Hostetler Cessna 336 Skymaster

[Patto]

I've moved onto sheeting the underside of the center section. It involves laying the wiring. I'm pretty set at this point on having one Rx in the wing for the 10 servos for the control surfaces and light controller then a second Rx in the fuse for the nose wheel, throttles, chokes, and starters. 18 total inputs, although the rudders and elevator servos will be on Y harnesses.

I am now struggling a little with the flap hinging plan. More on that later...

 

[Patto]

Need your advice folks (if anyone is still following this boring build!). This is my first scale build. While I am far from being a purist, I am trying to have some semblance of the real aircraft.

Looking at the "scale" style of installing the Robart hinges for the flaps, I am worried they will not be strong enough. Here are the pictures of them installed per the instructions that came with them and per the plans. This is ONLY for the flaps.

What do you think?

 

[Bipeguy03]

Need your advice folks (if anyone is still following this boring build!). This is my first scale build. While I am far from being a purist, I am trying to have some semblance of the real aircraft.

Looking at the "scale" style of installing the Robart hinges for the flaps, I am worried they will not be strong enough. Here are the pictures of them installed per the instructions that came with them and per the plans. This is ONLY for the flaps.

What do you think?

They will be fine, the shank on the Robart hinges are stronger than they look, just wait till you have to cut one! Lol

Also, you have plenty of hinges in the flap to spread out the load. Just make sure you get them glued in with a good quality epoxy or aphetic resin and you'll be golden!

I still lurk around and check in, keep it up it's looking great!

 

[Patto]

Thank you for the response. So, you don't recommend gorilla glue for these hinges?

 

[Bipeguy03]

I don't really care for Gorilla Glue for anything but that's a personal preference. A lot of guys swear by it so it could be absolutely fine, I've just rebuilt enough models that guys have used it on that I don't like it. It's rock hard and brittle.

Again, that's just my opinion

 

[Patto]

No gorilla glue, got it. I am fine with 30 min epoxy for hinging. I'll stick with what is on the plans for now as far as the flap hinges go.

Tonight I worked on finishing the underside of the boom where it meets the wing. In looking at the plans, it appears that the wing struts connect to the wings at the front underside of the booms. It made sense to me to make this part a solid block of balsa for a little extra support for the strut attachment area. I can add in a piece of hardwood later on when I figure out exactly where the strut attaches and how I want to accomplish it.

I whittled the block into the shape I wanted and then made it a twin brother for the other side. I framed up the area between the block and the already constructed portion of the boom.

Little by little, it's beginning to look like a Skymaster...

 

[dhal22]

I do not like gorilla glue for much but where it excels is balsa sheeting to foam. It bonds balsa to foam with a vengeance.

 

[Bipeguy03]

It's lookin good! looks like there is a lot of carving to do, that's always fun!

 

[Patto]

Okay, so I've finished with the sheeting on the wing center section for the most part. I still have to install the inner flap servo for one side.

I can only describe this omission as extreme slackery. But, to make up for that slackery, I built one of the inner flaps. They are not rectangular and have to be angled just perfect to avoid binding against the fuselage yet not having too much space when they are not deployed.

 

[Patto]

Progress is being made once again!

I finally came up with a plan for the dowels that go from the wing leading edge into the ply former at the front of the wing saddle. I fabricated a piece of 1/4" ply and did my best to get it incorporated into the wing structure to spread out the load from the G's I will be pulling someday.

I wish I had not sheeted the top of the wing center section. I have had to take several pieces back out.

Anyway, I lined everything up, did some measurements, and epoxied the dowels and ply into place after drilling into the spar box.

Once all that was set, I measured and drilled out the holes for the wing bolts. You will see nylon bolts in the pictures, but I will probably use metal bolts for flying. Still thinking about this one.

Now, after that I started on the scoop placement and finishing the lines of the fuselage above the wing center section.

The scoop is completely functional and needs to have the air intake eventually assist in cooling the rear engine. I'm working on making a tunnel for the air that will go into the rear cowl. Most likely, I will need to baffle enough that the air goes in the correct direction, but I may just wait and see if it's necessary before I do so.

That's about all for now. It's just a rough-draft kind of picture right now while I get a feel for how I want to do this. Hostetler does not provide much, nor did the pieces all align correctly. I had to do a lot of customization to get the scoop to sit at the right angle and to get the formers to a shape that I may be able to plank.