Building the Jarts

[CCx4]

Hi Joe,

The Jart fuselage/tail fin seems to resemble the F5/F20 somehow. Is it only me who see this?

Anyway, the aircraft in its entirety looks super nice!!! Should be a fast glider too, no? Any videos available?

Cheers

[joe yap]

It's not my design. You can go to www.jartworld.com for details. You can email the author to obtain a copy of the plan if you wish. He sent me a copy exclusively for me with my name on, so I guess I'm not supposed to distribute without his permission. Anyway, at no time should someone build it for commercial reasons. The 3 models I'm building are solely for myself and 2 other friends, no revenue gain.

[joe yap]

I anticipated the tail heavy problem, since the RX pack does not have the acces to be place very far forward. I dig a little foam in the nose section and placed a lead ball in each fuselage.

After that, all the inside jobs are considered done and the fuselage halves are assembled with epoxy. Plenty of masking tape for this job.

[CCx4]

Thanks for the link to Jartworld.com, Joe. Very interesting website for sure.

Cheers

[joe yap]

Work is still in progress, but due to the DH migration, I'll post the progress later on.

[joe yap]

Carbon strip longerons are installed on both sides of the each fuselage. After that, the fuselages are covered with a layer of medium weight glasscloth.

[joe yap]

While the fuselages receive thier final layer of lightweight glasscloth, I moved on to cut the wing cores. I only have enough material to cut 3 wing cores. I just purchase a second piece of foam for the other 3.

The airfoil chosen is RG15 instead of the original Selig 6062 airfoil, which was meant for aerobatics. Unless flown at Phuket, the S6062 although holds the plane inverted well, it will not take ballast as much as RG15 do, which can give very energetic performance. I prefer to fly this kind of glider fast and furious than holding it inverted throughout the flight.

[shaneyee]

My JART start!

Here is the beginning of a blasa JART.... I will either call it a JART lite or a JARTNot!

Shane

[shaneyee]

Balsa JART

[joe yap]

After months of stagnation, I wanted to put the project on hold due to other project commitments. However, the wind forecast on this Saturday at Sedili still shows very good winds and so it sort of relight the flames again. I already have some foam wing cores cut proviously and now I just need to build up at least a pair of wings.

Mind you that this is quite an expensive and heavy way to build the wings. The reason is being that the skins are cut from 1/64" plywood which are epoxied onto the foam cores, and thier leading edges are made of spruce instead of balsa to take the landing punishments at Sedili. Anyway, the weight seems like still will fall within the stipulated AUW as the plans. The result is a pair of very neatly done wings with sharp trailing edges.

The root of the wings are faced with balsa blocks to match with the fuselage joint. Wingtips yet to be fabricated. The joiner tubes are of brass and joiner will be a carbon rod.

[joe yap]

The fuselage and canopy receive a thick coat of primer before sanding.

[joe yap]

After sanding down most of the primer, I filled the small dents and cavities with putty and sand down again. Then followed by another coat of primer and very light buffing before it recieve the first coat of white paint. Turns out pretty well other than some dust got stuck on the paint job all over. I wouldn't bother much at this point and will let it cure completely before some light polishing. Anyway, I decide to leave it as such for it's maidedn flight this coming Saturday's Sedili trip. I'll do some final painting with colour scheme sometime after that.

[lu wei yao]

Hoah man, thats beautiful.


Thanx!

[joe yap]

I covered one of the wing with Pearl blue Monokote but it did not stick well onto the plywood skin. The problem lies with the heat sensitive adhesive on the Monokote needs realatively high temperature to get it sticky enough the stick on the plywood skin properly, which also forms bubbles along the way. I stripped off the Monokote and decided to go for Oracover.

The Pearl Yellow Oracover is sticky enough at relatively low temperature and I can just use my hair dryer to get it sticky before rubbing it down to the skin with a clean rag. Turns out very much better with no bubbles or wrinkles.

[gEcky]

Hi Joe,

could you share what brand/type of primer you used? Is this the "gesso" type used for acrylic paints?

Thanks!