F-445 Flap bearing block & seat belt bracket issue

I searched for past threads and found one where the exact problem I am having was brought up but there never was an answer.

The aft bolts in both my F-445 flap blocks are contacting the rear seat belt brackets in my QB fuselage. I haven't drilled the forward holes yet. Has anybody else encountered this and what did you do to fix it? I suspect that some careful work with a die grinder to relieve the interference from the bracket will be the cure. I have an email in to Van's but wondered if anybody had already asked this question and received an answer from the mother ship.

This is the factory aft hole for the flap block.


With the blocks in place and a bolt through the aft hole into the factory plate nut I get enough interference with the seat belt bracket that it will be impossible to tighten the bolt.


And the view from above.

Is that flap bearing block sitting hard down on the support angle it bolts to? I had to remove the harness anchor completely in order to get the rear bolt to fit, and the the anchor was able to be re-fitted without any modification once the bearing block was bolted down. Mine is a 2009 QB, but didn't have that aft hole pre-drilled like yours - so my bearing block position may be slightly different.
I don't think there would be any issue with modifying the anchor if you needed to, but there will be someone more qualified responding to you soon no doubt!
Cheers,
Hugh

The block is down. I don't think removing the anchor to install the block and then re-install the anchor will provide any help in this case. In these pics the floor panels are not even installed so in the finished product the block will sit even higher. At first I thought I must need to trim the block vertically since there are dimensions listed on DWG 77 but the raw block conformed to the spec'd dimension within a 32nd of an inch and that might have just been my eyeballs.

Sam,
I had same issue with my QB fuselage, I used a rotary file and provided the clearance needed for the bolt. It doesn't take much.

To close out with an answer.
Heard back from Van's. They said to create the clearance with a smooth curve. I place a socket head on the bolt and drew a line around it. Then I removed both anchors from the fuselage and made my clearance with a die grinder. Smoothed everything up with a file and sand paper and re-installed to check. Tomorrow I will re-re-install the anchors with new hardware and torque the new bolts up. I will try and remember to get a picture of the relieved section.

Mine's not a Quick Build

I had similar clearance issues with my slow build 8A. I substituted SHCS [socket head cap screw, the proper name for what is commonly called an Allen head bolt] bolts for the hex head bolts where needed. This suggestion is worth what you paid for it.
Charlie

I noticed today that with the floors in, the flap blocks are just slightly taller than space between the floor and the anchors. With the anchors installed I cannot get the flap blocks in place. If I remove the anchors and install the flap blocks it is not possible to get the anchors back in place without some minor cutting on the bulkhead the the anchor passes through. Anybody know if the vertical dimension of the flap block is critical? I have not measured it yet but I think 1/16" will get me the clearance I need.

If you remove the seat belt brackets and compare the radius to the plans you will notice quite a difference. Sand or grind them back to illustration and it should fit.

I'll have to look at it again tomorrow. Maybe I can slightly increase the size of my bolt head relief and clear the flap block completely. Thanks for the idea.

So to re-close up this thread I had a look today and was able to just slightly enlarge my relief so now the blocks can be installed with the anchors in place.

One of the areas where they are slipping.

We had the same issue with ours - I hate having to disassemble stuff to progress - it defeats the object.

Took the time to visit the other areas such as wrong spec nutplates etc.

Wait until you try fitting the wing bolts............ Oh Boy

I have found a few things so far from the QB folks that were not right so I am watching much more carefully now.

I have had the same issue with my seat belt brackets on my QB kit. Obviously an issue at the factory in the Phillipines!

I have also found wrong size anchor nuts fitted around the fuse, dud rivets etc. Need to keep a close eye on it all.

It's a bit frustrating especially having to undo work you had to pay for in the first place!

I found the same problem with my RV-8 QB today. So grateful for the resources of the Van's Air Force; found the solution here. I will remove the clecoed-in floor skins and break out the dremel grinder tomorrow.
(actually, I removed the brackets and did the curved notch with the bench grinder, scotchbrite wheel and scotchbrite dremel tool)