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Lowrider LSA

We ran the firewall thru the bead roller to stiffen it up some and it turned out to be a distored mess around the edges. We did 5 passes on one side and it curled the metal so we ran 4 passes on the other side and it took the curl out of the metal but left a lot of wrinkles on the edge. I'm in the process of putting that flange on now which should take out that out and make a nice flat straight firewall. Now, I wish I had riveted several angles on the back of the firewall to stiffen it rather than use the bead roller....live and learn I suppose.

BTW, I'm putting flanges on both front and rear of the firewall. One on the rear will get screws to attach the boot cowl and the front one will support the engine cowl...seemed like the strongest way to do it.
 
Lowrider said:
...BTW, I'm putting flanges on both front and rear of the firewall. One on the rear will get screws to attach the boot cowl and the front one will support the engine cowl...seemed like the strongest way to do it.
Click to expand...

Skip the front one. Just overlap the rear flange with the cowl. Install plate nuts in the rear flange to receive the cowl screws. Depending on how tight things are aheard of the firewall, you may find that the forward flange gets in the way. Also, if it were run across the bottom, it could deflect exhaust cooling air.
 
Good thought!

The bottom will not get a flange except to attach the "tunnel" that directs exhaust and cooling air under the belly.
 
I'm still looking at the bottom of the fuselage to see if there is an effective way to fair the suspension parts. The air flow is fairly smooth until it gets aft of the firewall then the angles become sharper. The use of a belly pod to smooth things out won't be easy to extend forward but it would be nice to be able to make a smooth transition from the firewall rearward....still thinking and looking.
 
In case you folks have missed it, Bill, Builder of the Javron Cub gave us a great idea... to use parallel jaw pliers to squeeze flush rivets in hard to reach places and it is a wonder to behold!! I bought some awhile back but just got around to trying them today...they work great...thanks to Bill for the idea!!!

I relocated my new instrument panel this morning and it fits very well. Also relocated switches so I can place their individual breaker over top of the switch. I like switches rather than using the "switch breakers".
 
Sky,

Zack from TruTrak was kind enough to send me generic drawings of the their servo and a method of attachment for both pitch and roll. I will install mounting plates to accomodate their servos for a future install of their autopilot.

Their servo uses 1.9 amps@12VDC peak each...question...can you run their autopilot on just your battery(s) alone and if so, for how long? I'm guessing the servo doesn't use near that much current most of the time.
 
Low,
I'm not really the one to ask about electrical stuff much beyond the basics. Basically if your battery has enough capacity to drain a certain number of amps for a certain number of hours which will cover your days flying, you are good to go. The autopilot servo will use more juice on a bumpy day that it would on a smooth day. That 1.9 amps is only being used while the servo is running, which will be intermittent.

I have a large odyssey battery mounted aft for weight and balance purposes. This has the capacity to run everything in the plane all day with several starts. The highest draw is about 3.5 amps continuous.
 
DSC_0006.jpg

Boot cowl and draft instrument panel...final should loose most of the steam gauges. I put in a 10* slant on the panel to make it a little easier to see and a 3" sun shade from the boot cowl which I may trim some.

With that set up, the windshield will be approximately 34* from horizontal and should give a little advantage for airflow over the fuselage.
 

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Just heard that I need to send a letter to the FISDO to have my engine from a Cessna 172 changed to experimental. Does anyone have a sample letter of some good idea what needs to be said and what should be included in the correspondence?
 
Lowrider said:
Just heard that I need to send a letter to the FISDO to have my engine from a Cessna 172 changed to experimental. Does anyone have a sample letter of some good idea what needs to be said and what should be included in the correspondence?
Click to expand...

Someone is feeding you a line of BS. Just put it in.
 
Never heard of that requirement... Of course being Canadian I guess that's not surprising. So if you use a Subaru do you have to explain that it's no longer a car engine? Or maybe the Rotax is no longer in a snowmobile?
 
No such engine requirement for exp. Where did you hear that one? Only issue is that if it is a certified engine you can qualify for 25 hours phase 1 flight testing vs 40 hours if equipped with a non-certified engine. Moving an engine from exp. back to a certified is a big issue but not the other way around. Call the EAA and they will tell you the same thing.

Marty57
 
That's kinda what I thought, but an A&P here was told by FAA (not further identified) that on experimental airframes the builder can do the condition inspection but if a certified engine is installed there needs to be an IA sign-off for the annual unless the engine is "decertified". I said it sounds like someone is confused but the A&P said a local fellow had problems with his carb and was told by the DAR that if he replaced it, the new carb would need to be yellow tagged.

The A&P also said he was told that insurance rates were higher if an experimental had a "decertified" engine.

I'd like to know if anyone else has heard this before I call the FAA and ask.
 
At your stage of use there is no issue. The situation arises IF the engine is taken out of your plane and installed in a certified airplane. Then all of it's history has to show that it's maintenance is traceable. If a non A&P (or just the P) has done anything to it that normally requires an A&P that is when this issue is an issue. If you intend to someday sell the engine for a certified use, you will need a proper log record. ex, if a non licensed mechanic person does a major assembly (overhaul) it will not have the proper paper trail.

There is a place in the FAR which addresses removing the data plate. Once you do, your goose is cooked. It is best not to stir the pot. If your DAR says to remove the data plate then you will have to. He is the authority.
 
My plan is and probably will be to list #2 son as a co-builder/owner and the plane will always be EAB so if the engine is ever removed it would need to be used in another EAB or airboat or something non-certified. I'll keep my head down and proceed.
 
If that's the case, you should consider having #2 get the repairman certificate so that he can do the condition inspections after you are no longer a participant in the plane.
 
I took a poll at the EAA meeting last night and NO ONE had heard of such a silly thing...ranks up there with a deflated football.

My wife and I started to do some fabric work on the tail feathers and my first impression of the Stewart's System is most favorable!! I had to do some experimenting with the temps on the small iron, but once I figured out what worked best the fabric and glue seems to just flow together then wipe it off just like Dan says in their video. So far, I have nothing but good thoughts about their products.
 
I spent some quality time looking at that photo. For me, it had it's up and downs....
Haha looks great lowrider
 
They do bolt together and have 90* bends on each side and that acts as the stop for the elevator. It's made out of 0.080 CM and the bottom part is made per plans and the upper part was added to change attach point and give different mechanical advantage when I changed from cable and pulleys to push/pull cable. It's plenty strong but perhaps ugly...fortunately, you need to pull a panel to see it's ugliness. Ugly control horns need love too!!
 
Sky,

Awhile back you mentioned using a balsa wood triangle on the front of the gear leg to fair the leading edge prior to covering. I'm guessing you did the rear also. How far in front of the gear leg did the triangle extend?
 
I mentioned placing the balsa fairing behind the round tubing, both of them. The drag which needs to be reduced is behind the tube. Also there should be a fairing at the "V" junction next to the axle. I would need to research some aerodynamics books to be able to say how far. It would be related to the diameter of the tube and the velocity of the air mass.


Some quick "googling" brought up this: http://www.rotaryforum.com/forum/showthread.php?t=32855
 
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Great ideas from the floppy wing crowd.

The conventional Cub gear with fabric covered legs is angled on the rear so does that reduce the drag enough that it is not worthwhile doing the rear streamlining, or do the builders just not bother??

I've pretty much given up on using a cargo pod to fair the gear and die springs so using an airfoil on the springs makes sense. The gear on the other hand needs help. While I have the fabric and Stewart's glue out I'm temped to make some ribs that would fair the front and rear of the covered gear legs and cover it with fabric. Biggest concern is rough field landings in high grass and what it might do to the fairings...maybe carbon fiber or Kevlar on the leading edge.
 
Remember that Piper covered all of their landing gears. The uncovering started in Alaska because it was always getting damaged for any of several reasons, so they just left it off. Since they were mostly using climb props and hauling all sorts of stuff, speed was not of much concern. There were some airplanes built during the 1920s which had airfoil shaped ribs in the gear "V"s. I couldn't find a picture. This picture shows a good cross section of a streamlined shape. At the very least you could place a pointy fairing behind the rear diagonal and cover the whole thing with fabric. Piper didn't do this because it costs them money and probably the improvement was not much.

gear4.jpg
 
So maybe the front of the gear legs don't need an airfoil shape but the rear certainly do.

What I'm thinking is make a shape similar to the part to the left in the photo and glue it to the front leg, cover the space between the legs and put maybe a 4" tapered piece on the rear of the back leg and cover the whole thing in fabric. That would be a lot easier than making individual ribs for each side to make them an airfoil. From what I could find out on the web the rear should be sorta sharp so maybe a 1/4" CM tube bent to fit behind the rear leg tapered from the bottom up. That would take the rear leg from 1 1/2" to 1/4" allowing the airflow to come back together cleanly...I think.
 
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