Andair Fuel Pump installation problems

[BSwayze]

The installation of my Andair Fuel pump assembly is giving me fits. After fiddling and working on this for way too long, I reached the big moment to start putting it all together only to find out my center cover, F-782C, doesn't fit between the two center floor stiffener ribs when I have the brackets and plate attached. I have posted a more thorough discussion and pictures on my web log here:

May 2, 2010 entry

and here:

May 3, 2010 entry

The problem, as I see it, is that my floor stiffeners are too close together causing my center F-782C cover to curve and warp. It's even worse when I try to install the pump assembly and bracket. Back about a year ago when I drilled them to the bottom floor skin, I drew a centerline down each stiffener and drilled them to the floor. How I wish I had known how critical the separation distance is between these floor stiffeners. A short note in the plans on Vans part would have saved me this mess. Look at these pictures, and you'll see what I'm up against:

I put a straightedge across it, shown below, to show just how bad it is.

I don't know what I'm going to do. I'm considering drilling out several dozen rivets and removing these floor stiffeners, and replacing them with new ones that are separated a bit more. It's a job I shudder to seriously consider, but what other option do I have? Has anyone else run into this? What did you do?

Is anyone else installing an andair system, that can share their experiences?

Thank you for any comments or help.

 

[SteveHRV7]

Bruce,
I also noticed that the brackets were a bit wide when I first made them. My F-782C cover fit fine by itself but when I added the brackets it was too long. I believe I heavily rounded the corners of the brackets so the nestled into the cover without widening it too much.
Steve

 

[miyu1975]

I have the same problem with mine...but I haven't dealt with it yet. One option I considered is to not put both the flanges of the of center piece outside of the stiffners. You could put one flange on the inside and one on the outside. You would have to redrill your platenuts accordingly. In the end, especially with carpet...no one will know but you.

 

[[email protected]]

ditch the cross braces...

i purchased my pump before andair had worked out a filter and attachment bracket and per recommendation from andy am using gasolators in each wing root as filters as he installed the pump in his rv. for mounting, i used a backing plate under the cover along with nutplates to anchor the pump and controller keeping the passthrough clear for the fuel, antenna, wiring, or brake lines for tri-gear models.

here is a link to my entry on mounting the fuel pump with a few photos for reference:
http://www.schristo.com/RV7/Log/Entries/2009/9/28_fuel_pump_mounting.html

one note on carpet... the center section is not insulated with sound batting (from classic aero designs, likely others as well) so that the finished carpet floor is the same height all the way across. i added 3/8 of sound matting in the tunnel... not sure if it will make a difference but it is right under the exhaust...

here is a link to my entry showing the sound batting, wiring, piping, etc.
http://www.schristo.com/RV7/Log/Entries/2010/4/12_more_lacing.html

 

[Bruce]

Z Brackets

I used Z brackets cut them in half and then mounted them
on the floor rail and the fuel pump bottom sits on top with the
screws going in from the top.
Much better solution to this problem.
On my web somewhere.

Hope this helps.

Boomer

 

[Bruce9A]

Andair fuel pump mounting

Bruce,
I didn't like the method that Andair suggested (it seems like it would interfere with running brake lines under the pump, and I couldn't get the pieces of angle to fit well under the Van's cover), so I ordered some 0.063 sheet and some 3/4" angle (same type as the floor stiffeners) from Spruce and made my own 782C. The angle pieces fit inside of the floor stiffeners, and they will be riveted to a cover plate made from the sheet. Attachment of the new cover to the floor stiffeners is just like the attachment of the Van's cover. I think the 0.063 sheet is heavy enough to support the pump, although I made a couple of stiffeners (3/4" angle with one of the sides trimmed down to 1/4" to allow clearance for brake lines) that will go on the underside of the cover where the mounting bolts for the pump come through. I'm still using about half of the Van's cover (from the pump forward), but there's no reason that a home-built cover couldn't go all the way to the firewall. I fabricated the parts about a week ago, so nothing has been permanently installed or flight tested, but I think it should work fine. With shipping, I think it all cost about 30 bucks, and I have a big piece of the 2'x2' 0.063 sheet left over for other projects.

-Bruce

 

[389JM]

Andair Pump

Bruce,

I sent you an email.

Jim Haran

 

[BSwayze]

Well, I'm very, very happy to report on the solution I came up with and show you the results. I tried hand seamers, but the problem was too severe to make this work. I also tried putting the flanges of the cover on the outside of the ribs. That didn't work either. So I ended up doing as some have suggested. I cut the flanges off the F-782C cover and riveted new ones in place.

I also decided to ditch the angle crossbeams shown in Andair's plans in favor of a stiffener plate. By the time you cut the angles to allow your brake lines and electrical lines, antenna lines, and so on to pass through underneath, there won't be much left of them anyway.

I have lots of pictures and details of how I did it in my web log starting here:

http://www.europa.com/~swayze/RV-7A/Fuselage/20100503.html

I'll give you the short version here and show you the results. It turned out real nice, I think. Here's the center cover before I cut off the flanges, with the new angle pieces and stiffener plate I used:

Here it is all riveted together and a shot of JetFlex to finish it up:

Trial fitting on the bench with the fuel pump and bracket:

And finally, the assembly in the fuselage. Everything now fits perfectly.

Now after messing around with this for way too long, I can finally get on with putting in the fuel lines, brake lines, and get this whole plumbing project wrapped up.

Incidentally, I think this is a good option for anyone who has a cover that doesn't fit right, whether or not you have the Andair fuel pump. I'm real happy with how nice this turned out. The cover is now flat as a pancake, fits snug as a bug, and looks really nice.

Thank you, gentlemen, for your hints and your help!

 

[RV7Factory]

I also decided to ditch the angle crossbeams shown in Andair's plans in favor of a stiffener plate. By the time you cut the angles to allow your brake lines and electrical lines, antenna lines, and so on to pass through underneath, there won't be much left of them anyway.

I was all set to start installing the angles, even ordered some supplies from ACS, but based on your statement above I may have to re-think my plan. Thanks for the info.

 

[BSwayze]

I was all set to start installing the angles, even ordered some supplies from ACS, but based on your statement above I may have to re-think my plan. Thanks for the info.

You're welcome, Brad!

I have no regrets about going this route. My EAA technical counselor, Dan Benua, had also noted previously on a visit here that those 1/8" thick crossbeams were overkill and that I could consider doing something different. Check my web pages for lots more details and more pictures of how I did this.

I have followed your progress for a long time, Brad. Your site has been a huge inspiration and help to me. Especially when I was building my wings. You have a reputation for doing excellent work and I'm sure you'll make a good decision here as well. I'm anxious to see what you decide to do.

 

[RV7Factory]

Bruce, thanks for your very kind words.

2009 was chaos for me, and I didn't get much done on the RV, but I am trying to get my butt in gear in 2010.

I've got a few ideas on how I will accomplish this. First, as you said, is to remove about 3/8" of material from the vertical component of the angle in the shape of an arch. This would give me roughly 9/16" clerance below it, which I am not sure is enough in the long run.

The other option is to replicate what you did by installing a doubler, but also tying it in to the vertical sides of the cover (perhaps by using some .063 angle). I've got a picture in mind and it shouldn't be hard to do.

 

[BSwayze]

I've got a few ideas on how I will accomplish this. First, as you said, is to remove about 3/8" of material from the vertical component of the angle in the shape of an arch. This would give me roughly 9/16" clerance below it, which I am not sure is enough in the long run.

The other option is to replicate what you did by installing a doubler, but also tying it in to the vertical sides of the cover (perhaps by using some .063 angle). I've got a picture in mind and it shouldn't be hard to do.

Brad, yes, that's exactly what I was thinking of doing at first. Cutting an arch in the angle, that is. In my case, I have installed some 1/4" soundproofing material to the floor, though, which limits the clearance even more. I'm considering another layer of the material applied to the underneath side of the cover, to create a "sandwich" of the material through which all the lines will pass. This will provide even better sound insulation as well as cushion all the lines from any vibration. So the angles just aren't good for me.

I see what you're saying about the .063 angle stock to tie the stiffener in to the side angles. I think it's all unnecessary overkill, though. Just my opinion. What may be another problem is that the angle built into your cover has a curved radius in it. The square corner of the .063 angle won't nest in it so you're in for some work to put a radius in the material. Then how strong would it be? Or you could use .032 angle so the radius is the same. If you want to overlap the stiffener plate and rivet it together, though, you'll also have to put a joggle in either the plate or the flange on the angle where it overlaps. It's all doable stuff if you have the tools and want to put in the time. I think you'll find, though, that it just isn't necessary.

If you could see how stiff and strong this assembly of mine is now, you would probably think so, too. Remember, the steel pump bracket adds even more strength The stiffener I made is large enough that it goes almost all the way over to the new angle on each side. I'm very pleased with it. The only thing I debated was whether to use .040 or .063 sheet for the stiffener. I ended up going with .040 since I had some on hand in my trim bundle. Plus, it won't be that hard to replace if I ever needed to beef it up. But I can't imagine that will ever be necessary. Time will tell.

Let us know what you finally decide to do.

 

[RV7Factory]

Just a quick follow-up with my research. Perhaps I am over-thinking this, but allow me to have my fun.

Here are the two options I mentioned. The first would be where I trim the angles, and the second is the use of a doubler and some angle along the edges for added stiffness.

By trimming the angles, I would end up with a space between the cover and the belly skin of approximately 5-3/4" x 3/4" (the block of wood is a 15/16" spacer I fabricted to set the cover height). It's probably adequate, but since I don't know what avionics I'll be using or how my electrical system will shake out yet, I am not sure if it's enough in the long run. You also have to consider that the pump mounting hardware will also penetrate this space.

The second option is to install a doubler (of .040 or .063) and use some .063 angle along the sides to stiffen it all up. This would leave almost the entire space under the cover available for use. The picture is just an example using some scrap, but I think you'll get it.

My vote, and the direction I am headed... Option #2.

 

[BSwayze]

I'm for #2

Brad,

Yes, I think you have a couple of workable plans here. I'm for #2, though, like you're thinking. Funny, the .063 angle stock I have seen has a square corner. Yours has a curved radius corner. So it would work much better than what I was thinking.

I still think the added angle is unnecessary, considering that the floor stiffener angle will stiffen the cover as it's bolted to it. So it acts as the stiffener you need. An additional one is redundant, as I see it. Not to criticize your approach, however. At all. Just my 2 cents worth. You're always better off having something too strong than to err the other direction. And your own comfort level matters the most.

If you do go with option #2, don't toss those angles you made just yet. Mine came in very handy to help me make and fit the forward fuel line. Using them, you can temporarily install the pump and its bracket using those angles, while leaving the cover off, so you have access and can see what you're doing. I described how it worked for me here:

Log Entry May 14th

Here's a picture:

I'm anxious to see what you end up with. Good luck!

 

[RV7Factory]

Funny, the .063 angle stock I have seen has a square corner. Yours has a curved radius corner.

That's cuz I put it there... the radiused corner that is.

I still think the added angle is unnecessary, considering that the floor stiffener angle will stiffen the cover as it's bolted to it. So it acts as the stiffener you need.

You're probably right, but I'm going to take the belt and suspenders approach with the fuel pump. The one thing that concerns me (even with a doubler installed), is the stress put on the bent corners of the cover over time. By doing what I am going to do, the angles will really beef up that area and prevent ANY vibration. Like you said, whatever gives me the warm fuzzies right.

PS - Nice tubing bends!

 

[erich weaver]

You guys are way too far along for this to be useful, but for others reading, take note: Due to a past manufacturing error, many oversized cover pieces were shipped by Vans that were a shade to wide to fit properly between the floor stiffeners. I suspect many of us (me anyway) cussed at it, jammed it in there, and made it work with everything kind of tweaked. Somebody on this list finally bitched to Vans and they eventually fessed up, fixed the problem and sent replacement parts for the asking. If yours is too tight, you likely have this problem.

erich

 

[BSwayze]

You guys are way too far along for this to be useful, but for others reading, take note: Due to a past manufacturing error, many oversized cover pieces were shipped by Vans that were a shade to wide to fit properly between the floor stiffeners. I suspect many of us (me anyway) cussed at it, jammed it in there, and made it work with everything kind of tweaked. Somebody on this list finally bitched to Vans and they eventually fessed up, fixed the problem and sent replacement parts for the asking. If yours is too tight, you likely have this problem.
erich

Wow, Erich,

Thanks for the info on this, even though it is way too late for me. I didn't know that! Mine's all fixed now and I'm finally happy, but I'm sure the cover was the problem in my case, it was so bad. I considered getting a new one, but thought it would be the same so what would be the point. I wish I had known. A new cover would have been nice. On the other hand, all the work that goes into that part is an big investment of your time, the bending of the louvers and all the tedious deburring followed by all the prep work, priming, riveting, painting, etc. It would have probably taken more time than the fix I engineered. So in the end, all's well that ends well. At least I don't feel so bad now thinking I installed the floor stiffeners "too close together". I went back and reviewed my pictures of how I installed them, and it was right on, by the book.

Hopefully this will help another builder. Thanks again!

 

[erich weaver]

well, at least you have some company in this regard huh?

The fit of the defective part was close enough to make you (and Vans) think its gotta be your own fault, but in this instance, that was not the case

regards

erich

 

[bruceh]

I'm contemplating getting my fuel system figured out and am considering the Andair Pump & Filter (already have their Valve).

My question is how can you access underneath the center tunnel once the pump is plumbed? It looks like with the access hole cut in the middle for snaking the fuel line that there is no way to take the tunnel cover off for wiring, etc. Is the lack of future access a problem, or do you just need to undo the fuel line if you need to get under there?

Looking at Van's Airflow Performance Fuel Pump set up, there is a separate aft tunnel cover and mounting bracket. It would be nice to have the Andair pump mounting be separate from the rest of the tunnel cover.

What are the options here? Cut the tunnel cover in two and fab up my own parts? Does Van's sell an AFP bracket without the various bends/cuts for mounting stuff? Leave it in one piece and put down some wiring conduit?

BTW: my tunnel cover also suffers from being just a bit too wide.

 

[RhodeIsland9]

cut the panel in half

I cut the original panel in two pieces and installed a .040 doubler and some .032 angle. The doubler was left long to fit under the front cover half and the fwd screw of the fuel pump cover fits into a nut plate in the doubler.

 

[BSwayze]

My question is how can you access underneath the center tunnel once the pump is plumbed? It looks like with the access hole cut in the middle for snaking the fuel line that there is no way to take the tunnel cover off for wiring, etc. Is the lack of future access a problem, or do you just need to undo the fuel line if you need to get under there?

Bruce,

I considered this question, too. The fuel line unscrews very easily and quickly, and the cover is easily removed. So I went that route. Good luck on your progress, whatever you decide!