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Thoughts on F640/F639 Floor

MNellis

Active Member
I cut and fit the pilot side forward seat pan (F-640, the sheet the control stick comes out of) and I'm concerned since things are not "looking" right. I followed the dimensions on the plans but that doesn't always mean it's correct.

This first picture shows the control column attachment to the spar bulkhead. On page 37 of the plans it shows a "Rev 3" that notes a "reverse flange on F-633" which is the control column mount. Below is a picture of that area. As you can see, the control stick is not centered between the ribs. If the control column mount (F-633) was swapped with the other side it would center the stick between the ribs.

DSC00147.JPG


Next is the fwd seat pan on the left side. Although I cut the sheet as shown on the plans you can see the rib on the left side is exposed as is the flange on the spar bulkhead. It doesn't show on my plans, but is this portion of the spar bulkhead flange suppose to be removed to get full forward stick movement?

Logic tells me that the cut out for the stick opening should line up with the seat rib flange on the left and right side and also with the spar bulkhead flange. I think I cut the opening correctly since the control stick is in the center. I'm hoping I didn't make a mistake when positioning the seat floor ribs but I haven't gone back and measured those yet.

I sure would appreciate any thoughts the group might have regarding this operation.

DSC00148.JPG


and another view.

DSC00151.JPG
 
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need to trim flanges

Looks to me like you're right on track.

I don't have my drawings handy but should be reflected in there where to trim as necessary to get full travel.
Pictures below taken during construction of my -6A.

Pilot side:

ElectricalWiring03.JPG



Passenger side:

ElectricalWiring04.JPG



A few other pictures on my web site at (it's actually page talking about my electrical system, but shows area under the seat pans):

http://rv6aproject.ckhand.com/panelAndElectrical/electrical/electricalPg7.htm
 
Totaly Awesome!

I am many years into my six, and just put in the floorboards.

I am getting ready for the control sticks, and guess what?

I saw your Photos of the controls :D

I picture is worth a thousand words, Thanks.

Your build site is well done, Thx x2
 
I am many years into my six, and just put in the floorboards.

Your build site is well done, Thx x2

I'm many years into my build as well. I followed Chris's lead but I went ahead and cut the whole flange off the floor rib so I would have a straight rivet line. It's not necessary really other than for aesthetics.

Here is what I ended up with. I still have to clean up the cuts and install the new flange but you get the idea.

DSC00165.JPG
 
Here is what that are looks like on the passanger side after removing the old seat rib flange and installing a new one.

DSC00167.JPG
 
That will work. You needn't have worried about a straight rivet line because 1) there are no rivets, just a few screws and 2) it gets covered by the seats and, optionally, stick boots.
 
RV-6 seat ribs

If you know about this before hand, you can reverse the flanges on the two seat ribs so you don't have to cut them down where the stick is. You just swap the left one for the right one and the flange points the other way.
 
If you know about this before hand, you can reverse the flanges on the two seat ribs so you don't have to cut them down where the stick is. You just swap the left one for the right one and the flange points the other way.

That's a good point and typically one that first time builders will not know about. It's one of those things that might be in builder sites and why it's a good idea to scour the net and read as much as you can from those that started before us. The real early builders of the late '80's early '90's had their hands full.
 
Swapping left/right ribs

Won't work if the floor pans are pre-punched. I can't remember if mine were or not...
 
Fuse ribs

I have one of the newest fuse kits and it is not pre punched except for the firewall. You can also reverse the center ribs for the channel the push pull tube goes in but that leads to a different set of issues. It makes more room for working in the channel for wiring/access, however, one of the bottom skins will need to be remade 5/8" wider to allow for the reversal. It's your snowballing effect when you change something. Also, don't forget to install you backside splice plates before you rivet everything up!
 
Here is how I did the reverse flange on my seat pan ribs to clear the control stick. Different method, same result as the rest.

FP15082010A00045.jpg
 
Here's my 10-year-old RV-6 undergoing a recent condition inspection. You can see where the flanges have been altered as suggested by your first post.

014.jpg


Also shown is the crotch strap mod if you're doing that, and the relay panel for the Infinity stick grip which mounts on the underside of the seat pan itself, not shown.
 
Here's my 10-year-old RV-6 undergoing a recent condition inspection. You can see where the flanges have been altered as suggested by your first post.

Also shown is the crotch strap mod if you're doing that, and the relay panel for the Infinity stick grip which mounts on the underside of the seat pan itself, not shown.

Thanks for the additional pictures Pat. I'm in the process of modifying my -7 crotch strap mount for use in the -6. It should be a simple modification. I, too, have the Allen servo relays and speed control units I plan on using. I've been wondering where to mount them and I like your idea of mounting them on the underside of floor. I may do something similar but it was good to see how you did it along with your stick wiring. I plan on using Infinity stick so I will have some additional relays/wires to deal with as well.

TrimServo.jpg
 
Yeah, here's a photo of the relay deck (homemade) mounted under the floor. This is really the most accessible place to mount it and very convenient.

028-1.jpg


And here's the photo with everything buttoned up. The four screws on the right are for the relay deck.

033-1.jpg
 
Excellent, thanks for that last picture. I'm disappointed in myself on how the F640/F639's turned out. I followed the plans and notched the left/right sides at the specified 4 1/4". 4 1/4" is about 3/4" more than is necessary so now I've got a gap that is a little unsightly. I know it won't show when the seats are in place but it's still irritating. I should have just measured and cut to fit but usually when I do that I overlook a "future something" so I try to follow the plans. In this case it screwed me up a bit.

BTW, how do you have your Infinity grip switches set up?

DSC00189.JPG
 
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I followed the plans and notched the left/right sides at the specified 4 1/4". 4 1/4" is about 3/4" more than is necessary so now I've got a gap that is a little unsightly. I know it won't show when the seats are in place but it's still irritating. I should have just measured and cut to fit but usually when I do that I overlook a "future something" so I try to follow the plans. In this case it screwed me up a bit.

BTW, how do you have your Infinity grip switches set up?

The good news is that when you slide your wings in, the spar will cover that 3/4" gap so it won't be as visible, not a big deal.

My Infinity is set up as follows:

Green button: Transponder IDENT
Red button: Autopilot Disconnect
Red Trigger: PTT
Coolie hat: Elevator trim; Aileron trim (I have an actual trim tab built into my left aileron)

I would make sure you do the entire Infinity grip installation with the stick out of the airplane! Now would be a good time to get that done before you permanently install the stick. I used a 9-pin D-sub connector pair inside the stick so that I can remove the grip for maintenance. This requires trimming the "ears" off the D-sub's so that they fit down into the stick tube. Here's a picture:

018-1.jpg
 
Notching those floor pans...

As you can see, you will notch the pan in two places to fit nicely around the F604 structure. Also when you rivet the nut plates along the floor rib next to the fuselage side (and along the same seat pan rib if you are making screwable seat pans) you will be challenged with a rivet squeezer because the arm rests are in place. I did not have my arm rests riveted and could remove them. Another builder just used mk319bs rivets after enlarging the holes to 7/64. Also before drilling the nut plate screw hole through the overlapping floor pans/seat pans across the ribs, make sure the hole is sufficiently forward of the rib gaps where the ribs transition from flat to sloped up. Some of a my floor ribs had excessive material removed and I had to add an piece of angle to give correct hole distance. As you have noted, I found many places where it is just better to measure and trim rather than using plan measurements.
 
The good news is that when you slide your wings in, the spar will cover that 3/4" gap so it won't be as visible, not a big deal.

My Infinity is set up as follows:

Green button: Transponder IDENT
Red button: Autopilot Disconnect
Red Trigger: PTT
Coolie hat: Elevator trim; Aileron trim (I have an actual trim tab built into my left aileron)

I would make sure you do the entire Infinity grip installation with the stick out of the airplane! Now would be a good time to get that done before you permanently install the stick. I used a 9-pin D-sub connector pair inside the stick so that I can remove the grip for maintenance. This requires trimming the "ears" off the D-sub's so that they fit down into the stick tube. Here's a picture:

Thanks for the tip, I'm glad you mentioned that, it's a good point and gives me a reason to order the stick grips in the near future.

Like you (and others) I also have the aileron trim built into the left aileron. Back around '99 when I ordered the wing kit w/electric trim, I didn't like the little tab hanging off the trailing edge of the aileron. At the time the the idea of putting the servo on the manual trim lever hadn't been proposed (or at least I didn't know about it) so I built my little tab. As with most deviations from the plans, it was a lot of work but ultimately I like how it turned out.

DCP02209.JPG
 
As you can see, you will notch the pan in two places to fit nicely around the F604 structure. Also when you rivet the nut plates along the floor rib next to the fuselage side (and along the same seat pan rib if you are making screwable seat pans) you will be challenged with a rivet squeezer because the arm rests are in place.

The nut plates along the fuselage skin is another good point to keep in mind, thanks. I have not gotten that far and didn't think about squeezing those. If I run into a problem getting the squeezer in there I'm not averse to using a blind rivet to secure a nut plate.
 
Like you (and others) I also have the aileron trim built into the left aileron. Back around '99 when I ordered the wing kit w/electric trim, I didn't like the little tab hanging off the trailing edge of the aileron. At the time the the idea of putting the servo on the manual trim lever hadn't been proposed (or at least I didn't know about it) so I built my little tab. As with most deviations from the plans, it was a lot of work but ultimately I like how it turned out.

[/IMG]

Your tab looks about the same as mine. You are absolutely going to love how well it works. You can totally empty one tank with the other one full and have enough tab to trim it out. Not that you would want to, but if you're going to have a trim tab, might as well have it work for the most extreme condition. I had been in RC so long that I actually enjoyed making these small tabs, made one for the rudder too! :) Sorry for the thread drift!

IMG_0711-1.jpg
 
What connects to the trim tabs to make them move. Is it like the trim tab on the elevator..?
 
Yes, it's a similar motor to the eleveator trim but with less travel depending on what motor you choose. In Pats picture above, you can see the access panel at the leading edge of the aileron. Remove that panel and the motor is underneath and connected with a rod to the trim tab.
 
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