Tyrella Model Aircraft Club Rotating Header Image

Fuselage-6

The next step is the addition of the undercarriage. First we have to make sure the u/c fits.
First all 544 part of the front support, 545 of the rear support and 546 main support are provisionally mounted. With the parts fitted, measure the distance between the wheels axles and building board, and axles and tail. Both sides should be equal of course. If not, check the position of the undercarriage and adjust until it sits correct. If everything looks fine, part 544 can be glued to the backside of 502 and the sides. When it sits properly, undercarriage 546 can be fitted into the slot. This means you have to pass the eye-screws through the holes in 544. Install the spring from the topside and tighten it up slightly. The eye of the screw must protrude from the bottom of the fuse. Next push the support for the rear undercarriage support 545 over the 4mm undercarriage wire, and glue support 545 from the front centrally on former 504.
After the glue has set, the holes in the 2 undercarriage mounting supports 547 (2 mirrored parts) must be transferred onto hardwood piece 544. The tongues of the supports 547 protrude from behind the undercarriage wire, they should be in line with the flying wires as much as possible, to lessen the bending moment on these parts. In order to drill the holes, it is easiest to fold the undercarriage backwards. Drill the holes in the locations that were transferred

In order to drill the holes for the supports, it is easiest to fold the LG backwards, pivoting on the rear wire. Use the metal part to mark the holes. At the 3 locations, M3 screws 548 and press-in nuts 549 are to be used.
After the holes are drilled, the LG can be put back in its proper position, and 547 can be fitted. I would secure the blind-nuts, by glueing some ply behind them, so that they can never fall out.

Now it is time to add the structure between the undercarriage wires. For this we have to add part 551 between the front 8mm and rear 4mm wires. Because of the tube on the lower part of the front wire, part 551 must be slightly cut back here. When the center parts fit, you can slide the hardwood parts 552 over the rear wire and over 551. You can also add the balsa parts 553 (2 left and 2 right) over the front wire and the centre part 551. You must make sure that the these wooden parts do not touch the fuselage, and that it stays free. The undercarriage needs some ‘air’ to work. When everything fits, all parts can be glued together. After the glue has set, the filler pieces 554 can be added to the hardwood covering the rear wire, and also supports 555. The front parts can be sanded to the contour of the glass sleeves 556.

Both parts, top and bottom must be carved in slightly (3mm) to allow for the diagonal bracing. When the glass sleeves 556 can be slid over the leg, the rest of the wood can be sanded into contour. Be sure to note that the lower part is slightly conical. Don’t glue the fibreglass sleeves yet!

Before glueing the parts, make sure the inner wheel pant support 557 and the wheel pants 558 fit properly.
On ONE side of the pants, you have to drill a 10 mm hole for the wheel axle. (Be careful the to drill a left and a right one!) Slide the bottom part of 556 in the top part. You might need to cut back the lower part so that it fits properly into the top half and can be slid into the wheel cover support 557.