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RV-8 Fuselage: What would you do differently if you'd build another one

MartinACFactory

Well Known Member
Hello !

This is just a general question to those who have built and are now operating a RV-8, or to those who have just completed building their RV-8 Fuselage.

My Question is: If you'd build another RV-8 Fuselage, what would you do differently ? Any features you would add to improve the serviceability of your aircraft, and that would be easier to implement while you'd be building the fuselage ? (example I have seen: hatch in fwd baggage bay bulkhead to access avionics. Any other suggestions ?)

I am getting my fuselage kit delivered this week. I am planning to start slowly the build. While I have all the parts on the table, it would be easier to implement small mods. Therefore, I am a taker for any suggestions.

thanks !

Martin
 
Mods I would make (some I did, some I didn't on mine)

Forward avionics door, yes for sure. I put my fuses on that door so they are easy to flip down and access from the baggage compartment.
Front skin fitted by Andy Karmy, on Flickr

Additional access panel in the bottom of the baggage floor to give easy access to the brake master cylinders. Wish I had done this.

Do the gear tower mod. I was on the fence and left them stock. What a pain to work in there once you fill it full of wire and fuel lines. Would be much easier to have a larger opening.

Enclose arm rests into to storage, especially in the front. They are useless as they are stock.

Add a storage bin to the right side lower panel (same panel as the fuel selector on the left) I did this and use it all the time. Very handy.
Drink cooler by Andy Karmy, on Flickr
Drink cooler by Andy Karmy, on Flickr

Cover the front floor with the flyboys non skid rubber wing walk material. Would make a nice floor covering and easy to install. I intend to do it soon.

Removable passenger stick. I did this and like it. Also enclosed the stick area on the rear stick with a panel cover from oregon aero.
Untitled by Andy Karmy, on Flickr

Rear avionics shelf behind rear baggage compartment. I did this and thus far it's been good. Not sure if I'll like working back there in the future, but it's mostly solid state equipment at this point.
Rv8 wiring by Andy Karmy, on Flickr
Peep-a-boo by Andy Karmy, on Flickr

That should give you a bit to think about.
 
I would go with Grove Aluminum gear. I built as light as possible, so I'm still trying to avoid any build-in storage, carpets, etc.
I would consider a tip over canopy, maybe a fastback if the weight is favorable.
The roll bar blocks my view for traffic, my wife's RV -4 with tip over has great visibility, and the fuselage skin above the RV-4 panel is removable. This alone is fantastic access and I would love that on my -8.
The slider canopy IS cool, but the tip over has advantages too.
 
Finish Paint

I would decide on an interior color prior to assembling the fuse and would give serious consideration to finish painting the gear towers and as many of the interior parts as possible prior to assembly.

Most importantly I would decide on a color for the powder coated steel parts. I'm pretty late in my fuselage construction and I'm not sure I like the light grey powder coat. Some of the parts are already permanently installed and at this point I really don't want to change the color. If you think you do want to change the color of the steel parts I would consider repainting or powder coating at the very beginning of the build.
 
I haven't done the avionics access door in the forward baggage compartment, yet.

I did do the gear tower mod and I love it with a capital L.

Swapping out the stock fuel valve for an Andair unit. Just started looking at that this afternoon.

Went with Grove gear. Have not hung them yet since I just got them last week.

Doing the Showplanes fastback conversion. I like that the roll bar is not right in your face anymore plus you gain a bit of extra room at the shoulders as the cockpit top rails get replaced with slightly narrower units as part of the conversion to FB.
 
Move the fuel filter outside to the wing root for easy servicing. No more leaking fuel inside when you remove the filter for cleaning.

+1 on grove airfoil gear..they are works of art!

access panels in the floor.
 
Stiffners.

Sure to the other ideas here, and one we found and did also. Back in the bottom of the tail boom. The lower skin there likes to oil can a lot. We put stiffeners in between the bulkheads along the bottom back there. Also the rear seat flooring got more stiffeners and the base of the front seat and it's floor area. That flooring and seat pan is a little easy to bend so it merited a little extra strength to hold up under stepping in and out all the time.
Just my two cents. Yours as always, R.E.A. III #80888
 
Step

I built an 8 and now I wish I would have put the 8A boarding step on. Its a big step to get on the wing walk and not step on top of the flap. Even with the flap down.

Eddy
 
I did some of these mods mentioned here and a couple others. I didn't need the avionics access door because I have the Showplanes fastback and have wide open access behind the panel. After almost 7 years of flying my RV8, I would do the fastback mod again. My bus fuses face forward into the forward baggage compartment (with a cover). I would build doublers into the fuse floor for com antennas, transponder, and UAT/ADSB antennas. I have four of them in my fuselage floor. I built armrests for the forward cockpit seat that attach to a panel on the inboard edge of the existing 'armrests' - which as someone else said is useless as an arm rest. My armrests allow my forearm to lay naturally in line with the throttle on the left and stick/switchpanel on the right. The cavity outboard of the panel holding the arm rest is a handy place to store logbook, checklist, pens, etc. I used a piloted reamer to open up all of my match-drilled holes rather than a normal twist drill. This leaves little or no burr and makes a perfectly round hole. There is little need to debur with the deburring reamer. You can usually remove any burr by just rubbing your finger over it, or lightly hitting it with a scotchbrite pad. If you're concerned about corrosion, you can quickly spray some primer over that area. Some of us remove too much metal while deburring, and it takes a lot of time. This technique saved me some time, and may have improved the quality of the assembly. I have a friend here in town building an 8 that is designing a 'washer' that captures the nut on the inside of the gear tower for the strap bolts, that hold the nut - not allowing it to turn. They will be torqued from the bottom - not inside the gear tower. These are the nuts that cause so much agony for most of us, and necessitate modifying the gear tower openings. I wish I would have done something like this.
 
Guys,

thank you very much for all your replies and your suggestions. Very useful. I see that some of you speak from experience, and I shall listen to your comments.

Just to sum up your suggestions, here they are:

1) Avionic access door in bulkhead: I am doing this one for sure :cool:
2) Access panel in FWD baggage area for brake cylinder: will investigate this one
3) Main Landing Gear Tower Mod: I wasn't sure about this one, cutting in primary structure carrying stress load, but will look into a way
4) Fastback + tip over: I like the slider...plus the current currency exchange rate USD to CAD and the Tax Man at the border have taken my budget for a potential fastback option :(
5) Paint interior color prior to assembly: Definitely ! This is how it is done with factory certified aircraft (I worked at Bombardier), This is how I will do it. Now, I've got to decide between a light gray or a beige interior....Other areas will be zinc chromate green.:D
6) Adair Fuel valve: Easy mod, not too pricey, will do for sure !
7) Storage bins and arm rest: Once I have a "canoe" I can sit in, for sure I will start looking at the ergonomics of my "flight deck". I think that's one of the fun part of this project !?
8) Grove Aftermarket replacement landing gear struts: I will investigate. for sure the weight saving is interesting. But similar to the Fastback, the bang for the (Canadian) buck must be there.
9) I am adding to the list, Panel skin damping installed on firewall, to damping engine vibration entering cockpit. Might be able to reduce noise a few dB in the cockpit.

Any how thanks again for all this very usefull info. I will fore sure consider all this.

Trucking company is dropping my fuselage kit tomorrow 9AM....so the fun start this weed-end :)

Regards,

Martin
 
I'm not a builder, but one thing I wish my RV-8 had is an external power receptacle for jumping the battery or plugging into ground power for playing with avionics, etc. The battery in my 8 is pretty hard to get to and if I ever needed a jump it would be a bit of a project.
 
I'm not a builder, but one thing I wish my RV-8 had is an external power receptacle for jumping the battery or plugging into ground power for playing with avionics, etc. The battery in my 8 is pretty hard to get to and if I ever needed a jump it would be a bit of a project.

Colojo,

That's a valid suggestion. A few years back, before I launched myself into building a RV, I saw on a builder site a guy doing this mod. I found it clever. I can't find this site anymore. I like the way he approached the problem by creating a connector box riveted to left side skin with an opening covered by a hatch door. He had put a skin doubler around the opening in the skin to restore the skin strenght.
I am tempted to do this mod. But much like the landing gear tower mod, i am nervous about cutting holes in primary structure without having the ability to do a stress analysis.
I will consider for sure!
 
My battery is in the rear. I installed a ground power jack on the bottom of the fuselage below the battery tray. Bob Knuckolls has an excellent write up on how to fabricate and install a ground power jack, complete with over voltage protection. I used this quite a bit during the build to provide power. I have not had the need to use it to jump start the plane.

Keep in mind that you can't use this setup to charge the battery since a charger doesn't provide sufficient power to keep the solenoid engaged. I have a power outlet connected to my battery bus for this purpose.

Details on how to build and install a ground power jack can be found here: http://www.aeroelectric.com/articles/grndpwr.pdf
 
Add a storage bin to the right side lower panel (same panel as the fuel selector on the left) I did this and use it all the time. Very handy.


I'm planning to do this for storage, but want to know if there are any gotchas on stuff routed underneath I'm not thinking about. How deep/tall is your bin?

Thanks,

Chris
 
I have a fairly large bundle of wire running underneath the box. I made the box out of fiberglass and riveted it to the top frame you can see in the picture. The box is deep enough to give about 1" of clearance at the front edge. The floor is sloping underneath so you get more clearance at the rear. One thing I had an issue with was clearance for the fuel line that goes through the side out to the wing. I ended up cutting a slot in the side of my box to make some room for it. You could adapt your shape to leave a bit more space on the right rear corner for that line. I wrapped my wire bundle with silicone tape just to make sure nothing rubbed on the bottom of the box. The box is about 4inches deep or so.
 
Salut Martin,
J'esp?re que tu vas bien!!

I mostly agree with the suggestions made.
I didn't do an access to the instrument panel but will consider it.

I would definitely encourage the gear tower mod. Even with the larger access, it still is tight to get in there, but I have quite large hands...
I'm no engineer so I can't say how it influences the rigidity but I feel confident that with adding a cover held on by screws, the integrity of the assembly should be kept (if not increased?)
PICT4813.jpg


The Andair fuel selector is a winner for sure, you will have to make a new bracket and modify slightly the cover.
This is a Duplex model for full fuel return to the tanks:
IMG_2147.jpg

IMG_3147.jpg

IMG_3148.jpg


Grove gear is also highly praised, I ordered the airfoiled model, not received yet though.

Amuse-toi bien !!!
 
Grove gear is also highly praised, I ordered the airfoiled model, not received yet though.

Take my advice: as soon as you get them; prime them! I ordered them early and didn't protect them. Had a big corrosion-removal job later on...
 
Agreed. Great advice.
The day my gear arrived was quite hot. I opened the crate and lifted one leg out to inspect it and then put it back. Three days later I get back to the hangar and the gear leg I handled has corrosion from sweaty hand prints starting.
 
Thank you all for your kind replies and suggestions.

I have received my fuselage kit last July 30th. Now with the parts in my hands, I can better see the mods. Most of them I shall implement prior to even assembly any parts.

So far, I've been very active on my kit. If you want to follow my progress, just check my thread once in a while about RV-8 s/n 80414.

Martin
 
I would install a bracket to support a ratcheting seat belt in addition to the standard front seat belt.
 
Some of these mods sound really interesting and I would be interested in including them on my aircraft once finished. However, I am contemplating going with the quick build fuselage. How many of these mods are realistically possible or worth the effort with a quick build fuse?
 
RV-8

I would add a battery access panel to the package shelf and the after part of the Rear baggage. Actually I had Dennis Millsap help me with this, since I'm getting pretty old! He did a nice job I think, with just 2 hinge pins to access, and it's quite secure. Since the idler arm for the elevator circuit is right under the Package shelf, I think it's very important that any access panel be quite sturdy.
 
Fuse Mods: Quick Build vs Slow Build

Some of these mods sound really interesting and I would be interested in including them on my aircraft once finished. However, I am contemplating going with the quick build fuselage. How many of these mods are realistically possible or worth the effort with a quick build fuse?

Hello Dale,

Your question is vary valid, and it comes down to advantages of both the Quickbuild fuselage over the Slowbuild. I started this thread two years ago with no clue about building a RV-8 fuselage. I am now in final stages of building my fuselage. I've gain a lot of knowledge building my -8 fuselage.

Despite taking a lot more time to build, the main advantage of the slow build over the quickbuild, it is that with a lot of planning, you can incorporate mods, design improvements or avionics bracketry at a stage where it is easy to assemble. The same is not true with Quickbuilds, as access is probably limited. Example, I am currently installing my bracket for the Garmin autopilot servo while I still have the parts on the workbench, not when the fuselage is entirely built. Thousand time more easy !

As per your question for the mods discussed here:

1) Landing Gear Tower mods: doable on a quickbuild, but will be very challenging
2) Avionic Access Door in Bulkhead F866B-1: That shall be easy. This bulkhead is not yet attached to the canoe when you receive your quickbuild fuselage
3) Fastback, same as the bulkhead above. the upper aft fuselage is not assembled on the quickbuilt canoe. You can still purchase the Fastback option and install it if you like
4) Andair Fuel Valve: A must...when you get the fuel valve delivered with the kit in your hands, you will place an order for an Andair fuel valve for sure....That said, adding the nutplate on longeron F844 for the new valve bracket you will make maybe challenging as the longeron is already riveted in place. On the slowbuild, you just take the longeron to your work table and make all the needed holes...easy !
5) No mod, but I was glad I had a slow build fuselage....Making all the fuel and brake lines, and bending them to shape. I can't imagine doing this with a completed quickbuild fuselage. It was already challenging to do with just the forward fuselage fully open, no skins on the sides. I didn't have to bend or twist myself to get in the little corner of fuselage to make nice fuel lines.

Anyhow, that is just a quick summary. Once I am done with my fuselage this upcoming fall, I will share here with pictures most of the mods and improvement I have done to my fuselage.

I don't regret at all going the Slowbuild route over the quickbuild for the fuselage. If I do this again someday, my choice would still be slowbuild fuselage, and quickbuild wings, no doubt about it.
 
Extra conduit

I haven't read all of the post so someone may have already mentioned this but I would run an extra empty conduit under the floor right and left side so if you have to run wires later to add or update something electrical you will have a path to do it. This has been a problem for me. For example we just added ADSB in/out and I wasn't able to run the wires the way I wanted to because I have no access under the cockpit floor. To me this is a must have.
 
I haven't read all of the post so someone may have already mentioned this but I would run an extra empty conduit under the floor right and left side so if you have to run wires later to add or update something electrical you will have a path to do it. This has been a problem for me. For example we just added ADSB in/out and I wasn't able to run the wires the way I wanted to because I have no access under the cockpit floor. To me this is a must have.

Running an extra empty conduit is a valid idea...At the same time, if you make your floor panel removable, replacing pop rivets with nut plates and screw at each floor panel attachment location, that underfloor accessibility would never be an issue. Simply unscrew the floor to gain full access to the under structure seat ribs.

Yes this mods takes time during assembly, but it is highly worth it during aircraft service life.
 
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