Z Bracket question

Cherokee Driver · Post by **Cherokee Driver** » Thu Jan 07, 2010 9:05 pm

Ok...the plans call out for one bracket (the 7th bracket ) to be drilled and fitted to the rear baffel. The instructions do not specify which location I should use for this bracket. I am clearly missing something obvious. Someone able to help me with what I am missing?

Thanks CD

Post by **Spike** » Thu Jan 07, 2010 10:05 pm

I am not sure I follow your question. On the 9 (close cousin in tank design I believe) all the z brackets were drilled and temporarily fitted to the tank. Then the tank is installed and you match drill the brackets back through the wing spar. The odd ball was that the inner most bracket had the nut plates on the spar web instead of on the bracket itself.

Wont all of your Z brackets get fitted to the tank?

Mike Balzer · Post by **Mike Balzer** » Thu Jan 07, 2010 11:58 pm

CD,
I don't have an exact answer to your question right now, but I would be more than happy to E-mail you my favorite RV-7 and RV-8 builders web sites that I use for reference. I think the wings are the same on both models. The Builders web sites I saved I believe did high quality work and an excellent picture progress of there work.

Hope this is helpful,

Mike Balzer

Cherokee Driver · Post by **Cherokee Driver** » Fri Jan 08, 2010 12:37 pm

Thanks guys...

Let me apologize for the poor wording of my question as I was rushing to post my request for help and in the process I botched on the clarity.

In the instructions, I was instructed to set aside a "Seventh Attach Bracket" (for each wing) that was only drilled on one side using an 1/8 in drill bit. The instructions referred later to this "Seventh Bracket" in the instructions that I have quoted below.

Cleco the drilled T-712 Attach Angles to the aft side of the pre-punched main wing spar so you have good access with a drill. Position them so the center line is centered in the pre-punched holes in the spar. Clamp the angles in place and drill the remaining holes using the spar as a guide.

Remove the angles and rivet the plate nuts to them, then bolt them in place on the front of the main wing spar.

Cleco the T-702 Baffle to the forward side of the T-712 Attach angles. Check to see that the centerlines on the angles are visible through the holes in the baffle.

Cleco the seventh attach angle to the tank baffle between the baffle and the spar. Verify that you can see the centerline on the angle through the holes in the baffle and the spar.

(Instructions continue)

I am good with most of this but I am unclear as to where this "seventh bracket" should be positioned on the spar. I understand it belongs "between the baffle and the spar" but at which particular bracket "Station" (my word).

Sorry for being so wordy, but I also want this to be clear in case there is someone else in the future that might struggle with this and might find my question helpful.

Sorry guys,

I don't try to be obtuse.

I am just missing something here.

Thanks for your generous help and Patience.

CD

Post by **Spike** » Fri Jan 08, 2010 3:37 pm

I wonder if they mean on the inner most station. On the 9 that station is different as the bolts run from front to back through the z bracket with the nut plates being located on the backside of the spar. That would be different from the other '6' z brackets where the nut plates go on the z bracket and bolted on from the rear of the spar forward (I believe these would be the ones you were instructed to bolt to the spar before you cleco the baffle.)

I hope this helps / applies.

Spike

Wicked Stick · Post by **Wicked Stick** » Fri Jan 08, 2010 9:24 pm

It sounds to me like its the "end" station if I understand what they are referring to. (sorry it's been over 3 years since I built my wing/tanks)

Is there not a drawing/diagram showing the position of all 7 z-brackets ?
The drawing should help show how it is orientated and it's location.

Cherokee Driver · Post by **Cherokee Driver** » Fri Jan 08, 2010 10:29 pm

Spike nailed it.

In answer to Dave's question...the drawing...I could not find any differentiation of this so called "seventh bracket."

So that I could avoid making some unforseen mistake over the weekend, I called Vans after I read Spikes post as this made sense. Van's confirmed that the "seventh bracket" is in fact the inboard bracket. Apparently this one gets aligned on the tank first while the others get aligned on the spar. At least that is what I took from the conversation.

Thanks again to everyone for being around to pitch in with help.

Have a great weekend everyone.

Eric

Wicked Stick · Post by **Wicked Stick** » Sat Jan 09, 2010 7:59 am

CD,

Glad you got it figured out between Van's and Spike

.

Be prepared to grind down a cheap pop rivet gun so you can pull the rivets on the Z-brackets when the time comes.

If you can cheat a little (1/16") away from the center line when you drill them, it will make it easier to pop rivet them later.

Post by **Spike** » Sat Jan 09, 2010 8:04 am

Wicked Stick wrote: Be prepared to grind down a cheap pop rivet gun so you can pull the rivets on the Z-brackets when the time comes.

Triple recommendation on this. I got a cheapo from Harbor Freight and whittled it down mercilessly. It worked like a champ.

airguy · Post by **airguy** » Sat Jan 09, 2010 9:40 am

Spike wrote:
Wicked Stick wrote: Be prepared to grind down a cheap pop rivet gun so you can pull the rivets on the Z-brackets when the time comes.
Triple recommendation on this. I got a cheapo from Harbor Freight and whittled it down mercilessly. It worked like a champ.

Same here - and then I was amazed that the damn thing kept working. It has steadfastly refused to die, and I'm still using that same poor tortured tool.

Cherokee Driver · Post by **Cherokee Driver** » Sat Jan 09, 2010 5:02 pm

DOH!!!!!!!!!!!!!!!!!!!!!!!!!

That was excellent advice. I didnt read it til after I drilled the holes.

Well, what this did do was justify me posting the question...someone else might read this and benefit from that tip.

Thanks again everyone for taking care of one who is well behind the vast majority of the group.

CD

Wicked Stick · Post by **Wicked Stick** » Sun Jan 10, 2010 7:35 pm

Z-Brackets are pretty cheap to re-order and re-drill if you think the holes are too close to get at later for pop riveting.

I did the same thing on my first wing (built them one at a time) and re-ordered the z-brackets and redrilled it on the first wing. The 2nd wing didn't need any re-do's.

If your first set is drilled on center, it will be tight, but you should be ok. It just means you'll have to grind off a little more material on the Harbor Freight rivet tool

.

BSwayze · Post by **BSwayze** » Mon Jan 11, 2010 9:47 am

I've got a lot of documentation and pics on my wing log pages, if it will help anyone. I did my z-brackets using the "Dan Checkoway" method, but now that his site is no longer online, you can see if mine will help you. I got excellent results using this method. The RV-7 wings are the same as the RV-8.

Also, I heartily agree with the comments about grinding down a cheapo Harbor Freight pop-rivet tool. I ground mine down so far it went all the way through the material, but it still works fine. Here's a picture of it:

Post by **Spike** » Mon Jan 11, 2010 10:34 am

Hey that looks like mine! Seems this is a fairly standard / good way of doing it.

Spike

cjensen · Post by **cjensen** » Mon Jan 11, 2010 2:27 pm

I did the same, of course, but make sure you have metal parts inside before grinding. I had to do this to two of them because the first one had plastic parts, and they were no match for the heat generated during grinding...

Cherokee Driver · Post by **Cherokee Driver** » Mon Jan 11, 2010 4:21 pm

Very interesting!

Thanks a lot. It is funny how someone says "grind down a 'little'" and I get one picture in my head...that was nothing like what it really took.

As a matter of fact I have an old rivet tool that is kind of junk...so I guess I know what that will be used for!

Again, thanks in advance for all the comments. (I gotta feeling I will be buying a round at the Otter.)

(What do you want to bet that that remark will generate some traffic on this thread!)

cd

Post by **Spike** » Mon Jan 11, 2010 4:56 pm

Generate some traffic? Heck you just convinced me to attend Osh this year

Wicked Stick · Post by **Wicked Stick** » Tue Jan 12, 2010 9:31 pm

I'm in... hope to be flying there this year in an unpainted RV-8

.
I need another EAA mug to go with the other one from last year.

Cherokee Driver · Post by **Cherokee Driver** » Mon Feb 01, 2010 3:44 pm

Just a follow up to the use of a ground down rivet puller. I had an old puller at the airport that I was going to grind down (after reading this post, it seemed like the tried and true solution) but forgot to pick it up on my last flight.

I needed to pull some rivets on the inboard spar on the flaps today and I did not have enough room for my puller to get in next to the angle attachment. So I tried something different that worked fine without grinding down a puller.

I started by inserting the rivet into the hole and putting a scrap piece of alclad on it drilled to the size of the rivet mandrel. A stack of washers provided the needed clearance and I was able to pull the rivet against the washers with my puller (the one I did not want to grind down.)

My puller's mechanism will engage the mandrel with the rivet half inserted. so it pulled just fine. Don't know if this is a new idea, but it worked ok for me and it might be an option for someone else who is pulling rivets in tight quarters.

CD

Post by **Spike** » Mon Feb 01, 2010 4:11 pm

Now that is a great idea! I guess you just have to make sure that the lower most washer touches a decent amount of the rivet's face.

Spike