jofunk

I glassed the bottom of the nose. That is as far as the nose is going to go for a while. While I had the glass and west systems out, I stiffened the ends of the fuel tank for my Panther. I cut and marked the fuel tank floor. I may use use it as a crutch and start the fuse inverted. It will need to be supported off the table by 10" for everything to clear. The doubled up quart paint cans are not going to be used. It was the only thing I had to temporarily get a look. I need to come up with the wing plug ins / landing gear mounts before any of the bulkheads get stood up.

jofunk

I figured out what I am going to build on. I picked up two 1 1/4"x 3/16"x 8' 6061 t-6 aluminum angles. They are the flattest things I can find. I will start the fuse upside down. I have a clearer picture of what is going on with only 4 points needed to support everything. I am still trying to figure out the wing plug ins. there is not a whole lot of room over the top for them on F-15. Some of this aluminum angle is also going to be used for the landing gear mounts. I gave myself 3 1/2" under the fuel tank floor and it will be tight getting the landing gear in there. The aluminum will take the place of the wooden mounting blocks.

jofunk

I cut two 21" pieces of angle off the 8' sections to make main gear mounts. It seem the easiest way to mount the mains is to make them a single unit by bolting them to the angles. The struts when retracted clear the aluminum with no problem. Some of the ply will need to be cut away. The angles will be bolted to some aircraft ply formers and the formers will get glued into the plane. The landing gear mounts and wing plug ins will be built outside the plane. Thank goodness this assembly is close to the CG because it has some pretty good weight to it. As soon as I get my plywood order I will be able to do more.

sr.odin

deleted

jofunk

Nothing earth shattering. just a slow go with flying season here. The main gear were mounted to two aluminum angles. That is the way they will mount into the fuse. Once in, the angles will stay and the gear will be able to come out. The drive motors will have their own separate mount.

jofunk

I cut F 13 and F 15 out of 3/8" aircraft ply and mounted the wing plug in channels at the proper height to run into the wing. F 15 also takes half of the main gear mount. a lot of F 13 will need to be removed for the retract to enter the wheel well. With the gear retracted I will have about 3/4" of F 13 to carry across under the fuel tank floor. It may need to be beefed up. Also the gear clear the outer skin by about 1/4". The next step is to jig F 13 and F 15 up so the plug in blades are parallel, level and square. Otherwise the wing will not plug in if something is running on a taper.

jofunk

Here is F 13 cut away with some aluminum angle added to carry to load. I also center punched a few spots in the aluminum where the plate will go for the drive motor.

pilot43

My Feedback: (3)

Excellent work! :-)

jofunk

After weighing my options I decided to try and make the gear hydraulically actuated. I will need Vladimir to make some clevics and a new smaller gimbal for the ends of the cylinder. If it works I can eliminate 6 limit switches and the need to cut out a big section of the fuel tank floor. Slow going for now.

jofunk

I temp. mounted the new gimbal Vladimir made to see if the geometry works. It looks close. Flush mounting to the fuel tank floor seems to be the way to go. The fuel tank floor in the gimbal mount area will be 1/8" aluminum plate. This is what I came up with after looking at it and walking past it for a month or so. Engineering the mounts for this gear is no fun.

jofunk

Vladimir started machining a nose gear strut and retract mechanism. Here is what he has so far in the approximate area it will be.

jofunk

I went to town with the hole saw making lightening /access holes. Vladimir machined some longer clevises so the cylinder shaft would reach the retract link point. The 1/8" aluminum gimbal plates got cut out and the gimbals got mounted to them. I mounted the left plate in the plane to see how everything lines up. It all looks good. An air pressure test will let me know if making the retracts operate hydraulically is feasible. The fuel / hydraulic pump puts out about 140 PSI so things need to operate below that.

jofunk

Here is a video and picture of the air pressure test. Things look reasonable with 50 PSI extending the gear in an inverted position. Extending the gear inverted puts the cylinder geometry at its greatest disadvantage and it seemed to work fine. The whole reason for this is to make a more streamlined and easier to install actuator than the electric motors, gear boxes, oversized gimbals and limit switches that I first thought I was going to use. https://www.youtube.com/watch?v=U7GC...ature=youtu.be

SHANEC

My Feedback: (4)

Looking Good!!

jofunk

Here are a few pix of a sketch of the spool valve I will need to find or make to control the hydraulic fluid for the retracts…….. Some large side plates will need to go into the landing gear/ wing spar box. As the gear retract the box was flexing a little bit. Extending had no flex because the gimbal plate was in tension.

Airliner-rc

My Feedback: (1)

What is the weight of retracts (total)?

jofunk

Hi Mike,

I don't know what the gear weigh. I will take that box off eventually. I can weigh the whole thing once I have it off……. Your Triple 7 project is impressive.


Joe

Airliner-rc

My Feedback: (1)

Will be interesting, looking strong, Joe.

jofunk

I have the box solid enough to take it off the fuel tank floor. I will do a round of cleaning off the work bench, and then start standing up the fuse. the box and landing gear weigh 15 lb. I laid the wings next to the box where they will plug in just to get a sense of size.

sierratango

The work looks great. Did you have a guesstimation about what the weight of that box would be and then what the total weight of the project will be once it is all finished, ready to fly, without radio and fuel?

I have never built a model of that weight nor do I have access to any of that scale to compare.

Looking forward to seeing the major parts now come together.

jofunk

Hi ST

I didn't make any guesstimations about the weight of the box. The landing gear is a little more than half of the 15 ibs. I built the box to make it reasonably strong enough to take the landing, the less than perfect landing, and wing loads. It is what it is. There is one thing that the box and landing gear have going for it. It is right on the C.G. The nose is 5 lbs, the engine box and control surfaces are 8 lbs, and the two wings are 5.5 lbs. With standard model building techniques I think everything will have a reasonable weight for the size of the plane………..The work bench has a slight belly in it front to back. I will need to shim a few things when it is time to start glueing things together. I removed the landing gear to lighten things up during the fuse construction. And cleaned the table.

jofunk

I opened up F 8 and F 9 to go on the fuel tank floor. I not sure I want to cut the floor down yet to slide them on. I made some balsa T stock out of a bunch useless hard LE stock I picked up at some swap meet a long time ago. It will attach the bulkheads to the floor. There are some "banana" bulkheads that will need to be tweaked as they are installed.

jofunk

The cross members will stay until the intakes are built up.

ravill

My Feedback: (11)

You builders are SO impressive. Wow. Great looking stuff over there.

jofunk

I took the bulkheads off AGAIN, hopefully for the last time. The T stock got glued onto the tank floor. I also cut away the floor to get F 8 and F 9 on the floor. I had to open up the intakes a little to get F 9 on. The nose gear will also be mounted somewhere in the F 9 area. Mount engineering will wait until I will see what Vladimir comes up with for a nose gear. I'm about two steps away from starting to glue this thing together. Then it becomes this not so little thing.