?Golf Clubs?

Can the bulkhead at the backof the baggage compartment in an RV7 be cut and a "tunnel" box be built extending into the fuselage in order to carry golf clubs?...and does in present an aft CG problem? I'm sure I'm not the only person that has ever wanted to carry golf clubs, skiis, fishing rods, etc. in an RV. I would appreciate any help or suggestions.

Fox

In my RV-6, I could fit two sets of clubs, the bags, and baggage all in the baggage compartment. I took the clubs out of the bags and layed the bags flat on the floor. The clubs could wedge in between the lower corner of the seat back up to the opposite rear corner of the canopy. Travel bags went on top of that.

My son and I went on multiple golfing trips this way.

The RV-6 that I purchased has one of these. Don't see any CG problems as long as the CG station and moment are appropriately calculated for both the construction of the tube and what you are putting in it. Of course any ski/club tube you construct will tell you where you are with regards to the CG loading envelope when you weigh the plane if you add one during the build.

Gotta remember to put the club heads at the front of the tube, generally keep the weight as far forward as possible, and consider any loss of useful load for the baggage compartment if you use the tube.

I asked Vans this question....

As it would have been a "no-go" issue for me if not possible. Their answer was "yes" if you make sure there is no elevator pushrod interference and W&B is tended to.

I ran some rough numbers and was convinced this can work from a W&B standpoint if provisions are made to keep the clubheads (most of the weight) over the existing baggage compartment. FWIW, my typical stand bag with a full set of clubs is about 22 lbs.

If you search the forums you'll find examples of a least a couple of builders who have done this - one that made a "tunnel" and one that made a "nest" of "golf club tubes". The tunnel variant is here: http://www.vansairforce.net/BuilderMods/NormanHunger/luggagecompartment_skirack.htm

I modified mine by adding a lower door on one side and enclosing the area by adding a panel in the center and then closing the bulkhead behind the baggage wall. That way nothing can get to the rudder cables or aileron pushtube. Not much weight added. Heads go in the baggage area. Easily handles two sets of clubs in travel bags. Lots of room but,.....





having said that, I asked Vans later (why always later) if it was OK and here is what Gus said: Usual soft disclaimer but no absolute red flags unless you consider "it's better not to modify it" a red flag ?? I called them as well and I did not sense any concern on his part but he wouldn't say it was actually OK.

Gus at Vans wrote:

>> "The baggage bulkhead is a structural part, so it's better not to modify it, though it has been done by other builders, apparently without problems.
Some reinforcement around the cut out and on the bulkhead to restore the lost strength is probably a good idea. We don't have the resources to analyze the effects of cutting a hole in it, and how to reinforce the cut out, so you just have to do what looks about right to you. "" >>

So should you do it,.... sounds like we're being a little experimental but it's real easy to replace the lower bulkhead if it's an issue. Be careful what you do 'cause it's up to you! NOT recommending anything here, just show and tell and notes from Vans.

Bill S
7a Finishing

Baggage Mod

Fox,
I did mine similar to Bill only not as deep. I figured that worst case, I could take the clubs out of the travel bag if I had to get two sets in. I really did it more for long guns as my son and I plan to travel back to Iowa hunting when it's done.

If you look at my January '08 entries in my kitlog there are quite a few pictures. I haven't updated lately so if you need some more, let me know.

Interesting the input that Bill S. received. When I asked Van's they mentioned nothing about structural issues, only CG and control systems.

I wonder what the structural function of the sheet metal portion of the bulkhead is? I could see how it would affect the torsional rigidity e.g. if all the sheet metal were removed, but it seems like it is mostly provided to keep objects out of the control runs.

Any aircraft structures guys out there?

If I remember correctly a number of years ago Van's stated that that bulk-head was structural and not to fly without it in place and screwed down.

Arrrrggghhh

Norman CYYJ said:

If I remember correctly a number of years ago Van's stated that that bulk-head was structural and not to fly without it in place and screwed down.

Click to expand...

I guess that's what I get for not asking Van's the question specifically enough. Looks like some structural engineering will be needed.

In another thread, Mel A. stated the bulkhead is structural for TORSIONAL loads. If that's the case, it would seem helpful to put the opening near the center of the bulkhead cross-section, to minimize the impact.

Hhhmmmmm

I just walked out and looked at mine again. In the area where I cut the door, (see above) there are only 4 screws on the outside edge and two screws on the center section. If there was a LOT of structual load or torsional load, I would think it would be more like one screw every inch instead of every 4 or 5 inches.

What I removed was one corner of a bulkhead made up of four squares. Each piece adding it's own structual support and more as a single piece unit. Now it is not quite a single piece. How much does the center piece and rear bulkhead make up for the hole in the front,.... don't know.

I think if it were a serious issue, Gus would be jumping up and down but they seem to be saying,..... ohh, just don't really know and have no way to test so best leave it be. The fact that sometimes they mention the structual piece and sometimes they don't,...seems to say it isn't a red flag to everyone everytime. CG is real issue if you put weight in the back but not if loaded properly.

Just my .02

Bill S

BillSchlatterer said:

I just walked out and looked at mine again. In the area where I cut the door, (see above) there are only 4 screws on the outside edge and two screws on the center section. If there was a LOT of structual load or torsional load, I would think it would be more like one screw every inch instead of every 4 or 5 inches.

<SNIP>

I think if it were a serious issue, Gus would be jumping up and down but they seem to be saying,..... ohh, just don't really know and have no way to test so best leave it be. The fact that sometimes they mention the structual piece and sometimes they don't,...seems to say it isn't a red flag to everyone everytime. CG is real issue if you put weight in the back but not if loaded properly.

Just my .02

Bill S

Click to expand...

I discussed this with my Dad (retired aerospace engineer) and his thoughts were along the same lines as yours. I would think the airframe designer would know either it is structural or it is not, and if it is, you wouldn't get varying answers. (In this case, "structural" meaning "a required part for the airframe to withstand the design loads"). Also I agree with your point, the fastening method using only about 2 dozen widely spaced small screws wouldn't seem to indicate a component that is a critical load path.

Holes in loaded sheet sections

Should be intuitively obvious from looking at a wing rib: transverse loads in sheets are absorbed at the edge of the sheet. Center sections can be removed (like lightening holes in wing ribs) with very little effect on overall strength.

This is not to take anything away from a rigorous analysis -- but considering the widely-spaced non-structural screws retaining the bulkhead, PLUS the vertical center section -- I'm designing a dual-hole modification (guns/clubs etc on each side of the center beam) which I expect to retain 90%+ of the cross-sectional torsional strength of the standard design.

I'll also make the "tubes" out of fabric, and I'm going to slant them downwards to help prevent missiles from shooting out of the baggage area due to any rapid deceleration.

As far as W/B concerns, it's only necessary to determine the CG of your clubs, guns, poles, skis, etc. and figure out the moment to that point. Club heads forward means that the CG is also forward, by my calculation no more than 6" aft of the bulkhead. This equates to about 120" instead of 110" moment, only a 10% hit from regular baggage and therfore not much of a penalty.

Now, how long to make the tubes? I'm just dying to shoot them all the way to the tail for no other reason than to get somewhere and pull out an 8' 2x4 just to watch somebody' expression. Lot of trouble to get back there though, so I'll probably just dream about the "long john", and install a more practical length.

G.

Not sure about the fabric tube on both sides thing. If you don't have a secure comparment, you run the risk of things fouling the rudder cables or worse the elevator tube on the pilot side. I thought it was pretty important to enclose solidly so that there is no chance of anything getting loose in the back and creating a safety issue. I don't have a good picture of a fabric tube keeping anything secure or clear of control structures.

The passenger side is much easier to contain than the pilot side because of the elevator tube locations. If you enclose at the passenger side bulkheads as shown above, a set of golf clubs fits nicely with the heads just behind the passenger seat and flat so that they can be easily strapped down. Ususally, not always, the passenger is the lighter one so having them on that side also makes some sense.

My skeet guns fit nicely and my trap guns are pretty snug ;-)

Be very careful about not letting anything get loose back there if you go vertical or roll steeply.

Bill S

Bill, do you have any more pictures of your installation? It's very similar to what I've been thinking of doing. Also, what is the rectangular gold-colored thing in the middle of the second picture? And what did you use to keep the door shut?

If it's not too much trouble, you can email photos to me at sisquoc (at) comcast.net

Thanks much!

Bag Tubes

I've been thinking about this. Irons aren't the problem. It's the woods (probably should call them the metals now). Why not cut lightening holes the same size as bag tubes. Install those plastic tubes. You would need to put a brace to support the rear . Slide your driver, 3 wood, whatever in the tubes and use a bunge cord to secure across the top. You could lay the bags with irons down across the back (assuming a side by side). Perhaps even have a cover flap so you could pull the tubes out when not in use and hide the hole (forgive the pun) thing.

Quick, easy to do, light weight, and hides when not in use. Come to think of it, you could also stick a fishing rod down the tube. Be good for those that don't break down.

Don't know, just thinking outloud.

shear strength?

I've been around building construction for many years, where we deal with structural integrity; and I consider this corrugated bulkhead wall to be a very structural "shear wall". As installed, it wouldn't take a mass amount of screws to do it's job, but I feel that it requires it's complete designed shape to remain rigid and do it's job in regard to shear. I'd consider it to be one of the most important bulkheads in the fuselage, and the reason it's corrugated by design. I'd never want to fly without it, as the fuse could utterly twist and distort.

Another example that's bugged me, is cutting into the channel behind the seats to extend seating area. I've seen this done.

I'm not an engineer, but take my cues from construction methods I've been around for the last 38 years.

L.Adamson -- RV6A

Here are a few more pictures. Not sure that the addition of the sheet in the rear bulkhead adds any "torsional" strenght but can't hurt. Again, not recommending it but others have done it with no complaints that I am aware of.

Here are a couple of early trial "fit" pictures. That is cheap travel bag but easily holds a full set of clubs. (Travel tip - two of them fit nicely in a single hard case and the airlines have (so far) thought it one bag). Note ELT on reinforcing structure that also keeps the center panel from tin-canning. Manufacturer said it was fine to ELT mount on its side as long as pointing forward.






Here is the locking mechanism but I would probably use a keyed lock like on the slider if I was doing it again. Note there is also a cover over the rudder cables so nothing can foul them. There is a piece of reinforcing angle across the cut to form the door frame and another up the center support to allow for attachment of the center panel. It's just folded at top and bottom and screwed in place. The bottom fold (hidden) goes under the elevator tube and keeps the center panel from ever getting close.








OK, again, not a recommendation, just my process. Please read what Vans said in EM above.


Hope that helps either decide to do or not to do ;-)

Bill S

Box

I built a box that extends from the baggage bulkhead to the bulkhead in front of the horiz/vert stabilizer. The top half of the baggage bulkhead is hinged and secured with Skybolt butterfly fasteners. The box is very useful. If doing again, I'd make a few changes to simplify the build and utility.

The box is constructed with aluminum angle and 1/8" thick aluminum strips 1" wide. The box has a bottom and sides but no top. The bottom and sides are made from 4 mil thick Coroplast. This is like plastic cardboard. It is light and very strong. The entire structure weighed less than 3 pounds.

I use the box to carry RC model sailplanes, golf clubs and other gear that will easily fit (sleeping bags, pillow etc...). I try to limit the cargo to less than 10 pounds. I only put the drivers in the box. The irons will fit fine in the baggage area.

I'm out of town and don't have the pictures with me. When I get home I can post pictures if anyone is interested.

BillSchlatterer said:

OK, again, not a recommendation, just my process. Please read what Vans said in EM above.


Hope that helps either decide to do or not to do ;-)

Click to expand...

I did read it, and it certainly wasn't absolute.

So I'll put it another way. I own a sheet metal shop. I've been building sheet metal whatever's for a long time.

So lets construct a box, and I'll build what amounts to four sides. At this point it's very flimsy. Then I'll add a top and bottom end cap, and use a tool that locks the metal edges together. Now, the box is very rigid and will easily support hundreds of pounds. It's the same reason our wing leading edges are so rigid (D-structure).

However, should I remove half a bottom or top, to make it a hinged door, then this box looses a lot of it's rigidity. I'd have to take that "door" and put lots of screws around the edges to get that strength back. Those top and bottoms are doing exactly what that bulkhead does.

This is just my personal observation based on building a lot of sheetmetal boxes over the years.

L.Adamson -- RV6A

Golf Clubs

1. If you have graphite shafts dont try to force them in . I nicked the shafts on two of my drivers and they broke the next time I used them.
2. I put in tubes so the heads are in the baggage compartment.Use nettng to hold them in place. We were worried that CG could be comprimised with a shelf. We have a shelf in at backs of tubes so nothing can fall through
3. Tubes act as good airconditoning vents. Higher pressure in the aft creates a nice breeze.

L.Adamson said:

However, should I remove half a bottom or top, to make it a hinged door, then this box looses a lot of it's rigidity. I'd have to take that "door" and put lots of screws around the edges to get that strength back. Those top and bottoms are doing exactly what that bulkhead does.

This is just my personal observation based on building a lot of sheetmetal boxes over the years.

L.Adamson -- RV6A

Click to expand...

So how would you feel about it if there were a hole about the same size as the interior frame instead of the door. In that case, wouldn't it be virtually the same as a lightening hole in a large bulkhead? It would be easy to reinforce around that with a slightly larger doubler and use aother sheet of the corrogated as a matching door? Lots of options, do you have a suggestion for a better method?

None of the other bulkheads are solid and I "think" that one has as much to do with sealing as with strenght with the corrogations to prevent tin-canning? If there is a twisting stress component caused by (?) rudder deflection, wouldn't that more likely affect the structure at the rear spar attach points?

Just wondering?

Thanks Bill S