Horizontal Tail interference with Rear Stab Pivot Mount

[LetMeFly]

Hi everyone!
I've installed the bushings and bearings in the HT and test installed it to the fuselage. I can't get the nose of the HT to go down as much as I've seen in other postings, and it doesn't go down enough to meet the trim jackscrew when fully retracted. The stab hinge mount interferes with the pivot mount. I've removed all the powdercoat. It looks like I need to either grind down the welds on the hinge mount, or grind out some clearance on the square pivot mount bracket. I've searched the forum for this problem but haven't found any posts mentioning this problem. Has anyone encountered this? Any suggestions? See pictures below.
Thanks.

IMG_5530.jpgIMG_5533.jpg

[n85ae]

Hard to tell from the images what you're saying. Can you post some images that are marked up maybe
showing the interference? I see the lower image where the powder coat is ground away, but not really
understanding the problem? In general grinding away the part interfering with the weld is the better
idea. You really don't want to grind away welds.

Guess the Tinman Tech Guru (welding website) doesn't call MIG Goose Poop welding without good reason ...

Jeff

[LetMeFly]

Hard to tell from the images what you're saying. Can you post some images that are marked up maybe
showing the interference? I see the lower image where the powder coat is ground away, but not really
understanding the problem? In general grinding away the part interfering with the weld is the better
idea. You really don't want to grind away welds.

Guess the Tinman Tech Guru (welding website) doesn't call MIG Goose Poop welding without good reason ...

Jeff

Hi Jeff,
The interference is circled in red.

IMG_5533_zoom.jpg

As the nose goes down, the tube contacts the fitting because the weld bulges out a bit.


IMG_5529_note.jpg

Yeah, I didn't want to grind weld and weaken the joint, but I'm worried about putting a weak spot on the fitting as well.

I decided to email John McB directly as well to get an official opinion, since it looks like this hasn't been addressed before.

[Denalifox]

its a common issue. You just need to remove a bit of material from the bracket to allow it to fit. Mine did the same thing.

[n85ae]

yeah grinding the bracket seems logical, you have plenty of material to work with

Jeff

[LetMeFly]

Thanks for the replies guys. I couldn't find anything on this problem so it's good to hear others have faced this. Misery loves company! I'll gradually take off some from the bracket till it clears and make sure it's a smooth transition. I'll post a some pictures when it's done for future reference.

[LetMeFly]

OK, finished the trim to stop the binding. I trimmed 0.030" on the starboard side and 0.025" on the port. Used a Dremel sanding wheel and cleaned up with 400 grit sandpaper. Per AC 43-13 1B, Par. 6-115 c, blended the trim at 20:1.
(Dang! Took me 20 minutes to get the pictures right! )

IMG_5543.jpgIMG_5544-1.jpg

[Delta Whisky]

Thanks forum!! DenaliFox's comment that this is a common issue caught my attention. In preparing for the flight to Sun-n-Fun (assuming the weather god's allow) I thought: "Why not check for this condition?". It turns out that I hadn't detected the itsy, bitsy, just-barely-makes-contact condition during assembly but it was there none-the-less. I've scheduled very minor surgery for tomorrow morning.