DavzLSA progress

[BTAZ]

Dave

I e-mailed you some photos. I think your engine mount bushings are a bit further in than typical.

On mine(and I don't recall exactly why) my brake master attach tabs are on the inside of the fuselage(instead of the outside as shown in the plans). I also have a small tube welded in the "V" area that the lower master cylinder pivot is mounted to.

[davzLSA]

Brad can you tell me the distance from the fire wall frame to the rudder pedal mounts on your plane? Im using the measurements on the plans but from your pictures it looks as though your rudder pedals are further behind the fire wall frame than the measurements would indicate.

[BTAZ]

Dave

I didn't get a chance to stop at the airport and take a measurement. AFAIK, I positioned everything per the plans which do show the small cross tube welded in for the lower cylinder mount.

Did you apply the 1:2 scale called out on the plans?

[davzLSA]

Hi Brad, Yes I scaled the measurement per the the drawing but it came out in the same spot every time. Anyway here is what I ended up doing and I think it will be OK. I have full travel of the rudder pedals and it came out to be a pretty neat looking job, pics are enclosed.

David

[sbmurphey]

Hi Dave, Great progress! Attached are some of my pictures of the brake/pedal area. I opted to move aft on my mounting locations to make room for cylinders with internal reservoirs. I am convinced that each install will be some what custom to get the geometry working correctly. My numbers aft of the firewall tubing are 2 1/4" and 4 1/4". I moved the adjustments all the way in and out on the cylinder mount to get a feel for the +/- of the movement. Then I cycled the peddles to make sure I could do so without the brakes coming on with heals on the floor.

[davzLSA]

HI Stephen, thanks for the info it looks like the bottom of your cylinders came out very close to the diagonal tube like mine did. I also noticed the angle of your rudder pedals, have you tryed them with the rudder attached yet? How much fore and aft movement did you have to move the rudder pedal to get full deflection of the rudder? Im thinking my pedals will be tilted aft a little to give the the deflection I will need. I wont know until I get the rudder attached to the rudder pedals. I know it will not require much movement. You do good work too, Ive been watching your progress also you are a great craftsman.

[davzLSA]

more progress today guys, I decided to work on the horizontal stab and get some of the trim tab control system installed. To avoid the getting the trim tab control horn on center line with the elevator push pull tube. I am installing a system like Btaz put on his plane. Today I got all the bushing welded into the horizontal stab ribs, I used some .050 plate to reinforce the area around the bushings on the rib webs. I welded the control horn to a tube that connected the 2 torque tubes in the stabilizers. An AN3 bolt will be used to retain the torque tubes in the tube between the 2 stabs that has the control horn. Here are the pictures

[sbmurphey]

Oh yes, having a rudder hooked up helps make the airplane noises coming from the shop sound even more real. Off of memory, it was about 1.5" of travel from neutral to full deflection. The way the angle worked, it was almost plum when fully applied. The clue that I used to set the final angle came from the rear pedal drawing on page 27. My front cables were made up keeping the front and rear pedals tracking parallel to each other. My biggest concern with the mounting location was the potential for a mechanical lock up by cam over.

I found Battson's video very helpful during this phase. https://www.youtube.com/watch?v=n_uk9o2N2zQ

[davzLSA]

HI Stephen, I see what you mean about that cam over lock, that would make your b hole suck seat cover? You would be stuck flying around in circles? And some good jams on the video too? My rudder pedal wont go over that far. I guess my geometry is a little different than that? The angles look about the same as mine and that amount of travel is about what I expected. Ill know more when I get the cables hooked up. Thanks for the info.

[davzLSA]

when I get my seat built and installed im going to have to try out the airplane noise thing it sounds like fun.

[Archer39J]

HI Stephen, I see what you mean about that cam over lock, that would make your b hole suck seat cover? You would be stuck flying around in circles? And some good jams on the video too? My rudder pedal wont go over that far. I guess my geometry is a little different than that? The angles look about the same as mine and that amount of travel is about what I expected. Ill know more when I get the cables hooked up. Thanks for the info.

I thought this was a non-issue once the system is primed with fluid?

[stinger]

Archer, you are correct they can not lock over as demonstrated when serviced. Stinger

[marcusofcotton]

I thought this was a non-issue once the system is primed with fluid?

Brake system failures are rare, but they do happen...

[Archer39J]

True, but the over-cam can only happen if there is no pressure in the system. Which I would argue is a bigger problem.

[marcusofcotton]

Archer39J wrote: "True, but the over-cam can only happen if there is no pressure in the system. Which I would argue is a bigger problem."

Call me odd, but if my brakes failed, I'd rather not have rudder control problems as well because of it.

[Bdflies]

Well, that would make me 'odd' too.

Bill

[davzLSA]

This all makes me think that once I get my brake system up I will manipulate it to see if I can get it in a failure mode. It would be a good thing to know at this stage of construction, a great time to fix any problems. That's what I like about the dialog we have here it always makes me think. Thanks guys.

[Archer39J]

Archer39J wrote: "True, but the over-cam can only happen if there is no pressure in the system. Which I would argue is a bigger problem."

Call me odd, but if my brakes failed, I'd rather not have rudder control problems as well because of it.

Think of a scenario where this becomes an issue. Is it in the air? How often are you at full rudder deflection while flying? And in that instant your brakes have also bled dry. That's when you can over-cam, which sure, would be catastrophic, but exceedingly unlikely...

Oh, and one would also have to have the habit of pressing the brakes while deflecting the rudder pedals. Is that common? Seems like not a great thing to do while, say, landing...