Kit Aircraft Modifications

Hello Everyone,

I recently had the final inspection completed  on my RV-10 and one of the snags surprised me. The inspector was looking at my beautiful Andair fuel caps and asked me whether they were ground bonded to the airframe. I didn’t know so we took a multi-meter and checked to see if there was an electrical connection between the Andair sleeve that gets bonded into the original fuel neck in Van’s wing tank and the wing skin. There wasn’t.

This meant that I had to come up with a way to electrically connect the original neck of the fuel tank and the sleeve that gets bonded in with tank sealant.

What I did to correct this was to  drill a hole in the Skirt of the Andair sleeve big enough to allow a 6-32 machine screw to almost pass through. I then drilled a smaller hole through the skirt of the tank filler neck right behind it. I had to countersink the outer hole so that the screw head would not interfere with the fuel cap. There is not much clearance. I used a tap and carefully started the threads in the Andair sleeve. I then threaded the screw that had been sharpened somewhat through both sleeves.

All of this had to be done carefully in order to keep any contaminants out of the fuel tank. I accomplished this by taking strips of masking tape and looping them down into the tank fill opening and just leaving the area exposed where I drilled the hole. When I finished I vacuumed out the hole and checked inside for filings. Anything that landed on the empty tank bottom was removed with a stick that had tape affixed to it sticky side out.

I tested the new configuration for continuity and found that electricity flowed from the inner sleeve to the wing skin. For all of the thinking it took to come up with a workable fix, it took only 10 minutes to actually perform the work.

The interesting thing about this problem is that Andair knows about it but couldn’t offer any suggestions as to a fix. I hope that this helps anyone else who has these fuel caps.

Keep on building,

Dave

Hi Everyone,

I found this mod in the back pages of  Doug Reeves’ site www.vansairforce.net

Paul Grey from Alabama came up with an arm rest for his RV-7 that is functional and nice looking. I have clipped his caption to explain the photos.

Dave

Hi all, Hope everyone had a good Christmas. Thought I’d post a couple pictures of my cockpit… er… the evolution on the cockpit. The cockpit was pretty much done then I decided I wanted an arm rest. This is what I came up with. Super simple and cheap. You’ll see I also moved the elevator trim knob to just under the armrest. The reason I moved it was because if I was in the seat with shoulder harnesses on, I really could not reach the knob without loosing the shoulder straps. Now, the only thing in the cockpit I can’t reach without loosening the straps is the fuel tank selector. The armrest is perfect as it places my hand right at the throttle. Very comfy. Reaching the trim knob, (and the aileron trim), is just a matter of coming at it from the passenger side of the armrest. Both are easily reached without loosening any shoulder straps.

Cockpit Before Mod

Arm Rest Frame

Arm Rest Attached to Flap Cover

Covered with trim knob moved

Finished Arm Rest

I thought that I would talk a little bit about the axillary fuel tank I have installed in the forward part of the baggage compartment in my RV-10.

The RV-10 is a four place aircraft and as such is pretty nose heavy when you are flying with only the front seats occupied. As such, many owners fly with removable ballast in the baggage compartment. This ballast can take many forms such as a bag of sand, tool bag or in my case fuel.

I designed a fuel tank that fits in the forward co-pilot’s side of the baggage compartment. It occupies the triangular shaped cavity below the cross member at the front of the baggage compartment. It is mounted to the airframe using four AN4 bolts into the upper cross member and seven #8 screws through 2 mounting flanges. One to the forward side wall and one to the front center tunnel cross member.

The tank holds about 11.3 gallons of fuel. At 5.83 lbs/gal that works out to 65.9 lbs of fuel. The tank itself weighs in at approx. 14 lbs. The associated pumps, wiring and plumbing weigh in at about 10 lbs. Total weight of the system with full fuel is around 90 lbs.

This tank is directly connected to the right wing tank supply line that runs to the main fuel valve. The line to the aux. tank tees off of the Right wing tank feed line and runs through a 12v NC (normally  closed) fuel shut-off valve that prevents fuel from flowing through the line when not energized.

Through a pair of wobble pumps I can either fill or drain the aux. tank from the right hand wing tank. There are both an electronic fuel gauge and a sight tube incorporated into the tank. The electronic sender is required if I want to directly supply the engine during takeoff. The site tube is there to aid in filling or emptying the tank as ballast.

There have been many trials and tribulations in the design, manufacture and installation of this tank. The process is not for the feint of heart. I have had some small leaks show up where the mounting brackets are welded to the tank body. I have also needed to add the fuel shut-off valve when I realized that the fuel in the aux. tank was gravity feeding back into the right wing tank. This oversight cost me a couple of days work in fabricating new plumbing in the pump bay to make room for the new valve.

What I do have now though, is a tool that will allow me to adjust the plane’s center of gravity depending on the mission. The plane flies much better with some additional weight in the back when the rear seats are unoccupied. I can now tailor the amount of ballast I carry and as a bonus I have an extra hour+ of fuel to be able to get into areas without fuel and the ability to be able to purchase a larger quantity of cheaper fuel.

I feel that this approach to the addition of extra fuel capacity in the RV-10 is much better option as compared to adding extra fuel to the outboard areas of the wing. By adding the weight to an area already designed to carry it I am not altering the wing in any way. I didn’t feel comfortable in adding the extra weight out at the end of the wing because I would not have been able to test it properly. The added outboard weight could have an adverse effect on the aircraft in the stall/spin envelope and I don’t play in that sand box.

Anyway, I have almost all of the kinks worked out of the design and have had fuel in the tank for calibration of the fuel level sender and sight tube. I have to determine the moment location of the tank and factor the weight of the fuel into the weight and balance calculations.

I will take some  pictures if I think about it and post them later.

Dave

Hi All,

I heard through the Matronix RV-10 forum that owners of RV-10s are finding the main gear wheel pants a bit loose when being inspected during the annual inspection.

What is happening is a purely material thing! The aluminum bracket that the wheel pant attaches to on the inboard side is attached to another steel bracket that is bolted to the axle. These two parts are not bolted directly together. Instead, they are separated by a  length of aluminum tube. This tube spans between the face of the aluminum pant attachment bracket and a 1/2″ steel insert that is reduced to 3/8″ where it rests in a hole in the steel bracket attached to the axle. Have a look at the picture to get a feel of how this all goes together.

What is happening is that vibration generated by the wheel/pant assembly  is placing a bending load on the three bolts that hold this wheel pant attachment bracket. This load is borne in compression by the aluminum spacers. Mushrooming of the ends of the spacers has been observed which leads to a shortening of their length. This length reduction results in a reduction in tension of the bolt/nut assembly and ultimately loose assembly and a sloppy wheel pant.

The fix for this is relatively easy. I chose as others have to replace the 2 pieces that define the gap between the two brackets with a single machined piece that has a larger diameter and more contact area. This will help distribute the loads over a larger surface area  between the brackets. I have also made the bushing from a more durable material. Due to the moisture in the wheel area 304 stainless was chosen.

This picture shows the two piece bushing set and the new replacement one piece bushing.

This picture shows the increased amount of contact area of the new bushing.

This is a picture of the new bushings installed between the aluminum and steel brackets.

This was an inexpensive fix that I was very happy to hear about before I finished the plane. I do not have my wings installed so it was an easy swap out.

I am going to  make a few sets for other RV-10 owners and builder. I haven’t got a price put together yet but they won’t be very expensive.

Have a great time building and modifying your experimental planes!

Dave

Good Morning,

I came across this mod on VansAirforce.net this morning.

Dean said that he had passengers in the back seat complaining of hot feet and cold shoulders. I have heard this a number of times in other conversations both personal and on the net.

Dean came up with a creative solution to the problem. He purchased one of the high quality eyeball vents from Steinair. In the photo below you will see how Dean cut a hole in the tunnel cover above the Tee manifold supplying warm air to the rear foot wells.

I like this idea as it allows the passengers the ability to regulate and direct the warm air where it is needed and most comfortable.

You can see Dean’s original post Here

Great Idea Dean!

I have been working on the upper cowl lately in preparation of bonding the windshield in. I have wanted to have a small sub-panel mounted on top of the dash to house the Angle of Attack display so I cut a plug from Styrofoam and made the fiberglass fairing. I attached it to the upper cowl with brackets and mounted the display and compass in a flat aluminum panel.

 The process took a long time and a bunch of head scratching to get it all covered in marine vinyl but it was very much worth the effort. Here are some photos of the finished product along with a laser-cut vent grill I designed for the two fans in the dash.

Hope you enjoy reading my blog. I’ll try to post more frequently.

 Dave

I received this post on the Matronics RV-10 forum last night and it was a review of the RV-10 Axle Spacers. I was very pleased to receive the feedback from John Gonzales after he received his package in the mail from Cleaveland Tools. Here is what he wrote:

“Mine came in the mail today so I haven’t had the opportunity to install them yet, but positive comment is in order.

Not only are these stainless steel pieces milled extremely well, but the pre-load spacer’s tight tolerance and fit are very, very close. With no grease on the threaded spacer, it is beautiful to feel how the two parts fit (Glide) together. This is no cheap piece of hardware and they would more so belong on a very, very expensive telescope tripod or on tooling machinery. Better than anything the dental industry puts out.

Nice Job. Shame it is going to eventually get covered in grime.”

I think that I made the right decision to make these out of stainless steel and that I didn’t comprise on the design. Of the units I have sold, all have been happy with the quality and functionality.

Dave

Hi Everyone,

This is a follow-up on what is happening with my axle spacers.

Cleaveland Tools and I  have been contacting the people who expressed interest in my axle spacers to determine the true number of people interested in them after the Matco offering.

When I first found out about the Matco unit I really didn’t think that many of you would still be interested in my version. Thankfully that wasn’t true.

In the interim I have received a couple of direct orders from the States and a couple of orders from guys here in Canada. These plus the confirmations from Cleaveland have allowed me to put together a small production run to satisfy those who have stuck with my design.

I have the parts being manufactured as we speak and the Cleaveland units should be shipped to them within 2 weeks.

I hope to now keep the design on Cleaveland Tools catalog but I think it is going to be done on  a pre-order basis.
I hope that this answers your question. If you have any more questions please do not hesitate to send them on.

Dave

Well I have received a couple of requests for my axle spacers even though the ones from Matco have been released. Thank you to those who like the design of my spacers over theirs. The comments that I have received are that customers want the stainless steel spacers I offer instead of the aluminum ones from Matco.

So here is what I am going to do. I am willing to produce these in small lots of 5 units and will put people on a waiting list until I get the 5 orders needed to manufacture them. This way I don’t have a whole lot of inventory sitting around.

I am also going to sell these units directly rather than through Cleaveland Tools. The numbers don’t make sense to have them keep stock.

I appreciate the trust that those who have purchased my products have put in me and I will continue to design high quality replacement parts and accessories for the kit aircraft market into the future.

Dave

Hi Everyone,

It seems as though I have been scooped in the marketplace!!

With the introduction of the Matco adjustable axle my product offering has effectively been run outta town! There is little chance of me being able to compete with a product being offered by the company with whom the problem originated. This is just how things go sometimes.

I would like to inform those who had contacted Cleaveland Tools to place a pre-order that I have canceled the product offering in fairness to Mike at Cleaveland Tools even though they had ordered product already. I would hate to have that product sit on their shelves with no interest in them.

To those who had the confidence to pre-order my adjustable pre-load axle spacers, Thank You. It is always gratifying to have the confidence of your peers.

I look forward to offering other accessories and parts to the kit builder and kit manufacturer alike.

Regards,

Dave