While out at the hangar today, I took a look at the 180 outboard bracket I had purchased. It was also 2024-T6 with a hardness of 76 HRB.

EZ, how far out are you at having your product certified?

Marty

180jocky wrote:EZ, how far out are you at having your product certified?

Marty

I cannot honestly say with any degree of reliability. However my mounts will be designed to fit aluminum gear legs not steel, which are different thicknesses.

Since our discussion is primarily about the inboard MLG mount bracket, there is a possibility that my bracket will be usable as a repair part, from a shape/form/fit standpoint. But this will not be certified in a few weeks. We have not done the drop test yet.

As much as I truly want to take your money (I can smell it from here), I must say your needs will be best met by making two new inboard brackets, and buying the PPONK outboard brackets and gear mounting angles.

EZ - It sounded like they were a ways out, I was just curious. I have many parts on their way (P Ponk brackets, all new hardware and a inboard GLSB from Skywagon City) should be able to get back at it today or tomorrow.

Marty

Well I guess I didn't get much done on the plane today (waiting for parts), but on the up note I didn't find anymore damaged parts........WooHoo. I did take a few pictures comparing the Cessna outboard GLSB and the P Ponk version.


Outboard facing sides


Inboard facing sides


Looking down on the tops


As you can see the P Ponk is much heavier.

Marty

Parts are trickling in from all over. Here's a picture of a brand new $800 hat I bought, it came with a scrap of aluminum.

The GLSB.....is that a new Cessna part, or salvaged? Does not show much sign of previous installation.

Nice hat....just think, to do my conversion project, I'll get to order two of them.
I guess one to wear forward and one backward.....
At the bargain price of $1600.00?????

Controlling lots of... NV


NVflyer....Dave

NVflyer - That is a used part from (as you may have guessed) SkyWagon City in Ontario. It came green looking used, but then I striped it. Peter did a very nice job drilling out the rivets, not a snowman among them. I'm going to do a dye penetrant to check for hidden cracks, then I'll acid etch and alodine all of the striped parts and zinc chromate them. Your right it shows very little use. Dave at Beegles Aviation had told me that Peter was very dependable, and I found that to be true.

Marty

Well the gear legs and the axles are on their way to be magna fluxed.

Gear with stripper on it.


One side all striped.

Hi,
Don't take this wrong, but I hope you used the right type of stripper, see the 1969-1980 180/185 Series Service Manual temporary revision dated Dec 1/2011 page 2A-14-04. Warns not to use stripper at all. For what it is worth most of these gears have been stripped at least once at some point up to now. It would be nice to know how to correct this after the fact, or if we just have to take our chances.

Tim

In the case of a recent stripping if a acid stripper was used which can cause Hydrogen Embrittlement, sanding can reduce or eliminate problems as there hasn't been enough time for much penetration. Baking may be an option as it is used after the plating process to prevent this. Might check with a approved aircraft plating company. Everything I have sent out for cleaning and plating comes back with a maintenance release specifying the baking information. Hopefully others who know more about this will respond because it is a serious problem with high strength steels.

More on Hydrogen Embrittlement.

http://www.chevelles.com/forums/archive ... 70319.html

Hey, thanks for the heads up. I hadn't given any thought to hydrogen embrittlement. I need to do some extensive research to determine if I've made a major screwup.

Marty

Well it's been awhile since I last posted, I thought I should update what's happened. After stripping the gear and seeing the posts on embrittlement I did a lot of research as to how badly I my have ######-up. After all that I'm still not entirely sure as there isn't a lot of definitive answers on this question. So thankfully I have another set of 180 gear legs I got with a 170 project that I bought last fall. I'll use the other set and send the questionable set into be inspected.

Other then that I've put the RH gear box back together. I was able to temporarily install the gear legs, so we could do a little hanger dance, and allow the spray plane I was in front of, to go back to work. Just in time for some beautiful weather.

As we didn't want to have both gear boxes thorn apart at the same time, I waited until the RH was rebuilt, before I opened up the LH. When I took the LH outboard GLSB out I found spider web cracking on the same bracket that had been in pieces on the RH. I should mention, again the cracked bracket was not easily spotted in place, because of the dirt and oil caked on it while in the plane.

I hope to be near completion by the end of this week.

Marty

The RH gear box rebuilt with the temporary leg installed.


The LH outboard GLSB with cracked bracket as removed.


Closeup of the cracked bracket (stripped for better visibility)

What kind of testing can be done to determine damage from stripping? I to have done extensive research on this subject and have no solid answers. Most gears are stripped with no thought of this and while there are failures, it does not seem to be a huge problem and in fact may be something else like a rust pit stress riser. One case involving wing attach bolt which were stripped incorrectly and investigated by a metallurgical lab, it was determined if no failure had occurred in 200 hours there was no damage, I would think that 200 hours would be white knuckles. Are we out of the woods if the gears haven't failed after 200 hours at least from the paint stripping? It appears to depend on the type acid and how long it was left on and other factors whether there is damage. I'm betting your gears come back ok. I have really enjoyed the methodical approach to your landing gear box rebuild. Keep us posted on the results of the gear test.

Well it started out a really good day. I had the new LH outboard bracket installed and I just needed to rivet the bracket that attaches to the top of the new outboard bracket up into the door post. Well this is the area that was repaired back in 1982. As I've stated in earlier posts whoever did the repair didn't do a very nice job of it. I was having quite a time trying to get rivet holes to line up. Peering up into the depths of the door post we could see one of the previously fabricated patches with a crack in it. NO BIG DEAL, I'll just drill off the repairs and fix the angled bracket that had the crack. (I should have known, on this project it wouldn't be that easy)

This is what I found


After drilling off what I thought would be 3 pieces, it turned into a cobbled up mess of 6 different pieces. There were scraps of varying gage aluminum placed in various locations as spacers for the patches. Then, I find the forward door post broken off at the bottom (see pic), this is the section that the upper bracket on the new outboard GLSB rivets to. So after a talk with Dave at Beegles Aircraft, I'm convinced that the only right way to repair this is to replace the forward door post (no easy task). Atleast I know what I'm doing for awhile.

I then get back to my original problem of not being able to get the rivet gun on the rivets for the upper bracket on the new outboard GLSB. So the only way to get the gun down where it needs to be is to take out the LH inboard GLSB. NO BIG DEAL, I un-bolt the bracket and drill 7 rivets out on the belly skin and slide the bracket out and lay it inside the plane. About this time Ben comes along to see how I'm doing, he's leaning in the passenger side and picks up the freshly removed bracket. On seeing this I jokingly say "now don't you go finding anything more". Well he doesn't listen to me any better today then he did as a teenager. Sure as hell there's a crack in the upper forward corner.

So it's looking like I won't be finishing it up this week as I thought.

Oh on a little different note you can see in the picture that about 3" of the angles forward and aft that the floor rivets to is bent upward. That was done per P Ponk's suggestion to install the outboard GLSB. After talking with Dave at Beegles (I had sent him this picture also) he said they always drill off the bottom skin and slide everything in and out from underneath.

Oh well I know I'll be finished when everything on the plane is new. You can all see this when my wife and I come to Johnson Creek in June.

Marty

P.S. I'll try to get more pictures.

Poor Marty's predicament is starting to sound like a better and better case for "owner manufactured parts". Sorry you are going through this headache. Keep going, you will have the support and encouragement from everyone on this forum. I have a set of outboard MLG to doorpost tie plates, 0713495-57/58 brand new. PM or e-mail if interested.

Whenever you're feeling like crap over all this, just stop and think that you may have been saving some family's life, because you and your son are taking a harder look into this airplane than most. (Harder than the other potential buyer who was newer and less experienced, and would have been taking his wife and two kids through mountain turbulence, or landing on a rough strip in an area where they could not have walked out after a LG collapse, etc.)

Thanks EZ, I needed that. I have to admit I was feeling pretty sorry for myself on Tuesday. However, I have made some fantastic contacts from this thread ie: Dave at Beegles Aircraft, Peter at Skywagon City, Steve at SeaPlanes North in Anchorage, Dave (NVflyer) and yourself from here on the forum, among others.

Marty

Just a quick update, if anybody really cares. I talked with a guy at Seaplanes North in Anchorage about the hydrogen embrittlement (they inspect and refurbish gear legs along with selling new ones) he told me that most legs at sometime in their lives, have been stripped with stripper. He then told me that the gas can be removed by placing them in an oven at 350 degrees.

So my younger son works at a steel fabrication plant in Sioux Falls, SD, and I gave him the legs and he put them in their big oven for 4 hrs at 350. Then he talk with the owner (his boss) who told him that powder coat was twice as flexible as paint, so I had him powder coat them. Now maybe he's wrong, but boy they look great, time will tell.

I've been pulled off my plane the last few weeks to help Ben finish up 4 different annuals a Thrush, a Fairchild ag plane, C182, and C206 so we've been busy, but I'll be back on mine this week I'm pretty sure.

Marty


Here is a picture of the finished gear legs.