, which is the same shipper that freights all of the Factory Five cars around. My driver showed up right on time and started to offload immediately. That is where things started to go not as planned. The cable hoist system in the truck would not power up... The driver narrowed it down to the solenoid on the main gantry, so we hopped in my truck and went to NAPA to pick-up a new solenoid. Apparently the solenoid was a 6v solenoid which my local NAPA did not stock, so we drove out 30 minutes to another store, grabbed a solenoid and headed back home.


By the time we got back to my house it was nearing 1200. Which started to put me in a time crunch because I had to get to work for a meeting (my company had just been acquired that day and there was an All-Hands meeting that I needed to get to). The driver got the new solenoid in, but the gantry still would not move. I grabbed some jumper cables to jump past the solenoid, and the motor would not budge.



I was about to give up and call it a day (in reference to completing the delivery), but the driver asked if I wanted to offload the fuselage by hand. There were only two of us so we unstrapped it to see if we thought we could do it by ourselves.




I am lacking photos of the next hour because it was a bit stressful and both of our hands were a bit full. We were able to off-load the fuselage with two people off of the trailer. If I were to do it again I would NOT do it with only two people. It really needs a third person and ideally a fourth. That said, we got it off the truck and into my shop with only one minor cosmetic scuff. 




Now we have a fuselage! In our garage!

\

06 January 2017

Stick Grips

The stick grip selection was surprisingly a difficult choice. It seems like just another plane piece until you really think about it. It is more than that. It is the connection between the pilot and the plane, and it deserves some thought and attention (and class). I really thought I was going to go with the Infinity Aerospace grips, but then after internally debating it for a couple of weeks I decided that it felt a little cheesy. I think the Infinity grips are cool and all, but this isn't a fighter jet.

There are loads of options out there and I started to gravitate towards the wood ones. The problem with the wood ones is that I feel like wood would be out of place based on all of the carbon fiber that is going to be in the interior.

Guy over at Pioneer Aviation had a good balance between the Infinity grips and some of the other wood grips that are out there. I had Guy custom stain me some maple grips in a light grey. I got the PTT, high-hat, autopilot disconnect, and another random button that I am not sure what I am going to wire to yet.



Guy was really great to work with and I am nothing but pleased with these beauties!

29 December 2016

Trim Wiring

My tail section came with a Ray Allen trim servo for pitch trim, continuing that I recently ordered another trim servo and roll trim bracket. I also recently ordered my stick grips with a 4 way high-hat and now it is time to start planning what wires I will need to put in place to control everything. I think I will be going with a G3X system (to include autopilot) as well as a VP-X electronic circuit breaker controller.


With this mix of electronics it is time to figure out what controls what and what else do I need from a trim and autopilot perspective. My first question was do I need a safety trim? In looking at the G3X system it looks like the preferred approach is to wire the trim servos through the GSA28 autopilot servos. While the VP-X system has safety trim built in, per their install manual, when you install GSA28s with a VP-X you configure the VP-X to disable the variable speed trim functionality. If you dig deeper into what the GSA28s are capable of everything makes a little more sense.

The Garmin servo provides a built-in interface to drive trim servos at no extra cost. When the autopilot is off, the servo provides speed scheduling for the manual trim commands. When the autopilot is on, the servo adjusts to constantly keep the aircraft trimmed. 

What does all of this mean? When the power is removed from the servos, speed scheduling is disabled and the trim commands are passed directly through the servos to the trim motors. Auto trim is not functional when the autopilot is disengaged, and manual electric trim via the stick hat is never disabled, but if you attempt to manually trim the plane when the autopilot is engaged, the autopilot will disengage to honor your request.

It is always your job to trim the plane when the autopilot is disengaged regardless of whether the servos are powered on (and providing speed scheduling) or off and the trim motor drive is passed through without speed scheduling. In general, with these systems, your servos will always be powered, even when you are not using the autopilot.

That seems pretty straight forward and confirmed by the VP-X install manual:



So I started thinking more about that and I got a fairly uncomfortable feeling. Not that I don't trust Garmin, but I don't really trust anyone. I especially don't trust electronics that I did not assemble. If you look at the wiring diagram above you quickly realize that in the event of an autopilot power failure you loose control to your trim. On the RV-10 there is no manual trim wheels so you would be SOL. How can that be? Well... Reading more into the Garmin manual I found this:

In the event that power to the GSA 28 is removed, a fail-safe system connects the trim input switch directly to the trim motor. In this condition, the trim switch powers the trim motor directly and the motor runs at its full speed when the switch is pressed. The same condition also occurs if a trim switch and motor are connected to the GSA 28, but the trim control function is disabled.

Well that makes sense. The next question is how does one wire in the trim switches. I would prefer having both control sticks have full control. I am not sure why other than I like symmetry. In the GSA28 install section you will find a the following note:

So looks like I should be thinking about a GAD 27 as I select my avionics. It is a $500 dollar unit that appears to have a bunch of functionality that I do not need. I went back to the VP-X manual and it looks like there is a trim mixer in that device. So assuming I disable all of the VP-X trim safety systems perhaps I can use the VP-X to mix my trim and G3X to provide auto-trim and speed scheduling. Other than that I still have to check to see if the G3X system has any form of runaway protection.







27 December 2016

Anti-Rotation Plates

I still have not decided if I am going with a factory new or something like a BPE engine. I did speak with BPE the other day and I told them I am just about to close up my fuel tanks. They told me regardless of my engine choice that it would be a good decision to install fuel return lines into my tank just in case I ever end up with electronic fuel injection. In the case that I go bone stock, I can just cap these connections off, and that seems like some pretty wise advice.

I plan on putting 3/8s AN fitting near my vent line in order to service fuel return. This basically looks just like the vent line, but with a larger fitting to match the flow of the pick-up line. I looked around on Vans for a while, but I did not see an anti-rotation plate for 3/8s fittings. Back to the mill!



There is nothing really earth shattering here. I drilled a couple of #33 holes to have a close fit for some 4-40 screws to hold down the sheet to a scrap delrin block. I will later drill these #33 holes to #30 in order to rivet the plate to the end rib on the tank. From there I milled out a hex pattern to accept the AN fitting.



About the only annoying thing here is that I don't have a CNC. I have gotten fairly decent at running 45 degree lines by hand, but 60 degrees I have yet to master.




PVPV-D Parking Brake Bracket

I want to put a parking brake into the plane. I looked around what others were doing and the Matco PVPV parking brake seems to be pretty standard. So much so that airward sells a bracket for the brake. I have no issues with the airward bracket, but I do have a mill in the basement and this seems like a pretty low stress project for when it is too cold to work in the shop.

I started with building a solidworks model of the PVPV-D from the mechanical drawings. The drawings call out that you need 27.5 degrees of deflection on each side of the "up" position to go from on to off. I built the axial limits on the model stop at 30 degrees on each side.






From there I designed a bracket around the PVPV-D that will:

  • Securely mount the valve to the firewall
  • Allow the replacement of the valve
  • Give 30 degree end stops on the arm travel
  • Hold the control cable




After the design stage I moved over to the mill and faced a hunk of aluminum. I have a TIG welder so I plan to build this in 2 pieces so I don't have to hog out 3 square inches of aluminum. I drilled and tapped the parking PVPV-D mounting holes with a 10-32 tap.


I am still waiting on my fuselage kit to arrive so for the time being I only placed the two valve mounting holes, and none of the firewall mount holes.



 

At this stage I forgot to keep on taking photos. The second piece I machined was the vertical bracket that provides the end stops and cable holding. I need to purchase a cable yet, so for now, I am going to keep the project in this state until I get the rest of the pieces. I still have a lot of metal to get rid of, but from a proof of concept, the bracket is working.

16 December 2016

More Fuel Tanks

Not too much to talk about lately. I have been spending my time working through the fuel tanks. I went back and re-read my last post. I guess a couple of things have changed since then. On the first couple of ribs of the right tank I went with the cleco, cure, and then wet rivet method. I ended up not really liking that method. I started to find the riveting of the ribs while wet quicker and cleaner. I know that sounds counter intuitive given all the complaints about that process, but I like it. It goes quickly, and I do think it pulls the skins to the ribs in a more desirable way.

One of the other interesting things was the right tank fuel sender rod bends. I remember a couple of people complaining that the float hits either the stiffeners or the vent line and that you have to make a couple of bends to get around this. I did not find this to be the case. I started with 3/32 tig rod and made sure I had my bends just right.



After I got everything where I wanted I bent the real rod and checked the clearance and travel. According to the multi-meter I had full travel and there were no clearance issues with the stiffeners or the vent.