Building Tips




Got a sure fire-way to tackle one of those "challenging" tasks on your project or flying RV?
Drop us a note and we'll post it here.


* * * * * * * *


Painting it yourself! - How to roll your own outstanding paint job

RV-8 builder Scott Elhardt finished his RV-8 in the spring of 2012. He decided to paint his new RV himself and documented his methodical and through approach to this seemingly overwhelming task. Here is the LINK to his story:

Paint


Pitot-static line installation (Doug Weiler)

I am finally to one of the more enjoyable (but challenging) parts of my RV-7 project: the instrument panel. Finally it seems here things begin to come together and all of that planning and dreaming of a panel full of goodies starts to take shape. Recently I had SteinAir cut out my panel and now I was able to start to put some of the cool electronic doo-dads in place at least temporarily.

IMG_0704


After getting some of the preliminaries of the electrical system laid out, I thought now would be a good time to get the pitot-static lines hooked up to the various EFIS boxes and instruments. SteinAir sells those intriguing plastic air lines and fittings, which seemed like a vastly improved method of installing the pitot static system. Yes, I could be an “old school” guy like my mentor Tom Berge and install a system of aluminum tubing and AN fittings. But my skill level in cutting and bending aluminum tubing is sub-standard and the plastic air lines seemed cutting edge and MUCH quicker.

My panel requires pitot inputs to one AFS EFIS box, the Tru Trak autopilot controller, the standby airspeed, and the Tru Trak ADI-2 standby attitude indicator. I also need to provide static inputs to the all of these items plus the standby altimeter. So lots of branching of the lines was needed.

I sat down and selected all the air fittings that would work including:

Pasted Graphic

several T fittings,

Pasted Graphic 1

a Y fitting,

Pasted Graphic 2

a three-port manifold fitting,

Pasted Graphic 3

and several straight connectors that comprise a ” NPT fitting that screws into the back of the instruments.

I installed the straight connectors first and everything went well. Tom Berge warned to be sure to wrap additional Teflon tape around the threads to provide additional sealing capability. Screwing these fittings to the brass receptacles of the AFS EFIS box and the UMA standby instruments was no problem.

But the both the Tru Trak autopilot controller and the ADI-2 have plastic fitting receptacles which just didn’t seem to tighten up very well. And just to prove how incompetent I am, I twisted the pitot fitting into the ADI-2 just a little too far and it CRACKED!!! UGH!! How could I be so dumb??? I quickly took it out of the panel, boxed it all up and sent it off to Tru Trak to get it fixed.

With that screw-up behind me, I throttled-back and looked at this differently and decided to approach the pitot-static installation in a more logical manner. Tom B and I had heard of several RVs nearly ready to fly with big-time pitot static leaks. Once the airplane is all together it is REAL hard to find out where the leak is. THUS… I decided I was going to check the system as I assembled it. I highly suggest checking all of the integrity of the system right at the panel while everything is wide open.


IMG_0955


So first you need a source of pressure and suction. Nothing works better than a BIG syringe hooked up to plastic tubing. Mine was a leftover from a TCP fuel additive kit that I bought long ago and worked perfect.


IMG_0942


The P501 connectors installed into the Tru Trak autopilot controller with Tite Seal


So basically I just checked the fittings into each of the instruments once by one and then the integrity of the system as I added various lines and connectors. One BIG tip that Stein helped be with was how to install the P-501 into the plastic receptacle blocks on the Tru Trak instruments: wrap a couple layers of Teflon tape around the fitting and then a thin “smear” of Tite Seal. Tighten the fitting into the block up to about a 1/16” of reaching the flange of the fitting. There should be a nice shoulder of Tite Seal around the fitting flange. That’s it…. Don’t let the fitting bottom out or you may hear the discourage “crack’!

After getting everything all hooked up (still not the permanent installation), I did a static leak test and everything was rock solid:

IMG_0950



Now you have determined the integrity of the pitot static system behind the instrument panel. Now when you do the final assembly of your airplane you can hook up the wing pitot line and the fuselage static lines with confidence that any leaks that then show up will be outside of the panel.

IMG_0957


The end product will route the green pitot lines and the white static lines to the various instruments on the panel.





RV Fuel Tank Repair


Hello to all! My name is Paul Beck, and I have been working as an A&P mechanic for Willmar Air Service for 15 years now. We work primarily on the Mooney fleet of aircraft. As some or most of you know, Mooney's are famous for leaking fuel tanks! My former employer here in Willmar and I knew something had to be done to address the problem as it was compromising the value of the Mooney fleet.


Me


During the last 9 years, with the help from my former employer, Bruce Jaeger, we developed a system of removing all the poly sulfide sealer from inside the fuel tanks, without the nasty task of having to hand scrape it out! The result of this process is a truly clean tank, ready to accept new sealer. I personally have completed around 300 Mooney aircraft, one Vultee BT-13, and one Thrush crop sprayer this way. I also have developed a process for the Piper fleet of aircraft with removable aluminum fuel tanks. I am currently looking into working with the Grumman fleet that also incorporate the wet wing style of fuel tank.


RV pics 2


I had the opportunity on Tuesday, March 23rd, 2010 to isolate and repair a leak on Mark Kenworthy's RV-9A. The construction of tanks on the RV aircraft are very similar to the Piper and somewhat the Mooney tanks. Talking with Mark I developed a real interest in the aircraft and especially the fuel tanks. I could see a real value in assisting owners of the RV's in finding leaks or constructing new tanks for their planes, should they choose not to.

RV pics


So that's my ideas! If any one needs help or knows anyone I could call to get into helping assemble the tanks for new owners, I would greatly appreciate it!

For more information, check my website HERE.

Paul Beck
Weep No More
Willmar Air Service

Cell-320-295-1671
Work- 320-235-4844

Personal
email-vair73@yahoo.com

* * * * * * * *


Alex Peterson’s Tire Balancer


My plane has always had a little vibration around 22 to 24 knots. This has been true with several sets of tires, from Van's cheapies to Michelin to my current favorite, retreads from Desser. I've never worried too much about it, since that speed is a bit faster than typical taxi speeds, and during takeoff and landing, one passes through those speeds fairly quickly. However, after the last annual, during which I rotated the tires inside to out, the vibration showed up a fair bit more noticeable. In fact, it was quite noticeable right after landing as well, probably picking up the 2x excitation speed of 46 knots.

I built the balancer shown in the pictures below. I used a couple very small ball bearings for minimal friction, a precision 1.25" shaft, and a couple collars to clamp the wheel bearings snugly. I put the first wheel on, and it lazily found a preferred position. It didn't seem like a lot of imbalance, but it took a fairly sizable piece of lead (don't tell California) to bring it to balance (the small wheel diameter). The other wheel took a piece perhaps 1/4 the size of the one in the picture. I used some 3m double sticky pads to attach the lead.

I went out flying, with some taxiing up to 28 knots, and no vibration at all! On landing, I held the speed up down the runway, exploring the whole range of speeds, and not the slightest sign of any vibration.

What was quite a surprise is how little imbalance there seemed to be when I first put the wheel on the balancer. I really would not have thought it to be a problem, until I saw how much lead it took.

The small bearings, without seals, are key, as anything larger probably would have had too much friction.

Wheel balancer 1


Wheel balancer 3


Wheel balancer 2

__________________
Alex Peterson
RV6A N66AP 1100+ hours
Maple Grove, MN
www.n66ap.alexap.com


* * * * * * * *

Tom Berge's Tire Removal Contraption

So, it’s time to replace your tires. Sounds simple, doesn’t it? First, let the air out. Very important! Second, loosen the three bolts holding the wheel halves together. Then take out the bolts and set the brake disc aside. Third, pull the wheel halves away from the tire…….wait a minute. This part just took all the fun out of a simple process. The darn tires are stuck to the wheels. Seems nothing will pry them free without damaging the wheel halves. Put the hammer and pry bar, a.k.a. screw driver away.

After years of struggling with the dreaded tire removal job, I finally decided that a simple, cheap solution could be had. I know there are tools you can buy to do the task, but why spend lots of money for something that is done so infrequently? So here goes.

One 5/8 threaded rod / 12” - $3.29
Two 5/8 fender washers - $.45 each
Two 5/8 nuts - $.45 each
24” 2 x 4 – Free in most workshops
30” 1 x 4 – Free in most workshops
Couple of adjustable wrenches – Better be in your workshop already!

1. Cut the 2 x 4 to about 10 inches and drill a inch hole in the middle. Need two.

2. Cut the 1 x 4 to about 7 or 8 inches long and cut a curve on the side a bit bigger than the wheel. I used the hub cap that came with the wheel kit as a template. Need four.

RV7 pictures 033


3. Attach one 1 x 4 to each end of the 2 x 4 using 2” screws with the curved edges facing each other and spaced a bit wider than the wheel.

Picture 034



RV7 pictures 031


4. Put one 2 x 4 on each side of the tire, being careful to center the wheel inside the curves.

5. Put a nut and washer on one end of the threaded rod, slide it through the 2 x 4’s and put a washer and nut on the other end.

RV7 pictures 029


6. Tighten the nuts, keeping the wheel centered

Popping the tire off without all the fuss, Priceless!

I timed myself starting with the removal of the valve stem and had the wheel halves off in 6 minutes. Not bad for about $6 in parts and a half an hour of planning/construction.


* * * * * * * *

Tom Berge's Brake Bleeder Contraption

OK, I just love coming up with contraptions. It’s a great way to be both clever and cheap. Besides, there’s a job to be accomplished. Over the years, I have always used a pump style oil can to fill the brake systems on RV’s from the bleeder valve. This involved hooking up the can with a plastic line to the brake bleeder valve under the wheel cylinder and adding brake fluid without introducing air. It’s sometimes tough to find an oil can that can pump just fluid without air.

Peter Fruehling and I had just finished installing his brake system and needed to fill it. I decided this time to find another method. Buying a pressure bleeder was out of the question due to my cheapness. Eighty-five bucks was too much. I thought, “Why not roll my own?” After much searching, I found the perfect container. A small Vlasic Sweet Relish jar in my fridge would fit the bill fine. Now I’m sure a regular relish jar would work just as good, but I have my standards. After dumping the contents into a convenient Tupperware container and thoroughly cleaning the jar, I started the actual construction.


IMG_8714


Now I know that most RV builders will, by this stage of construction, have a few extra parts lying around. I scrounged up two -3 bulkhead fittings with the associated B-nuts and sleeves from my excess stuff drawer. I then drilled two 3/8 holes into the jar lid and installed the bulkhead fittings. On fitting #1, I attached a 3/16 aluminum tube that extended to the bottom of the jar with just a bit of clearance off the bottom then added a piece of aluminum tubing to the top side. On fitting #2, I attached a short piece of aluminum tubing just to the top. I then attached a 3/16 plastic line from fitting #1 to the brake bleeder valve.

IMG_8719


The way a pressure bleeder works is applying air to the “can” from one line which will force the fluid out the other line. Pretty simple. The risky part for me was how to add the pressurized air. Putting a twist type valve inline would have worked great, but I didn’t have one of those in my junk drawer. Cheapness prevailed. I stuck a piece of the milky white tubing that is included in the RV kit onto the inlet side of the jar to act as an interconnect for a regular air sprayer. These sprayers are not known for their precise metering of air, but what the heck. The worse that would happen is I over pressurized the jar and brake fluid would spray all over Peters fuselage and the hangar floor. I was OK with that since it wasn’t my fuselage or hangar floor!

IMG_8715


The moment came, Peter and I set up. I practiced controlling the air flow and then gave it a whirl. It worked like a charm. The fittings and related parts are about $9 if you don’t have any. The Vlasic Sweet Relish jar was about $1.69 at your local grocer and you still get the relish. Pretty darn sweet.