Skycam41

Received my landing gear this morning.....it looks like a 4WD flying plane! Well I won't need to worry about ground clearance that's for sure.

kd7ost

Very nice looking skycam41. It's really coming along well. Your building is great looking. I like to see that.

Dan

Skycam41

You don't think it is too high from the ground Dan? I guess I will need prop and ground clearance from the tail feathers though. I forgot the location of the main gear formula. Should the front edge of the wheel be 1.5" aft of the CG?

Skycam41

Couple more pictures...thanks for the kind words Dan

kd7ost

No, I think its fine height wise. You can stick an AV antenna straight out the bottom and it will clear the ground.

The mains should be placed so the axle is on a line that intersects a line drawn 15 degrees back from vertical. The line should start at the center of lift. In your case that will be the center of the spar.

On your plans draw a line straight down from the spar that is 90 degrees from the flat bottom. Then starting at the spar again, use a protractor to draw a line at a 15 degree angle from the 90 degree line towards the rear of the plane. Then place your mains so the axle is on that line. Being off a little is OK as long as you don’t go too far. You want to rotate easily without jumping off the ground but you don’t want to be so close that the nose wheel bounces during a takeoff or landing and you can’t steer with it. That 15 degree back from center of lift is where to put it for ease.

Dan

Skycam41

I have ran into one snag that I did not think about when planning the build. The main gear will be secured to a 1/4" ply plate but U did not give much thought to the installation of the ply plate. Having it mounted just between the two 1/4" stringers will never be enough support for anything less than a greased landing on a smooth surface. Any thoughts on how to mount the plate so it is securely tied in with the airframe? My thought was to mount a 1/8" ply plate on the fuse bottom from the firewall to the sheeted area you see in the picture.

Skycam41

Hey, look what I found while digging around the hobby room. This is the original landing gear that came with my BTE Flyin' King (I installed the optional heavy landing gear). The newly found gear is 3.3/4" wider in stance and 2" lower than the Dubro gear I just bought. I took a picture so you can see the difference. Basically the aluminum gear which weighs about the same as the composite is wider and lower. Wider would be good for ground stability...it looks like one of those land yacht things you see on the beach..haha. What do you guys think? Wider and lower or taller and narrower? With the aluminum ones I still get 5" of ground clearance.

W4UAV

Wide and low. I noticed the nosegear on the other taller Dubro gear looking really spindley and I was worried about it. I like the BTE gear. The Dubro gear is good for tail draggers with a 4 stroke to give good prop clearance. I just didnt realize it was going to be that tall.

As far as the plywood plate, reinforce it as much as you can. Its basically on the CG so you can spend a little more attention there.

Mike R.

Skycam41

I think you are right Mike...with the tall gear I think I was going to run out of nose gear leg length for the servo arm...I was just poking around in the basement and I found it and thought hmmmm! I still have 5" of ground clearance which I think will work OK even when the wing and booms are mounted. Thanks for your input.

kd7ost

Yep, wide is good. I think you could go with either gear height wise with no trouble but the wider gear is great. I ended up on my Pegasus ordering a custom made gear to get me my height and width. I would land sometimes in pretty small places and have to crank in a turn before running out of room. I went through some tip skids. With the wider gear I don't have that problem.

You definitely want to distribute the load of that landing gear within the airframe though. If you can add in some 3/16� or ¼� balsa sheet inside the walls extending front and rear and tie it into the LG plate with some big triangle stock that should do you. Greasing the landings is always good but once in a while we all have a bad bounce or a hole or rock.

Skycam41

Well low and wide it is! I put the tape meaure there so you could see the length of the wheel base. The front of the tape is at the front edge of the nose wheel. This thing would go like a rocket with no wing and tail...haha. I hope my ground handling will be OK and not bouncy on the nose wheel..did not think much about it's position in the planning stage

Skycam41

This is getting vewy vewy exciting! I was just checking out locations for my 480 line CCD bullet cam. The landing gear leg has worked for me in the past and with the wing being directly above it will make for a bit of a sun shade also. I have made modifications to the port wing panel so I can install the cam out on the wing tip also. I think I am actually starting to get excited

Skycam41

Well the landing gear plate is now in place and so I was able to work on installing the 14oz fuel tank and remote fuel filler which will go right behind the wing for easy access...see picture. I have nice gentle curves in the fuel line although the picture makes it look like it is a sharp bend.

W4UAV

Mike, you may want to move that futher back toward the engine, putting it above the langing gear plate, itll be nearer the CG and you wont have any balance issues with the fuel tank.

Skycam41

The middle of the tank is right on the CG. The picture is a little deceiving with the wide angle perception. I remembered your advice about the location of the tank when installing it

Mike

Skycam41

Starting with the electrical installtion now, just figuring out what is going where. Note the pitot tube coming out the nose of the plane.

typicalaimster

For the first flight you may want the tank slightly in front of the CG line. When you blast off the fuel is going to move back toward the end of the plane. This may change your CG a bit as you position the plane in different angles.


--Scott

Skycam41

Well what do you think guys? I sheeted the fuse with 1/16" balsa as it was very light. The fuse is very solid and I fear I have over built the dang thing! The wing is holding me up, well I should say the postal system [:@] The left side of the fuse shows a "window" of very thin plexi type of plastic so I can see that the camera is working!

kd7ost

It's coming along very nicely Skycam41. I especially like the way you tapped muffler pressure to the main landing gear for adjustable suspension.

Those little pieces of plywood haven't gotten there yet? [] What the heck? They got mailed about 3 weeks ago I think. I hope the corners haven't been poked through the cardboard envelope by now. [:@]

Dan

Skycam41

That's hilarious...now I have the hicups!!

yardlight

Lookin good mike! way to put that sheeting on fast do you even sleep at night!!

Skycam41

One location of my 480 line CCD bullet cam. The small ball tripod head is one of the best things I ever bought for AP use on model planes.

lvspark

Thats looking real nice.. I am a little concerned about the front LG, looks maybe a little weak, and a hard landing (like those ever happen right?) might let your cam eat some dirt, or worse[X(]

Skycam41

The nose gear is a Fults and is pretty strong...I have it bent backwards for looks, it is not the weight of the plane bending it rearwards

The job I loathe the most....joining wing panels [:'(] I can sand till the cows come home and still not get a good tight fit..always end up sanding in some type of a curve it seems! Can anyone sand the edge of balsa 100% square? I know I can't. Thanks to my good friend Dan in Idaho the joiners he sent arrived this afternoon and now they are gooped up with epoxy so that will have to sit for a good 24 hours.

Fieldrut

I have found (not sanding wing joins but other things that needed to be mated) that getting a square of safety glass, the laminate type from the wreckers, the old style truck windows (big rigs)

then place the paper on the surface, tape the arrow edges (there is an arrow of lay on most sandpapers on the back, it is the direction of particle aggression when applied to the backing paper) and hold the face needing to be sanded and stroke in the same direction to the arrows for less shave... the opposite for more...

(don't you hate ( )'s )

you will be able to see it come flush real quick this way.

This 0.02c has been bought to you by the letters.....opps wrong forum...lol, I speak funny and have a grand child I get ALL my ideas from!!!

I have used this version of a flat plate sander/lapper for mating metal to metal in engineering projects, and some weird stuff I did when I was playing full back for the Romans.

Ken