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MadMan

Rear Landing Gear Bulkhead

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I just noticed that I some how installed the rear LG bulkhead in backwards (8 plies to the rear) and I already drill the holes for the strut.:irked: Do I need to remove and build another one or will it be OK like it is?

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I was thinking you could add additional plys to the front face, and deal with the weight penalty. The problems will be down the road when you add the tubes to the LG strut ears, it won't fit between the bulkheads.

 

Cut it out, reverse it. If the holes don't line up, fill them with flox (unless way out of line, you'll enlarge them later), and redrill once you've added one of the final LG bulkhead reinforcements.

 

YMMV.

 

Rick


Rick Hall; MK-IV plans #1477; cozy.zggtr.org

Build status: 1-7, bits of 8-9, 10, 14 done! Working on engine/prop/avionics.

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I did the same thing with F22 on my Long-EZ. After kicking myself for making such a mistake, I tried to salvage the bulkhead but in the end I could not. Once I realized it was not worth saving, the remanufacturing went real fast.

 

Overall it did not cost me that much time and I don't have to worry about it causing me a problem down the road.

 

My suggestion...... make a new one.


T Mann - Loooong-EZ/20B Infinity R/G Chpts 18

Velocity/RG N951TM

Mann's Airplane Factory

We add rocket's to everything!

4, 5, 6, 7, 8. 9, 10, 14, 19, 20 Done

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RickH and Tmann are correct. Take it out and either flip it, if possible, or remake it. Do not, with structurally critical components, think that it's OK to make things up as you go along, as others may recommend. There's generally a reason why things are designed as they are, and unless you can get the information out of either Burt or Nat's head, it's best to do what the plans say.

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RickH and Tmann are correct. Take it out and either flip it, if possible, or remake it. Do not, with structurally critical components, think that it's OK to make things up as you go along, as others may recommend. There's generally a reason why things are designed as they are, and unless you can get the information out of either Burt or Nat's head, it's best to do what the plans say.

i have to go with answer 4 as well.

i have seen a gear hit so hard that it was flat, and it removed about 5" of foam all around the bulk head . so if you were to add plys to the back side a the landing bh then hit hard you would remove both layups and 5" of foam.

marc is right.....but, add the plys and move on :bad:


Steve M. Parkins

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Hi

I did as Steve said, and added the plies to the front it only added about 3/64"s to the thickness, I was a little wide on the 8" dim. so now its exactly 8" I tried to contact Mr Puffer today, but they were not home. I made the mistake by looking at drawing M-9 if you look at the drawing the front of the rear bulkhead looks to have the 3 ply side to the front. I'll be sure to always check the text from now on. :o

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Hi

I did as Steve said, and added the plies to the front it only added about 3/64"s to the thickness....

Sorry Steve, I would have gone with answer #5, knowing that the 8 screws used for attaching MG-1 & 2 will most likely need to be longer now and that the MG-4's may not be long enough to completely bear on MG-1 due to the increased thickness of the bulkhead depending on Madman's layup thickness in the additional plys added in chapter 7 & 9.

 

While that doesn't seem like a big deal to order different bolts and make longer MG-4's if needed, it does say something about the "make things up as you go along....." statement as there is (typically) something in the next chapter or later that will bite you, and flipping that bulkhead or having to rebuilt it may have been easier and might have saved some head scratching later.

 

I think I just agreed with TMann too?? ...........I need a drink!


Regards,

Jason T Heath

MarkIV #1418

heathjasont@yahoo.com

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Sorry Steve, I would have gone with answer #5, knowing that the 8 screws used for attaching MG-1 & 2 will most likely need to be longer now and that the MG-4's may not be long enough to completely bear on MG-1 due to the increased thickness of the bulkhead depending on Madman's layup thickness in the additional plys added in chapter 7 & 9.

 

While that doesn't seem like a big deal to order different bolts and make longer MG-4's if needed, it does say something about the "make things up as you go along....." statement as there is (typically) something in the next chapter or later that will bite you, and flipping that bulkhead or having to rebuilt it may have been easier and might have saved some head scratching later.

 

I think I just agreed with TMann too?? ...........I need a drink!

that sounds like good "year one thinking" but I'm at year 5 , sorry

and at year five....WE FIX SHI* and move on.

remember what Randi said 3 years back measure with mic's, mark with a sharpie, trim with a chain saw. there is flex in that bulk head:rolleyes:


Steve M. Parkins

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that sounds like good "year one thinking" but I'm at year 5 , sorry,,,

I know a guy that's in year 12 of his Berkut project so is he a better source of information?

 

All I can say is that it is a bad precedence to accept less that perfect before you even skin your fuselage. I didn't want to cut out my bulkhead but it only set me back a partial day. I was able to remanufacture it between other tasks I was working on an had it done in one day.

 

When I was done, I was sure I had done the right thing.


T Mann - Loooong-EZ/20B Infinity R/G Chpts 18

Velocity/RG N951TM

Mann's Airplane Factory

We add rocket's to everything!

4, 5, 6, 7, 8. 9, 10, 14, 19, 20 Done

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that sounds like good "year one thinking" but I'm at year 5 , sorry

and at year five....WE FIX SHI* and move on.

Steve, as of last summer, you hadn't even completed all of those layups or installed the MG plates in anticipation of using retracts, I know becuase I responded to the post you made inquiring about them, so please, none of this 5 year crap!! I haven't used any SHI* on my plane yet, haven't seen it in the plans, but when I do, I'll call you for assistance.

 

there is flex in that bulk head:rolleyes:

Not after you install all the required plys and close out the top there isn't! They will only "flex" if your gear leg doesn't have a machine fit and you try to compress the bulkheads onto the strut when you tighten the 1/2" studs, which is bad...... but at year 5, you should already know that!

 

 

And that's twice in less than 12 hours you've made me agree with TMann............Waitress!!


Regards,

Jason T Heath

MarkIV #1418

heathjasont@yahoo.com

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Hi Builders

I just wanted to say that I E-mail Mr. Puffer (as Marc Z said I should do) about the stupid mistake I made installing the Rear Landing Gear Bulkhead in backwards (8 plies to the rear) and his reply was it would be OK to add the plies to the front.

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I just passed the stupidity-test and did the same thing - i.e. mounting the aft landing-gear bulkhead with the plies facing backwards. Just curious to know - before I hack them loose again - why does it matter what side the 8 plies are?


Erlend Moen
Norway
Cozy MK IV #1556 - Chapter 20
http://cozy.ljosnes.no

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I just passed the stupidity-test and did the same thing - i.e. mounting the aft landing-gear bulkhead with the plies facing backwards. Just curious to know - before I hack them loose again - why does it matter what side the 8 plies are?

Yes, the extra plys take the shear load of the bolt. if there is space between the landing gear tab and the extra plys there will be a bending load on the bolt. not good

Evolultion Eze RG -a two place side by side-200 Knots on 200 HP. A&P / pilot for over 30 years

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Yes, the extra plys take the shear load of the bolt. if there is space between the landing gear tab and the extra plys there will be a bending load on the bolt. not good

Ah.... I see. That makes sense. Off it goes :)

Thanks!


Erlend Moen
Norway
Cozy MK IV #1556 - Chapter 20
http://cozy.ljosnes.no

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