The order form for Unitract oleos asks for the anitipated all up weight of the model so I was hopeful that the springing and damping would be appropriate. When they arrived, I was pleased to see that they look just right for the job
Laid over the plan, the leg looks a little long, but the dihedral in the wing takes care of that. The construction of the oleos is very simple, the damping being achieved by an O ring and a special grease
The springs feel quite powerful and, combined with the tenacious nature of the grease, made the units feel very stiff in operation. You can see from this picture that the leg is only just beginning to compress under a load of nearly 4lb.
Unitract confirm that they have taken account of my AUW estimate of 5lb and urge me to try the legs as they are before contemplating down rating the springs. They do have 25 years experience in the field so, as a complete newcomer to the world of oleos, I do feel I owe them that.
With the 1/8in balsa doubler and top and bottom basswood strips, the centre of the spar feels very solid. Making this joint at the outset does though lead to a wing which can be quite awkward to work with, particularly on the underside.
The flap control arrangement is the same as used on the Astrohog. I have now used up all my spare nylon bearings so will have to think of something different next time!
Rear spars were inserted, top and bottom, fore and aft of the hinge line for the flaps and ailerons. The space between the top spars is to accommodate the facings, the gap between the lower spars is greater in the outboard section to allow some downward movement of the (top hinged) ailerons. (Flaps will be bottom hinged so need no gap.)
Undercarriage mounting blocks were fitted, then the framework prepared for sheeting.
Because the rear portion of the wing section is flat bottomed, the centre section sheeting could be applied in one piece. What really takes the time though is all those cap strips!
I did wonder whether to dispense with the torque rods and rely entirely on the oleos for shock absorbtion. However, because I operate from grass fields, it seemed safer to leave them in.
