Chapter 9      Main landing gear and landing brake.    

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Ok here’s a big one, both in bucks & time.   I flew my Cherokee over to Ukiah, Ca to pick up my Featherlight landing gear strut. It just barely fit between the aft bulkhead and the Flap handle, not even an inch to spare! Also it had to be twisted from inverted to right side up as it entered the plane. We had a nice trip and got to meet Larry and Mike. I took Larry out to lunch and got to hear a few Rutan stories.  It was worth the price of admission!   The bad news was once I tried to use it I discovered  as many have that is was warped. This is usually not a big deal as it can be compensated for  at several steps. This one was too far gone by a long way. I could place one end on the table and slide my hand under the other end with room to spare. I called Featherlight and they offered to replace it no problem. I flew back and  replaced it. I don't blame them for it. Because I knew they were coming out of the cure oven on a certain day and I was waiting for it I just waltzed in and grabbed one litteraly as it came out of post cure.  I don't believe they had time to check them.

                                                                                              

                                                                           

Here you can see the LGB’s in place, several reinforcing 
lay-ups are placed, aluminum  hard points installed and
line bored as accurately as possible. Again not enough pictures!		           I  Alodine everything I can.


     

          

 Cutting the strut ends, some wasted effort here as these nice cuts get removed after all  if you use the Matco brakes.   Finding the strut center and ends is important  however. The  last pic is  the strut end all prepped for the Matco axels. the cut-outs are for caliper  clearance.

                                                                                                                                                                      

 

                                                      

 I did not take any pics of the torsion lay-ups,  but this one was a little tricky to keep the fiber orientation correct as the glass follows the curve of the strut. Also I suggest you mount the strut at least 5’ off the table, the plans nail method leaves little room for the layup. I recommend using only genuine McDonalds straws for the brake conduit,  I can’t say that about their hamburgers. But these straws are a little larger than most and you will want all the room you can get.  You may find Slurpy straws (7-11) are even larger. The larger you can find the more options you will have when you plumb the brakes.  If you decide to use SS/Teflon hose you will havea though time getting -4 hose thru,  -3 is ok but the fittings are spendy.  Find a drill bit the right size, heat one end of the straw with a heat gun, force the drill bit in an inch or so to bell-mouth the straw. Then you can slide the ends together  just like the PVC pipe you get at the Depot!

 

                                          

                                                                                                                         

           

Here we see the strut in the tab box. I had an issue here,(1st pic) the plans tell you to remove no more than 
1/8”From the “bump” at the tab location. Ok I did, now the issue was the strut was too wide for the box by
about .1” This after the torsion lay-ups.  So I had to sand more off, cutting thru the torsion lay-ups. I’m
told it won’t matter as there will be dozens of lay-ups over this area when the tabs are placed. The
problem was I sanded thru an area that was outside the tab. Bad news!  OK so I make my repairs using 
the plans repair methods,  then for added measure (and weight!)  I extended the tab outboard a little
so it will cover the repair. Probably overkill.  I think that making the tab box a tenth wider would prevent
this without any trouble with fit between the LGB’s later on.

 

                                                                                                   

        

        So here is the other issue I and a fellow builder both had;
        after all plys were installed the tabs were not 1” wide as
        Nat requires.  Both of us were certain of our count yet we
        came up short. Nat told me to simply add more until it
        was 1” thick.  Ok, Roger, wilco, out.  I suspect I simply put
        too much pressure on the clamps and it would have been
        just fine without the additional plys and added weight.
                                                                                                                                                                       

The cover for the MLG and the cover flanges and click-bonds.
Again I took a tip from Wayne Hicks and didn’t make the joggles 
in my tub bottom for the MLG cover. I simply made some flanges
between the bulkheads and used Clickbond nutplates to hold the screws.
I think Wayne has a winner on this one.  Much cleaner and easier 
to use this method, IMO! I  the  nutplates are more durable than
the aluminum hard  points the plans describe, and as a bonus they
are self-locking !

                                                                              

 Next the axels are mounted, accurately, in regards to FS, (flight station) and WL,
 (water line) correct sweep,  perpendicular to fuselage center line and correct toe-in!  
 A lot of measuring, re-measuring, re-re-measuring using state of the measuring art, 
 carpenter squares,string lines, plumb-bobs, chalk, chewing gum and  baseball cards. I did buy a 3 beam torpedo laser level for this step, it projects in 3 directions at once making it easy to find square, plumb.
  Matco supplied the wheels, brakes & axels . Heat shield, axels & brake spider installed.
Keep the nuts on the axels to protect the threads!		         I think I’m done with dis guy, next!

                                                                                                                                                                            

                                                                                                                      

Next the landing brake is tackled. I lected to go ‘lectric! I purchased a #75 12VDC linear actuator, fabricated a bracket  following Bob Bitner’s site. It works just dandy thank-you. But I think anyone doing this might take a look at the idea guy’s web site (Wayne Hicks) for a little better mounting method. He mounts the  bracket to the seat back and gets a little better geometry and may save a little foot room as well.  Notice the slotted hole for adjustment.

 

 

                                           

Here is the hard point for the actuator,  1,  4” X 4” BID,  2 EZ points, 2,  4” X 4” BID      over the  EZ points. Nothing scientific or engineered, just a wild-ass guess! This method (if it works) prevents bolts running thru the map pocket.  

                                                                                                                                                 

                                                                                                                         

 It was a little time consuming fitting the landing brake to the recess in the tub, micro,
 sand, micro, sand several times. It finally ended up very nice with not too much micro  A year later I noticed the brake had warped a little. It had been perfect and I really didn’t think this could happen after fully cured.  I built a hot box (160 f) and clamped it slightly convex. I took several attempts but it is now just slightly warped in the other direction. It’s not noticeable but works in my favor now as when retracted the corners contact the recess first, then the actuator pulls it the final 1/16” or so.  This I hope will eliminate the sagging corners you  see on some retracted landing brakes.  A lot of extra trouble but in the end I think it’s better now than  had it been perfectly flat.    

                                                              

                                                                         

 I made the hinge a little wider and the plywood hard point insert a little larger than plans on advice from other builders.  With the manual system you will instantly know if you attempt to extend the brake at too high air speed, ( just like a Cherokee’s flaps) you probably won’t get any  feedback if you try this with the ‘lectric actuator,  that is until the prop flies off after eating the landing brake.

 

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