Chapter 9 - Step 2 - Preparing the Strut for Installation

December 4, 2005

The landing gear bow is here and I started by unwrapping it and sanding the whole bit down. Pay attention to the plans here. They say to wear a long shirt and lots of protection for a reason. You will itch for about a week if you don't adhere to this warning.

After getting it all sanded down, I used a bit of copper tape running down the inside of the bow to see how large the bow was. It needs to be 95" interior circumference. That told me how much I needed to cut off each end. I then make the piece of wood with the 8 degree angle on it to measure the cant. This I transfered to the gear (below right) and then made the cut to length.

Now there was quite a long break between getting that first part done and this next bit. In the interim, I got tired of filling propane tanks to heat the garage so I plumed in for natural gas. WooHoo! It seems to burn WAY more clean.

BUILDER NOTE: The plans tell you that you can knock down the "bulge" about 11 inches, each side of the center by 1/8th inch. an easy way to measure this is to set the gear down on the trailing edge flat on the table. It just so happens that if you sharpen an carpenters pencil (center) the distance between the sharpened lead and the table when it is laying flat is 1/8th inch so all you have to do it lay it flat on the table and draw the line at the bulge (which is obvious one you have this thing in hand) Once you have it drawn, you just take your belt sander to it.

Next you have to perform a couple reinforcing layups. This requires you to precut quite a bit of UNI. I rolled it all out on a clean wood floor in the house because my table has the gear on it right now. Plans call for 12" wide strips of UNI cut at a 30 degree angle to the selvege. I Measure the angle with a carpenter's square and to make sure that it was 12" wide I used a piece of wax paper. The type I use comes in exactly 12" wide rolls. So once you get the angle you just move the paper over and keep cutting. The strips are pretty long when cut at that angle and the plans say that you will need at least 13. Since this isn't messy I brought it inside.

Once I got all that done I moved out to the garage with my cut cloth and put the gear bow up on a couple nails per plans in preparation for the 4 ply (each direction) layup. It takes at least 2 strips per ply. So I figure I'll need 8 for the fore to aft layups and again that many for the aft to fore, then maybe 1 or 2 for the airfoil-trailing edge layup.

December 11, 2005 - Continuing preparation of the landing gear.
This went pretty well. Earlier in the week, I got the gear exoxied up on 3 nails in preparation of the first big reinforcing layup per plans. Saturday I got first 4 layer BID glassing done that is training edge to forward edge. I peel-plied it per the plans and planned on sanding the leading edge Today but this time of year cures take a bit longer. I use all slow and I have noticed that you really need 2-3 days before you can really sand a part. So Sunday I took the peel ply off and checked it part. It looks good. I am going to have to cut 2 more pieces of cloth to get this step done. I'll work on that next.

After getting this done on saturday, I moved back to chapter 8 to work on the shoulder rests. These chapters seem pretty good to be-boop back and forth between when waiting for cures.

December 18, 2005 - Preparation of the landing gear - Continued.
Work continued this week on this long step in this chapter. I removed the peel ply and knocked the gear off the stand. Every thing looked pretty good. On the advice of another builder I didn't worry too much about making the plys meet up at the bottom during the first set up layups. This made things a bit frazzled in places (middle below) but this is MUCH easier to deal with with the Fein tool than to try and worry those layers together. Everything got sanded smooth on that side and then I flipped the gear back over and epoxied on the pass-through brake-line tube. This is there so that if you ever need to replace the brake lines you just pull them out and feed in new ones keeping your gear all nice and clean and aerodynamic looking.

This next part was a small personal triumph on my part. The plans say to use some sort of stiff aluminum tape that 2 trips to hardware stores weren't able to turn up. What you are supposed to do is tape one side as a sort of layup jig to be begin the process of making more of an airfoil shape out of the gear leg. (you;ll get the picture in a moment.) Basicly, the gear come is with the cross section of an elongated egg. What it is supposed to look like when you are done is a sort of fat wing shape. After looking at it all for a while and doing my usual pacing around the table that I do when something has me stumped I came up with the idea of cutting the tops of wax paper boxes off and covering them with box tape, then taping them in place and try to bend them to the right shape. Well I ran out of wax paper boxes and I reached for an especially wide (18") box of aluminum FOIL.... DUH... ! Then it came to me. Just take a couple long strips of aluminum foil and keep folding them in half till I get the thickness I want! TADA!!!!!

This WORKED GREAT!!!! (see below) I reccomend it. It uses a cheap product that you already have on hand.

The next part was a 2 layer bid layup with peel ply. I'll wait for this to cure then flip this all over and run 4 more plys over the other way then this will be complete.

January 22, 2005 - THE GREAT CHAPTER 9 DISASTER... and recovery

Everything started out well early this week. On tuesday I went out the the garage / hangar to do that last set of reinforcing layups on the gear leg. I had all the cloth cut and everything seemed to be going great. Then DISASTER STRUCK. I already wrote an article about it that I published on the main pages of this website (Blog Pages) and I will put it here:

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Well, it has been an interesting week so far on the plane project. After getting back from a great visit to Washington D.C. and the newest member of my extended family, I promptly got back to work Tuesday night.

Tuesday:
I had the landing gear turned over and jigged up so that I could to the fore to aft reinforcing lay-ups on it. Things just started out a bit rocky... The epoxy pump was a bit clogged, stop to fix that, continue on but I couldn't seem to find my groove. Then about 2 cups of Micro epoxy into the lay-ups the hardener reservoir ran dry of hardener on the last pump into a cup, ruining that cup... Throw that away and dig out more hardener... aw.. might as well put a bit of resin in that reservoir since I have the whole thing open... OK all set again...

back to the lay-up... working working working.... this epoxy seems thicker than normal... (something tickles the back of my mind)... must be because the resin wasn't totally up to temp... (3 hours elapsed) FINALLY... DONE! Whew....

Now, I normally keep my garage at about 75-80 degrees when I have parts curing in there, but it got pretty cold here Tuesday night and I set the heater on low. The garage got down to a chilly 68 degrees when I checked in the morning... Oh well... Let me check to see how this part is curing.... Hmmmmmm still pretty tacky... (something tickles the back of my mind) Turn up the heat and off to work.

10 hours later I return home to a 75 degree garage and a lay-up that is still tacky.... (something really tickles the back of my mind) This is definitely not right. I do the scratch test on a couple of the later cups of epoxy that I used.... the last one is gooey.... OH crap! Maybe if I ignore this till tomorrow it will go away... (please :-)!

Wednesday:
Now at this point I realize that the epoxy pump ratio must have been off for the lay-up... So I check the first couple cups, both micro (contains micro-balloons not small) mixes and they are perfect then I remembered running out of hardener while making my first batch of regular epoxy. Over to the cabinet door I go and look at the ratio setting..... NOT EVEN CLOSE. I check the ratio by weight.... NOT EVEN CLOSE... I then remembered bumping into the pump pretty hard when filling the reservoirs and realized that I must have bumped it off.

I spend the better part of the next hour re-calibrating the pump to perfection again, pump out a small cup of epoxy, mix it and let it set to cure for a test....

SIDE NOTE: I regularly check the ratio by weight on my pump (read: at least every 4-5 layups) with an electronic scale that I bought at the beginning of the project when I wasn't sure I would use a pump, and have never had a problem, with one exception; where I let it sit for about 5 months with epoxy in it without doing any work on the plane. I then broke it down, cleaned it, re-built it and re-calibrated. Perfect) I was even asked about this recently by a new builder visiting my project and I told them this... I guess I didn't knock on wood.

Now, there are very few parts that you must buy when building this plane because you make most of them. The core of the landing gear bow is one of them and it is NOT cheap to say the least. You don't want to have to buy more than one... EVER! To put it in perspective, I'd say that it is the equivalent of buying an alternator for a Ferrari except you have the only one in the world that runs backward and there is only one supplier.... If you can imagine that then you have some Idea of what it is like to have to buy this part...

Anyway, you don't want to have anything go wrong when you are working with it. Before you cut it you measure about 9 times and then check your work twice. You prep for your lay-ups on it in advance and you generally treat it like the queen of England. Gently and Correctly. Because of this, the idea that you may have just permanently screwed up the landing gear bow and lost all the work you already had into it as well as possibly having to write a check for another one is.... well..... Unattractive. I am going to sleep now. This is just a bad dream and I will wake up soon.... please.

Thursday: Yep it's still sticky and the cups are still gooey except for that one I mixed up yesterday after correcting the ratio. That one is hard as nails, just like it should be.

Now what to do about the 2/3 cured, tacky, very difficult to remove lay-up? Well I started by trying to peel it off. Then I tried scraping it off. Then I tried heating it a bit to try to get the epoxy to flow better so that I would come off. When that didn't work, I tried using mind power. As a last resort I considered whether the moisture from my tears would soak it off but then figured when that didn't work I might just dig a hole in the back yard, throw in the whole project, crawl in after it and pull in the dirt out of frustration so this last try had better be a bit more thought out and founded in reality.... DEEP SLOW BREATH.

Ok... Call the company I got it from (Feather-lite)... I can't be the only bonehead on the planet whose epoxy pump ratio has been off in the past, see if they have any ideas for me.

Now I called Featherlite and got Mike on the phone. Mike was calm, Mike was friendly. Mike let me blubber on until my entire story was out. ...And then, in the last, when I asked how much this mistake was going to cost me and did they have another in stock , Mike told me that everything was going to be alright and that if he were me, he wouldn't buy a new one. He then told me the best way to remedy my problem. It was tough, it involved work, it involved no damage to my landing gear... But!!!, I was an experimental aircraft builder and had already overcome a ton just to be one and to have gotten this far. He then suggested I go buy this $5 tool.... Yes you read that right... $5! "Buy a couple just in case you break one." he said. It was called a Sureform tool... "That's a brand name." he said, "But don't buy the brand name one, just get a generic one." He described it to me. I have one of those!!!!!!

That was the ticket!!! 4 hours worth of scraping and fiddling and I had those crummy half-cured, crappy epoxy ratio layers off there and there was NO damage to the gear. A bit of sanding and some gummed up sandpaper later and I am good to go. but not tonight....

Whew! Bullet dodged!

Back at it tomorrow though... Just gotta pay more attention to those tingles in the back of my head...
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OK! Now that I got that mess all taken care of It's time to start again. This time I started the day before the reinforcing layup. I mixed up a very thick mixture of micro. Now I wasn't terribly happy the way the trailing edge (airfoil shape) worked out last time anyway so now I have an opportunity to fix it righ by filling the whole bit in right. (Left) I had a bit of micro left over, so I let it dry a bit and then formed it into 2 micro balls that my cats later found entertaining because of the nose they make when rolling across the wood floors. On saturday after It all dried and after I did one of the LG Bulkhead reinforcements, I sanded the the micro smooth, jigged the whole bit back up and made it ready to do again.

Sunday I got back out there and removed the peel ply from the LG reinforcements and started on that gear reinforcement. I started by verifying that the ratio was right. (Exaclty on) and then went to town. I didn't take any pictures of doing it the secong time since everything was the same except the epoxy ratio!. :-)

Once I was done The Inspector(Left), The Project Manager(Center) and the Company Receptionist(Righy) took a look and verified all was right.