Ch 13 Nose and Nose Gear

Cutting foam is getting easier using an extra long jigsaw blade. It took a bit of thought to get the right size foam pieces.

Fitting them is tricky due to the angles required. If the foam is forced into position NG31 will distort. I made the right side a touch short and later microed a 1/8″ sliver on the end. Fit is not critical according to the plans.

Nice to see the fuselage looking a little bit bigger.

Cutting foam

Trial fit

Looking longer

Time to layup the nose floor with two plies of BID. I tried the hardshell technique to see if it reduced very small areas of air in my BID layups.

I microslurried the floor as usual but let it cure. Then there was a lot more sanding as you can’t lay up on a shinny surface. It took a while. The layup was done with pure epoxy on the floor then the dry cloth on top. The usual squeegee work then the second ply.

Finally an extra ply just on the floor where heels go. The hardshell thing worked OK. Not a perfect layup but still nice. I did get epoxy going off early as the fuselage was close to the room heater…I have to watch that. The extra step was a lot of work and may not be worth it given it introduces a secondary bond. All edges were peel plied.

It was a tricky layup going up the sides and front as well as aft behind F22 for an inch but worked out OK.

Hard shell floor

2 ply BID left

2 ply BID right

PVC foam is used for my floor, Divinycell H35 as were the seat backs and sides. There will be no urethane in my aircraft build.

Foam is fitted between F22 and NG31 and the NG30 side plates with an oversized outside curve. Next a depression is carefully sanded and filled out as access to the lower nut of the NG6 assembly.

After working out how to clamp it in place, wet micro is used to glue the floor in position. As it was coolish I used a hairdryer at the end of a box and a few pieces of plastic to ‘tent’ the assembly so it would be cured and ready for more work the next day.

Foam cut and scolloped

Micro floor in place

Heat box cure

This one is getting done a little early. I thought if the strut is in the middle now, when I add the sides and floor of the nose it will still be in the middle. There is definitely sideways play in the NG30’s given their lack of attachment at this stage.

The task is just to cut through almost to the floor plys so the strut can sit flush on the fuselage. Its right on the bare glass in the centre and still seems slightly proud. I’ve left it pretty tight.

It does seem as if there is a slight twist in the leg as the top plate is not perfectly flat. This is more cosmetic as the leg is confirmed straight with the laser and as long as the wheel is mounted correctly the aircraft will taxi straight.

I will have to open this area up later for a faring box thats yet to be made and a bit of wiggle room for the strut.

The tail can wag the dog

Initial cuts

Strut confirmed straight

Two ply BID tapes with a 1″ overlap on F22 bulkhead provide a lot of strength.

I laid these up on foil and wetted them out which makes positioning very easy. Of course I draw a few lines and prep the surfaces with pure epoxy after a light sand and a wipe with acetone. The usual procedure.

The 3rd pic shows the position of the taxi/landing light although it will be a bit lower than this to allow for the heated pitot. It does give an idea of where the nose might end up. That’s going to be interesting.

F22 Nose tapes

Foil tapes

Light position

Here we flox on the Nose box. I got the fuselage on my work table with a line down the middle. These lines were matched to the nose box lines in an attempt to get it on straight.

The critical thing is that the gear leg ends up in the middle of the plane so it will taxi in a straight line. The alignment of the front wheel assembly is very important as well. Where NG6A, the gear fork pivot is the important bit the rest gets covered in foam and becomes the nose shape.

I used squares, a plumb bob and rulers and did the best I could. It was surprising how strong the flox join felt afterwards just in that small gluing area.

I trimmed back F22 just a touch and rounded the edges so tapes would lay around here nicely. Then a little micro inside the box, again so we’d end up with no air under the tape edges.

Pic 3 shows the outside tapes around F22 and the box.

Lining up the Nose Box

Micro edges

F22 adjusted

This step is just adding tapes to the inside of the nose box, It takes a short time to do properly and it seems the peel ply to protect the edges from delaminating is more a part of being tidy than much else although I would always do this step.

I glassed over the nice holes I made as you can see in pic three. No harm done and if I don’t need the access then its a few grams lighter.

Nose box tapes

Peel ply those edges

Access holes glassed over

Over several days I made up the NG31 end plate that goes on the NG30 assembly and the little F6 bulkhead.

The plans have all this happen at once while I’m going bit by bit and really trying hard to get it all straight. NG31 gets one ply of BID which I peel plied and F6 gets two ply.

F6 does have holes cut out and I did them now for easy access. Later 2 plies go over this to secure it to the NG30’s. I’ll leave the holes sealed until I’m sure they have to be there. Its just going to let air in yet I may need a small hole for some cables. This way I have both options available and its not heavier.

Lots of measuring and lining up again with a little sanding too. The two parts were floxed onto the nose box and plenty of weigh used to hold it down while curing. I put two of the tapes on the end plate, NG31, and will do the other ones after the flox is cured. Seemed a good way to do things and a lot better than the plans method. Just not as quick..

NG31 and F6 ready for glass

Trial fit

Floxed and secured

This is fitting NG1. I positioned the leg in the center of the NG30 plates which are bolted at two points. I spent a while with little spacers and the micrometer to ensure things were as parallel as I could make them and the leg in the middle.

Then I used 5 minute glue and had NG1 secured to NG6A. It was then easy to drill out the 4 bolt holes using NG6A as a drill guide. This seemed a reasonable method to have it all lined up.

The leg came away easily and it was only a quick clean up. I decided to alodyine NG5… the squarish plate. Probably over kill. I believe it helps with adhesion but I was bolting it all anyway.

I countersunk the plate holes and did a trial fit to ensure my bolts were the right size and that I would get them with at least 1 thread showing. The assembly was then floxed and bolted together. The flow fills up the sides nicely. I used a bit of peel ply to stop the still wet flox from oozing out the sides. Works pretty well.

NG1 fit

Drilling the holes

Floxed and bolted

The front strut, NG1 requires two ply of BID as a torsional wrap. It is done as a U shape, per plans, which takes care of both sides of the leg.

I mounted the leg on three screws and used ‘bondo’ to keep it in place. Laying up on foil first made the single ply easy to position on the job. I peel plyed the part where the second ply would go later. After cure I carefully trimmed the part and did the second layup. Then the cure and then trimmed again.

It took a few days but straight forward.

Foil wrap

2nd ply

NG1 trimmed

This was a couple of days trial fitting the electric retract system, NG6 and the front gear leg NG1. I really wanted to get an understanding of how this all fits together and what holes needed drilling.

The electric actuator gets positioned after the nose is on the plane, but the plates are attached now but only with one bolt. Once this was clear I could see how the 3″ middle gap works out.

Then it was a good look at the leg (NG1) and seeing my next step was a couple of layups over it and to ensure it would still fit all the parts after it was a little thicker.

Trial fit of the electric retract

NG6A and plates

NG1 Trial fit

This step is just making two 2024-T3 metal plates that bolt onto NG30 and have the nose gear pivot assembly NG6A between them. For some reason this took quite a long time…nearly a week of fiddling.

I marked out the disks, then drilled the holes and countersunk for the screws with my very expensive 100 degree countersink tool. Easy.

Then I cut the disks out on the bandsaw and shaped them on the linisher. The hard part was getting Alodine and prep solutions. I also had the wrong nuts from Spruce but sourced some locally. My first go at it had them too long in the alodine bath so I removed the coating and had another go a few days later. Its not quite as yellow as the pics now.

Then I had trouble getting the right screw length so cut some down which took a while. After installing the assembly as in pic three …all nicely floxed in, I later just had a suspicion that they might just be shanked. It was very close. That was enough to go and buy some better screws. Meanwhile I had to heat each screw up to remove them carefully ( remember the flox…) using a large soldering iron.

I now have structural machine screws in place at the correct length with fresh nuts and I’m 100% happy. The final ones are not pictured. You’ll just have to take my word for it that they are very pretty.

Bore and countersink

After Alodine

Bolted in place