Jart from scratch

[joe]

Will you do all the glass/carbon at once or one layer at a time?

Had my Jart LT out a few days ago down by the sea. Lots of wind. Haven't flown it in decent lift for a long time. Really good. The best flights I've had with it. It really suits the smooth coastal lift. Well, I guess thats what it was designed for after all. Unfortunately only got half an hour in before the wind showed up.
Just some encouragement for you Bill.

I'm sure your fuse will be solid Bill. The LT version is like an egg shell. Rotor slammed me into the ground twice and I have a nice big crack to show for it. The gel coat is very brittle and the layup is very light for this sort of machine. Will try get some carbon in there one of these days. That pointy nose is not the easiest to get into though!

[billscottni]

Probably a layer of glass, then carbon followed by at least 1 more layer of glass. Carbon will be in the high stress areas e.g. wing seat, base of fin.

Usually don't do them all at once, which means they have to be lightly sanded before the next layer goes on

[joe]

doing it all at once it a PITA. Don't ask me how I know. Might be a little lighter that way but you probably get a better smoother job with one layer at a time.

[Alan_Perse]

Looks great Bill. But just one question. How do you make sure that the fin is straight on the plug.

[billscottni]

the good old mk 1 eyeball, checked from in front and above!!

nothing fancy Alan.

[billscottni]

One of my New Years resolutions, apart from losing weight (Doctors orders!), is to get my ass in gear on the builds I have on the boards.

Ordered some bits I need for both the KA-3 and the SU25, (mainly brass tube, piano wire and carbon tube/rod).

Then I got on with glassing the lost foam fuselage. Attached is a pic of the fuz with the first layer of light glass added. Tomorrow I will put on some carbon reinforcement, (around the wing mount and LE of the fin).

[joe]

Hi Bill. Good to see the jart back on the building board. What weight and how many layers are you going for?

[billscottni]

Not aiming for any particular weight Joe. More concerned with durability.

That first layer is a light cloth (50g/m), easier to work with on the smooth tape surface. I'm then planning on a length of 50mm carbon tape along the bottom from nose to tail and layer of the same tape on the LE of the fin. Possibly a criss cross pattern of Carbon tow nose to tail to give an overall strength. Then at least 2 layers (maybe 3) of a heavier cloth (100g/m), finishing off with another layer of the 50g/m.

That's the current plan, but I will adjust if the strength doesn't seem too good. Hope to get the carbon and one layer of 100g/m done tomorrow and then cut tails for it.

[billscottni]

Not as much done as I'd hoped today.  :?

Got the carbon reinforcement along the bottom of the fuz and LE of the fin done. Carbon reinforcing and another layer of glass (100g/m) on the hatch, which doubles as a wing cover too. (see the second pic in my first post).

Sanding down of the first layer of glass took longer than anticipated and I was a lazy bugger and had a lie in!! :!:

[billscottni]

As I said in my Fiu thread, a productive weekend. Spent today sanding the final layer of "heavy" cloth in the Jart fuz. Resorting to the angle grinder on a couple of stubborn spots to remove epoxy runs. Carbon tape aling the bottom and fin LE. Carbon tow reinforcement in a couple of strategic places. One layer of "light" cloth now needed to finish it off before a final sanding and shooting primer/filler on it.

[joe]

You've gone building mad Bill!!

[billscottni]

Ex-wife pissed me around over seeing the kids, so I needed to do something to get it out of my system :!:  :!: